Author(s): Vo Ngoc Duong; Philippe Gourbesville
Linked Author(s): Philippe Gourbesville
Keywords: Deterministic hydrological modeling; Sensitivity; Multi-calibrate; Long-term simulations; Vu Gia Thu Bon catchment
Abstract: In order to create a tool to help hydrologists and authorities having good understandings about happenings in stream flow regime and its variation in the future under the impact of climate change in Vu Gia Thu Bon catchment, a deterministic hydrological model–MIKE SHE from DHI-is constructed. The model covers the major processes in hydrologic cycle and includes process models for evapo transpiration, overland flow, unsaturated flow, groundwater flow, channel flow, and their interactions. Each of these processes can be represented at different levels of spatial distribution and complexity, according to the goals of the modeling study, the availability of field data and the modeler's choices. This model is calibrated and validated against the daily data in period 1991-2000 and 2001-2010, respectively. The performance of model are showed by good statistical coefficients at seven gauging stations. The Nash Sutcliffe and relation coefficients could reach to 0.78 to 0.82 and 0.89 to 0.92, respectively when comparing the discharge. With the water level, because the limitation of resolution, these coefficients are lower than comparing with the discharge. However, these are still high in upstream when The Nash Sutcliffe and relation coefficients could reach to 0.63 to 0.77 and0.81 to 0.89, respectively. This study is confirmed again the performance of deterministic distributed model in simulating the hydrological process and the capacity of this kind of model to projected climate change, at least confirm the usefulness of this model with ungagged catchment or large catchment. This study also prove the role of multi calibration in increasing the accuracy of hydrological model for a large catchment.