Trends in Civil Engineering and Challenges for Sustainability

The principle of building design is to achieve the assigned objectives under the prescribed demand. Cases of large-scale damages to structures are due to unpredictable, higher-level loading, arising out of environmental loading; blast loading is one of them. The purpose of this research is to calculate blast parameters by analytical approach and obtain the pressure variation on different faces of building using IS:4991-1968. Three explosion weights (100, 500 and 1000 kg) are exploded in three different standoff distances (15, 30 and 45 m) and at 0, 6 and 12 m vertical in air. Blast parameters and pressure variation on different faces of building are calculated for different explosive weights and respective distances.

Base isolation is found to be a very efficient earthquake-resistant construction method. When base isolation is introduced, the transfer of large amount of inertia forces is prevented by the moving action of an isolator during an earthquake. The application of base isolator in regular buildings is done from long before, but the usage and effectiveness of base isolation in irregular buildings are a topic which needs more research. In this study, single friction pendulum isolator is used to isolate the buildings and the effectiveness of isolators is discussed in regular as well as plan irregular buildings. Modal analysis and time history analysis using Chi-Chi earthquake accelerogram data is done. Time period obtained from modal analysis and the results of time history analysis, such as base shear, storey acceleration and storey drift of regular, as well as plan irregular buildings are compared. The time period is found to increase significantly and base shear, acceleration and storey drift are decreased significantly with the application of single friction pendulum isolator. Also, the effectiveness of isolator got reduced with the introduction of irregularity in the structure.

Steel is used in construction industry due to its hardness and tensile strength. Cold-formed steel is type of steel which is manufactured at lower temperature. Cold-formed steel becomes more popular in twentieth century in civil engineering field as it possesses high strength to weight ratio and post-buckling strength. Research in cold-formed steel has increased considerably in past few years. Researchers have been working to develop direct strength method to replace conventional effective width method which is more tedious and less accurate. In this paper, we have studied various methods adopted for estimation axial load carrying capacity of cold-formed steel channel, angle and Z sections by various researchers.

Application of pre-stressed concrete for the construction of civil engineering structures especially bridges has increased tremendously. In the pre-stressed post-tensioned concrete structures, anchorage zone is the critical area of concrete ahead of the anchorage device. During application and diffusion of the pre-stressing force in a post-tensioned girder, tensile bursting stresses are developed at some distance ahead of the anchorage device in a region known as the general zone. These stresses often lead to serviceability problems and congestion of reinforcement at the anchorage zone. In this paper, a rectangular end block of 600 × 600 mm, with a bearing plate size of 214 × 214 mm, subjected to a concrete pre-stressing force of 2204 kN was analysed using the methods like elastic method, deep beam analogy, strut-and-tie model approach, finite element analysis and also using the codal provisions specified in IRC: 18 and British code BS: 8110. From the analysis of 2D finite analysis, it was observed that the variation of bursting stress in the end block is parabolic in nature. It was observed that with increase in eccentricity of bearing plate, there was a decrease in bursting tensile stress, whereas the value of spalling tensile stresses increases drastically. However, with increase in the size of the bearing plate, both the spalling and bursting stresses decrease considerably. It was also found that the grade of concrete has negligible effect on the distribution which is of bursting tensile stress. The finite element analysis of anchorage zone with multiple anchors indicates that spalling stresses are more critical than the bursting stresses for the design of anchorage zone.

The performance of reinforced concrete primarily depends on the bond strength and is defined as resistance to slipping of the reinforcing steel bars from the concrete. This slipping resistance is predominate mode of failure in predicting the mechanical performance of RCC, particularly to its failure mode and adhesion between steel reinforcement and concrete. In the present study an attempt is made to study the bond strength of structural grade concrete (M35) with high strength steel (Fe415) of 12, 16 and 20 mm (Fe500) embedded in the core of concrete. The pull-out test was carried out for various mixes of concrete with an addition of GGBFS as partial replacement with cement (10–30%). Also, attempt is made to evaluate the resistance for slippage, rupture behaviour and stress distribution are studied using finite element analysis tool. The study reveals that the bond strength improves the consideration of mineral admixture and also seems to improve with diameter of reinforcing bars for GGBFS binder-based concrete. The microstructure (SEM) is also evident for the minimal voids and densification with addition of GGBFS as binder, which enhances the bond strength with a partial replacement of cement. The numerical study closely reviews the experimental investigation.

Due to degradation and non-availability of the natural resource, a numerous research is under taken to find a sustainable and eco-friendly construction material. One of the ways to achieve this is by replacing the major materials of the normal cement concrete, completely or partially with different materials using low cost, easily available industrial by-products or waste material. Considering all these facts, the present study focuses on an alkali-activated cement with the complete substitution of conventional cement binder with GGBS, fly ash and glass powder for the production of standard solid masonry blocks of standard size. In the study, locally available quarry dust is used as fine aggregates as a complete substitution of river sand. This investigation is aimed to study the strength aspects such as compressive strength, split tensile strength and flexural strength of the masonry blocks as per IS 2185-1-2005. As per the results obtained, it is revealed that alkali-activated concrete masonry blocks have superior strength aspects when compared to OPC concrete masonry blocks.

Improving productivity, increasing output for the same inputs have been a longstanding concern of the construction industry. The different approaches to improving labour productivity in formwork will be briefly explained. The influence of the buildability elements on formwork labour out of key in situ reinforced concrete factors such as foundations, walls, columns, beams and slabs is yet to be gritty and quantified. The key results of several questionnaire surveys will be presented, and the major deterrent to improve buildability and by which buildability problems are being overcome are identified.

Effect of corrosion on RCC–SCC deep beams subjected to three different percentages of corrosion have been investigated in the present study. These SCC mixes were designed for obtaining a cube strength of M-30 grade using river sand as finer portions of the aggregate and 12.5 mm downsize jelly as coarse aggregate. Design of SCC reinforced concrete deep beams was carried out as per IS-456:2000 and the accelerated corrosion technique has been employed for carrying out the corrosion. All the trial SCC mixes were subjected to different flow ability tests in order to evaluate their SCC property as per the EFNARC guidelines. From the obtained test results, it can be observed that for the lower percentage of corrosion decrease in ultimate flexural strength was observed due to decrease in arch action. Further with increase in percentage of corrosion showed an increased ultimate flexural strength due to increase in arch action.

Reinforced self-compacting deep beams were developed, and their performance with varying percentages of steel fibers has been investigated in the present research. Fine aggregate being river sand along with 12.5 mm downsize jelly as coarse aggregate, and all the concrete mixes were proportioned for attaining a strength of M-30 grade concrete. Based on standard code IS: 456-2000, all the reinforced SCC deep beams were designed. As per the EFNARC guidelines, all the SCC mixes were subjected to different flowability tests for ascertaining the concrete as SCC mixes. Test results concluded that the ultimate flexural strength of the reinforced concrete deep beams increased with the increase in the percentage of steel fibers due to the better stitching actions of the steel fibers with the cementitious matrix.

The configuration and symmetry of the building plays a major role under lateral loads in the building. This paper contains the study on seismic behaviour of Open Ground Storey (OGS) building with different combination of plan configuration and elevation symmetry. Further, comparative study on results obtained from response spectrum analysis is carried out. Modelling is done as per the guideline given in Indian earthquake code IS 1893:2002 and 2016 by using CYPECAD-2018 analysis software. The applicability of code provisions has been checked in this study.

Soil-structure interaction refers to the effects of supporting soil medium on the motion of structure and its subsequent response during earthquakes. Multi-storey buildings could have multiple basements for varied functions, viz. automobile parking, boiler system, air-con system, electrical distribution system and cable TV distribution purpose. This study involves soil-structure interaction analysis of a multi-storey building with multiple basements supported on stratified soil medium. The building has ten floors above the ground and 2 below. Response spectrum analysis has been performed on the structure assuming fixed base, flexible base due to homogeneous soil and flexible base due to non-homogeneous or layered soil beneath the foundation using finite element software SAP 2000. Soil properties are included in building model by continuum approach to perform soil-structure interaction analysis. Seismic response of multi-storey building, viz. lateral displacement, storey drift and modal time period is studied for Indian seismic zone V as per I.S. 1893–2002. Presence of non-homogeneous soil beneath foundation of multi-storey structures with basements increases the seismic response of the structure significantly compared to homogeneous soil beneath foundation.

Although rigid floor diaphragm is a reasonable assumption for seismic analysis, certain building configurations may exhibit diaphragm flexibility. Detailed investigations have been carried out on modelling of flexible diaphragms compliant with various codes such as ASCE-07 and UBC 1997. Studies have shown that diaphragm flexibility amplifies both the deformation and the shear in the diaphragm. However, additional studies are essential to assess the magnitude of such amplification and to account for it in the design. The methodology is outlined by three major elements such as the choice of building models, the adopted method of analysis and the parameters studied. Buildings with large cut-outs and openings are observed to exhibit flexible behaviour. These models are analysed dynamically using a site-specific response spectrum developed from probabilistic seismic hazard analysis (PSHA) for Mangalore region (a coastal city in Karnataka, Southern India). The analysis is carried out using a G+10 RC building. The effect of percentage of openings in the diaphragm is studied using structural parameters such as storey drift, base shear and storey displacement with the help of ETABS 2015 software, and the optimum shape for these openings in a building plan is finalized. Further, time history analysis is performed over the models, and the results obtained through response spectrum and time history analysis are compared. The study highlights the importance of diaphragm flexibility in determining the seismic response of a building. This flexibility causes significant increase in the building period, which results in reduction in the earthquake-induced base shear. Since the seismic input used for the study was developed for the moderate seismic zone, the outcomes of this investigation are believed to have vast applications.

With the growing interest in the use of fiber-reinforced concrete in the construction industry, attempts have been made to clarify its performance have become important. This study investigates the effect of steel fiber-reinforced concrete. Generally, steel fiber is used for mitigating the cracks width and enhancing in the concrete member strength. In this present investigation, the study is carried out using steel fiber as reinforcement in concrete (hooked end). In this investigation, properties such as workability of concrete, compressive strength, split tensile strength and flexural strength of the different percentage (0, 0.5, 1, 1.5, 2%) of steel fiber were carried. From the experimental investigation results, it is noted that, by the inclusion of the steel fiber (hooked end), ductility of concrete improved by increasing fiber percentage in concrete. The use of hooked steel fibres also resulted in increase in the load bearing capacity, reduction in cracks and increase in flexural capacity of concrete.

Diagrid system for tall building has evolved as efficient system in terms of lateral stiffness. In this study, an attempt has been made to study the seismic response of diagrid structure with different slab system (conventional slab, i.e. with beam and flat slab) by using response spectrum analysis. The models studied are square in plan with aspect ratio H/B (where H is the total height and B is the width of structure) as 3.1. Five different diagrid angles 41°, 50°, 56°, 61° and 64° are considered. Earthquake analysis is carried out according to IS 1893:2002(Part-1). Based on the study, the efficiency of slab system and optimum diagrid angle is presented in terms of storey displacement and storey shear.

Nanomaterials are currently one of the trending research topics in material science. Due to a larger surface area, size, aspect ratios, and superior mechanical properties, the nanomaterials can be beneficial in the hydration process and nano-pore filling activities. Graphene oxide is one such nanomaterial with one its side in nanoscale, and other two sides are in larger scale. Because of the presence of oxygen functionalities, the graphene oxide can be easily dispersed in the aqueous solution when compared to other nanomaterials. Due to increase in traffic condition and environmental impacts, the pavements are not performing up to the design life. The current investigation is about the use of graphene oxide as cement additive and checking its suitability for the pavement application. In this study, polycarboxylate-based superplasticizer is used to improve the adhesion and dispersion property of the graphene oxide. The graphene oxide is added in the dosages like 0.05, 0.1, 0.15, and 0.2% by weight of cement. Number of tests has been conducted to analyze the impact of additive. The workability of graphene oxide concrete gradually decreases with the increase in its dosage, and the loss of workability is not so significant. The mechanical properties of concrete like compressive, flexural, and tensile strength are greatly increased with the addition of 0.15% graphene oxide, which is found out to be optimum dosage. The percentage increase in flexural strength is more than the percentage increase in compressive strength at 7 and 28 days. The percentage improvement in early strength is more when compared to later percentage improvement. SEM images show, with the presence of graphene oxide, there is a formation of dense microstructure. The overall test result shows that graphene oxide can be used in pavement quality concrete.

Finite element method is a numerical technique used to obtain approximate solutions to the problems with boundary values. It is simply a technique used in solving problems which have partial differential equations and boundary conditions. This method gives approximate results at each and every discrete number of points over the domain. A consistent model is to be developed for easier, faster and less expensive structural development. In this regard, artificial neural network can have high possibilities as these networks are universal approximators that can carry out any uninterrupted mapping and can provide general mechanisms for building models from data whose input–output relationship is highly nonlinear. In this paper, the behavior of trough shape folded plate roof is studied in terms of displacement and stresses for different boundary conditions using the software SAP-2000 (v-20) by varying geometrical parameters (thickness, bay width and height of FPR) and to extract the information on the importance of the input parameter on the prediction of output results using artificial neural network model.

This paper addresses the analysis of irregular multi-storied RC frame building according to different seismic design codes. A RC multi-story building is subjected to most dangerous earthquake; the main reason for failure of RC buildings is irregularity in its plan dimensions. This paper presents analysis of irregular building using different seismic design codes. Building is compared in terms of structural displacement, drifts and story shear. And also focuses on three seismic design codes India (IS 1893), USA (ASCE 7) and Europe (EC8). Irregular L-shape ten-story buildings are analysed using the equivalent static load method (ESL).

High-rise structures are growing speedily around the world. The unique geometric arrangement of the system provides the efficiency of structure and beauty capabilities; the new structural system with diagrid has been used extensively for the recent high buildings. The diagrid is an arrangement of triangulated beams; it has a straight or curved and horizontal ring system which makes the combined structural system for skyscrapers. Diagrid structure uses fewer materials than traditional structural systems with orthogonal members. The efficiency of diagrid system reduces number of inner columns so that the design of the plan gets more flexibility. This research study aims to explore the applicability of diagrid systems in high-rise buildings, over conventional construction systems. A square plan 32 m × 32 m dimensions is taken to study of behaviour of high rise building with a diagrid system. All structural members like beams, columns, etc., are analysed considering all load combinations as per IS 800:2007. Similarly, analysis of G + 40-, G + 60- and G + 80-storied structures with diagrid system is taken for comparison of the results for parameters like storey shear, storey drift and storey displacement which are also represented in paper. For modelling and analysis purpose, ETABs software is used.

This paper communicates organized work on copper slag drawn from scientific literature which comprises evaluation of physical and chemical characteristics, mechanical and durability properties in the marine environment. Analysis of test data derived from previously available sources reveals that copper slag having similar basic characteristics is an acceptable alternative material to river sand to produce concrete of all grades. The lesser water absorption property of copper slag is very significant peculiarity which attributes to develop high strength in concrete. The behaviour of concrete produced using copper slag to the concrete made corresponding to sand component shows identical behaviour in the fresh and hardened states. As an aggregate, copper slag has an ability to be replaced with fine aggregate, thereby the advance progress in the concrete technology will revolutionize the mixture of different conventional ingredients to uplift the expected properties of concrete to renew its definition. Hence, alternative materials to be used as fine aggregate will reduce the burden on the environment which is being extensively investigated all over the world looking to the significant requirements, quality and properties which have been a global consensus on the materials.

Sand has always been an integral part of construction in our civilization. It has been the most easily available and acceptable source for the same. However, the depletion of river sand availability has started looking at the alternatives including some industrial by-products. One of them is slag obtained from manufacture/refining of metals which would help in the utilization of industrial waste and conservation of natural resources to have a sustainable construction. This paper provides the gist of organized overview involving the evaluation of physical and chemical characteristics, assessment of mechanical and durability properties for the effective utilization of steel slag and processed granulated blast furnace slag (PGBS) that could be modelled from previous researches related to the study. The basic properties of steel slag and PGBS exhibit requisite properties like river sand which is an indication for a possible alternative material to the conventional aggregate. The multiple processing of slag has its influence on strength, durability, and workability of concrete. These recent innovations have made the slag economically viable and environmentally friendly, and also profitable salvaging of processed by-product.

The bacterial concrete is a self-remediation biomaterial under favorable conditions. Bacteria can precipitate calcite in concrete or form a layer of calcite precipitation which plays an important role in remediation of the plastic shrinkage microcracks thereby increasing the long-term structural integrity and durability of concrete. This study investigates the impact on compressive strength of concrete by addition of aerobic microorganism such as Bacillus subtilis and Bacillus megaterium, which microbiologically induce the mineral precipitation. The bacteria were incorporated into the 100 mm concrete cube in different concentrations in two stages formerly by curing in distilled water and later by curing in peptone-based nutrient medium. The results show the positive impact on compressive strength of concrete cubes with an increase in the strength of 30% with Bacillus megaterium. The strength enhancement is due to the precipitation of calcite within the pores which in turn improves the pore structure of the concrete. The study also revealed the importance of culture media, type of microorganism and cell concentration on the strength properties of bioconcrete. However, there was no much improvement in strength by curing in nutrient medium.

Durability of concrete is assessed by its permeation. Water ingress is the major factor for deterioration of concrete, and there is always an urge to find a simple and reliable way to measure the material properties of concrete which can be related to durability. Water sorptivity is a useful single material property which is useful in service life planning and prediction. This paper presents the results of sorptivity of self-compacting concrete (SCC) and comparable normal concrete (CNC). SCC mixes were developed for different paste contents of 0.38, 0.41 and 0.43 with filler fly ash and cement contents ranging from 300 to 450 kg/m3. SCC has its own unique advantage over CNC due to its characteristics of higher powder per se paste with higher flow and better lubrication of the aggregate with reduced interparticle friction and superior densification of microstructure. The results show better performance of SCC in terms of capillary absorption compared to CNC. The sorptivity value decreased as the volume of paste (Vp) increased and higher paste content generally makes the mix robust with better densification of the microstructure, thereby improving the durability and making the concrete more sustainable with improved long-term performance. The sorptivity based on secondary absorption can be effectively used as a durability index to predict the time duration required for the ingress of water to penetrate the concrete, which has practical significance.

The use of composite materials is more in repairing and retrofitting of concrete structures in the last few years, so that many concrete structures would be strengthened by these materials. One of these applications is carbon fibre reinforced polymer (CFRP) material used in fortifying and retrofitting of strengthened solid structures. The primary explanation behind this is it is conceivable to get a decent reinforcing impact with a generally less work exertion. It is additionally conceivable to complete a reinforcing work without changing the appearance or measurements of the structure.

Restoring the strength and performance of the structural element has become the current topic of the research study. It is also been observed that well-established strengthening techniques are available for beams and columns such as section enlargement, jacketing, external bonding and near-surface mounted techniques, whereas the available strengthening methods for the slabs are limited. The saturation of carbon fiber reinforced polymers or commonly known as CFRP composites and glass fiber reinforced polymer commonly called GFRP composites, encourages the research activity for the product development of an alternative material to be used in structural retrofitting and rehabilitation of structures. Most importantly materials which are economically viable are very much required for the developing country like India. Polypropylene fibers, which are very much used in the industries like mining, agriculture, fabric industries, sports, hospitals and chemical industries and find a limited applications in construction industry. The economic analysis of the wrapping material was calculated based on the cost of the material, area of wrapping and strength achieved and it was found that the percentage increase in the ultimate strength of the strengthened slabs using the plus and square wrapping configurations was in the range of 2.9–6.4%.

The composite construction has always been the area of interest for structural engineers as the use of two or more material to make one structural member have always proved to be beneficial. The concrete-filled steel tubes (CFST) and concrete-encased steel (CES) columns are gaining popularity and have been adopted for the construction of high rise buildings. In the present work, CFST columns and CES columns subjected to axial compression were analysed. The columns are assumed to be having fixed-free end and the loads were applied on the loading plate for even distribution of loads. The circular, square and rectangular shapes of columns are considered. CFST columns were considered for varying steel tube thickness of 3 mm, 5 mm and 7 mm, and the I-section selected was ISMB 100 for CES columns. CFST and CES columns were analysed separately. The behaviour of these columns and their ductility was studied. The analysis was carried out using the finite element software ABAQUS. The modelling and meshing were done in the software and analysed. The loads versus deformation graphs are plotted for each column. The ductility factor and load carrying capacity for all CES and CFST columns are compared. The circular CFST column with 7 mm tube thickness was found to be the better in terms of ductility and load carrying capacity.

The purpose of structural design is to fix the dimensions of a structural member, to safely withstand the loads anticipated during its life cycle and to serve the intended purpose satisfactorily throughout its service life in the environment it is built for. The main aim of the present work is to determine the probability of satisfactory performance of flanged reinforced concrete beams in limit state of strength in flexure. For this purpose, two methods, namely simulation approach and analytical approach, have been made use of. For the study purpose, standard T-beam bridge cross sections for different spans as recommended by MORTH have been made use of. The typical load combinations as specified in IRC: 6-2017 are considered. Also, the special vehicle load which was introduced in the recent code IRC: 6-2017 is also considered to check the performance of bridge beams against limit state of strength in flexure. The various basic random variables are assumed to be statistically independent normal and non-normal random variables. The moment of resistance is found to follow normal distribution, external moment found to follow Type-1 distribution, and the safety margin is found to follow lognormal distribution. The reliability index value tends to decrease with an increase in span.

The seismic responses of structures on sloping areas are fairly different as compared to the flat ground. Step back and set back structures have geometrical irregularity; hence, these structures are more vulnerable to earthquakes on the inclined ground. In this paper, an attempt has been made to evaluate the seismic performance of reinforced concrete buildings on flat and sloping ground with sloping angles such as 20°, 30° and 40°. The response spectrum method of analysis has been performed using by ETABS v 17.0.1. The earthquake resistance codes IS 1893 (Part 1): 2016 and IS 13920: 2016 have been referred in this study. Results are discussed in terms of base shear, storey drift, storey stiffness, short column effect and overturning moment for the plain and inclined ground with different inclinations. In inclined ground structures under seismic loads, the short column effect is a common problem; hence, the discussion of critical issues of step back and set back structures is presented for different slope angles.

Base confinement system for a structure is acquainted to decouple the building structure from possible movement incited by the movement of the seismic tremor, keeping the building superstructures from retaining the quake vitality. Base isolator increases the regular time period of the general structure and diminishes its shear increasing speed reaction to the seismic movement. In this explanatory examination, a ten-storey reinforced concrete (RC) building with lead elastic bearing, high damping elastic bearing and triple-contact pendulum framework bearing is acquainted with the structures, and correlation is made between fixed base and the base-secluded structures. Demonstrating and investigation are conveyed utilizing ETABS 2015 v15.2.2. The investigation examination is performed to check the ampleness of the working against the lateral displacement, inter-storey drift, story shear and story acceleration. It is found from the investigation that reaction of working to lateral load diminishes, while modular period is expanded in both X and Y bearings. Furthermore, it was reasoned that triple grating pendulum bearing is increasingly compelling in examination of different direction utilized in this investigation.

Stone mastic asphalt (SMA) is a gap-graded asphalt mix consisting of high coarse aggregate content and rich mastic (asphalt and filler) content. The stone to stone contact between coarse aggregates results in higher rut resistance compared to other asphalt concrete mixtures. The rich mastic in the SMA Mix leads to increased durability and higher resistance to moisture damage. Due to higher asphalt content and stabilizing additive used in the production of SMA Mix leads to an increase in production cost which is one of the major disadvantages. This research evaluated the performance characteristics of SMA incorporating sugarcane bagasse ash (SBA) as a filler material and to study the cost-effectiveness. Four mixtures with different proportions of SBA used to assess the performance of the SMA. Mix 1 consisted of 2.5% SBA, Mix 2 consisted of 5% SBA, Mix 3 comprised of 7.5% SBA and Mix 4 consisted of 10% SBA by total weight of the mix. The resistance to moisture damage of Mix 1 and Mix 2 was within the allowable limit, and indirect tensile strength of Mix 1 and Mix 2 was higher compared to conventional mixes. Decreased draindown of bitumen for SMA mixtures without fibres containing SBA was observed. The results obtained show that the mix containing up to 5% SBA exhibited superior performance when compared to conventional mixes.

Throughout the evolution of the human society, the one thing that each person has looked up to is the facilities that are available which includes basic infrastructure, roads, etc. When it comes to construction, the durability and quality are important factors. For a stable structure to be constructed, the most essential requirement is the presence of a stable base. In the earlier time, when there was no suitable soil beneath the structure, soil replacement was one of the methods used to be carried to attain stable strength and durability. In some of the places, the method of soil replacement could not be adopted, and hence, the stabilization of the soil by either physical or chemical methods is carried out. When it comes to soil stabilization, the main aim is to stabilize the soil with minimum cost and causing less harm to the environment. The present study focused on the investigation of the effect of polyurethane foam as a stabilizer on weak sub-grade soils. This study involves the stabilization of black cotton (BC) soil as it is declared as one of the problematic soil as construction on this soil is very difficult. The study takes place by the addition of liquid polyurethane foam in different percentage by mass of the soil and index, and engineering properties are carried out. The study also furnishes the optimum percentage of polyurethane foam to be added for effective stabilization. It is observed that the strength of black cotton soil can be improved when treated with liquid polyurethane foam. It was observed that soaked CBR values increased after treatment with liquid polyurethane foam.

This paper focuses on the development of an android-based mobile application by the name ‘Ground IQ’ for foundation works in the field of civil engineering. The first stage involves manual calculation of safe bearing capacity of soil based on codal provisions of IS-6403 [1] and equations developed by Terzaghi [2]. Its value is compared with that which is obtained as a result from the application developed. In the second stage, the computed SBC is used to design footing or foundation on the site from where the soil sample is collected. The design can be then compared with that obtained from the application developed and checked for accuracy. The Integrated Development Environment (IDE) or the platform used for the development of this application is Android Studio which supports Java programming language for coding.

The current study is aimed at to determine the optimum mix parameters for developing the mortar blocks using red mud (RM), cement kiln dust (CKD) and silica fume as binder. In the present study, an attempt is made to prepare alkali-activated mixes containing red mud (RM), cement kiln dust (CKD) and silica fume as binder. Various strength properties of mortar blocks at different time intervals (days) were investigated. From the results, it was found that the compressive strength of red mud blocks improved with the addition of higher contents cement kiln dust and silica fume. The mixes with red mud as sole binder and with lower contents of CKD and silica fume displayed higher water absorption and total porosity. The UPV values mixes showed a better performance with increasing contents of silica fume and CKD. The resistance to abrasion was found to be better for mixes which contained higher proportions of CKD and silica fume, respectively. All the mixes displayed sufficient strength and durability performance to suit the requirement of bricks based on the type or class of bricks.

Leachate is a hazardous liquid which percolates through the landfills and extracts dissolved and suspended hazardous matter from it. Large quantities of municipal solid waste which consist of chemical, industrial and biomedical wastes are received by dump yards, which creates environmental problems such as pollution of soil and groundwater. In the present study, the laboratory test was conducted on both contaminated and uncontaminated (collected soil sample from college campus) lateritic soils to determine the effect of landfill leachate on the performance of subgrade soil. The contaminated soil samples were prepared by mixing the soils with MSW leachate in the increments of 0%, 5%, 10% and 20% by weight. Finally, all subgrade soil properties were analyzed. For contaminated soil, Atterberg’s limits increase with the increase in the leachate content. The MDD is maximum till 10%, and after that, it is decreased. The results showed that the MSW leachate affects the compaction characteristics, shear strength and Atterberg’s limits of the lateritic soil.

Due to the particular characteristics of hospitals, the hospital buildings are highly sensitive to environmental noise. However, they are usually located close or within urban agglomerations and in particular main roads. Hence, hospitals are, in many cases, exposed to high levels of environmental noise. In this study of comprehensive one-month research project, traffic and community noise levels were measured and monitored at five sensitive areas (near hospitals) in its spatial–temporal aspect, at the city of Mysuru, Karnataka. Noise measurements were taken at different peak sessions in morning and evening, for duration of one hour. Observed noise values were analysed and compared with the recommended permissible limits (40–50 dB) as stated by the Central Pollution Control Board (CPCB). The measured values exceeded the CPCB noise limits prescribed for sensitive areas. This paper presents an analogy of obtained noise readings with the national CPCB standards for silent zones.

The development in commercial, residential and industrial areas has led to an increase in traffic load further causing the deterioration of the pavements. To keep the pavements in good serviceable condition, it is necessary to carry out the functional and structural evaluation of the pavement. In the present study, the functional and structural evaluation was done by visual observation of the pavement and Benkelman beam deflection (BBD) technique, respectively, on a village road in Nitte and SH 37 in Hosmar, Udupi District. Soil subgrade samples were collected from both the sites and soil tests such as compaction, and CBR was carried out on the soil subgrade. The Benkelman beam deflection data were analysed. The overlay design was selected based on the characteristic deflection and design traffic obtained for the respective pavements.

This study was conducted to investigate the new method comprising of sequential anaerobic followed by aerobic batch reactor treatment for 2,4-dichlorophenoxyacetic acid (2,4-D). The various parameters influencing on the anaerobic digestion like pH, temperature, oxidation reduction potential (ORP) have been monitored during the 60 days study period. pH range of 6.5–7.2, temperature greater than 31.4 °C and ORP values between −250 and −300 mV have reported better reactor performance with high 2,4-D removal and biogas production. The complete biotransformation of 2,4-D in the anaerobic reactor is indicated by disappearance of intensity peak in the high-performance liquid chromatograph (HPLC) report, high biogas production of 12–18% than control and COD removal efficiency of 99%. Dominant bacterial community in the sludge was identified using SEM images. The results of this study indicate that anaerobic reactor and aerobic post-treatment method can make the treatment highly efficient.

The most toxic pollutants in mine drainage are heavy metals. The JOGMEC Company is using a wastewater treatment plant which is highly expensive to maintain. As for that reason they have thought of using constructed wetland method for the removal of heavy metals from mine drainage. For this project, they have asked KANSO CO. LTD. along with Prof. Satoshi Soda and his team to conduct initial survey, which includes laboratory-scale analysis for removal of heavy metals. Synthetic mine drainage in laboratory-scale is to be treated using constructed wetland in a sequence batch to assess heavy metal removal efficiencies. In this project, two sets of laboratory-scale constructed wetlands are prepared and feed with synthesized mine drainage water and checked for the efficiency of heavy metal removal from the mine water. This project’s main intention is to obtain effective and higher efficiency for removal of heavy metals and then to compare the efficiencies of the planted and unplanted construction wetlands.

The present investigation aims at removing excess fluoride from spiked groundwater to the BIS prescribed drinking water standards of 1.0–1.5 mgL−1 using electrochemical coagulation (EC) followed by adsorption. A set of batch EC experiments were conducted for varied initial F concentration and varied cell voltage by keeping a constant ET of 60 min. The optimum operating conditions were determined by running a series of batch experiments employing 6 number of electrodes at F0 = 5, 10, 15, 20, and 25 mgL−1. The varying cell voltage of 8, 12, 18, and 24 V was used. Batch EC studies revealed that, the highest treatment efficiency was obtained for the largest current input, i.e., 24 V. Fluoride concentration of 15 mgL−1 was found to be the optimum initial concentration with respect to maximum fluoride and solids removal. These optimum operating conditions were incorporated in the continuous treatment processes carried out at different flow rates and different depths of sand. It was observed from the continuous studies that with the increase in flow rate and there was decrease in the fluoride removal efficiency. Increase in the depth of sand increases fluoride removal rate as the surface area available for adsorption will be more. Flow rate of 4lph and depth of sand as 45 cm showed maximum fluoride removal efficiency of 94.6%.

The seasonal air transport pathways and the potential sources contributing to air pollution in Delhi for the period March 2015 to February 2016 have been identified with the help of PM2.5 data (particulate matter with diameter less than 2.5 μm), potential source contribution function (PSCF), cluster analysis and concentration weighted trajectory (CWT) method. The local sources are identified with the help of conditional probability function (CPF). The presence of re-circulating air masses has shown that the major contributors to air pollution in winter seasons are the local sources and the neighboring states of Haryana and Punjab. Northwesterly flows can be observed throughout the year and are highest in the winter season and comparatively lower in the monsoon season. PSCF values greater than 0.7 and CWT values greater than 110 μgm−3 are observed within the state in the winter season. Haryana and some parts of Uttar Pradesh also have higher PSCF values. The frequency of occurrence of long distance pathways is less in all the seasons in Delhi. The influence of the dust pathways from the Thar Desert areas can be seen in the monsoon season. Slower moving northwesterly and southwesterly flows are associated with high concentration values and indicate high pollution along the pathways. Higher CPF values occur in the northeastern direction. Therefore, the industrial sites, traffic congestion and emission from vehicles in the roads connecting Delhi and Uttar Pradesh have high influence in the rise in pollution levels.

Herbicide poses a serious threat to living organisms owing to their non-biodegradability and toxicity. Among all, 2,4-D is one of the endocrine disrupting compounds (EDC), which is used to kill the weeds in the crop field. During heavy rainfall, the residual 2,4-D joins the surface water body, thereby increasing the toxicity level. Hence, in this study, electrocoagulation (EC) using copper electrodes was applied to remove the 2,4-D in water. The electrocoagulation has several advantages, which include ease of operation and the scope for automation. Here, the effect of three factors, viz. pH, time and 2,4-D concentration on the removal percentage was studied. In pH 5, 7 and 9 with two electrodes configuration, the 2,4-D concentration removal was 35, 47 and 82%, respectively, whereas for four electrodes, the removal efficiency was 52, 82 and 99%, respectively. The maximum 2,4-D removal was observed with pH of 9 in 50 min. Higher the initial concentration, lesser the removal efficiency was observed.

Investigation of the rainfall homogeneity along with bivariate frequency analysis of drought considering change points in long-term annual precipitation series has been carried out in this study. Nonparametric Pettitt’s test was applied for detecting change points of annual precipitation series at different grid locations over the Ghataprabha River Basin. Depending on the results of change point analysis, we divided the entire period of 1950–2013 into two subperiods: from 1950 to 1980 and 1981 to 2013. Characterization of meteorological drought is performed with the help of the Standardized Precipitation Index (SPI) at a time scale of three months for the period before the change point (1950–1980), after the change point (1981–2013) and for the entire period of 1950–2013. Three Archimedean copulas, namely Clayton, Gumbel–Houggard, and Frank, were tested for joint distribution modeling. The Akaike’s and Bayesian information criteria have been implemented for selecting the best copula; the Gumbel–Hougaard copula performed comparatively better for all three periods. Drought return periods were calculated using the joint distribution of drought characteristics. The study gives valuable insight into drought risk management on a regional scale.

For the design and construction of a vertical-caisson breakwater which is more significant task in the field of ocean engineering, since the incidicent wave and reflected wave acting on the structure causes severe bottom scouring and final leads to failure of the structure. The influences of wave height, wave period, and toe armor unit stability are under investigation in this study. The experimental work conducted by Brebner and Donnelly [1], was put forward, that for a certain fixed relative foundation depth (d1/d) and wavelength (L), the significant wave height (Hs), will have an exponential relationship with the number of rocks displaced in the armor layer of the toe of the vertical-caisson structure. The investigation are conducted in the regular 2D wave flume at wave mechanics laboratory, NITK, Surathkal. The present paper provides the required information regarding the damage level of toe armor units in transition water depths and the effect of wave parameters are analyzed.

The water sources surrounding the Mangalore dump yard have been highly contaminated by the leachate percolating to the water bodies as it contains high content of toxic metals like lead, mercury, cadmium, arsenic, etc. The geo-synthetic clay liner at the bottom of the dump yard is worn out, and hence, there is direct percolation of water into the water bodies. Geo-synthetic membranes are the latest and the most effective for containing the contamination. In this paper, the use of geo-synthetic membrane or simply geo-membrane as a filter material for filtering the toxic metals is explained. A miniature model of the dump yard is prepared, and geo-membranes were laid around the periphery of the model. Geo-membranes like polypropylene of matrix density 500, 600, 700 have been used, and a considerable reduction in contamination percentage has been obtained.

Surface water sources have become highly contaminated due to the presence of undesirable substances making it unfit for consumption and other uses. The concentration of impurities can be reduced by several methods. Membrane technology is the latest and the most effective one. In this paper, glutaraldehyde-grafted chitosan-PVA polymer composite membrane has been synthesized and characterized. Solution casting method has been used to synthesize the membrane. PVA is dissolved in distilled water, and then chitosan powder is added to the solution. Membrane is fabricated and then grafted with glutaraldehyde. Scanning electron microscopy (SEM) was used to characterize the developed composite membrane in terms of morphology and performance. Water optic studies were carried out to study the pore size of membrane. This paper is aimed at developing a simple water filtration unit using adsorbents like coarse aggregate, activated charcoal sand, and composite membrane.

Spatial and temporal analysis of crops and other land surface features is the major application of the present spaceborne sensors. Among most of the spaceborne sensors, synthetic aperture radar (SAR) is having the advantage of all-weather capability with low-frequency bands. SAR data is useful for decompositions, crop classifications, etc. In this study, paddy fields are classified using Sentinel-1 ground range detection. Synthetic aperture radar data with the combination of vertical polarization with the horizontal receiver (VV and VH) is selected for the temporal variation analysis and classification analysis of paddy fields along with the plantations. Multi-temporal classification analysis is done using random forest classifier, and correlation obtained is 0.78 and 0.45 in VH and VV polarization, respectively, and the error rate shows significant variation in both the polarizations, i.e., 0.05 and 0.25 (in VH and VV polarizations, respectively), which indicates more error rate in VV polarization band. In this study area, VH polarization shows better classification and correlation compared to VV polarization due to double bounce effect of urban features, paddy and plantation at the stem elongation and booting stage in VV polarization.

Soil erosion is considered as one of the major causes of land degradation and reservoir sedimentation. Therefore, modeling of runoff and sediment yield at the catchment level is necessary. In this study, an attempt was made to simulate runoff and sediment yield of hydrologically similar basins of Kali River and Aghanashini River which joins west coast of India. A conceptual, continuous time and semi-distributed SWAT2012 (Soil and Water Assessment Tool) model was selected for the modeling purpose. For the last two decades, Kali river basin experienced a very high rate of soil erosion due to various developmental activities in the basin. Therefore, it is essential to identify the soil loss within the basin. There are five dams constructed across the Kali river basin for various purposes. The presence of these reservoirs regulates stream flow and thus sediment load in the basin. However, the free movement of water across the Aghanashini river catchment leads to the unobstructed passage of sediments to the river mouth, as the catchment is not disturbed by the reservoir. This study deals with the impacts of the dams on stream flow, sediment load and the response of shoreline. Digital Shoreline Analysis System (DSAS) tool was used to analyze the shoreline changes. Simulated and observed values of runoff are compared, and calibration and validation were done for the basins using SWAT-CUP. Analysis of calibration and validation results shows that the model has a good performance. Therefore, the SWAT model can be used to conduct further studies in these study areas. Sediment yield obtained at the catchment outlet was 1.07 t/ha/year and 4.58 t/ha/year for Kali and Aghanashini basins, respectively. Less amount of sediment load in the Kali basin indicate the influence of reservoir operation on stream flow and sediment yield. The shoreline analysis of both the basins concluded that Devbagh beach connecting with Kali river estuary is under erosion and Aghanashini beach is under naturally nourished condition.

Most of water resource projects are carried out after analysis of rainfall data. Intensity–duration–frequency (IDF) curves are used to analyze the quantity of rainfall of different duration (t) and return periods (T). The study area in Aghanashini watershed lies between 74°18′15.95″ and 74°55′22.84″ E longitude and 14°15′26.21″-14°37′17.65″ N latitude. Area is about 1400.47 km2, and altitude ranges from zero meters to 784 meters above mean sea level. The river extends from Sirsi to Kumta of Uttara Kannada, Karnataka State where it reaches Arabian Sea. The daily rainfall data of nine stations collected from Directorate of Economics and Statistics Bengaluru for years 1998 to 2016 was gone through, and 24-h maximum annual rainfall data was extracted. Indian Meteorological Department (IMD) proposed formula is used to estimate rainfall values for various shorter duration such as 0.083, 0.167, 0.25, 0.5, 1, 2, 12, 24-h. Probability distributions is used to estimate maximum annual rainfall values for various duration (t) and return periods (T) and Chi-square test is carried out to check the best probability distribution. Chi-square test shows that normal distribution is best fit to calculate rainfall intensity (mm/h) for six stations (Balale, Nilkundi, Sirsi, Hittalahally, Tyagali, Katagal), Log-Pearson type III probability distribution is best fit for two stations (Bandal and Siddapur) and Log-Normal distribution for one station, i.e., Kumta in Uttara Kannada.

Climate hazard group infrared precipitation with station data (CHIRPS) is one of the latest high-resolution quasi-global satellite-based rainfall datasets. It is available in daily, pentadal and monthly time scale from the year 1981 to present. In the present study, the performance of the CHIRPS product is evaluated over the Kerala state on a monthly time scale. For the evaluation of this climate hazard group, product rain gauge data from sixty-seven-gauge stations which are distributed all over Kerala was used. Validation statistics such as mean absolute error (MAE), multiplicative bias (Mbias), Nash–Sutcliffe efficiency (NSE) and coefficient of determination (R2) were used for the evaluation. The results show that the efficiency of this satellite rainfall estimate is very high with an overall NSE value of 0.72. The accuracy of CHIRPS data was very high mainly in the low-lying areas of Kerala, i.e. at the coastal areas and it was found to be decreasing when in approaches towards the Western Ghats. Overall CHIRPS product is good enough for use in water resource applications in Kerala.

Flood is the most common hydrologic event frequently experienced in India. The states of Kerala, UP, West Bengal, Karnataka and Assam were the mainly affected by flood in 2018. In Kodagu, the southern district of Karnataka, many people have been affected by heavy rains. Landslides in hilly terrain and flooding have worsened the lives of people and led to the destruction of 800 homes, 240 bridges collapsed, road networks of 2225 km damaged and 65 government buildings affected. The cost of rebuilding road infrastructure and buildings is approximately Rs. 3000 crores. While developing flood mitigation measures, flood inundation maps are an essential component, which will be useful for the planning stage. The mapping is expected to estimate the prone flood zone based on river flood stage without performing additional simulations and quantification of the flood risk with respect to different vulnerability parameters giving a clear picture of the planning stage. These are going to be achieved by both 1D hydrodynamic models and GIS environment. This study gives an insight about how unscientific development activities may increase the negative impacts of natural disasters. It can support the planners to correctly identify the non-vulnerable places while rebuilding the damaged infrastructure. This can help people to resettle permanently in a safer place, so that they will not be affected in the case of future disasters. Depending on the severity of the water levels, we can identify the area for construction of hydraulic structures for flood protection.

Flash floods are ranked on top in the number of people that are affected and amount of damages caused. The sudden nature of this disaster gives less time for the victims to prepare, thereby ending up with a disrupted social, economic and political stature. The study aims at analysing the possible peak discharges with the help of a rainfall–runoff model for the flood events that have occurred in the Harangi River basin in the Kodagu district and estimate the economic damage induced. The SCS curve number method is used for simulating the runoff. Fourteen peak events over the months of July and August of two different years are chosen for the validation and calibration of the model. Discharges are simulated using the HEC-HMS extension in WMS software. The effect of variation of rainfall and land-use practices in the runoff volume is studied. It is observed that the changes in land-use practices have more effect on the runoff volume than the rainfall volume. Rapid urbanization and industrialization has increased the intensity of flood damages. The largest flow was recorded when a natural bund of water collected in the upstream was collapsed.

Riverine resources which are the basis of life are being transformed through urbanization. This has to be analyzed effectively in order to rejuvenate riverine ecosystems. The effects of land-use dynamics are a factor to be analyzed, and using hydrological modeling which is adopted in this study aids for the same. Soil and Water Assessment Tool (SWAT) is used as an effective tool in modeling the river basin due to its ability to quantify the alternate input data provided to the model. 14-year daily data was simulated in the model provided; the warm-up period for the model is 2 years. Coefficient of determination value of 0.74 and Nash–Sutcliffe efficiency (NSE) to be 0.71 were obtained from the analysis which indicate that the simulated values fall within a good range. The parameters which influence most are found to be curve number, available water capacity in the soil, groundwater delay, Manning’s n and plant uptake compensation. The fitted range was obtained, and this was used to increase the accuracy in SWAT Calibration and Uncertainty Procedures (SWAT-CUP). Sequential Uncertainty Fitting ver.2 (SUFI2) was found to be effective because of its uncertainty consideration criteria, and it accounts for all uncertainties that may occur in the mode. Hydrological modeling of a river basin can help us to assess the impact of alternative input data on the stream flow.

Water and land are the finite natural resources to be utilized for their optimum productivity. The management of these resources for sustainable development is the need of the hour. The modern techniques such as remote sensing (RS) and geographic information system (GIS) are used for creation of digital database of different thematic maps which require to assess the land suitability for different crops based on the land suitability. The suitability of land is assessed considering the cropping system, for optimizing the use of piece of land for a specific use (FAO, 1976). The suitability is a function of crop requirements and land characteristics, and it is a measure of how well the qualities of land unit match the requirements of particular form of land use. The study area chosen is Kabini Command which spreads in Mysuru and Chamarajnagara districts. It is geographically located between 76°12′0″ E and 77°12′0″ E longitude and 11°58′0″ N and 12°16′0″ N with an area of 707.284 km2 and is covered in Survey of India (SOI) Toposheet numbers 57H04, 57H03, 57D16, 58E01, 58A13, 57D12, 57D08, 58A05 and 58A01 on 1:50000 scale. RS and GIS techniques are used in the application to estimate the command area, watersheds within the command and preparation of different thematic maps. Analytic hierarchy process (AHP), RS and GIS have shown as an efficient tool to derive the crop suitability within the command area.

Quick and accurate mapping of properties of soil is considered to be critical for agriculture and environmental management. Rapid assessment of soil properties is a daunting task in monitoring the environment. The conventional field sampling is a laborious as well as time-consuming job. The conventional methods are restricted to a specific region but there is a need to analyses the soil properties at landscape levels. Hence, this study emphasises on hyperspectral remote sensing which to some extent helps in rapid assessment of the properties. The hyperspectral data used for the study is AVIRIS-NG data. The study explored the potential of AVIRIS-NG hyperspectral data in mapping soil properties which were analysed by in situ laboratory methods and compared with them by geostatistical method of spatial interpolation. Hence, the method adopted for this purpose is the study on spatial variability of soil properties by using Kriging interpolation technique. Also, a review study is carried out on the visible and near-infrared analysis (VNIRA), multiple regression analysis approach and spectral angle mapper supervised classification technique on the high-resolution AVIRIS-NG Hyperspectral data, which will yield as an empirical model for predicting the soil property in question from both wet chemistry and spectral information of a representative set of samples and classifies the data accordingly.

Meteorological data retrieval is the fundamental process for any hydrological research. Precipitation data collection from some constrained territories like high slant geography and inaccessible areas is exceptionally troublesome. Setting the rain gauges is a matter of expense and timely maintenance. To overcome these issues, satellite sensors producing high spatial and temporal resolution datasets can be utilized in the studies involving precipitation component. These satellite products are affected by biases, and hence, there is a need for calibration and verification by using ground observation data based on the statistical coefficients. In this study, the most accessible satellite data products, i.e., CHIRPS, PERSIANN-CDR and TRMM, are employed to check the accuracies against IMD gridded data for the years 2000–2012 using a statistical approach. Selecting the data product having a high coefficient of correlation and low PBIAS is utmost necessary. The current study was performed based on catchment-to-catchment (C-C) method by comparing IMD gridded data with satellite datasets obtained from Google Earth Engine. The results can highlight the data product which can conquer the issue of data inaccessibility in the investigation territory and can be utilized as reference precipitation dataset for different hydrological applications.

The study of frequency analysis is crucial to find the most fitting model that could predict extreme events of certain natural phenomena, e.g., rainfall, flood. The study aims to determine the best-fit probability distribution model for maximum daily rainfall of four stations in Mangalore city. Statistical analysis such as log-normal, log-Pearson, and generalized extreme value (GEV) was applied, and parameters of these distributions were estimated. The predicted values using these distributions subjected to the goodness of fit test using the Kolmogorov–Smirnov test, Anderson–Darling test, and Chi-squared test. Generalized extreme value distribution gave the best-fit model and thus, used for deriving the intensity duration frequency (IDF) curves for Mangalore city. IDF curves using empirical equation and GEV distribution were compared, and GEV distribution IDF curves give higher rainfall intensities.

The dynamics of land use/land cover can be studied by using digital change detection techniques which are highly significant for the evaluation and development of management strategies in a region. The environmental and hydrological processes prevailing in the area can be interpreted only by analyzing the alterations in the past and present land use and land cover classes. In view of this, the present study is executed to analyze the typical land use change in the coastal region over the three decades by analyzing historical and current land use/land cover (LU/LC) datasets. Landsat 5 and Landsat 8 satellite datasets were considered for change detection analysis using unsupervised classification method. K-means algorithm, a widely used unsupervised classification technique, was adopted in this study to classify coastal region of Karnataka for the years 1990 and 2019. The level-II classification was performed on LU/LC raster datasets (Landsat 5 and 8) which segregated the entire study area into ten classes, namely agricultural land, barren land, built-up area, water, forest, fallow or cultivated land, scrub forest, sandy area, swampy forest and wetlands. This study encapsulated that about 40% of the study area was occupied by water body followed by forestry with a percentage of around 30%. Major changes were observed in the barren land and scrub forest between 1990 and 2019, where the barren land was replaced by scrub forest in 2019. The accuracy assessment is performed to analyze the efficiency of the algorithm and the precision of the classified image which showed an accuracy of 81% in 1990 and 84% in 2019 demonstrating the ability of an algorithm to classify reliably.

Satellite radar altimetry is exclusively designed for the oceanographic studies such as wind speed, sea surface level, tide height, and volumetric changes. In spite of the fact that the satellite radar altimetry is predominantly intended for oceanographic studies and ice sheet monitoring these days, the utilization of altimetry information is reached out to think about water dimension of inland water bodies like reservoirs, rivers and so on. This study covers the use of SENTINEL-3 Ku/C Radar Altimeter (SRAL) for the monitoring water level of Nagarjuna Sagar reservoir located in Telangana state, India. Satellite altimetry works on the principle of range measurement that is the measure of the travel time of microwave pulse from emission to receiving which is interrupted by many atmospheric conditions which cause a disturbance in travel time of microwave pulse which is to be adjusted to get corrected depth of water level. The SRAL information is handled utilizing Broadview Radar Altimetry Toolbox (BRAT) programming. The consistency of derived water level is compared using field data, and all the depths are within error range of one meter. Water body mapping is carried out utilizing cloud-free data of Landsat-8 from January 2016 to March 2019 which showed a gradual decrease in water level from November to May.

In the present paper, the study emphasizes on providing suitable water conservation measures to study area as it is a drought prone area. The rainfall is uneven and non-uniform, and it poses a severe water scarcity problem in the region as agriculture is the main occupation of the people. Hence, a proper water conservation practice would solve the water problem. Thus, the paper presents the importance of rainfall pattern study on land use and land cover changes analysis prior to locating the water conservation structures as it is rain fed area. The NDVI method and unsupervised classification technique using Landsat images of different years of the same date are used for the study. The analysis is carried out taking Thiessen average rainfall from the different rain gauge stations were studied. Thus, in the paper, feasibility assessment for the catchment area has been conducted using the change detection analysis before planning and development of the watershed.

Climate can be defined as the weather conditions or the weather patterns that is present in the particular geographical area for a very lengthy period. It can be assessed by the important factors like temperature, humidity, wind, precipitation. The climate of the region also depends on the latitude, terrain, water bodies, etc. Coastal Karnataka receives an average rainfall of 3456 mm; at summer, the temperature lies between 33.5 and 40 °C and the minimum temperature of 23.3 and 27.9 °C. Tropical monsoon climate covers whole coastal places of Karnataka and other nearby places too. Rainfall time series is divided into four periods. This region has a very hot climate with extreme rainfall in monsoon season, i.e., June to September. These drastic changes in the climate severely affect the various activities throughout the coastal area of Karnataka. Understanding the variability of climate in the region is essential. In this study, the variation in the climate for a period of 1984–2017 is observed and investigated and changes in the trend in the grid points can be noticed. Mann–Kendall trend test is applied for the precipitation to find trend patterns, and the magnitude of the trend is determined by Sen’s slope estimator. Increase in trend was found in the grid point 3 and grid point 4.

Coast belonging to one particular stretch happens to be versatile because of its dynamicity. This dynamicity is accounted because of both natural and man-made activities. Hence, it is necessary to monitor any fragile coastal stretch’s dynamicity in a temporal basis. In this study, an attempt is made to study the dynamicity of coastal morphology using geospatial and numerical approach. Shore-line on both sides of Kasaragod River firth, laterally Karnataka coast of the India, has modified following construction of breakwaters for fishing harbour. The breakwaters were constructed between 2010 and 2015 after which a severe change is observed in shore-line. Construction flaws were reported as a result of which strong waves were formed leading to the difficulty in launching boats into the sea. Coastal morphology needs to be further analysed to propose a more scientific and lasting solution. Shore-line is extracted from field surveyed data (supplied by Department of Harbour Engineering, Kerala). To ensure the forecast end point rate (EPR) and linear regression rate (LRR) for shore-line data, digital shore-line analysis (DSAS) technique was applied and compiled for up to 2017 in response to the construction of a pair of breakwaters at river inlet.

Saline water ingression and the salinity hazards of fertile lands in microwatersheds near and far off the main river channel in the coastal district of Dakshina Kannada are grave problems resulted due to the haphazard land and water management, and excessive use of groundwater for the wet crop cultivation in this area. The current study aims to analyse the hydrogeochemical characteristics of water resources in a low-lying microwatershed on the approach of Nethravathi river mouth to assess the surface and groundwater quality for domestic and agricultural purposes and the extent of their contamination. About twenty-one water quality parameters viz: temperature, pH, Turbidity, TDS, EC, Ca-H, Mg-H, TH, DO, BOD, Cl−, F−, SO42−, NO3−, CO32−, HCO3−, Fe, Ca2+, Mg2+, Na+ and K+ were analysed to delineate the extend of saline water ingression. The result analysis shows enough evidences of saline water ingression in the study area. It is very much necessary to have a sustainable integrated microwatershed development approach through proper planning and management practice for the reclamation of this fertile microwatershed from its salinity hazard before going for any other development activities.

Solar energy replacing conservative non-renewable energy is being witnessed in often around the world. Solar energy has a massive prospective in a humid country like India. Most parts of the country get around 300 sunshiny days in a year with 8 h of daily sunlight. Presently, one of the most interesting problems is how to mend the effectiveness of generating solar energy. Before installing solar panels, evaluating where solar panels should be positioned can considerably benefit panel performance. The present study is aimed at carrying out site selection analysis for setting up of solar panel using geographic information system (GIS). Telangana is a state which ranks fourth in terms of capacity to harness and utilize solar energy. The project is aimed at mapping the areas with high solar energy potential at both macro- and micro-levels. The solar irradiation data (GHI and DNI), land use data and digital elevation model (DEM) have been used in GIS environment while retaining land use criteria and topography to omit unsuitable sites for harnessing solar energy. The study carried out concludes total suitable area of 11,520.60 km2 at macro-analysis for economical and effective harnessing of solar power.