秃尾河流域径流衰减驱动力因子分析

掌握流域径流演变规律,探讨其影响因子,对流域水资源合理开发利用和科学管理具有重要的意义。论文依据秃尾河流域1956—2010年径流、降水资料以及榆林站1956—2010年气温资料,采用高桥浩一郎公式计算了流域蒸散发量,利用Kendall秩次检验法分析了流域降雨、径流和蒸发的趋势演变特性;采用主成分分析法研究了多因子对流域径流衰减的影响;建立了径流衰减量与主要影响因子之间的统计模型。结果表明:1)流域径流量呈显著减少趋势,而蒸发量和降水量减少趋势不显著;2)在径流衰减驱动力因子中,人类活动因子权重为71.1%,而气候因子权重为28.9%,各驱动力因子对径流衰减的贡献率由大到小依次为:林草梯田坝地流域用水量年降水量年蒸发量;3)径流衰减量与林草、梯田的指数回归模型能较好地反映径流衰减量与驱动力因子之间的定量关系,可以为流域治理和水资源开发利用提供科学依据。

Driving Force Analysis of Runoff Attenuationin Tuwei River Basin

Tuwei River originates in Shenmu County of Shaanxi Province, China, which is the tributary of the Yellow River with the length of 139.6 km and drainage area of 3 294 km². There is serious soil erosion in the Tuwei River Basin, and the area of soil erosion is 2 965.3 km², being about 90% of the whole basin. With the rapid development of industrialization and urbanization, runoff of the Tuwei River is getting less, along with which there are more and more serious water pollution and deteriorating water quality. Research on evolution of water resources in Tuwei River Basin can provide a basic knowledge of the main characteristics and driving factors of water deterioration, which has a significant meaning to the reasonable development and utilization as well as scientific management of the resources. In this study, the annual flow and precipitation data of Tuwei River Basin during 1956-2010 and the annual temperature data of Yulin Station during 1956-2010 were used. Based on Takahashi Koichiro Formula, the evapotranspiration in the basin was calculated and the evolution characteristics of rainfall, runoff and evaporation in the basin were analyzed. And the orderly sequence clustering test method was adopted to find the catastrophe point. According to the method of principal component analysis, the multi-factor influence on runoff attenuation was studied. Besides, by establishing the natural driving force model, the influence of human forces on runoff attenuation was discussed. The results show: 1) Among the essential factors of water cycle, annual runoff has a significant trend of reduction, while the change of annual evaporation and annual precipitation is minor. The most likely catastrophe point is 1978, dividing the whole period of 1956-2010 into reference period (1956 to 1978) which is hardly affected by human activities and measures period (1979 to 2010) which is greatly affected by human activities. 2) Among the factors which affect the runoff attenuation, the weight of human activity and climate factor is 71.1% and 28.9%, respectively. The contribution rate of each factor to the runoff attenuation, from the largest to the smallest, is: woodland and grassland > terrace > silt dam > water consumption > precipitation > evaporation. 3) The index regression model of runoff attenuation and grassland and terrace can objectively reflect the quantitative relationship between runoff attenuation and the driving force factors. The research provides a scientific base for river basin management and water resource utilization.