Shuitu baochi tongbao (Dec 2023)
Soil Erosion and Soil and Water Conservation Measures at Xiliugou Watershed in Ten Tributaries Area in Inner Mongolia
Abstract
[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.
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