Environmental Hydrology Effects Of Urbanization On Jialu River

The study of Land use/land cover change (LUCC) is the forefront of global issues. Rapid urbanization and high-intensity human activities, which changed the city's land use/land cover dramatically, become the main force of hydrological effects on the city's ground surface. Jialu River is one of the tributaries of Huai River, its main channel is flowing through Zhengzhou City. Based on the Soil and Water Assessment Tool (SWAT) model, developed by the Agricultural Research Service and Texas A&M University, the hydrological effect of Jialu River attributed to the urbanization of Zhengzhou during the past 10 years is simulated. In addition to analysis the changes of runoff and water yield during 1990s and 2000s, the study also predicted the potential hydrological changes, which is attributed to the construction of New District in Zhengzhou city. The result of this research could provide both theoretical and practical suggestion to Jialu River's water resource management in the future.The main research conclusions of this thesis are summarized as following:(1) Established the model of Jalu River Basin based on SWAT. After doing the spatial data handling of the study area, making the contour maps and stream data vector, and developing the Digital Elevation Modeling (DEM) as well, one can obtain the direction of water flow in each grid, the boundary of watershed and the hydrographic net. According to these three factors, the whole watershed can be divided into subbasins. Based on the regional information, a map which states the soil types and another one showing the land use condition were founded separately, using the ArcGIS software. The different soil and land use combinations determines the final number of the hydrological response units (HRU).(2)Established a database required by SWAT model. Referred to the default database attached in SWAT, and considered the actual situation of the Jialu River watershed as well, the new database is much more accurate. The database includes information about meteorology, soil properties and land use situation in detail.(3)Simulated the runoff of Jialu River, calibrated and validated the model. Among the daily rainfall data of Zhengzhou City and the statistical data collection from the hydrological station located in Chenqiao, Zhongmu County, selected the data series from 1990 to 2001 for model calibration. The procedure of adjusting correlative parameters, the initial boundary condition and other limiting factors, made the value resulted from model calculation closer to the statistic value. The data series from 2002 to 2008 was used to validate the model. Use the relative error, correlation coefficient and the Nash-Sutcliffe efficiency coefficient to judge the adaptability of the model, results showing that the precision of SWAT model is in good range.(4)The hydrological response to the construction the New District in Zhengzhou was discussed, and some reasonable proposals were offered.