Risk Assessment Of Spring Wheat Drought Disaster In North Xinjiang

In the context of global warming,drought has been a widespread and serious natural disaster for a long time,and its impact on human life is getting more and more serious.Especially in agricultural production,its impact is extremely obvious and severely restricts local economic development.As our country’s main grain producing area,the northern Xinjiang region is affected by drought to varying degrees due to global warming.Therefore,it is of great practical significance to conduct drought risk assessment on spring wheat,one of the main crops in the region.Based on 1961-2016 meteorological data and spring wheat growth data from 26 major weather stations in northern Xinjiang,using the Penman-Monteith formula recommended by the FAO and the adjusted relevant crop coefficients,we explored the crop water requirements and irrigation water requirements at each growth stage of spring wheat Climate response to changes;using the water deficit index model,combined with historical drought data records in Xinjiang,analyze the inter-annual variation of the drought intensity at each growth stage of the spring wheat in northern Xinjiang from 1986 to 2016,the inter-annual variation of the drought’s impact range,and the temporal and spatial distribution characteristics of drought frequency;The principle of natural disaster risk starts from the four factors of hazard,exposure,vulnerability and disaster prevention ability,introduces weight coefficients,and uses the analytic hierarchy process to determine the different degrees of impact of the four factors on the occurrence of spring wheat drought disasters in northern Xinjiang.Establish a drought disaster risk assessment model and carry out drought risk zoning for spring wheat in this area.Research indicates:(1)From 1961 to 2016,the spring wheat crop water requirement and irrigation water requirement in northern Xinjiang showed a decreasing trend.Among them,the crop water requirement and irrigation water requirement were the largest during the heading-milk stage,and the crop water requirement decreased during the jointing-heading stage.The trend of irrigation water demand is most obvious,and the decline in irrigation water demand is most obvious during the milky-mature period.Meteorological factors have a strong correlation with the water demand and irrigation water demand in each growth period of spring wheat.The influence of precipitation is the most significant.The average relative humidity is the second most affected.(2)From 1986 to 2016,except for the parallel stage of spring wheat vegetative growth and reproductive growth,the range of drought affected by drought showed a slight increasing trend,while the drought intensity and range of drought in the other growth stages showed a downward trend.Severe drought and extreme drought affected the vegetative growth of spring wheat.The frequency of concurrent reproductive growth is the highest,and the frequency of mild and moderate drought is the highest in the reproductive growth phase of spring wheat.During the vegetative growth phase of spring wheat,the frequency of severe drought in northern Xinjiang is higher than that in other regions,and the vegetative growth and reproductive growth of spring wheat are in parallel.In the northeastern part of northern Xinjiang,the frequency of severe drought and extreme drought was higher.In the reproductive growth stage of spring wheat,the frequency of severe drought in the southwestern part of northern Xinjiang was higher than that in other regions;the frequency of severe drought in the northern part of Xinjiang was higher in spring wheat growth.In the three growth stages,except for the reproductive growth stage,the frequency of moderate drought was the highest.The frequency of severe drought in the other two periods was higher than that of other grades,while the frequency of extreme drought was the lowest.(3)The spring wheat drought high-risk zone and the second-high-risk zone in northern Xinjiang are mainly located in the eastern part of the Altay region,the southern part of the Tacheng region and most of Changji Prefecture;the high-exposure zone and the second-high-exposure zone are located in Qinghe County of the Altay region;the high vulnerability area is mainly located in the west of Bozhou and Tacheng areas,the second-highest vulnerable area is located in the northwest of Altay and Tacheng areas and most of the Yili area;except for the southeastern part of Yili area,the middle part of Tacheng area,and most of Changji Prefecture,which are areas with moderate disaster prevention capabilities,the rest are areas with second-high disaster prevention capabilities.The high-risk areas and second-high-risk areas of spring wheat in northern Xinjiang are concentrated in the north-central part of the Altay region;the medium-risk areas are mainly located in Hebuksail County and Shawan County in the central part of Tacheng area,low-risk areas and sub-low-risk areas are distributed throughout the Yili area,most of Changji Prefecture,the western part of the Tacheng area and the eastern part of the Altay area.