广东小良水保站三种生态系统地表侵蚀的研究

A STUDY ON THE EROSION OF SURFACE SOIL IN THREE ECOSYSTEMS OF XIAOLIANG EXPERIMENTAL STATION

摘要:

在系统地研究了广东小良水保站的混交林，桉树林，裸地等三种生态系统类型的水文效益以后，本文着重探讨了它们的水土保持效益。结果表明裸地的降雨侵蚀率分别是桉树林的５．２倍，是混交林的２２８．１倍；径流侵蚀率裸地是桉树林的１１．３倍，是混交林的３１．９倍。从总体上来看，无论是降雨侵蚀率还是径流侵蚀率都是混交林的最小，而且从侵蚀物的组成来看，混交林地表径流中的悬浮物占较大的比重。侵蚀物与降雨量存在ｘ＝ｆ（ＰＡ）的相关关系，Ａ的大小反映了降雨对侵蚀的影响程度，不同的土壤是不同的，混交林Ａ＜１，桉树林Ａ＝１．４８，裸地Ａ＝１．８５，侵蚀率的年间变化以混交林的最大。用灰色系统的ＧＭ（２，１）模型，本文较为成功地预测了年际间的侵蚀率。

Abstract:

Based on the systematic study on hydrological effects of mixed forest, eucalyptus forest and naked land in Xiaoliang experimental station, Guangdong Province, the profits of water and soil conservation were examined. It was shown that the total erosion rate by rainfall for naked land is 5. 2 times than that for eucalyptus forest and 228. 1 times as high as that for mixed forest,while the erosion rate by surface flow for naked land is 10. 3 and 30. 9 times higher than that for eucalyptus forest and mixed forest, respectively. The eroded components from mixed forest are mainly made up of smaller particles. There is the experimental relations X=f (PA) between erosion (x represents weight in unit of kg) and rainfall (P, mm), in which the parameter A represents the influence of precipitation on erosion. For various soils, A is different. In mixed forest, A< 1; eucalyptus forest, A= 1. 48, and naked land, A= 1. 85. Mixed forest has a larger change of erosion rate among different years. At the same time, we successfully estimated the annual erosion rate by applying the theory of "gray system"model GM (2, 1).