黄土高原小流域雨水资源化环境效应分析

水土流失和干旱缺水是黄土高原经济落后和生态环境恶化的主要原因。雨水资源化是解决或减缓水土流失和干旱缺水的有效途径。将雨水利用的方式归纳为雨水就地拦蓄利用、覆盖抑制蒸发、雨水富集叠加异地利用3种方式。分析了雨水资源化对水文环境和土壤环境的影响。不同的雨水利用措施都能在一定程度上调节和控制水文过程,改善流域的水质,减少土壤的非点源污染,提高土壤的质量,提高土壤的含水率;而人工林草植被不同程度地减少了土壤含水率,覆盖措施可以延长水在土壤水库中的集蓄时间。

ANALYSIS ON EFFECT OF RAINWATER RESOURCFULIZATION ON ENVIRONMENT OF SMALL WATERSHED IN THE LOESS PLATEAU

Water and soil loess and drought and water scarcity are the main reasons that lead to the backware of economy and worse environment.Rainwater resourcfulization is an efficient way to solve or alleviate the above problems.This paper summarized rainwater utilization from three aspects as following:retarding use in the same place, mulch restraint evaporation utilization,rainwater collecting reiterative utilization.When rainwater resourcfulization offered the water resource to ecology construction and drinking water to mankind and livestock,it also changed the distribution pattern and cycle process of water and nutrient and affected the environment of small watershed.This paper analysed the effect of different rainwater utilization on hydrology environment and soil environment.Rainwater utilization can modulate and control hydrological process,improve the water quality, soil quality and soil moisture of watershed. However artificial forest and grassland reduced soil moisture of watershed to different extent;mulch restraint evaporation utilization can prolong the time of rainwater kept in soil pool.At the same time this paper discussed the relationship between rainwater utilization and break-off discharge in the Yellow River and dried soil layer.