Author(s): Meng-Chiu Hung; Kwan Tun Lee; Yu-Hsun Liao
Linked Author(s):
Keywords: Vailable water analysis; TOPMODEL; Flow duration curves; Exceedence probability
Abstract: Since Taiwan suffers by the uneven distribution of rainfall and coupled with rapid current, water conservation work is comparatively difficult. Moreover, severe floods and droughts seem more frequent than before, and the increasing of water demand has resulted in water distribution for agriculture and industry uses to be a serious problem during drought. The objective of this study is to analyze the available water during drought in the Daan Creek watershed. In order to perform the available water analysis at any location of the watershed, the Daan Creek watershed was firstly separated into several subwatersheds based on a specified threshold area using a digital elevation model, and then the detail geomorphologic factors of the subwatersheds were obtained. Since hydrological record is unavailable at any location of the watershed, conventional black-box models cannot be applied for flow analysis in ungauged areas. Consequently, a physically-based runoff model, TOPMODEL, was performed to implement the hydrological simulations. In this study, long-term rainfall data was input to the TOPMODEL to generate daily-flow series. The series could be applied to obtain the flow duration curves and accumulated as ten-day flow series for further exceedence probability analysis. Consequently, the flow duration curves and the flow exceedence probability of the subwatersheds could be treated as an index for available water determination. The analytical results showed that the simulated flow series were in good agreement with records both in the wet and dry seasons. The flow duration curves and the flow exceedence probability obtained by using the TOPMODEL in the watersheds could provide valuable information to authorities for water distribution during drought.
Year: 2013