喀斯特地区百花湖流域水土流失生态风险研究OA

Taking the Baihua Lake basin of Guiyang City as the research object,the ecological risk of the lake reservoir basin was discussed from the perspective of soil erosion,which provided a scientific basis for protecting the ecological security of the plateau lake reservoir.Based on the"source-sink"theory,the ecological risk pattern and process of land area and reservoir area in the Baihua Lake basin were analyzed from the perspective of soil erosion through RUSLE,and the relationship between soil erosion intensity and land use was analyzed through sub-basin as a unit.The results show that:(1)Soil erosion in the Baihua Lake Basin was mainly slight,and the area above slight only accounts for 19.54%.Using 1 t·(hm2·a)-1 as the critical value of soil erosion risk,the proportion of risk area was raised to 30.98%,and the risk area was mainly distributed in the east,south,and west of the basin,and the spatial distribution was more consistent with that of human activities.(2)Calculated with the sub-basin as the evaluation unit,the intensity of soil erosion was negatively correlated with the proportion of woodland,cultivated land,and waters,and positively correlated with the proportion of construction land.(3)The annual soil loss in the Baihua Lake basin was 1.51×106 t·a-1,and the annual reservoir capacity loss was 0.12%.The estuary of tributaries showed a deposition trend,the self-purification capacity of the water body was weakened,and a large number of nutrients,such as nitrogen and phosphorus,entered the lake with soil and water loss,and dissolved in water or deposited on the bottom of the lake which formed the sediments,causing the risk of eutrophication of the water body in the reservoir area.Taking the land area of the Baihua Lake Basin as the"source"and the reservoir area as the"sink",soil erosion in the Baihua Lake Basin not only causes damage to the ecological environment of the land area but also directly affects the healthy development of the water ecological environment in the reservoir area.