The Agriculture Drought Risk Assessment And Regionalization In Ningxia

Global warming has become an indisputable fact. Drought is the main climatic characteristics of the northwest China, and the response of the northwest to climate waring is more sensitive. Though the drought problem of this region worth widspresd concern. Ningxia has less and undulating precipitation because of it located inland and away from the sea, so the frequency of drought is very high in this area. Agriculture plays a decisive role in China, and severely depends on natural condition. With the increase of extreme weather events caused by climate change, the losses brought by meteorological disaster, especially drought, to agriculture is increasing. In this context, it is significance to assessment the risk on agricultural drought risk on the region of Ningxia for guide the local agriculture to take appropriate prevention and mitigation measures.On the foundation of the previous disaster science research, generally, the drought disaster system includes disaster inducing factor, disaster-affected body and disaster-pregnant environment. Based on the above theory, applying the spatial analysis faction of ArcGIS, considering a number of factor including precipitation, socio-economic condition, landuse patterns, topography and soil type, this paper analyzed the law of meteorological drought in Ningxia, combined with agricultural drought risk, vulnerability and sensitivity to assessment and to regionalization the agricultural drought risk of year and sensons in Ningxia. The results show that:(1) The average frequency of meteorological drought of Southern mountainous> Central arid zone> Yellow Rever Irrigation in Ningxia. The seasonal average drought intensity of winter> summer> autumn> spring. The drought intensity shows a slight upward trend in spring and winter, though the drought intensity show a downward trend in summer and autumn festival, and the trend was more evident in autumn.(2) The year-scale agricultural drought hazards degree of Ningxia show significant northeast-southwest of differentiation in space. The hazard continues to reduce from northwest to southeast. The four seasons of drought hazard degree showing a different law in space distribution.(3) The drought vulnerability of Ningxia map shows a north-south differentiation law, in which low vulnerability areas include most of the centeral and north region. The parts of medium vulnerability areas are mainly related to the most of the Yanchi, Zhongning, Zhongwei and the part of Guyuan. The central arid zones include of Tongxin, Haiyuan and the southern mountain are the high vulnerability areas.(4) Taking into account three factors including slope, aspect and soil water holding capacity, the agricultural drought sensitivity generally show that the northern sensitivity level of distribution is more concentrated, and the southern region has a high degree of fragmentation, but the sensitivity grade level has no significant differences.(5) The agricultural drought risk in Ningxia presented obvious north-south difference. The low-drought area is mainly located in the Qingtongxia Irrigation because of its advanced economy, good irrigation condition and flat terrain. And next came Weining Irrigation. While the high-risk area include the loess hilly region with fragile ecological environment that most of ground covered by the dry-field and the southern mountainous area that has more precipitation but backwardness economy. The results of assessment and district accord with actual situation of the local disaster. Finally, considering the causes of drought and the difference of the regions of Ningxia,this paper bring forward the corresponding prevention and mitigation measures.