内蒙古十大孔兑西柳沟流域土壤侵蚀及水土保持措施调查

目的] 内蒙古十大孔兑地区属黄河中上游多沙粗沙区和生态脆弱区，对该区典型流域西柳沟的土壤侵蚀进行实地调查，分析流域土壤侵蚀特征及成因，为该区水土流失防治提供科学依据。方法] 于2022年9月19—26日和2023年6月21—26日沿X640解柴线（解家营—柴沟堡）和G109京拉线（北京—拉萨）2条公路分别布设15个调查点和14个集水区，对调查点及集水区植被、土壤、土壤侵蚀特征和水土保持措施等进行调查。结果] 流域内草地片蚀较为严重，耕地侵蚀不严重，沟谷内裸地风蚀较为严重。上游黄土高原丘陵区沟蚀严重，且溯源侵蚀、下切侵蚀及沟岸扩张未停止，伴随较为严重的重力侵蚀。中游风沙区以风水复合侵蚀为主，大幅增加了流域的产沙总量。流域内道路建设及边坡开挖等人为扰动进一步加剧了侵蚀风险。径流泥沙含量测定结果验证了流域泥沙的主要来源为上游地区。流域内水土保持措施以植被措施及工程措施为主，虽已起到一定水土保持作用，但由于形式单一而未能发挥理想效果。结论] 西柳沟短历时高强度的降雨特点叠加下层砒砂岩土壤条件共同加剧了该区土壤侵蚀，经济发展压力下的人类活动扰动加剧了生态风险，当地政府亟需持续增加水土保持投入，提高监管能力，加强对于土壤侵蚀的监测与机理研究，完善水土保持综合治理。

Soil Erosion and Soil and Water Conservation Measures at Xiliugou Watershed in Ten Tributaries Area in Inner Mongolia

Objective] The Ten Tributaries Area in Inner Mongolia belongs to the sandy and coarse sediment area and the ecologically fragile area in the middle and upper reaches of the Yellow River. A field investigation was conducted on soil erosion at Xiliugou watershed (a typical watershed in the Ten Tributaries area), and the characteristics and causes of soil and water loss in the watershed were analyzed in order to provide a basis for soil erosion control in the Ten Tributaries Area. Methods] From September 19 to 26, 2022, and from June 21 to 26, 2023, 15 investigation sites and 14 watersheds were respectively set up along the X640 Jiechai (Jiejiaying-Chaijiapu) line and G109 Jingla (Beijing-Lhasa) line to investigate the vegetation, soil, soil erosion characteristics, and water and soil conservation measures of the investigation sites and watersheds. Results] Grassland erosion in the watershed was observed to be severe, while erosion of cultivated land was not severe. Wind erosion of bare soil was more serious in gullies. In the upstream of loess plateau hilly area, there was severe gully erosion, and the processes of headwind erosion, downcutting erosion, and gully bank expansion had not ceased during the study period. These processes were accompanied by significant gravity erosion. In the midstream sandstorm region, wind-water complex erosion was the main type, which greatly increased the total sediment yield of the watershed. Man-made disturbances such as road construction and slope excavation further increased the risk of erosion. The results of runoff sediment content measurement verified that the main source of sediment in the watershed was from the upstream region. Soil and water conservation measures within the watershed mainly consisted of vegetation and engineering measures. Although these measures have made some contributions to soil and water conservation, they have been relatively limited in their forms, and have not fully achieved the desired effects. Conclusion] The short duration and high intensity of rainfall that occurs at Xiliugou watershed, combined with soil dominated by arsenic sandstone, have led to soil erosion in the area. Human activities under economic development pressure have exacerbated ecological risks. The local government should continue to increase investment in soil and water conservation, enhance regulatory capabilities, strengthen research on the monitoring and mechanisms of soil erosion, and improve comprehensive soil and water conservation management.