论文部分内容阅读
Based on hydrometric data and extensive investigations on water-extracting projects, thispaper presents a preliminary study on water discharge changes between Datong and Xuliujing duringdry season. The natural hydrological processes and human factors that influence the water dischargeare analyzed with the help of GIS method. The investigations indicate that the water-extractingprojects downstream from Datong to Xuliujing had amounted to 64 in number by the end of 2000,with a water-extracting capacity up to 4,626 m3/s averaged in a tidal cycle. The water extraction fromthe Changjiang River has become the most important factor influencing the water dischargedownstream Datong during dry season. The potential magnitude in water discharge changes areestimated based on historical records of water extraction and a water balance model. Thecomputational results were calibrated with the actual data. The future trend in changes of waterdischarge into the sea during dry season was discussed by taking into consideration of newly builthydro-engineering projects. The water extraction downstream Datong in dry season before 2000 had agreat influence on discharges into the sea in the extremely dry year like 1978-1979. It produced a netdecrease of more than 490 m3/s in monthly mean discharges from the Changjiang into the sea. It isexpected that the water extraction will continually increase in the coming decades, especially in dryyears, when the net decrease in monthly mean water discharge will increase to more than 1000 m3/sand will give a far-reaching effect on the changes of water discharge from the Changjiang into thesea.