Analysis Of Spatial And Temporal Differentiation And Vulnerability Of Agricultural Meteorological Drought In Henan Province From 1960 To 2016a.

In the context of increasing global warming trends,agriculture is the most sensitive area affected by climate change.China is not only an agricultural country,but also a country with frequent drought disasters.Henan province is a major agricultural province and has great significance in ensuring food security for China.However,in recent years,meteorological disasters have been frequent,especially the meteorological drought caused by the precipitation reduction,has had a great negative impact on agricultural production in Henan province.Due to the large number of agricultural population in Henan province,agricultural meteorological drought has become a major meteorological disaster affecting the production and livehood of people in this region.Therefore,to explore the development pattern of drought in historical period in Henan province,it is very important to mitigate the negative influence on agriculture by drought,reduce the vulnerability of agricultural drought,further to ensure that farmers livehood,food production and food security,promote agricultural sustainable development and the rise of central China.Based on a large number of related literatures,this paper mainly focuses on two aspects:First,to explore the definition of agricultural meteorological drought.Based on the definition of drought index and establishment of drought index system,the development law of agricultural drought in Henan province is analyzed and studied.By means of ArcGIS spatial analysis technology,the spatial and temporal distribution characteristics of agricultural meteorological drought in Henan province were analyzed from the perspective of the whole and the seasons.The occurrence frequency,intensity and influence range of agricultural drought in Henan province were discussed.Second,according to the regional disaster vulnerability theory,agricultural drought disaster is formed by the combination of droughtand agricultural drought vulnerability.Drought vulnerability is the root reason that causes drought disaster.Therefore,the article focuses on the sensitivity and resilience of agriculture,according to the study area condition.17 vulnerability evaluation indexes are selected from the natural and socio-economic perspectives.The evaluation system and mathematical model of agricultural drought vulnerability in Henan province were constructed by entropy method and weighted comprehensive scoring method.Finally,using ArcGIS technology,the spatial quantitative analysis of the vulnerability assessment structure of Henan province is acomplished.According to the preliminary study,the following conclusions are drawn:(1)In Henan province,near 57 a,the occurrence frequency of agricultural meteorological drought is high.The scale of the disaster is large,and the drought is mainly regional.The duration lasts long.And the geographical difference of occurrence frequency of agricultural meteorological drought is obvious.(2)The drought distribution has some time difference and spatial mobility.In time,the seasonality is obvious,and there are more spring dro1 ught and summer drought.From the intensity of drought,spring and summer drought and severe drought;the decadal space difference is significant.In space,occurrence frequency of agricultural meteorological drought in the west of Henan province is severer than the east region,and occurrence frequency of agricultural meteorological drought in the north of Henan province is severer than the south region.In addition,the seasonal difference is also obviously,the spring drought is mainly distributed in the northern and western regions of Henan,while the summer drought is mainly distributed in the western and eastern regions.The intergenerational characteristics are significant,there is an obvious east-west upward shift between generations,there is a certain similarity between the distributions of drought in the decadal.(3)Entropy method is used to calculate the objective weight of 17 vulnerability indexes.The data of 2000 and 2015 were selected for comparative analysis,it can be seen thatagricultural drought vulnerability in Henan province is affected by sensitivity factor and recovery factor.But overall,the influence of the sensitivity factor is decreasing,and the effect of recovery factor is increasing.(4)In this paper,the weighted comprehensive scoring method is used to construct the mathematical model.Calculated the vulnerability of 110 counties and cities in Henan province in 2000 and 106 counties in 2015,it is divided into four levels: mildly fragile zone,moderately fragile zone,severe fragile zone and extremely severe fragile zone.Comparative analysis shows that the vulnerability of Henan province in 2015 is lower than that of 2000.It shows that the drought vulnerability of Henan province shows a decreasing trend.In particular,in the year 2000,Henan province as a whole was highly vulnerable and the vulnerability was significant,it is subject to extremely serious and severe fragile areas.In space,western Henan is higher than eastern Henan,and north of Henan is higher than Henan.In terms of quantity,compared with 2000,2015 shows a significant reduction in the extremely serious and vulnerable areas,and the increase in the moderately vulnerable areas and the mildly vulnerable areas.(5)Based on the analysis of spatiotemporal characteristics and vulnerability assessment of agricultural meteorological drought in Henan province,to adjust agricultural production structure according to local conditions,control population density,strengthen economic development and increase investment in agriculture,etc.Continuously reduce the sensitivity of Henan agriculture,improve its recovery,in order to effectively resist drought disaster and impact on agriculture,promote the rise of central plains and guarantee regional and national food security.