『Abstract
　This paper examines the long-term field performance of the check-dams in mitigation of soil erosion in the Duozhao catchment of Jiangjia stream, southwest China. Since their construction between 1979 and 1982, the check-dams have been functioning effectively. The examination is made via comparisons between the environmental conditions of the Duozhao catchment with its adjacent Menqian catchment in the stream, because no check dams were constructed in the Menqian catchment. The examination is based on recent field investigations and aerial photograph analyses, and covers four aspects: (a) bed gradients of catchment channels; (b) stability of bank slopes; (c) rates of land erosion; and (d) vegetations on bank slopes. The field data demonstrate that the check-dams have had the following good functions for mitigation of soil erosion: (1) restricting the channel depth and lateral erosions, (2) protecting the channel erosion base, (3) reducing the bed gradients of debris-flow channels, (4) fixing the channel bed, (5) stabilizing the bank slopes, as well as (6) facilitating the growth of vegetations.

Keywords: Check-dam; Debris flow; Soil erosion; Environmental management; Jiangjia stream; Case studies』

Introduction
Jiangjia stream and its soil erosion
Check-dams and performance in Jiangjia stream
　General introduction
　Dry packed random rubble check-dams
　Pointed random rubble check-dams
Key question and methodology
　Key question
　Methodology
Long-term performances of check-dams
　Bed gradient
　　Reduction of bed gradients above check-dams
　　Backfilling of check-dams in series
　　Bed gradient reduction along the Duozhao ravine
　Bank slope stability
　　Bank slopes of streams without check-dams
　　Bank slopes of streams with check-dams
　Soil erosion rate
　　Solid contents in water
　　Comparison of surface erosion rates in the upstream areas
　　Comparison of erosion amounts
　Slope vegetation coverage
Summary and conclusions
Acknowledgments
References