The hydrological characteristics of Hehuan Mountain watershed and impact assessment of climate variation

Abstract

Due to the variations of the global climate the hydrological system has undergone tremendous changes in many places of the world including Taiwan To delineate the response of a hydrological system to the impact of climate variation the use of hydrological model is challenging Hehuan Mountain watershed at Taiwan is chosen as the research site The catchment is with few anthropogenic activities It is located at central Taiwan with an area of 1 52 km2 a slope of 14 94° SWAT model is adopted and conjunctively use with MODFLOW to establish the hydrological model After model is calibrated and verified future meteorological projections (including rainfall and temperature) from GCM model using Coupled Model Intercomprison Project Phase 5 (CMIP5) experiment scenarios are used With downscaling meteorological data hydrological response to the climate variation are simulated Results show that hydrological components react differently Precipitation changes toward increasing in wet seasons for most 100% and decreasing in dry seasons to 40% Temperature consistently increases for around 2℃ Percolation and outflow highly correspond to the precipitation Groundwater is very sensitive to the change of precipitation ET is significantly influenced by temperature All these hydrological components show fractal in time series with spectrum analysis The hydrological components can be inversely derived from the rainfall using the transfer function through this characteristic Based on this approach the data-driven model may serve as an alternative of the physics-based model for hydrological modeling

Date of Award	2019
Original language	English
Supervisor	Kuo-Chin Hsu (Supervisor)