中国天山山区降水形态转变的驱动因子辨析

Discrimination of driving factors of precipitation forms in Tianshan Mountains area of China

利用天山山区1960-2017年18个气象站点的逐日降水、平均气温、相对湿度、平均气压、平均风速、日照时数、小型蒸发、海拔、坡度、坡向、经度和纬度资料,通过分离主要降水形态、计算表征降水形态转变态势的降雨日数/降水日数比率(RPR),以及构建影响因子指标体系,并采用BP神经网络改进的决策与试验评价实验室法(BP-DEMATEL)和多元线性回归模型(MLR),辨析了天山山区降水形态转变的驱动因子。主要结论如下:12个指标因子中,气温是BP-DEMATEL模型中唯一的强驱动因子,同时在MLR模型中气温的贡献率也最大,表明气温是影响天山山区降水形态转变的关键驱动因子,其次,地表温度、海拔、纬度和气压是影响降水形态转变的次要驱动因子。

Major precipitation forms were separated by using daily precipitation,average temperature,relative humidity,average pressure,average wind speed,sunshine hours,small evaporation,elevation,slope,aspect,longitude and latitude data from 18 meteorological stations in the Tianshan Mountains area from 1960 to 2017 Morphology,rainfall days/precipitation day ratio(RPR)was calculated,and impact factor indicator system was constructed.Key driving factors of precipitation forms transformation in the Tianshan Mountains area were discriminated by using decision-making and experimental evaluation laboratory method(BP-DEMATEL)improved by BP neural network and multiple linear regression model(MLR).The main conclusions are as follows:Among the 12 indicators,temperature is the only strong driving factor in the BP-DEMATEL model,and the contribution rate of temperature in the MLR model is also the largest,indicating that temperature is the key driving factor affecting the precipitation forms transition in the Tianshan Mountains area,surface temperature,altitude,latitude and pressure are the secondary driving factors affecting the transformation of precipitation forms.