China's regional vulnerability to drought and its mitigation strategies under climate change: Data envelopment analysis and analytic hierarchy process integrated approach

Climate change makes extreme droughts more frequent with heavy economic losses in China, thus this study aims to evaluate China's regional vulnerability to drought and propose proper mitigation strategies for drought-vulnerable areas. In this paper, an integrated index containing exposure, sensitivity and adaptive capacity is developed to measure regional vulnerability to drought, and it is calculated by the integrated approach which combines slacks-based measure (SBM) model in data envelopment analysis (DEA) with genetic algorithm-based analytic hierarchy process (AHP). Accordingly, 65 cities in Anhui, Henan, Jiangsu and Shandong provinces of China are chosen as the study area. The results show that Anhui and Henan are more vulnerable to drought, and the proportions of cities with inefficient resilience to drought in the two provinces are 64.7% and 55.6% respectively. Compared with coastal areas, the inland regions have more drought-vulnerable cities. In addition, the cities in the south are less vulnerable to drought than those in the central and north regions. Meanwhile, we conclude that the integrated index can measure the efficiency of resilience to drought and reveal the causes of drought vulnerability. It also indicates that adequate investments in drought preparedness and promotion of water efficiency are the crucial ways for drought vulnerability reduction. Finally, this study proposes some policy recommendations to alleviate the impacts of drought under climate change.