湘北红壤坡地雨水过程的水土流失及其影响

Observation Studies on Water and Soil Loss in the Process of Rainfall on the Slop Lands of Red Soil in North Hunan

模拟主要利用方式构建的垫面为主导因子,采用径流场实测方法,通过4a(1998～2001年)实地观测试验,剖析不同下垫面对雨水地表径流及其过程的影响。研究表明:降雨(时间分布及其强度)是影响地表径流特征的主导因素;年降雨量与地表径流量和系统水土流失量呈正相关。不同垫面地表径流产量有显著性差异;雨水径流过程的土壤和养分流失有相似的表现。在假定雨水年份的基础上,应用不同雨水年份出现概率指标,推算出:湘北红壤坡地现今利用状况下,雨水产地表径流过程的年均水土流失量及其养分(有机质、N、P、K)损失量;和可最大开发利用时,可能带来的水土流失与养分损失。提出"利用坡地集雨利用优势,构建与单元生态系统水循环平衡相适应的坡地农林复合生态系统,通过水平衡生态建设来维系生态系统的水分平衡"观点。

Simulating the main utilization pattern of landscape, this paper studied the influence of difference land utilization mode upon rainfall surface runoff and system erosion in the process in the years of different rainwater on the basis of the field observation experiments from 1998 to 2001 The results showed: that rainfall (time distribution and its intensity) was the main factor influencing on surface runoff characteristics The precipitation in per year was positive correlated with surface runoff and water and soil loss Among the different landscape, there was significant difference in surface runoff The order was: farming >* tea plant > slash pine > persimmon plant > * orange >* natural degradation > natural recuperation And soil loss was accord with nutrient loss in the process of rainfall runoff According to the probability index of various precipitation years, the article also calculated the soil and water loss at present on the slop lands of red soil in North Huanan and nutrient (OM?N?P and K) loss Making use of rainwater of slope lands, agroforest multiecosystems in the hilly land adaptive for water equilibrium of unit ecosystems were constructed And this ecological construction can maintain ecosystem water balance The viewpoint was put forward