期刊名称：Journal of Environmental Hydrology (ältere Jahrgänge)
印刷版ISSN：1058-3912
电子版ISSN：1996-7918
出版年度：2006
卷号：14
出版社：IAEH
摘要：In the 1990's, runoff at the Tangnaihai hydrologic station experienced a serious decrease which attracted considerable attention. Changes in temperature and rainfall would have an important impact on the availability of water resources. From the point of view of water cycling, runoff coefficients are important indices of water resources conditions in a particular catchment. The Kalinin baseflow separation technique is an improved method based on the characteristics of precipitation and streamflow baseflow. First baseflow is separated, then runoff coefficient(R/P), baseflow coefficient (Br/P) and direct flow coefficient (Dr/P) are estimated. Statistical analyses are applied to assess the impact of precipitation and temperature on runoff coefficients (including Dr/P, Br/P and R/P). Results show that in the source regions of the Yellow River, the mean baseflow coefficient is higher than that of direct runoff. Runoff coefficients are in direct proportion to precipitation and inverse proportion to temperature. The decrease of runoff coefficients in the 1990's are closely related to the decrease in precipitation and increase in temperature. In different subbasins of the source regions of the Yellow River, runoff coefficients responded differently to precipitation and temperature. In the area above the Jimai hydrologic station where temperature is very low, temperature is the main factor influencing the runoff coefficients; runoff coefficients are inversely proportional to temperature, and precipitation has nearly no impact on runoff coefficients. In the subbasin between the Jimai and Maqu hydrologic stations, Dr/P is mainly affected by precipitation while R/P and Br/P are both significantly influenced by precipitation and temperature. In the area between the Maqu and Tangnaihai hydrologic station all three runoff coefficients increased with the rise in annual precipitation, while the direct runoff coefficient is inversely proportional to temperature. In the source regions of the Yellow River with the increase of annual average temperature, the impacts of temperature on runoff coefficients become weak.
