In gneiss area of tai - hang mountain of hebei province , the rainfall of each year is small , and the allocation of rainfall is not equality , 80 percent of rainfall is in summer . this is the main reason of drought in this area , which makes the entironment fragiled 河北省太行山片麻岩山区年降雨量小，且雨量分配不均， 80集中在夏季，这是造成该区干旱缺水、生态环境脆弱的主要原因，而干旱缺水已成为限制该区经济发展的最主要因素。
The calculation results show that the method designed is quite satisfactory . the models can reproduce the annual precipitation sequence and monthly precipitation sequence . and then the regional aridity index can be estimated statistically , in addition , they can reproduce the characteristic of history precipitation series 这两类模型分别用于生成模拟年降雨量序列和月降雨量序列作为地区干旱指标序列，从而对所研究地区干旱特征量的统计特性进行估计，并对已发生的地区干旱的重现期进行识别。
Annual precipitation series about 50 years is stable and no period ; further , the climate drying and desertification are n ' t caused directly by the decrease of precipitation during the period of the research according to the relational analysis among precipitation temporal - spatial change , runoff , evaporation , potential evapotranspiration and soil water ; longyangxia reservoir which was built in 1986 does n ' t have influence on precipitation up to now ; but annual temperature series in gonghe is unstable , having a linear upward trend , and it increases about 0 . 0247 , 0 . 0422 and 0 . 0272c per year , and temperature rise must be having an influence on desertification , but there is a very little temperature change , so that the effect is very small ; annual potential evapotranspiration series is stable too , so climate change has little influence on plant water consumption . 2 在青海共和盆地，近50年的年降雨量序列是平稳的、无周期，其时空变化与径流、蒸发、潜在蒸散和土壤水分的关系表明，气候干燥和严重的荒漠化不是由于降雨量减少直接引起，龙羊峡水库对共和盆地年降雨量变化没有影响；但是年气温序列是非平稳的，茶卡、恰卜恰和贵南的年气温平均每年升高0 . 0247 、 0 . 0422和0 . 0272 ，且气温升高2 ，年潜在蒸散增加57mm ，盆地内气候逐渐变干燥，但影响比较小；由于历年潜在蒸散序列是平稳的，因此气候变化对盆地的作物潜在蒸散的影响在研究期内是较小的。
