环青海湖地区草地蝗虫发生测报的气候指标研究

采用次序统计量方法,以1988～1999年环青海湖地区草地蝗虫发生程度资料和气候资料研究了蝗虫灾害等级与当地气候指标的定量关系,建立了春季和夏季预测模型,并以此对2000～2003年该地区蝗虫发生状况进行了预测试验。结果表明,敏感气候因子有:上年11～12月气温、3～6月温度及5～6月降水量等。春季预测模型中的指标为:(1)T11<-6℃;(2)T12<-10℃;(3)T3>-4℃;(4)T4>2℃。夏季预测模型中的指标为:(1)(T11+T12)/2<-8.5℃;(2)(T3+T4)/2>-1.5℃;(3)(T5+T6)>7.5℃;(4)(R5+R6)<48mm。当模型中有3个或4个指标满足,则当年可能发生严重蝗虫灾害,当没有或只有1～2个指标满足,则不会发生严重蝗虫灾害。

Climatic predictors for infestation of rangeland grasshoppers in the areas around Qinghai Lake

Climatic predictors for infestation of rangeland grasshopper (IRG) in the areas around Qinghai Lake were investigated by means of order statistics. IRG was sensitive to the following climatic factors, i.e. the temperature from November to December in the previous year (T11T12), from March to June in the present year (T3T6) and the precipitation from May to June (R5R6). The four indices for spring model are: a. T11<-6; b. T12<-10; c. T3>-4; d. T4>2. The four indices for summer model are: a. (T11+T12)/ 2<-8.5; b. (T3+T4)/ 2>-1.5; c. (T5+T6)>7.5; d. (R5+R6)<48mm. Severe grasshopper disaster may take place if 3 or 4 of the above-mentioned indices are satisfied. Slight or no grasshopper infestation will happen if 0 or 1 of the indices is satisfied, or otherwise, a moderate grasshopper infestation may be seen.