曹江中上游流域水文要素的气候变化特征

Climate Characteristics Change of Hydrological Elements in the Middle and Upper Reaches of the Cao River Basin

受气候变化影响,流域水文循环特征变化显著。基于曹江流域降水径流水文循环要素,6个雨量站和1个水文站近50 a的实测水文数据资料,运用小波周期分析、Mann-Kendall检验等相关分析方法,分析曹江流域水文循环要素的稳定性、趋势性及周期性等气候变化特征。结果表明流域内降水的相对变率比较小,均在18%以下,降水相对比较稳定,但是流域内的降水有较强的分布不均匀性;流域内各站点的年降水量大多数站点呈增加趋势,但增加趋势均不显著;同时流域暴雨和特大暴雨日数增加;典型站点年降水量存在28 a的主周期;径流量存在21~29a的主周期。综合降水趋势和周期分析,曹江流域现在正处于降水量的偏少期,预测曹江流域将很快进入下一个降水偏多期阶段。

Affected by climate change, hydrological cycle elements river basin changes significantly. Based on characteristics of hydrological cycle elements Cao River basin and the measured data of 6 precipitation stations and 1 hydrological station about nearly 50 years, using periodic wavelet method, Mann Kendall test and other analysis methods the stability, trend and periodic variation characteristics of hydrological cycle elements Cao River basin have been analyzed. The results show that the relative change rate of precipitation within the basin is relatively small, below 18%, which is relatively stable while the precipitation is along with strong in homogeneity; The annual precipitation of most sites in the watershed has a trend of increase, which is not significant; The rainstorm and heavy rainstorm days in the watershed were increased; The main period of annual precipitation in typical stations is around 28 years; as for runoff is 21 ~ 29 years. Integrating the analysis of precipitation trend and precipitation cycle, the Cao Jiang river basin is in the precipitation of the partial few periods now, predicting it will soon enter the next phase of partial multiple periods.