基于ArcGIS的晋北黄土高原区典型频率年降水量分布特征研究

Study on distribution characteristics of typical frequency annual precipitation in Loess Plateau of Northern Shanxi Province based on ArcGIS

为了对晋北黄土高原区典型频率年降水量分布特征进行研究,本文选取山西省大同市、朔州市15个县区在1956—2016年间的年降水资料,用P-Ⅲ型曲线进行拟合得出各县区频率为5%、50%、95%的年降水量,并利用ArcGIS软件绘制各典型频率年降水量等值线图。研究结果显示:频率为5%的年降水量由云冈区、怀仁县向东西两侧方向逐渐增大,频率为50%的年降水量由新荣区、云冈区、怀仁县、平城区及云州区西部向东西两侧方向逐渐增大,频率为95%的年降水量主要由左云县向东西两侧逐渐增大;年降水量最大值,除频率为95%的主要位于浑源县外,其余均位于灵丘县;年降水量最小值除频率为95%的主要位于左云县外,其余均位于怀仁县、云冈区以及新荣区。

In order to study the distribution characteristics of typical frequency annual precipitation in the Loess Plateau of northern Shuozhou Province,this paper selects the annual precipitation data of 15 counties and districts in Datong City and Shuozhou City in Shanxi Province from 1956 to 2016,and uses P-ⅲcurve to fit the annual precipitation of 5%,50%and 95%,and draws the isoline map of typical frequency annual precipitation by ArcGIS software.The results show that the annual precipitation with a frequency of 5%gradually increases from Yungang District and Huairen County to the east and west sides,while the annual precipitation with a frequency of 50%gradually increases from Xinrong District,Yungang District,Huairen County,Pingcheng District and western Yunzhou District to the east and west sides,and the annual precipitation with a frequency of 95%mainlyincreases from Zuoyun County to the east and west sides.The maximum annual precipitation is located in Lingqiu County,except that the frequency of 95%is mainly located in Hunyuan County;The minimum annual precipitation is located in Huairen County,Yungang District and Xinrong District except Zuoyun County,where the frequency is 95%.