基于GIS下的旱地马铃薯干旱风险区划技术探讨

通过榆中县马铃薯逐年减产率与实测资料计算出的马铃薯不同生育时段的农田蒸散 量进行线性回归分析，建立干旱监测模型。以减产率农业干旱指标等级⑴为标准，通过干旱监 测模型计算出马铃薯的农田蒸散量农业干旱指数，用此指数统计马铃薯不同生育时段干旱等级 的发生概率，用Pearson-Ⅲ频次密度函数⑵统计出马铃薯全生育期不同重现期的各乡镇减产率， 最后利用GIS 空间分析模块绘制马铃薯干旱等级概率分布图、不同重现期下的减产率分布图、不 同干旱等级风险区划图。

Discussion on the risk zoning of potato drought in dry land based on GIS

Based on the linear regression analysis of potato yield reduction and measured potato evapora? tion at different growth periods in Yuzhong County, a drought monitoring model was established. Based on the agricultural drought index grade 1 of yield reduction rate, the agricultural drought index of potato field evaporation was calculated by drought monitoring model, and the occurrence probability of potato drought grade in different growth periods was calculated by using this index. The probability distribution map of potato drought grade was drawn by using Pearson- III frequency density function 2 to calculate the yield reduction rate of potato in different recurrence periods during the whole growth period. Finally, the probability distribution map of potato drought grade was drawn by using GIS spatial analysis module. Different reappearance The distribution map of yield reduction rate and the risk zoning map of different drought grades.