Spatiotemporal characteristics and obstacle factors identification of agricultural drought disaster risk: A case study across Anhui Province, China

Identifying the spatiotemporal characteristics and obstacle factors of the agricultural drought disaster risk is essential to reduce grain losses and ensure food security. However, due to the high uncertainty in drought disaster risk system, there are few effective risk evaluation and diagnosis methods. In this study, the uncertain information contained in sample data was mined and utilized, and a calculation method of the dynamic difference degree coefficients for the five-element connection number was proposed. Then, a quantitative risk evaluation and diagnosis model was established. Furthermore, the spatiotemporal characteristics and key obstacle factors of the agricultural drought disaster risk across Anhui Province, China from 2008 to 2017 were identified. The results indicated that the risk grades of the connection number values of North Anhui, Central Anhui, and South Anhui in 2008 were 0.359 (high risk), 0.072 (medium risk), and 0.097 (medium risk), respectively, and those in 2017 were 0.103 (medium risk), 0.196 (medium risk), and 0.368 (low risk), respectively. Thus, there were salient spatiotemporal characteristics in which the risk decreased from north to south and tended to decrease over time. In addition, the long-term high risk in North Anhui was due to the severe drought hazard, low forest cover, high exposure to drought, and low drought resistance capacity. The worse risk status in Central Anhui was caused by the small precipitation and water resources amount, low relative humidity, and large agricultural population. The factors inhibiting risk reduction in South Anhui were the large paddy field areas, low reservoir regulation and storage, and fewer water-saving irrigation areas. In summary, this method is effective and exhibits high sensitivity to risk change, and it can be applied to other grain production areas. The results can provide a scientific basis for formulating the targeted measures of agricultural drought disaster risk control in Anhui Province.