基于RUSLE模型的喀斯特峰丛洼地土壤侵蚀及其养分流失评估

以中国南方典型喀斯特峰丛洼地为研究对象,基于GIS技术和RUSLE模型,对喀斯特峰丛洼地的土壤侵蚀空间变化特征进行了分析。探讨了峰丛洼地土壤侵蚀与土壤养分流失之间的关系,揭示了该地区不同土壤养分流失之间的空间变化差异。结果表明:2015年研究区土壤侵蚀总量为1 950.21×10~4 t·a~(-1),占研究区国土面积的76.75%。土壤侵蚀空间分布整体上呈现出南北两侧向西中部变化的条带状的空间分布特征。因土壤侵蚀引起的土壤有机碳(SOC)、全氮(TN)、全磷(TP)和全钾(TK)等养分流失总量为57.76×10~4 t·a~(-1),其中SOC、TN、TP和TK的平均流失量分别为38.13、1.18、0.16和6.00 t·km~(-2)·a~(-1)。研究区土壤侵蚀的空间变化整体上是随侵蚀等级增加,侵蚀面积和侵蚀量逐渐减少而平均侵蚀模数增加的过程,土壤侵蚀的空间分布差异决定了土壤养分流失空间分布差异。

Evaluation of Soil Erosion and Nutrient Loss in Karst Peak - Cluster Depression Based on RUSLE Model

The spatial variability of soil erosion was analyzed, which the relationship between soil erosion and soil nutrient loss was discussed in karst peak cluster depression, and the spatial variability of different soil nutrient loss was revealed. the typical karst peak cluster depression in southern China using GIS technology and RUSLE model. The results show: the total area of soil erosion was 1950.21×104t.a-1 in 2015, accounting for 76.75% of the study area. The spatial distribution of soil erosion is characterized by the north and south sides to the central changes in the strip. The total nutrient loss caused by soil erosion was 57.76×104 t.a -1, and the average losses of SOC, TN, TP and TK were 38.13, 1.18, 0.16, 6.00 t.km-2.a -1, respectively. The spatial variation of soil erosion is overall: erosion area and erosion mount gradually decreased with the erosion level increases, but the average erosion modulus increase process in the study area. The spatial distribution of soil erosion determines the spatial distribution of soil nutrient loss.