基于GIS的贵州省玉米干旱灾害风险评估

Risk Assessment about Drought Disaster of Maize in Guizhou Province Based on GIS

基于玉米不同生育阶段降水负距平百分率划分的干旱标准、信息扩算理论计算的干旱发生概率、减产等级以及相应的发生概率,建立了干旱灾害风险模型,结合GIS技术对玉米不同生育阶段干旱灾害风险进行了区划。结果表明:贵州省玉米播种—出苗期旱灾风险从西南到东北方向大致呈现先增加后降低的趋势;出苗—拔节期旱灾风险高,极高风险区主要位于贵州省东北部,中部和西南部为中低风险区,干旱风险从中部到东北部呈现逐渐增加的趋势;拔节—抽穗期旱灾风险从北部至南部大致呈现逐渐增加的趋势,北部风险沿东西方向呈现先增加再降低的趋势;抽穗—灌浆期旱灾风险从西北部至东南部呈现阶梯状逐渐增加的趋势;灌浆—成熟期西部的旱灾风险低于东部,少量地区除外;全生育期旱灾风险呈层状分布,在这种层状分布中,旱灾风险呈现从西北部向东南部逐渐增加的趋势。

Based on the drought standard which was divided by the percentage of precipitation anomaly of various growth stages of maize,the probability of drought occurrence which was calculated through information diffusion theory,the reduction levels and the corresponding probability of the drought occurrence,the risk assessment model of drought disaster was established in the paper. Then,combined with GIS technology,the comprehensive risk division of drought disaster in the different stages of maize was conducted. The results showed： the risk of drought disaster general trended to firstly increase and then decrease from the southwest to the northeast at the sowing-seedling stage of maize in Guizhou Province; at the seedling-jointing stage,high and extremely high risk areas of drought mainly located in the northeast of the province,middle and low risk areas mainly located in the southwest and middle part of the province,and the risk of drought disaster presented a gradual increasing trend from the middle part to the northeast; at the jointing-heading stage,the drought risk presented an increasing trend from the north to the south,the risk in the north of the province firstly increased and then decreased along the northwest direction; at the heading-grouting stage,the drought risk presented a gradual stepped-increasing trend from the northwest to the southeast; at the grouting-filling stage,the drought risk in the west was lower than that in the east,and except a few areas; the risk of drought disaster in the whole growth period presented a stratified distribution,and in this stratified distribution,the drought risk presented a gradual increasing trend from the northwest to the southeast.