苏北花岗片麻岩地区USLE模型的试验研究

Experimental Study on USLE Model in Granite Gneiss Region of Northern Jiangsu Province

针对苏北花岗片麻岩地区水土流失的自然状况,建立了6种径流小区进行试验研究,通过对各小区364次降雨径流与土壤流失量的相关分析,得出适合本地区降雨侵蚀力因子R值的简便算式,确定了USLE模型中其它诸因子的取值。运用USLE模型计算各小区的土壤侵蚀量与实测值进行偏差分析,偏差为-3.5%-9.9%,可信度达90%以上。在实际应用检验中,梯田偏差5.64%,坡耕地偏差12.36%,可信度达87%以上。由此说明,USLE模型及其诸因子的取值方法在该地区的土壤侵蚀定量分析中具有很好的适用性。该项试验研究成果为该地区的水土流失预报与监测、水土保持规划及小流域综合治理提供了科学的依据。

Based on the natural conditions of soil and water loss in the granite gneiss region of northern Jiangsu province, 6 types of runoff plots were set up and experimental study was carried out. By correlation analysis of runoff and soil loss from 364 events of rainfall, a simplified and convenient mathematical formula that is suitable to calculate rainfall erosion factor R value for the local region was established and other factors of USLE model were also determined. Error analysis of the soil loss of various plots calculated by USLE model and the actual measured value showed that the percentile error ranged from -3.5%-9.9% and the confidence level was more than 90%. In addition, practical application verification showed that the percentile error was 5.64% for the terrace field and 12.36% for the sloping field, and thus the confidence level was above 87 %. This research result has provided a scientific basis for forecasting and monitoring the water and soil loss, for the comprehensive treatment of small watershed and for the soil and water conservation planning for the local region.