六安市近45年来降水量空间分布研究

为了进一步探明六安市降水量空间分布的特征,主要采用基于Arc GIS的Kriging插值法,对六安市近45年来的逐日降水量数据进行处理,得到各季节、年均和汛期多年平均降水量的空间分布图表,并分析了降水量的空间分布特征及其特异性原因。结果表明:六安市秋冬两季各地降水量差异不大,春季降水量从南向北、从西向东分别受到纬度和地形的影响,逐渐减少,夏季降水量受地形影响从西南向东北骤减,西南山区两县降水量较多,达到600 mm;年降水量整体上由西南向东北减少,即越靠近大别山腹地降水量越大,达到1 370 mm,南北相差达470mm,但在山区和平原地带内部变化不大;汛期降水也是自西南向东北递减,但降水集中系数却在南部地区自西向东递减,降低至0.56,然后向北部地区突增,达到0.67。说明六安市北部年内降水量变率大,这是受到地形与雨带的进退速度和时间等因素的综合影响。

Study on spatial distribution of precipitation in Lu'an for recent 45 years

In order to study the characteristics of spatial distribution of precipitation in Lu'an, the paper used Kriging interpolation method based on ArcGIS, and mainly to dispose the daily precipitation data in recent 56 years of lu'an.Then it got the rainfall spatial distribution and analyzed the spatial distribution characteristic of all seasons, average annual precipitation and flood season precipitation. The results show that the precipitation difference of autumn and winter in Lu'an is unobvious.The spring precipitation gradually reduces from south to north nd from west to east because of the influence of latitude and terrain. In summer, the precipitation is mainly influenced by terrain drops sharply from southwest to northeast. In southwest mountainous area, the precipitation is up to 600mm;the spatial distribution of annual precipitation reduces from southwest to northeast. The closer to the Dabie mountain hinterland, the greater the rainfall is.The most precipitation reaches 1370 mm,the difference is 470mm. But in the mountains and plains belt,the falling gradient is low;the spatial distribution of precipitation in flood season also reduces from southwest to northeast, but the precipitation concentration efficiency reduces from west to east in south area, which reduces to 0.56 and then jumps to 0.67 in northern region. The result indicated that the inner-year variation of precipitation is great because of the influence of speed and time of terrain and rain belt.