Determining the influencing distance of dam construction and reservoir impoundment on land use: A case study of Manwan Dam, Lancang River
Introduction
Approximately 70% of the world's rivers are modified by large dams and reservoirs constructed for hydropower generation, seasonal flood control, irrigation, and drinking water (Kjaerland, 2007, Kummu and Varis, 2007). However, dam and reservoir impoundments have significant effects on the environment (Coker, 2000, Bombino et al., 2006, Benjankar et al., 2012). Dams can reduce river connectivity, fragment watersheds, and degrade adjacent land resources (Tiemann et al., 2004, Hu et al., 2008, Lü et al., 2012). Impoundments and reservoirs not only change hydrological regimes, sediment regimes and chemical, biological, and physical characteristics of water bodies (Ligon et al., 1995, Poff and Hart, 2002, Hu et al., 2008, Zhao et al., 2012b), but also flood large areas of land.
Land use dynamics are among the most sensitive indicators of the interactions between the natural environment and human activities (Zhang et al., 2010). Land use dynamics research is often performed to assess natural landscape status, to evaluate anthropogenic influences at different spatial and temporal scales, and to provide recommendations for future management (Munsi et al., 2010). As a high-impact form of habitat disturbance, hydropower development can induce a chain reaction in land use dynamics (Zhao et al., 2010). Thus, understanding how hydropower development affects land cover is important for guiding hydropower project development and regional land use management.
Remote sensing (RS) is a valuable tool for monitoring, mapping, and inventorying various resources (Zhang et al., 2010, Benjankar et al., 2012) because of its high spatial and temporal resolution and the consistency of information available for regional analysis. The combined use of RS with geographic information systems (GIS) has proven useful for the timely assessment of land use dynamics (Geneletti and Gorte, 2003, Wang et al., 2010). Many studies have investigated land use dynamics associated with dam construction and reservoir impoundment using RS and GIS techniques (Rautela et al., 2002, Verbunt et al., 2005, Zhou et al., 2008, Zhou et al., 2010, Ouyang et al., 2010). These studies focused primarily on land use and its influences at the regional scale (Rautela et al., 2002, Porter-Bolland et al., 2007, Raumann and Cablk, 2008, Zhou et al., 2008, Zhou et al., 2010, Lü et al., 2012). However, few studies have attempted to identify the influencing extent of dam construction or to distinguish the impacts of dam construction from those of reservoir impoundment (i.e., after dam completion). Buffer analysis has recently been used as an effective GIS-based method to assess the spatial extent of urban sprawl, road network construction and other activities (Zeng et al., 2005, Liu et al., 2006, Liu et al., 2008, Xu et al., 2007) but has not much previously been applied to assess the impact of dam construction.
For the current study, buffer zones characterised by several variables (e.g., distance to dam site, distance to riverway) were generated to assess land use dynamics. To quantitatively analyse how dam construction and reservoir impoundment affect land use, a single land use dynamics index, an integrated land use dynamics index, and the number of transformational patches (patches transformed from other land use types between two periods) were calculated for the entire study area and each buffer zone. This study was conducted in an area of great scientific interest (Lancang-Mekong Basin, Yunnan Province, southwest China), where 14 cascade hydropower stations are planned within the mainstream, with several dams already constructed. Construction of the first of the 14 cascade dams, Manwan Dam, began in 1986, with river closure occurring in December 1987 and operation of the first generator beginning in 1993. Adjacent land use has been significantly affected by the construction of the Manwan Dam (Zhou et al., 2008, Zhou et al., 2010); however we still have know little regarding the spatial influencing distance of dam construction and how impacts vary over time (i.e., between dam construction and reservoir impoundment) and space (i.e., between upstream and downstream areas).
The purpose of this paper is to address the following questions: (1) How do dam construction and reservoir impoundment impact the intensity and extent of land use dynamics? (2) What are the effects of reservoir impoundment in upstream and downstream areas? Answering these questions will enhance our understanding of the impacts of dam construction and reservoir impoundment on sustainable development in this region.
Section snippets
Study area and data management
The Lancang River, the largest international river in Asia, originates from the eastern Tibetan Plateau in China (Liu et al., 2008). It has a main channel drop of 5000 m along its entire, 4880 km from the headwater to the mouth at the South China Sea (Fu and He, 2007, Fu et al., 2008). Average yearly rainfall ranges from approximately 250 mm in the northwest to 500 mm in the southeast (Jacobs, 2002, Hu et al., 2009). Its unique geographic features and hydraulic properties provide many advantages
Dynamics of land use in the study area
The classification of land use in 1974, 1988, and 2004 is shown in Fig. 1, and the area of each land use type is shown in Fig. 2. Land in the study area was composed primarily of forestland and scrubland in all three years. In 1974, forestland and scrubland occupied 66.8% and 24.6% of the area, respectively, while water areas and construction land occupied only 0.8% and 0.2% of the area, respectively. Forestland area decreased from 75,311 ha in 1974 to 61,258 ha in 1988, while scrubland area
Analysis of the driving forces behind land use change in the study area
In the study area, the primary types of land use change before dam construction were farming and deforestation (He et al., 2004); however, following the implementation of the cascade hydropower plan, dam construction and reservoir impoundment became the dominant human activities (He et al., 2004, Zhou et al., 2008). Several studies have investigated the effects of road networks on land use (Spooner et al., 2004, Zeng et al., 2005, Liu et al., 2006, Liu et al., 2008, Munroe et al., 2007). The
Conclusion
We used GIS and RS tools, buffer analysis and calculations of land use dynamic indices and transformational patch densities to analyse spatio-temporal changes in land use characteristics induced by dam construction and reservoir impoundment. Our analyses were based on Landsat MSS and TM images acquired in 1974, 1988, and 2004. Buffer zones designated at set distances from either the dam site or the riverway were used to calculate the spatial extent of influence stemming from dam construction
Acknowledgments
This research was funded by the Nonprofit Environment Protection Specific Project of China (No. 201209029-4) and the National Natural Sciences Foundation of China (No. 50939001). The authors would like to thank Wei Fu of Jiangsu Provincial Urban Development Institute and anonymous reviewers for their constructive suggestions and comments on early draft of this manuscript.
References (58)
- et al.
Simulating demographic and socioeconomic processes on household level and implications for giant panda habitats
Ecol. Model.
(2001) - et al.
Modeling the choice to switch from fuelwood to electricity: Implications for giant panda habitat conservation
Ecol. Econ.
(2002) - et al.
Fish passage principles to be considered for medium and large dams: the case study of a fish passage concept for a hydroelectric power project on the Mekong mainstem in Laos
Ecol. Eng.
(2012) - et al.
The impact of river modification and dam operation on floodplain vegetation succession trends in the Kootenai River, USA
Ecol. Eng.
(2012) - et al.
Assessment of the effects of check-dams on riparian vegetation in the mediterranean environment: A methodological approach and example application
Ecol. Eng.
(2006) - et al.
Sedimentation in the Manwan reservoir in the Upper Mekong and its downstream impacts
Quat. Int.
(2008) - et al.
Effects of dam operation and land use on stream channel morphology and riparian vegetation
Geomorphology
(2006) - et al.
Annual and seasonal streamflow responses to climate and land-cover changes in the Poyang Lake basin, China
J. Hydrol.
(2008) Small hydropower in China: a new record in world hydropower development
Refocus
(2004)- et al.
The influence of dams on ecohydrological conditions in the Huaihe River basin, China
Ecol. Eng.
(2008)
A real option analysis of investments in hydropower – the case of Norway
Energ. Policy
Sediment-related impacts due to upstream reservoir trapping, the Lower Mekong River
Geomorphology
Evaluating the influence of road networks on landscape and regional ecological risk – a case study in Lancang River Valley of Southwest China
Ecol. Eng.
Carbon retention by check dams: regional scale estimation
Ecol. Eng.
Monitoring landscape fragmentation in an inaccessible mountain area: Celaque National Park, Western Honduras
Landscape Urban Planning
Vegetation response to 30 years hydropower cascade exploitation in upper stream of Yellow River
Commun. Nonlinear Sci. Numer. Simul.
Land use dynamics and landscape history in La Montaña, Campeche, Mexico
Landscape Urban Planning
Change in the forested and developed landscape of the Lake Tahoe basin California and Nevada, USA, 1940–2002
For. Ecol. Manage.
The hydrologic impact of land cover changes and hydropower stations in the Alpine Rhine basin
Ecol. Model.
Dynamics and changes in spatial patterns of land use in Yellow River Basin, China
Land Use Policy
Development and test of SWAT for modeling hydrological processes in irrigation districts with paddy rice
J. Hydrol.
Landscape change and hydrologic alteration associated with dam construction
Int. J. Appl. Earth Obs. Geoinf.
Effect of dam construction on spatial-temporal change of land use: a case study of Manwan, Lancang River, Yunnan, China
Proc. Environ. Sci.
Conversion of a flood control system to a sustainable system: the energy requirements for pipeline transport of silt
Environ. Sci. Technol.
Yunnan-Tibet Road
Modeling change-pattern-value dynamics on land use: an integrated GIS and artificial neural networks approach
Environ. Manage.
An analysis of ecological environment change in the storage areas of Manwan Hydropower
Territory Nat. Resour. Study
Analysis and prediction of sediment trapping efficiencies of the reservoirs in the mainstream of the Lancang River
Chin. Sci. Bull.
A method for object-oriented land cover classification combining Landsat TM data and aerial photographs
Int. J. Remote Sens.
Cited by (41)
High-resolution mapping of land use changes in Norwegian hydropower systems
2023, Renewable and Sustainable Energy ReviewsA higher river sinuosity increased riparian soil structural stability on the downstream of a dammed river
2022, Science of the Total EnvironmentCitation Excerpt :Furthermore, without enough supplementary sediments from upstream, periodically discharged “clear” water could exacerbate bank collapse (Li et al., 2007), and reduce riparian soil stability in downstream areas. A mechanism of such impact could be suggested to link with the distance to the dam, since the damming effects are reported as being receded along with the increment of distance to the dam (Zhao et al., 2013). Apart from the factors of large-scale spatial distance, riparian soil may also be structured by other factors at a site scale, for instance, geographic region, elevation, and slope gradient, etc., (Bronick and Lal, 2005).
Linking reservoir ecosystems research to the sustainable development goals
2021, Science of the Total EnvironmentEnhanced riparian denitrification in reservoirs following hydropower production
2020, Journal of HydrologyCitation Excerpt :The island (24°43′44′’N, 100°23′5′’E) is located 30 km from the Manwan Dam (Fig. 1a). Manwan is the first-built (completed in 1993) hydropower reservoir on the mainstream of the upper Mekong River, with a total storage capacity of 9.2 × 108 m3 and an installed capacity of 1750 MW (Zhao et al., 2013). The island is oval shaped with a surface area of 1.3 × 104 m2 and a mean water level of 994 m (Fig. 1b).
Dynamics of heat transport across sediment deposited hyporheic zone inside reservoirs following hydropower production
2020, Science of the Total Environment