Elsevier

Ecological Engineering

Volume 28, Issue 4, 22 December 2006, Pages 333-344
Ecological Engineering

Ecological engineering methods for soil and water conservation in Taiwan

https://doi.org/10.1016/j.ecoleng.2006.09.005Get rights and content

Abstract

This paper describes the development of Taiwan's localized ecological engineering methods to make the mitigation works more effective. To strengthen the soil and water conservation and protection of the ecological environment, comprehensive mitigation planning is necessary with considerations that include balancing the safety, ecology, and landscape, and treating the whole watershed as a unit. To demonstrate the achievement of the promotion of the ecological engineering methods in Taiwan, this paper illustrates two complete mitigation examples for a debris flow torrent and a stream. Most of the mitigation works have survived and are still stable (with some minor damages) after the two strong typhoons of 2004. We show that the developed ecological engineering methods are very suitable in mitigation and worthwhile for further promotion for Taiwan's ecological environment.

Introduction

One of the important measures in soil and water conservation in Taiwan is the ecological engineering method. It can be an index of protection and restoration for ecology. In 2001, the Soil and Water Conservation Bureau (SWCB) in Taiwan began to promote the innovative ecological engineering methods. Disaster prevention, ecological conservation and recreation have been interwoven by the adoption of ecological engineering. Ecological engineering methods are suitable for regions with medium size flooding potentials. They can be used to regulate stream course, guide dangerous current to floodplain or detention ponds for safety, and reduce some sweeping forces of rapid currents. The method should not be considered a complete flood control measure. With debris flow torrents or very rapid stream flow, conventional engineering may be inevitable to maintain the overall stability of areas vulnerable to landslides or debris flow, and to control any debris overflow. If the much stronger conventional structures such as slit dams and check dams are indicated, environment friendly considerations should be made as much as possible while building them. When the unstable hazard zone is properly protected by conventional works, the risk of washout/failure of the much more flexible ecological engineering methods can also be reduced; and the functions of ecological engineering methods can develop faster and help the environment and habitats to restore gradually. This is like an “ecological therapy” to nurse the once damaged environment.

For ecological engineering, two major approaches were adopted: develop new techniques and apply newly developed ecological engineering methods. The tasks for promoting ecological engineering methods include the development of reference drawings for ecological engineering methods, ecological investigations, habitat improvement, establishment of ecological indexes, development of vegetation methods in landslide areas, and holding a series of conferences for ecological engineering methods. The methods are created to suit the domestic biological and environmental conditions. The merits of ecological engineering methods lie in the emphasis of comprehensive considerations in all aspects for soil and water conservation tasks. This paper shows that ecological engineering can be properly applied to mitigation of watershed disasters, protection and restoration of ecology. In addition, recreation infrastructures, rural community, and agricultural economic can be simultaneously developed.

Section snippets

The functions of ecological engineering methods

  • (1)

    Improving the revival ability of ecosystem (for large scale hazards such as landslide and debris flow): Ecological engineering methods can be suitable for mitigation of large scale natural hazards if the works are designed to provide the ability of revivification for the natural environment, ecosystem, and the corresponding peripheral characteristics.

  • (2)

    Improving the protective ability of ecosystem (for medium scale hazards such as scouring of streambank and streambed): The methods should consider

Fundamental concepts

  • (1)

    Consider balance in safety, ecology and landscape

    Consider the priority and balancing of safety, ecology and landscape according to the regional characteristics. Safety shall be the first considered for the hillslopes near urban areas. In contrast, ecology should be the major factor for mountain hillslopes with various ecological systems. For other areas safety, ecology and landscape should evenly considered.

  • (2)

    Develop suitable mitigation according to local environment

    Create integrated design to be

Selected examples of the ecological engineering methods of Taiwan

Selected examples of the ecological engineering methods of Taiwan are introduced as following (SWCB, 2002a).

  • (1)

    Stone revetment

    The main purpose of stone revetment is to protect the toe of streambank and avoid erosion (Fig. 5, Fig. 6). In particular it can prevent piping caused by seepage. Well-constructed stone-paved revetment can be considered a retaining wall that withstands active earth pressure of streambank. Stones and the finished surfaces have a natural appearance. The spaces and voids

Inspection of the ecological engineering methods in Taiwan

Properly designed ecological engineering methods are effective for restoration of ecosystem. During planning and design stages of mitigations, the factors such as safety, ecology, landscape, geomorphology, and hydrology were considered by the SWCB. It was found that the ecosystems reinstate gradually after using the ecological engineering methods. Through the two-year ecological investigations directed by SWCB (2003a) for Liu-chung Creek in Tainan, Mu-dan Creek in Taipei County, and

Integrated mitigation for debris flow Torrent—an example of Hua-shan Creek in Gu-keng County, Taiwan

Hua-shan Creek is not a perennial stream. Water flow only appears during heavy rainfall for a couple of days. Therefore, the aquatic life form in the creek is very rare. The geological condition in the watershed of Hua-shan Creek is generally unstable with high potential of debris flow. The mitigation for the creek considered safety first, and ecology second. The disasters of the debris flows were triggered by a heavy rainfall event in 2000 and Typhoon Toraji in 2001. As a result, the stream

Integrated mitigation for a stream—an example of Ding-zi-lan-keng Creek in Taipei County

Ding-zi-lan-keng Creek was planned to protect its original pools and shoals, to create more riffles, torrents, turbulences, slacks, and backwaters using ecological engineering methods, and to enhance stream functions for various aquatic and terrestrial animals. Scenery recreational function for human was also considered (SWCB, 2003c).

The major mitigation of Ding-zi-lan-keng Creek is described as follows:

  • (1)

    The integrated design (Fig. 19): the mitigation plan for Ding-zi-lan-keng Creek is divided

Challenge for promoting ecological engineering method in Taiwan

  • (1)

    Difficulty of land acquisition: More land is usually required for general approaches of ecological engineering methods such as gentle slope for streambank protection, sabo dam, pool, and shoal, but it is difficult to acquire enough land in Taiwan.

  • (2)

    Large number of habitats to be improved: Conventional engineering work such as concrete dams and concrete revetments that could impact the ecological environment needs to be improved. However, the number of those facilities is significant. How to

Concluding Remarks

Due to the high average annual rainfall and special landforms of Taiwan, the promotion and application of the ecological engineering methods are more difficult than other countries. It is better to develop localized ecological engineering methods complying with the special geological, hydrological, and environmental conditions of Taiwan. For soil and water conservation and sustainable development, we should deem the ecological engineering methods as a general guideline and apply more “flexible”

Acknowledgement

The authors gratefully acknowledge Mr. Zong-ru Zuo for his valuable and constructive comments.

References (16)

  • FISRWG, 1998. Stream Corridor Restoration: Principles, Processes and Practices. The Federal Interagency Stream...
  • D.H. Gray et al.

    Biotechnical and Soil Bioengineering Slope Stabilization: A practical Guide for Erosion Control

    (1996)
  • Hsieh, J.D., 2004. Stones from other mountains: foreign natural ecological engineering methods,...
  • M.H. Li et al.

    Biotechnical engineering as an alternative to traditional engineering methods: a biotechnical streambank stabilization design approach

    (2002)
  • R.F. Noss

    Landscape connectivity: different functions at different scales

  • Soil and Water Conservation Bureau, 2002a. Assessment Index and Design Reference Drawings for Ecological Engineering...
  • Soil and Water Conservation Bureau, 2002b. Manual for Soil and Water Conservation of Debris flow and Landslides Using...
  • Soil and Water Conservation Bureau, 2003a. Investigation of Wild Stream Habitats and Modeling of Habitat Improvement....
There are more references available in the full text version of this article.

Cited by (47)

  • Driving forces of NPP change in debris flow prone area: A case study of a typical region in SW China

    2020, Ecological Indicators
    Citation Excerpt :

    Implementation of the ecological restoration projects guaranteed the security of the regional eco-environment, and, in addition, brought positive effects to the prevention and treatment of mountain disasters (Rey et al., 2019; Ricci et al., 2020). Comprehensive consideration of ecology, landscape, and safety, disaster reduction planning, which considers the basin as a whole, can greatly increase soil and water conservation capabilities and reduce disaster risks (Cui and Lin, 2013; Wu and Feng, 2006). He et al. (2017) summarized the achievements of typical eco-engineering technology for mountain disaster management in the Xiaojiang River Basin in the past 30 years; the results show that eco-engineering has an important role in the prevention and control of strong gravity erosion caused by mountain disasters.

  • Constructions of an evaluation framework for soil and water conservation techniques

    2020, Catena
    Citation Excerpt :

    Various soil and water conservation techniques have been implemented around the world. Since the mid-20th century, many theoretical and practical studies have investigated soil and water conservation techniques based on a systematic understanding of the causes, processes, and mechanisms responsible for soil and water losses, such as quantitative evaluations of the comprehensive benefits of soil and water conservation (Horner et al., 1960; Burt, 1981; Taylor and Young, 1985; Pattanayak and Mercer, 1998; Pressey et al., 2002; Sun et al., 2009; He et al., 2010), models of soil and water loss control (Bennett, 1974; Knisel, 1980; Mcconnell, 1983; Elliot, 1988; Nearing et al., 1989; Aksoy and Kavvas, 2005; Zhu et al., 2012; Ding et al., 2019), and the ecological restoration of soil and water resources (Cox, 1983; Whigham et al., 1986; Burns and Sauer, 1992; Mitsch, 1995; Allen et al., 2002; Wu and Feng 2006; Liu et al., 2016). However, due to variations in the technological level and differences in the scope of application and the diffusion of specific techniques, many soil and water conservation techniques are still considered unsuitable for the local soil and water conditions.

  • Landscape and avifauna changes as an indicator of Yellow River Delta Wetland restoration

    2016, Ecological Engineering
    Citation Excerpt :

    The common use techniques are avifauna survey, ecological engineering of biodiversity, wetlands ecosystems for receiving wastewaters, wetlands ecosystems for receiving wastewaters, etc. (Odum and Odum, 2003). The functions of ecological engineering methods are to improve the revival ability of ecosystem, improve the protective ability of ecosystem, improve the recoverability of ecosystem, and improve the functions of streams (Wu and Feng, 2006). This research developed avifauna surveys for data collection.

View all citing articles on Scopus
View full text