福建省降水资源时空变化特征分析

Analysis of spatial and temporal characteristics of precipitation resources in Fujian

降水是十分重要的水资源之一,加强气候变化背景下区域降水的变化特征研究具有重要意义.利用1961—2015年福建省66个县市区逐年降水量数据资料,应用线性倾向估计、显著性检验、突变检测等气候统计与诊断技术,对福建省近55年年降水时空变化特征进行分析,运用Arcgis地理信息软件对其降水空间特征进行区划和演示.结果表明,福建省年际及年代和区域降水分布都极不均匀,年降水量呈略增趋势(递增率为34.11 mm/10 a),但变化趋势不显著;季节降水春雨最多,秋雨最少,月降水存在单峰与双峰型两种结构;年降水在1980年发生突变.降水的地域分布呈现东南部向西北部、东北部递增的特点,福建降水分布与其地形和天气系统影响关系密切,降水与海拔呈显著正相关,各县市降水变化分布也不一致,中部变化小,沿海变化大.1961—1990年,大部分年份降水为负距平,干旱多发,1991年以后,大部分年份降水为正距平,洪涝多发,距平振幅加大,降水更不稳定,发生洪涝或干旱的不确定性和风险性加大.

Precipitation is one of the most important sorts of water resource,thus strengthening the variation characteristics of regional precipitation in climate changes is of great significance.By applying Linear tendency estimation,significance test,mutation test,and other climatologically statistic diagnosis techniques to the annual precipitation records of 66 counties in Fujian from 1961 to 2015,the spatial-temporal variations of annual precipitation Fujian in recent 55 years can be analyzed.ArcGIS has been used to zone on the basis of spatial characteristics of precipitation and demonstrate.The results indicated that inter-annual precipitation distribution,inter-decadal precipitation distribution,and regional precipitation distribution were all inhomogeneous.The annual precipitation showed a slightly increasing trend(with 34.11mm/10a growth rate),but the trend was not significant.In terms of seasonal precipitation,rainfall tends to be concentrated mostly in spring and least in autumn.Both single peak structure and double-peak structure occur in monthly precipitation,and there was an abrupt change in annual precipitation in 1980.In terms of regional distribution of precipitation,the precipitation increases from southeast to northwest and southeast to northeast.The precipitation distribution was closely allied to synoptic system and terrain influence.The precipitation was correlated positively with the increase of altitude.Different counties and cities had different precipitation variation distribution.Such changes were small in central areas while great in the coastal areas.From 1961 to 1990,the precipitation was negative anomaly in most years,and there were droughts frequently.Since 1991,the precipitation was positive anomaly in most years,and there were floods frequently.With the amplitude of anomalies increasing,precipitation became unstable,the uncertainty and risk of floods or droughts occurrence would be increased.