Retrospective Evaluation of the Vulnerability of Watershed Sustainable Water Development Using a Time-Series-Based Space Geometry Model: Xiang Jiang Watershed, China

Abstract

The ability to retrospectively evaluate the vulnerability of a watershed can identify potential risks influencing sustainable water development over time. More importantly, the effect of watershed management policies can be evaluated to help government assess and improve current policies. In order to identify vulnerability factors and evaluate the vulnerability state of a watershed, this paper proposes a time-series-based vulnerability analysis framework that integrates several approaches and methods, including: (1) a combined driving force-pressure-state-impact-response (DPSIR) and hydrology-environment-life (HEL) framework for the selection and classification of evaluation parameters; (2) the coefficient of variation method to determine the weights of the evaluation parameters; and (3) the space geometry model to determine the vulnerability level. In addition, the paper describes a robustness analysis that was performed to evaluate the impact of changing the evaluation parameters on the results. A case study of the Xiang Jiang watershed in China is presented; empirical analysis showed that hydrologic vulnerability experienced large interannual variations. The environmental vulnerability of the Xiang Jiang watershed is subject to a high level of risk, whereas the living vulnerability is subject to a low level of risk. Despite many challenges, Xiang Jiang watershed water development is sustainable; this was determined based on the decreasing trend of total vulnerability. The findings demonstrated the effectiveness of the local government’s policies for watershed management. Moreover, the results of the robustness analysis showed that the proposed vulnerability analysis framework was adaptable to using slightly different evaluation parameters in cases in which data for the proposed parameters are not readily available. The proposed framework can be used by local governments and decision makers to effectively manage the sustainable development of watersheds.