Many rainfall-runoff models require a basin to be subdivided into smaller areas, or sub-basins, because of the limitations of unit hydrographs. With watershed subdivision, the runoff at the outlet in a basin can be estimated by channel routing after analyzing the rainfall-runoff process for each sub...
Many rainfall-runoff models require a basin to be subdivided into smaller areas, or sub-basins, because of the limitations of unit hydrographs. With watershed subdivision, the runoff at the outlet in a basin can be estimated by channel routing after analyzing the rainfall-runoff process for each sub-basin. In reality, runoff models based on two conceptual models, the linear channel model and the linear reservoir model, have been developed and applied to represent many hydrological processes. Hydrological routing models are often applied to obtain hydrologic quantities essential in the design of hydraulic structures. Because hydrological routing is based on continuity and storage equations, the selected storage equation must accurately represent the target, whether it is a watershed, channel, or reservoir. Based on the runoff characteristics of a basin followed by watershed subdivision, it is possible to express the storage effect in a basin in terms of the storage coefficient. This research focuses on an analytical approach to hydrological routing that allows the runoff characteristics of sub-basins to be identified. Initially, the Clark instantaneous unit hydrograph (IUH), which is based on the linear channel model and the linear reservoir model, was derived analytically. Following this, a time-area curve that presents the shape of a real basin as an ellipse was obtained. The derived Clark IUH was then tested by applying it to two smaller sub-basins within the Pyungchang river basin in Korea. Based on the parameters of the Clark model, a method for determining the parameters of the Muskingum channel routing model (MCRM) was proposed for the analysis of sub-basin runoff. Based on the assumption of a linear system, the proposed method was applied to the Chungju Dam basin in Korea for evaluation. A methodology allowing the analysis of the rainfall-runoff process was applied to the specific sub-basin within the Chungju Dam basin that included the Yeongchun-Chungju channel section. Furthermore, this research used the Clark model to consider the lateral inflow in the sub-basin. In addition, the storage effect of reservoirs was quantified with a storage coefficient using a nonlinear reservoir model. An exponential function representing the relationship between a reservoir's storage and discharge was presented. The nonlinear reservoir model proposed in this study was then applied to the Chungju Dam and the Soyanggang Dam in Korea; the storage effects during flooding were estimated to be about 23 hours and 43 hours, respectively. Finally, an estimation method for the storage coefficients in a parallel and serial watersheds is suggested, the results of which are based on a series of linear reservoirs. The characteristics of the storage coefficients can be also expressed in the case having dams within a basin. The applicability of the proposed method is evaluated using sub-basins within the Paldang Dam basin, Korea. Results of the present study indicate that the proposed methods are useful for the identification of runoff characteristics based on both linear and nonlinear reservoir models and the evaluation of parameters in runoff models when quantifying the storage effect using a storage coefficient. Thus, the use of these methods will allow decision makers in charge of water resources to accurately estimate flood runoff and compare the storage effect of each basin using storage coefficients. It can also lead to more efficient watershed management and significantly reduce the environmental, economic and social damage arising from flooding.
Many rainfall-runoff models require a basin to be subdivided into smaller areas, or sub-basins, because of the limitations of unit hydrographs. With watershed subdivision, the runoff at the outlet in a basin can be estimated by channel routing after analyzing the rainfall-runoff process for each sub-basin. In reality, runoff models based on two conceptual models, the linear channel model and the linear reservoir model, have been developed and applied to represent many hydrological processes. Hydrological routing models are often applied to obtain hydrologic quantities essential in the design of hydraulic structures. Because hydrological routing is based on continuity and storage equations, the selected storage equation must accurately represent the target, whether it is a watershed, channel, or reservoir. Based on the runoff characteristics of a basin followed by watershed subdivision, it is possible to express the storage effect in a basin in terms of the storage coefficient. This research focuses on an analytical approach to hydrological routing that allows the runoff characteristics of sub-basins to be identified. Initially, the Clark instantaneous unit hydrograph (IUH), which is based on the linear channel model and the linear reservoir model, was derived analytically. Following this, a time-area curve that presents the shape of a real basin as an ellipse was obtained. The derived Clark IUH was then tested by applying it to two smaller sub-basins within the Pyungchang river basin in Korea. Based on the parameters of the Clark model, a method for determining the parameters of the Muskingum channel routing model (MCRM) was proposed for the analysis of sub-basin runoff. Based on the assumption of a linear system, the proposed method was applied to the Chungju Dam basin in Korea for evaluation. A methodology allowing the analysis of the rainfall-runoff process was applied to the specific sub-basin within the Chungju Dam basin that included the Yeongchun-Chungju channel section. Furthermore, this research used the Clark model to consider the lateral inflow in the sub-basin. In addition, the storage effect of reservoirs was quantified with a storage coefficient using a nonlinear reservoir model. An exponential function representing the relationship between a reservoir's storage and discharge was presented. The nonlinear reservoir model proposed in this study was then applied to the Chungju Dam and the Soyanggang Dam in Korea; the storage effects during flooding were estimated to be about 23 hours and 43 hours, respectively. Finally, an estimation method for the storage coefficients in a parallel and serial watersheds is suggested, the results of which are based on a series of linear reservoirs. The characteristics of the storage coefficients can be also expressed in the case having dams within a basin. The applicability of the proposed method is evaluated using sub-basins within the Paldang Dam basin, Korea. Results of the present study indicate that the proposed methods are useful for the identification of runoff characteristics based on both linear and nonlinear reservoir models and the evaluation of parameters in runoff models when quantifying the storage effect using a storage coefficient. Thus, the use of these methods will allow decision makers in charge of water resources to accurately estimate flood runoff and compare the storage effect of each basin using storage coefficients. It can also lead to more efficient watershed management and significantly reduce the environmental, economic and social damage arising from flooding.
주제어
#Hydrological Routing Watershed Subdivision
※ AI-Helper는 부적절한 답변을 할 수 있습니다.