内蒙古草原生长季干旱预测统计模型研究

Study on statistic models of drought prediction for grassland in Inner Mongolia

选取蒸降差作为草原干旱指标,利用内蒙古自治区的20个站点1971-2004年的逐日气象资料和相关的土壤水分及牧草产量资料,建立生长季4-9月逐日统计预测模型,并进行了30年的回代检验和4年的试报检验,结果表明:各月逐日统计预测模型均能较好地模拟出草原蒸降差的变化趋势,其中4-8月统计预测模型(R2≥0.96),回代检验和试报检验的平均相对误差均在10%以内,准确率均在90%以上,有较强的实用性,9月逐日统计预测模型相关系数较低,模拟偏差较大,这可能与对异常气候事件、大气环流、未来气候背景、生物与非生物因素等与草原干旱的因果关系考虑的不够深入有关。

Using evapotranspiration and precipitation as drought index, statistic models of growth season from April to September were founded based on 34 years＇ daily data from 1971 to 2004 from 20 weather stations and other factors related to soil moisture and pasture yield in Inner Mongolia, 30 years＇return test and 4 years＇ trial forecast were also conducted. The results showed that daily statistical prediction model was able to better simulate trends of difference between evapotranspiration and precipitation. And by return test and trial forecast, the mean relative errors of April to August model mate, biological and non-biological factors and grassland drought.