Risk assessment of maize drought hazard in the middle region of farming-pastoral ecotone in Northern China

Abstract

Global warming has drawn great attention in recent years, and the resultant extreme drought events have seriously influenced food security. Drought hazard has become a major stress factor for food production in China. The present study aimed to assess the drought hazard risk of maize in middle region of farming-pastoral ecotone of Northern China using spatial maize drought hazard intensity index. The drought hazard intensity index model was set up based on the output variable water stress of environmental policy-integrated climate model and yield loss contribution rate α of water stress in each growth stage. The yield loss contribution rate α is calculated based on the relationship between the water deficit in different stages and the yield loss. Added with the spatial data in time series, results are used for risk assessment. It shows that the tendency of maize drought hazard intensity index was increasing from 1966 to 2011 and was becoming significant after 1996. The volatility is becoming stronger, especially in central basin and northwestern plateau of the study area. The extreme drought events were more frequent. The degree of maize drought was aggravated, and scope of influence was extended after 1999. And the risk of drought hazard is relatively high in the study area, especially in the central basin. In conclusion, this paper presents an effective way to analyze maize drought hazard risk. For the middle region of farming-pastoral ecotone in Northern China, the seriously increasing maize drought hazard is demonstrated by the temporal and spatial analyses and the probability distribution of maize drought hazard intensity index, which presents its sensitivity to climate change and its representativeness to the study of agricultural drought hazard.