in the upper-middle jinghe watershed of malian river, annual stream runoff and runoff modulus almost have no change during the last 30 years. but in the whole watershed the stream runoff decreases;
在泾河流域马莲河分流域,年径流和径流模数在过去30年中基本维持稳定,整个泾河流域年径流量逐年下降;
there are many factors that affect the runoff modulus and the variation coefficients of flood discharge and low flow, such as climate, rock, soil, land form, and so on.