水蚀区生产建设项目用地开挖面分类体系及其应用简

开挖面广泛存在于各种类型的生产建设项目用地,对其进行分类,是构建开挖面土壤流失量测算模型和方法、指导生产建设项目用地开挖面水土流失监督执法的基础.以我国东部水蚀区为背景,通过对东北黑土区、北方土石山区、西南土石山区及南方红壤区内多个不同类型生产建设项目用地开挖面的实地调查,在总结分析水蚀区开挖面特征及水土流失特性的基础上,构建了开挖面分类体系.体系划分为3个层次：第1层次按照开挖面质地与物质组成,把开挖面分为均质面和非均质面;第2层次根据开挖面上方有无来水,把开挖面分为无汇水影响开挖面和有汇水影响开挖面;第3层次按照开挖面形成的时间,把开挖面分为非稳定面和稳定面.该分类体系,不仅打破了现行工程边坡分类中区域性和行业性的界限,而且为开挖面土壤流失量测算模型和方法构建奠定了基础.最后,对分类体系在土壤流失测算中的应用提出了建议.

Classification of artificially excavated surfaces in construction project lands and its application in water erosion areas

Artificially excavated surfaces are common in construction project lands,and classification of them provides a basis for establishment of calculation methods for soil loss,as well as a technical support for controlling soil loss on them.Taking water erosion areas of eastern China as test background,and by field investigation of numerous kinds of construction projects located in different regions,including northeastern black soil areas,northern rocky mountainous areas,southwestern rocky mountain areas and southern red soil regions,the characteristics of artificially excavated surfaces and soil loss properties on them were analyzed,and a reasonable classification system proposed.According to the system,excavated surfaces are firstly classified into two categories,namely homogeneous surfaces and heterogeneous surfaces,in terms of texture and material composition.Then the surfaces are classified into confluenceimpact and non-confluence-impact surfaces according to influences of confluence above excavated surfaces.Moreover,in terms of the periods for excavated surfaces exposed to air,surfaces are further classified into stable and non-stable types.At last,the application of the proposed classification system in prediction of soil loss was introduced.In general,our classification system not only overcomes limitation of the current classification for project slopes,but also supplies a basis for promotion of calculation models and methods for soil loss.In addition,the system can also be convenient to popularize and promote in grass-root units for soil and water conservation.