Model and simulation of grassland social-ecological system risk assessment: a case study of Yanchi County, Ningxia

To effectively control desertification and reduce the disaster risk of grassland social-ecological systems (SESs), in 2002, China launched a grazing-prohibiting policy in severely desertified areas. At present, a new grazing-prohibiting policy is about to start. Whether the policy needs to be adjusted and how to adjust have become issues that need to be considered. Based on this, Yanchi County, a typical desertification reversal area, was taken as an example to build the grassland SES dynamic model. By adjusting the prohibited grazing time and area, this study assessed the risk of grassland SES. According to the dynamic results: 1) under the current policy, SES resilience will remain stable, and the disaster risk of SES will be gradually reduced; 2) when the prohibited grazing time was 273 days and the grazing time was from June to August, the resilience was the strongest and the disaster risk was the lowest; and 3) by adjusting the prohibited grazing area, when the proportion of grazing prohibition was 100%, the disaster risk was the lowest.