Attributing the Changes of Water Availability for Haihe Basin, China

Código

I-EBHE0225

Autores

Xingguo Mo

Tema

WG 1.02: Decomposing Complexity

Resumo

To quantify a basin's water availability and attribute its changes is important for water resource management and planning. However it poses challenges by the complicate mechanisms involved if both human activity and climate change act to the basin dramatically, such as in the Hai River Basin, the cultural, political and economic center of China. The VIP (Vegetation Interface Processes) distributed dynamic eco-hydrological model is established for Haihe basin to simulate the temporal evolution and spatial pattern of water availability. The factor separation method is used to attribute its changes. Since the start of this century, the urbanization area in the Haihe River basin has seen an increase by more than 30%, with the impervious area increasing especially evident. At the same time there was a serious drawn down of groundwater under the pressure of high irrigation demand for winter wheat - summer maize, the traditional main cropping system in the basin, and low water supply capability from surface water. To adapt to these challenges, there have been more dry lands turning into forest and grassland. The greenness of natural vegetation in the basin has also increased in recent decades, which is enhancing the ecological water consumption. Furthermore, the intensity and frequency of extreme hydroclimatic events have changed under climate change in the basin. Changes in climate and environment will inevitably lead to changes in eco-hydrological processes in the basin, which will affect the availability of water resources and their spatial and temporal distribution. There are many uncertainties in understanding and prediction of its change characteristics. In this study the above issues have been taken into account by the VIP model, the changes in vegetation ecological water demand and available water resources in the basin are predicted, the water resource security risks in the basin is projected. The answer to such questions as how much of the change of water availability is from natural vegetation areas for example will provide a basis for decision-making for the ecological security and sustainable development in the water limited basin.