云南高原湖泊洱海流域年降水量时空分布特征研究

为更好地保护洱海生态环境、高效利用水资源和实现湖泊资源的可持续利用提供技术支撑,采用数理统计、趋势法和小波分析等方法,对洱海流域年降水量的地区分布和时空变化,以及年内、年际、多年变化趋势和丰枯变化情况进行分析。研究结果表明:洱海流域年降水量由南向北、由西向东递减,在流域西部和北部,降水量受地形影响较为明显,随高程升高而增大,垂直变化较为显著;全年降水量主要集中在5—10月,占全年降水量的84.9%~93.2%,说明该时段降水量较大程度地决定了年降水量,每年11月至次年4月降水量仅占全年降水量的6.8%~15.1%,最大月降水量出现在7月或8月,最小月降水量出现于12月;洱海流域年降水量年际变化相对较稳定,但呈逐年减少趋势;并存在丰→枯→丰等多个循环交替。

Study on spatiotemporal distribution characteristics of annual precipitation of Erhai Basin

In order to protect the ecological environment better, take advantage of water resources efficient-ly, and achieve sustainable use of lake resources of the Erhai Lake, we use the methods of mathematical statistics, trends and wavelet analysis to analyze area distribution, spatiotemporal change, change trend dur-ing the year and interannual change trend of the annual precipitation in the Erhai Lake basin.The results show that the annual precipitation in the Erhai Lake basin decreases from south to north, and from west to east.The precipitation is evidently affected by terrain and it increases with altitude in the north and west of the basin.The precipitation mainly concentrates in May to October, and it accounts for 84.9%~93.2% of the annual precipitation.The precipitation in November to April in the following year accounts for only 6.8%~15.1% of the annual precipitation.The maximum monthly precipitation occurs in July or August, and minimum monthly precipitation occurs in December.The interannual change of the annual precipitation in the Erhai Lake basin is relatively stable, but the trend decreases year by year.There are many cycles of the annual precipitation, such as abundance, drought, and abundance.