水土保持措施对山区水循环的影响——以宁夏南部山区为例

The Effect of Soil and Water Conservation on Water Cycle:A Case Study in the Mountainous Area of Southern Ningxia

为了彻底治理宁夏南部山区的水土流失,改善当地恶劣的自然生态环境,当地规划了若干水土保持工程,这势必会对山区水循环产生影响。水土保持措施可以有效的拦蓄径流和改善山区水循环,对于一次降水而言,水土保持措施既减少了径流和对地面土壤的侵蚀,又增加了降水入渗进入土壤水和地下水的机率,从而提高了人类可利用的水资源量。本文以宁夏南部山区为例,就水土保持措施对山区水循环的影响进行定性分析,在此基础上开展了定量计算和分析。为了对比不同水土保持措施下的减水效果,本文根据不同水资源配置以及人口经济发展战略情况确定两种水土保持方案。经计算:在高方案发展水平下,2010年、2020年和2030年规划水平年区域地表水资源量减水率最高值分别为33.2%4、8.8%和57.6%;在低方案发展水平下,各规划水平年区域地表水资源量减水率最高值分别为15.6%、27.4%和37.8%。结果表明,由于气候、水文及工程措施等不同因素的影响导致区域间综合减水效果差异较为明显,但总体上看各区域的减水效果较好。所以,实施水土保持措施对治理水土流失和改善生态环境是非常有效的。

Water resources have become an important factor restricting economic development. Therefore, more and more researchers focused their study on water cycle and the effect of soil and water conservation. For the purpose of preventing the loss of soil and water in the mountainous area of southern Ningxia, many engineering measures of soil and water conservation have been planned which will be certain to affect water cycle of mountainous area. The soil and water conservation measures will retain effectively the runoff and improve the water cycle of the mountainous area. The runoff is retained by the soil and water conservation project, which decreases the erosion and increases the probability of precipitation infiltrating into the soil and ground. Consequently the available water resources will be added and the environment will also be improved. This paper analyzes the influences of soil and water conservation on water cycle. By comparing the efficiency of the different soil and water conservation project, this paper chooses two schemes based on the water resources allocation and the development of economy and population. In the first scheme, the percent of retained runoff is 33.2%, 48.8% and 57.6% respectively in 2010, 2020 and 2030; in the second scheme, the percent of retained runoff is 15.6%, 27.4% and 37.8% respectively in 2010, 2020 and 2030. The results show that the differences of the integrated efficiency of soil and water conservation project between regions are evident because of the different engineering measures. But the total efficiency in each region is well. Therefore, it is very effective to prevent the loss of soil and water and improve the environment with these engineering measures.