淮河流域国家水土保持重点工程土壤侵蚀防控效果

Control effects of the national key project of soil and water conservation on the soil erosion in Huaihe River Basin

为探讨国家水土保持重点建设工程对项目区土壤侵蚀的防控作用,以淮河流域沂蒙山大峪小流域项目区和大别山桃岭小流域项目区为对象,采用遥感调查和地面调查相结合的方法,研究重点工程实施后,项目区土壤侵蚀状况的变化,分析不同措施对土壤侵蚀的防控效果,以期为认识和评价国家水土保持重点建设工程的实施效果提供参考。结果表明:1)2个项目区在重点工程实施后,土壤侵蚀面积和土壤侵蚀模数大幅度降低。沂蒙山大峪项目区和大别山区桃岭项目区土壤侵蚀面积消减率为88.9%和76.3%,侵蚀模数降低率76.7%和72.1%,侵蚀模数降低到243和314 t/(km2·a)。土壤侵蚀防控效果以沂蒙山大峪项目区高于大别山桃岭项目区,主要原因与2项目区实施的防治措施配置不同,以及与不同防治措施对土壤侵蚀防控效果的差别有关。2)重点工程不同防治措施对土壤侵蚀的防控效果,以梯田工程措施和水平阶工程措施明显大于封禁补植措施。2项目区中,坡耕地梯田工程区的土壤侵蚀模数降低率82.5%和83.8%,坡式林地水平阶工程区(大别山区桃岭项目区)的土壤侵蚀模数降低率70.3%,疏林地封禁补植区的土壤侵蚀模数降低率39.5%和55.2%。

[ Background] The national key project has been implemented in the fifth period （2013- 2017）, taking up a lot of financial, material resources and manpower, however, the investigation and research about the control effects of the national key project on soil erosion were not conducted yet. Therefore, the study of the control effect of the national key project of soil and water conservation on soil erosion in the two project regions may provide the reference for understanding and evaluation of the national key project. [ Methods] In this study, we selected two typical project areas, Yimeng mountain area of Shandong Province and Dabie mountain area of Anhui Province, in Huaihe River Basin. Using remote sensing and ground survey to study the change of soil erosion in the project status after the national key project, and analyzing the effect of soil erosion in project regions with different measures. [ Results] 1 ） The reduction rates of soil erosion area in Dayu project region of Yimeng mountain and Taoling project region of Dabie mountain were 88.9% and 76.3% respectively, the reduction rates of soil erosion modulus were 76.7% and 72. 1%, and soil erosion modulus were 243 t/（ km^2· a） and 314 t/（ km^2· a）. The effect of prevention and control of soil erosion in Dayu project region was higher than in Taoling project region, which mainly resulted from two reasons ： the allocations of the measures in 2 regions were different, and the control effects of the different measures varied. Yimeng mountain and Dabie mountain belonged to two different climatic regions, correspondingly, their leading foundations of soil and water conservation were in different functional areas. Therefore, the occurrence characteristics of soil and water loss, and the prevention and control measures of soil erosion were different. 2） The reduction rate of soil erosion modulus in the terraced project of slope farmland on the 2 regions was 82. 5% and 83.8% respectively. The reduction rate of soil erosion modulus in the level-terrace project of afforested slope land was 70. 32%. The reduction rate of soil erosion modulus in the enclosure and replanting, and in open forest land was 39.5% , and 55.2% respectively. [ Conclusions] There were great reductions of soil erosion and soil erosion modulus after the national key project implemented in the two project regions. The prevention and control effects of soil erosion with different measures were different in the regions of the national key project. The effects of prevention and control of soil erosion in terrace project and level- terrace project were much better than enclosure and replanting, and terrace project better than level- terrace project.