Studies On The Law Of Water And Soil Loss Of Different Planting Models In Karst Rocky-desertification Area In The East Of Yunnan

Karst rock-desertification is caused by both fragile environment and unreasonable activities and is a result of the aggravating human-land relationship.The ecologic and geologic environment is very frail and the rocky desertification is very obvious(the rocky desertification area is 34772.76 km～2)in Yunnan karst area which seriously restrict the sustainable development of local economy. The engineering of rocky-desertification treatment is especially important for ecological restoration and sustainable development in southwestern.In order to combine the policy of southwestern rocky-desertification treatment engineering,the experiment field is chosen in a named Sandaoqing forsest farm of Fuyuan county,Yunnan province, where is the typical plateau rocky-desertification ereas in eatetern of Yunnan province.The conclusion provides a theoretical support for the restoration and management of rock-desertification eco-environment.Five planting models in rocky-desertification erea are practiced and studied.Five models are mixed wood,natural coniferous forest,natural broad-leaved forest,crop land,grassland and bare land.In this paper,research which is based on runoff field,contents include:rainfall characteristic and its relative model,physical and chemical characteristic of soil,soil and water loss,nutrient loss, and build some relative models according to different conditions for five planting models.Research results indicate:the year rainfall of 2007 in experimental area is 1231.1mm,the rainfall of flood season from May to October account for 83.80%of all-year rainfall,is 1031.7mm; in all-year,rainfall times are 238,but rainfall days are 186;the model relation between month rainfall and its erosion is Logistic,the model relation between time rainfall and its erosion manifest negative exponential function;in all rainfall factors,rainfall has the maximum and mixed factor has the least influence to runoff;typical time rainfall influences large for sediment·loss in 2007,and the sediment loss which is pruduced by several typical time rainfalls account for most of sediment loss in all 2007; it is effective to improve soii physical and chemical conditions,prevent soil and water loss and nutrient loss for planting restoration models;there are different planting models between runoff and sediment,between runoff and rainfall,between sediment and rainfall for different plantingl restoration models;Antierodibility of 0.25 to 0.05mm and 0.05 to 0.01mm is better than other parts of water stability aggregate,it is also preferably in land used pattern which suffers from less disturbeing;...