以标准化降水指数(SPI)为工具,以鄱阳湖流域为研究对象,选择流域内13个气象站共50a的逐月降水量和5个水位站共50a的逐日水位为实验数据,通过Mann-Kendall检验方法和Kriging插值方法,分析了鄱阳湖流域干旱的时空演变特征,以Spearman秩相关系数为评价指标,比较了流域不同时间尺度的SPI值与各站湖水位、不同时间尺度干旱强度与各站年最低水位之间的相关程度.研究表明:鄱阳湖流域的干旱具有明显的季节性特征,春季和秋季具有较为明显的干旱化趋势;鄱阳湖的干旱覆盖面较广,干旱在不同区域内的不同时期都有可能发生和转移;鄱阳湖流域的气象干旱对湖水位具有较为显著的相关性,湖水位对3个月尺度和6个月尺度的SPI值响应最为明显,其与湖水位的相关程度,自近出湖口地区向远离湖口地区递增.
A degradation of the function oflakes can be probably caused by drought~ Analyzing the drought characteristics of lakes systematically and quantifying the impact of drought on lakes are of great practical significance Based on the monthly precipitation data of 13 meteorological sta- tions and the daily water level data from 5 water level gauging stations in the Poyang Lake basin from 1958 to 2007, negative trends of the standard- ized precipitation index (SPI) in spring and autumn were recognized by using the Mann-Kendall tesL By using Kriging interpolation method, it was also found that drought can occur and transit in different periods and different regions. An evident relationship between the drought phenomena and the lake's water level were demonstrated by using Spearman's rank correlation coefficient. Water level is sensitive to SPI values with 3 and 6-month time scales, and the further the station is away from the outlet of the lake, the more strongly the drought may affect the water level.