A Distributed Monthly Water Balance Model for Identifying Hydrological Response to Climate Changes and Human Activities
气候变化及人类活动影响下的潮白河月水量平衡模拟

A blueprint(FH69 blueprint) for a physically-based digitally simulated hydrologic response model was published by Freeze and Harlan in 1969,which initiated the studies on the distributed hydrological models(DHMs) at the watershed scale.Nevertheless,in spite of three decades of modeling development,distributed hydrological models are today being used in practice only at a fraction of their potential.The applications of DHMs based on the FH69 blueprint are confronted with difficulties because of deepening in theory,which simultaneously indicate that the complex models are not always good ones.According to the scientifically modeling protocol,a simple monthly subbasin-based water balance model is put forward,where the revised Bagrov evapotranspiration model is developed to parametrize the distinguishes between various land covers,and a parameter set is introduced to represent the impacts of human activities on runoff generation and evapotransipiration processes.In the case study of the Chaobai River Basin in North China,the model was used to quantificationally identify the impacts of climate changes and human activities on runoff.In the Bai River Basin,the annual mean precipitation of the 1980s(1980-1988) and 1990s(1989-2001) decreased by 9% and 5% com-pared with that of the 1970s(1961-1966 and 1973-1979),but the runoff reduced by 54% and 52% respectively.The simulation results indicate that the contribution rates of climate changes and human activities are 44% and 54% respectively.In the Chao River Basin,such contribution rates are 24% and 74%,i.e.,human activities are the main reason for runoff decrease.