南流江流域降水序列周期特征及变化趋势

降水序列的变化规律和变化趋势是流域防洪抗旱时需要考虑的重要问题。以北部湾经济区南流江流域为例,尝试利用小波分析和R/S分析方法研究年降水量周期特征和变化趋势。研究结果表明:在短周期范围内,南流江上游流域具有3~8a的主周期,未来年降水量出现减少的趋势;中游流域具有3~8a的主周期,未来年降水量出现增加的趋势;下游流域具有5~8a的主周期,未来年降水量出现增加的趋势。因此,未来短期内南流江干流的防洪重心主要在于中下游流域,需要预防突发性降雨。

Analysis on Period Characteristics and Variation Trends of Rainfall Series in Nanliujiang River

Attention should be paid on variations and trends of rainfall series before basic flood control and drought relief. By taking the Nanliujiang river basic of Beibu gulf economic region as an example, this paper used wavelet analysis and R/S analysis to research the period characteristics and variation trends of rainfall series. Studies were discussed for flood control scheduling in the range of short period. The results of wavelet analysis and R/S analysis showed that upper reaches of Nanliujiang river had an obvious period about 3 or 8 year, the annual rainfall is tending to decrease in the future; that middle reaches of Nanliujiang river had an obvious period about 3 or 8 year, the annual rainfall is tending to increase in the future; that lower reaches of Nanliujiang river had an obvious period about 5 or 8 year, the annual rainfall is tending to increase in the future. It was concluded that the flood control focuses on the middle and lower reaches of Nanliujiang river, but also need to prevent unexpected rainfall.