Towards Determining Global River Discharge Using a Distributed Hydrological Model and Global Mapping
作者单位：Dept.of Civil Eng.Univ.of TokyoBunkyo-kuTokyo 113-8656Japan. Dept.of Civil Eng.Bangladesh Univ.of Eng.and Technol.Dhaka-1000Bangladesh
会议名称：《International Symposium of Iahs-Pub and the 2nd International Symposium of China-Pub》
会议日期：2008年
学科分类：08[工学] 081501[工学-水文学及水资源] 0815[工学-水利工程]
关 键 词：Asian water cycle initiative Bangladesh distributed hydrological model global mapping Meghna River river discharge TRRM ground validation
摘 要：正To improve global water resource assessment,quantification of the global river discharge while considering the effect of slopes is *** patterns need to be transformed into discharge by a distributed hydrological model（DHM）.The model is expected to represent the spatial variation in aspects of digital global mapping such land use,land cover,vegetation and ***,a digital elevation model（DEM） is crucial for tracking the flow direction and defining the river network in a *** this study,the performance of a 1 km resolution DHM is compared with that of a 90 m resolution DHM in simulating the discharge of the Meghna River in *** basin,which is poorly gauged,runs from the Assam and Tripura mountain regions of India to the metropolitan area of *** the Bangladeshi area of the basin,the slopes are very gentle and typical of flat plains,which make it difficult to represent the geomorphological characteristics with *** expected,the 1 km resolution model had more constraints in representing the actual river ***,using a national drainage map it was possible to improve the DEM hydrologically using geographic information system *** input rainfall was obtained from the Tropical Rainfall Measuring Mission（TRMM） 3B42 V6 products available almost globally at 0.25°spatial *** original TRMM data was improved using available rain gauges over Bangladesh. These correction factors were then also extended over *** simulated discharge was evaluated during a flood event at two stations:Zhakiganj at the intake of the upper Meghna River and Bhairab Bazar at the oudet of the models. In summary,the simulation of river discharge using the 1 km resolution model gave reasonable results even though the condition of the slope was ***,the procedure here shows the feasibility of developing global river discharge using global *** future development,after setting thresholds at different co