Chen Zu-Ming, Wang Bin
Three-gorges Reservoir Area (Chongqing) Forest Ecosystem Research Station, School of Soil and Water Conservation, Beijing Forestry University, Beijing 100083, China.
Ying Yong Sheng Tai Xue Bao. 2022 Mar;33(3):703-710. doi: 10.13287/j.1001-9332.202203.016.
Due to the basic topographical characteristics of the gentle and long slope lengths in the Mollisol region of Northeast China, severe soil erosion is easily aggravated by the concentration of surface flow. The spatial distribution of water depth and hydrological connectivity index were introduced to evaluate the effects of typical soil and water conservation practices on the overland flow path and hydrological connectivity based on the GIS and SIMWE (SIMulated Water Erosion) model. We analyzed the effects of different soil and water conservation practices on the hydrological connectivity, water flow path, and spatial distribution of soil erosion and sediment yield by quantifying the variations of soil infiltration rate and surface manning roughness, as well as by constructing an artificial terrain digital elevation model (DEM). The results showed that: 1) terraces could effectively affect the hydrological connectivity of the slope and regulate flow path, with significant differences between the responses of hydrological connectivity and flow path under different forms of terraced fields and ridges. The characteristics of spatial distribution of soil erosion and sediment yield varied with changes in water flow path, which would eventually lead to the intensification of local erosion; 2) practices of vegetated buffer strips and contour tillage presented limited effectiveness on runoff path controlling, though they played a significant role in sediment retention; and 3) conservation tillage could reduce the hydrological connectivity and improve the retention capacity of runoff by increasing surface roughness. This study quantified the effects of different soil and water conservation practices on the hydrological connectivity, flow path, and spatial distribution of soil erosion and sediment yield, and could provide a theoretical reference for scientific layout of soil and water conservation practices in black soil region.
由于中国东北黑土区地势平缓、坡长较长的基本地形特征，地表径流集中容易加剧严重的土壤侵蚀。基于GIS和SIMWE（模拟水蚀）模型，引入水深空间分布和水文连通性指数，以评估典型水土保持措施对坡面流路径和水文连通性的影响。通过量化土壤入渗率和地表曼宁糙率的变化，并构建人工地形数字高程模型（DEM），分析了不同水土保持措施对水文连通性、水流路径以及土壤侵蚀和产沙空间分布的影响。结果表明：1）梯田能有效影响坡面的水文连通性并调节水流路径，不同形式梯田和田埂下的水文连通性和水流路径响应存在显著差异。土壤侵蚀和产沙的空间分布特征随水流路径变化而变化，最终会导致局部侵蚀加剧；2）植被缓冲带和等高耕作措施对径流路径控制效果有限，尽管它们在拦沙方面发挥了重要作用；3）保护性耕作可通过增加地表粗糙度降低水文连通性，提高径流拦蓄能力。本研究量化了不同水土保持措施对水文连通性、水流路径以及土壤侵蚀和产沙空间分布的影响，可为黑土区水土保持措施的科学布局提供理论参考。
