内蒙古东北部牧区近30年蒸发量变化特征分析

利用内蒙古东北部呼伦贝尔市牧区4个站1971~2000年20 cm口径的蒸发量资料,采用线性趋势、距平等方法,对30年来内蒙古北部牧区蒸发量的变化特征、异常特征和水分盈亏地表状况进行了分析。结果表明,30年来内蒙古北部牧区年平均蒸发量为1503.5mm,四季中夏季的平均蒸发量最多,其次是春季和秋季,最少的是冬季。内蒙古东北部呼伦贝尔市牧区过去30年蒸发量虽然季节变化的幅度变化剧烈但总体呈现减少趋势,其倾向率为-59.7 mm/10a;四季倾向率春季和冬季为正值,蒸发量最多的是5月份,最少的是1和12月,各月蒸发量均有不同程度的上升趋势。

Characteristics of Evaporation Changes in Northeast Pastoral Areas of Inner Mongolia in Recent 30 Years

Using evaporation capacity data of 4 stations in northeast pastoral areas in Hulunbeir City in 1971-2000,this paper analyzed characteristics of changes in evaporation,abnormal characteristics,and water surplus and deficiency and surface conditions by linear trend and anomaly methods.Results indicated that average evaporation capacity of northeast pastoral areas in Inner Mongolia in recent 30 years is 1 503.5 mm.In the whole year,the highest evaporation capacity appears in summer,the next is spring and autumn,and the lowest is winter.Changes of evaporation capacity in recent 30 years are sharp,but the overall trend is decline,with the inclination rate of-59.7 mm/10a.For the four seasons,the inclination rate is positive in spring and winter.Among 12 months,the highest evaporation capacity appears in May,and the lowest is January and December.The evaporation capacity of every month has certain ascending trend.