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沈河水库淤积非常严重,推移质多来自支流清水河的基岩山地,悬移质泥沙主要来自稠水河的黄土丘陵区。悬移质是水库泥沙淤积的主体,其产沙条件有四点:(1)岩性:黄土丘陵由于黄土质地均匀、疏松、多孔,易遭受流水冲刷,故水库泥沙粒径基本和黄土粒径相当。(2)地形:丘陵区因新构造上升运动影响,河流垂直侵蚀强烈,沟谷纵横,地面破碎,相对高差大,谷坡陡峻,大多在11—25°之间,有利于坡面径流侵蚀。(3)降雨:稠水河年降雨量917.8毫米,雨量集中于夏季,且多暴雨,冲刷能力很强。(4)重力作用:坡面块体运动有撒落、崩塌、错落和滑坡等,其中以滑坡最发育,其面积约占沟谷面积70%左右。由于重力作用破坏了原土结构,扩大裂隙,失去粘着性,易遭受流水侵蚀。因此,重力作用是沟谷产沙的主要原因之一。沈河流域治理:在沟谷里兴建拦泥和蓄水工程;滑坡治理应以地表排水工程和植物措施为主;黄土梁源区应加强保塬固沟,以防止径流冲刷。
Shenhe reservoir siltation is very serious, the easing quality mostly from the tributary Qingshui River bedrock mountain, suspended sediment mainly from the thick water of the Loess Plateau. Suspended sediment is the main body of reservoir sediment deposition, and its sand production conditions have four points: (1) Lithology: Loess hilly loess texture as uniform, loose, porous, easy to water erosion, so the reservoir sediment size and loess The same size. (2) Topography: Due to the influence of rising tectonic movement in the hilly area, the vertical erosion of the river is vertical. The vertical and horizontal valleys, the ground is broken, the relative height difference is large, and the valley slope is steep, mostly between 11-25 °, which is favorable for slope runoff erosion. (3) Rainfall: The annual rainfall of Chushui River is 917.8 millimeters. The rainfall is concentrated in the summer months, with heavy rain and strong erosion capacity. (4) Gravity: There are scattered, collapsed, scattered and landslides in the block, of which the landslide is the most developed, and its area accounts for about 70% of the valley area. As a result of gravity destroyed the original soil structure, expanding cracks, loss of adhesion, vulnerable to water erosion. Therefore, gravity is one of the main causes of sand production in the valley. Shen river basin governance: in the valley to build mud and water storage project; landslide should be based on surface drainage projects and plant-based measures; loess source area should be strengthened plateau furrow to prevent runoff erosion.