摘要
在野外调查的基础上，将黄土高原地区城镇建设中的人为弃土堆积归纳为新生斜坡型、陡坡增长型、新生台地型和洼地迭加型等４类人为堆积微地貌。针对人为弃土堆积斜坡和人为弃土堆进行了降雨侵蚀实验，实验结果表明：（１）在短历时、高强度降雨条件下，人为弃土斜坡可发生剧烈的土壤侵蚀，其侵蚀量是裸露撂荒坡的１０．７６～１２．２３倍，而人为弃土堆侵蚀产沙量相对较少；（２）人为弃土斜坡的侵蚀产沙与降雨产流历时具有幂函数或对数函数关系；（３）人为弃土斜坡与裸露撂荒坡相比，坡面的细沟侵蚀占有较大比重。因此，应禁止随意倾倒建设开发产生的废弃土方，对已倾倒堆积形成的人为弃土斜坡及排土场需加强治理，以减少城镇侵蚀的产沙来源。
Around or in the cities and towns of loess plateau area,there have been many mandumped soil slopes from constructing sites or from exploiting mine filed.These mandumped soil can be eroded seriously by rainfall.The simulated rainfall experiment has been designed for analysing erosion of mandumped soil slope. The results prove that sediment yield of mandumped soil slope is 10.76～12.23 times that of the natural steep slope under heavy or storm rain.Therefore it must be forbidden for people to dump soil on the surface of natural slope everywhere.Meanwhile,some conservation measures must be taken to control soil erosion and sediment yield from those mandumped slopes.
基金
国家自然科学基金
