侵蚀影响下土壤碳和养分空间变化及其过程模拟

Soil Carbon and Nutrient Change and Model Under Soil Erosion

通过小区采样并进行了机械组成和化学分析 ,认为侵蚀过程导致的土壤颗粒坡面分布变化点在 0 .2 m m左右 ,同时认为侵蚀是坡面土壤碳和养分再分布过程及分布差异的主要因素 ,当其它条件一致时 ,侵蚀和堆积决定了特定点或区域的土壤碳和养分含量的高低。通过建立土壤碳和养分变化模型及侵蚀模型 ,在 IDRISIW的支持下对侵蚀条件下流域各地块土壤碳和养分含量变化过程进行了模拟和长期预测 。

The results of physical and chemical analysis of soil samples showed that the diameter changing point of soil particles caused by soil erosion is about 0.2 mm in slope land, and soil erosion is one of the main causes of spatial distribution and redistribution of soil carbon and nutrient in slope land. As other conditions are fixed, the intensity of soil erosion and deposition determines the concentration of soil carbon and nutrient in slope land. After models of soil carbon, nutrient changing and soil erosion have been constructed, soil carbon and nutrient changes under soil erosion in each land unit of Wangjiaqiao watershed have been simulated and forecasted, which are based on IDRISIW GIS. The results of simulation showed that different element of soil nutrient (C, N, P, K) has different soil acceptable erosive modulus in different land use types, which means that one kind of soil element will decrease when soil acceptable erosive modulus is higher than the limited value.