陕北能源化工基地河川径流特征和产流机理

Characteristics and yield mechanisms of stream runoffs in the Northern Shaanxi Energy and Chemical Industry Base, China

陕北能源化工基地东、西部河川径流特征迥异,产流机理和"三水"转化关系各不相同,探讨径流的时空变化特征和产流机理是进行水资源合理开发、高效利用的关键。根据1956—2005年径流的系列资料,综合运用水文计算、基流分割、Mann-Kendall检验、特征指标等方法,分析了研究区河川径流的空间组成特征和年际、年内的变化规律,并对其产流机理和水资源开发模式进行了相关的探讨,认为:黄土沟壑区流域下垫面介质为粉土质黄土,不利于降水入渗而利于产流,径流过程线表现为暴涨陡落型,地表径流主要来自降水补给,宜采取以地表水为主、地下水为辅的水资源开发模式;风沙滩地区流域下垫面介质以风积粉细砂为主,利于降水入渗而不利于产流,径流过程线表现为平缓型,地表径流主要来自地下水补给,宜采取地表水、地下水联合开发的模式。

There are entirely different runoff characteristics, yield mechanisms and transformation relations of three waters （precipitation, surface water and underground water） of rivers in the east and west part of the Northern Shaanxi Energy and Chenfical Base. Revealing spatial-temporal characteristics and yield mechanisms of runoffs is the key to rational development and efficient use of water resources. Based on the runoff data from 1956 to 2005, this paper analyses the characteristics of the space composition, inter-annual variation and intra-annual change of runoffs by using such methods as hydrological calculation, base flow separation, Mann-Kendall statistic test and characteristic index analysis. Meanwhile, the yield mechanisms of runoffs and the development pattern of water resources are also discussed. The underlying surface of the loess gully area consists of silty loess, which is unfavorable for precipitation infiltration but favorable for runoff formation. The surface runoffs fluctuate rapidly and are mainly recharged from precipitation. On that basis, it is advisable to adopt the pattern of development mainly of surface water with subordinate underground water in this area. By contrast, the underlying surface of the blown-sand area consists predominantly of eolian silt and fine sand, which is favorable for precipitation infiltration but unfavorable for runoff formation; thus the surface runoff fluctuates gently and is mainly recharged from groundwater. It is advisable to adopt the pattern of combined developnmnt of surface water and subsurface water in this area.