基于 Mann-kendall法的嘉陵江流域降水量时空分布规律

选取嘉陵江流域11个气象站点经过处理的1961-2015年月降水量数据资料,以Mann-kendall非参数检验方法为主,分析嘉陵江流域降水量时空分布特征,为其水资源检测、评估和防治提供一定理论依据和基础.结果表明:(1)嘉陵江流域近55年年均降水量为977.7mm,整体上呈现出下降的趋势(Z=-0.56),且存在多个突变点;(2)降水量在春季和秋季均呈减小幅度,秋季最为明显(Z=-1.35),且主要集中在夏季,约占全年降水量的48.3%;(3)年均降水量空间分布总体表现为自东南向西北地区逐渐减少.遂宁地区降水量春季减小幅度最大(Z=-1.86),夏季上升最为明显(Z=2.49),秋季除武都地区增加(Z=0.21),其余地区均呈减小趋势,冬季巴中地区降水量上升幅度最大(Z=1.00).研究降水量的变化,预测和防治流域内旱涝和泥石流等气象灾害的发生,并在一定程度上预测未来气候变化趋势具有重要的意义.

A Mann-Kendall Method-Based Study of the Temporal and Spatial Distribution of Precipitation in the Jialing River Basin

In order to provide some theoretical foundation for water resource detection and evaluation and for meteorological disaster prediction and prevention, the monthly precipitation data of 1961-2015 from 11 meteorological stations in the Jialing River Basin were selected and the Mann-Kendall nonparametric test method was used to analyze the temporal and spatial distribution of precipitation in this area. The results showed that the annual mean precipitation in the Jialing River Basin was 977.7 mm in the past 55 years (1961-2015), and it exhibited a decreasing trend (Z=-0.56). And there were multiple mutation points in precipitation. The precipitation in summer and winter showed a moderate upward trend, and the precipitation was mainly concentrated in summer, accounting for 48.3% of the annual precipitation; and the precipitation in spring and autumn showed a downward trend, being the most significant in autumn (Z=-1.35). The spatial distribution of the annual precipitation in the Jialing River Basin was uneven, increasing gradually from the southeast to the northwest. In Suining, the precipitation showed a decreasing trend in spring (Z=-1.86) and a significant rising trend in summer (Z=0.249). In autumn, the precipitation in all areas showed a decreasing trend except in Wudu, where autumn precipitation increased (Z=0.21). In winter, the precipitation in Bazhong area showed the greatest increase (Z=1.00).