The Study On General Watershed Load Function (GWLF) Model For Algorithmic Improvement And Practical Application

The Generalized Watershed Loading Function (GWLF), a worldwide famous watershed model, was set as the research object in this paper. The model algorithm was reviewed in detail, and a series of innovative algorithms were proposed as alternativestrategies to address the weakness inoriginal GWLFmodel. The effect of model revision was tested based on a case study, the result of which indicated that all the additional algorithms could refine thehydrologic framework of GWLF model. With the revised GWLF model, a remarkable improvementof estimation accuracy to streamflowin low-flow months could be achieved, implying a more reliable model result.In sequence, the Quqiao Reservoir watershed in northern china and the Xin’anjiang watershed in southern china were picked out as case sites for GWLF application in practice facing local real management demand. The model results showed that the revised GWLF model had a great ability in describeing the monthly hydrochemical process of target watershed andestimating the source apportionment of typical polltion load, as well as itsdiversities under different spatial and temporal circumstances, including different water regimes, seasonal patterns, loading levels, andman-made districtboundary. Theseresults indicated that there is a great applicability for GWLF model to be achieved in China. The data requirement for model organization is modest in accordwithavailable data scale, while the accuracy and scope of model outputcanmeetgeneral demands of watershed environmental managementin China, representinga great value and potential to be extended.Thus, for advancing the popularity of GWLF model in China, a absolute GWLF software with full Chinese graphical user interfacewas developed in JAVA flatform based on classical GWLF algorithm. This software has the parameter calibrationmodule and is divided into basic mode and professionalmodefor different user groups with different demand, which couldpromote the application of GWLFmodel in Chinafrom both academic and practicalview. To sum up, a series ofresearches have been made in this paper, with the worldwide GWLF model as core, for model applicationfacing Chinese water environmental manaagement demand as goal, and to validate the model applicability in China as purpose. The conception of scientificdecision-making support system based on model technologyprovide a novelapproach to advance the management level in watershed environment of China. The case study can be set asreferencefor further GWLF applications and the GWLF software with Chinese graphical user interface developed here can be used as credible tool to achievescientificdecision-making support information.