论文部分内容阅读
根据渭河流域两个典型小流域的实测水文和气象资料,分析了不同气候和下垫面条件的流域水文特征及其差异性.结果表明:清源河和牛谷河流域的年平均气温呈上升趋势,降水、径流、泥沙、降水径流系数均呈减少趋势;两个流域的降水、径流和泥沙历年变化不一致,1998-2013年清源河流域降水量相对牛谷河流域减少了8.6%,1993-2013年牛谷河的径流相对减少了21.4%,2000-2013年清源河的泥沙相对减少了24.0%;两个流域的面积、河长、海拔、植被覆盖率等流域特征值相对差在-29.4%~-4.5%之间,气温、降水等气候特征值相对差在-27.4%~16.7%之间,而径流特征值相差较大,相对差在-90.2%~-84.7%之间,泥沙特征差异性更大,相对差在292%~347%之间.对气候、下垫面和人类活动对水文要素的影响进行了研究,受人类活动的影响,清源河流域1996-2013年年径流减少11.6%,牛谷河流域1993-2006年年径流减少25.9%,2007-2013年再减少10.5%,研究人类活动的调水减沙效应,对流域综合治理、生态环境建设具有一定的指导意义.同时,充分利用不同小流域实测水文气象数据,分析水文气象要素的变化规律,可以为分布式水文模型研究和中小河流洪水预警预报提供重要依据.
According to the observed hydrological and meteorological data of two typical small watersheds in Weihe River Basin, the hydrological characteristics and their differences of watersheds under different climate and underlying surface conditions are analyzed.The results show that the annual mean temperature in Qingyuanhe and Niuguhe valleys is on the rise, and precipitation , Runoff, sediment and precipitation runoff coefficients all showed a decreasing trend. The precipitation, runoff and sediment variation in the two watersheds were not consistent over the years. The precipitation in the Qingyuan River Basin decreased by 8.6% compared with that in the Niu Guhe River Basin during 1998-2013. From 1993 to 2013 The runoff of Niugu River was relatively reduced by 21.4%. The sediment of Qingyuan River was relatively reduced by 24.0% from 2000 to 2013. The relative difference in the features of river basins such as area, length of river, elevation and vegetation coverage ranged from -29.4% -4.5%, and the relative difference of climate characteristic values such as temperature and precipitation is between -27.4% and 16.7%, while the difference of the characteristics of runoff is relatively large with the relative difference between -90.2% and -84.7%. The difference of sediment characteristics The relative difference is between 292% and 347% .To study the impact of climate, underlying surface and human activities on hydrological factors, the annual runoff in Qingyuan River Basin decreased by 11.6 %, Niu Guhe River Basin annual runoff decreased from 1993-2006 25 .9% from 2007 to 2013, a further decrease of 10.5%. It is of great significance to study the effects of water and sediment reduction in human activities on the comprehensive management of the river basin and the construction of the ecological environment. At the same time, taking full advantage of the measured hydrometeorological data in different small watersheds, The changes of hydrological and meteorological elements can provide an important basis for the study of distributed hydrological models and early warning and forecasting of medium and small river floods.