Modification of General Watershed Loading Function and Its Simulation on Different Time Period

Autor: I-wen Lin, 林怡妏
Rok vydání: 2012
Druh dokumentu: 學位論文 ; thesis
Popis: 100
Water resource is an important issue in the 21th century. Due to the climate change, the streamflow is becoming varied extremely in wet seasons and dry seasons. The supply and demand of water resource is much more difficult to meet everyone’s expectations. Therefore, numerous models simulate the streamflow are established which yield good examples of water resource management. General Watershed Loading Function (GWLF) is one of the models that analyzes the quantity and quality of water in catchment areas which is easy to operate so that it’s widely used in related researches. For the original GWLF overestimates evapotranspiration and vertical percolation, and underestimates groundwater flow at periods lacking rains, this research had made some modifications to GWLF model and applied it to simulate the water flow of catchment area of Lan-Yang River by entering the current status of land utilization, hydrological data and meteorological data to the model. This modified model takes soil resistance into consideration when calculating evapotranspiration, and meanwhile adds the parameters of moisture content in unsaturated zone and hydraulic conductivity to the calculation of vertical percolation. This model also considered preferential percolation of root zone. The modifications enable the GWLF model to simulate the nature of daily streamflow. The result indicated that the modified GWLF model could improve the calculation of percolation and evapotranspiration in root zone in dry seasons. As the penetrated percolation enhances groundwater flow, we adjusted the underestimations at periods lacking rains to simulating daily streamflow. It shows that the modified GWLF model can be more appropriate for simulating not only monthly but daily streamflow.
Databáze: Networked Digital Library of Theses & Dissertations
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