浙西山区水土流失成因分析

Analysis on the present situation of soil and water erosion in the hilly area of Western Zhe Jiang Province

本文就浙西山区水土流失现状及其成因，进行了分析研究。近二十多年来，本区水土流失加剧，表现在河流含沙量和输沙量增加，流域侵蚀量成倍增大，导致土质沙化，土壤肥力减退，河床淤高，水库淤积，生态环境日趋恶化。究其原因有自然因素和人为因素两方面。只有在一定的地质、地形、气候和植被等自然条件下，才能产生水土流失。但它相对于人为因素而言，是较稳定且变化缓慢，通常不会造成生态环境的剧烈变化。而人类对山区的自然、经济规律缺乏正确的科学认识，不合理的开发利用，造成自然植被的破坏，森林覆盖率下降。这是水土流失加剧的关键所在。本文在分析水土流失成因后，提出了防治水土流失，合理利用山区水土资源的原则性意见，供有关部门参考。

During the last twenty years, the soil and water erosion in the hilly area was increasing,which was expressed by the increment of silt content and total silt dischage in the rivers and doubling the erosion volumn in the watershed. It resulted in the siltation of river bed and reservoir, soil fertility decrement and ecological environment getting worse.The factors which effect in the change of soil and water erosion are both natural and human. The natural factor includes geology, land form, climate, vegetation and so on .Compared with the human factor, the natural factor is of stability and slow so does not cause the rapid change of the ecological environment. Lack of scientific knowledge about natural and economical law on the mountain region and irrational exploration cause vegetation to be destroyed and forest coverage to be decreased. After the analysis on the present situation and its origin, several principles on conservation and rational use of soil and water resources are provided.