WATER RESOURCES ASSESSMENT IN THE HUAI RIVER BASIN: HYDROLOGICAL MODELLING AND REMOTE SENSING

摘要

The Huai River basin, in China is subjected to strong human pressure, and is geographically, meteorologically, and therefore hydrologically, very heterogeneous; it faces severe water management problems, concerning flooding and irrigation in particular. The Chinese local authorities are responsible for the management of the basin and the design of the infrastructure; a comprehensive water resources assessment using remote sensing technology and integrated hydrological modelling could be a great help to find long term solutions to the pending problems. In this paper, an attempt at developing such a complete water resources assessment is proposed, focusing first on a sub-catchment, the Shiguanhe watershed, which is well representative of the heterogeneity of the whole Huai river basin. The tools for this assessment are described here, both in hydrological modeling and in remote sensing. Meanwhile, a first attempt at modelling the Shiguanhe basin will help to define future developments that would allow these tools to be adapted to the Huai River basin and its complex hydraulic system, including many dams and irrigation channels. For this purpose, the MODCOU model was used; it is a distributed hydrological model using a conceptual reservoir-based approach. The processing of a digital elevation model first serves as a basis to build the structure that MODCOU needs; the model is then run with basic land-use and meteorological data, which might later be made more accurate through remote sensing data processing. A new function was developed within the MODCOU model to take the large artificial reservoirs into account. The first results provided a reasonable agreement between the measured and calculated flow at the outlet of the basin, and also showed the attention that has to be paid to the complex irrigation system, and to additional improvements that are required to accurately model such a complex system.