关键词: 鄱阳湖流域, 径流, NDVI, 相关分析, Morlet小波分析

Abstract: Based on the 8km resolution multi-temporal NOAA AVHRR-NDVI datasets and the daily runoff data from four hydrometrical stations during 1982-1999,the characteristics of NDVI and runoff and their relationships in four sub-regions of Poyang Lake Basin were studied at annual and inter-annual scales by using the methods of inter-decadal variations,correlation analysis and Morlet wavelet analysis. The results indicated that the mean annual NDVI increased all in four sub-regions from 1982 to 1999 and the inter-annual NDVI varied with the same trend. NDVI was mainly influenced by precipitation and runoff. The correlation coefficient between NDVI and runoff were positive and significant statistically in the whole region,and NDVI maximally respond to the variation of runoff with a lag of about 3 months. The runoff generally oscillated with a cycle of about 12 months in all sub-regions,and in several sub-regions,it oscillated with the cycle of about 35 and 62 months. The frequency distribution of each oscillation signal was different,not only in time domain but also in intensity,of which the cycle of 12 months was the strongest of all and the short cycle was stronger than the long cycle. The NDVI had the same characteristics of cycle oscillation as that of runoff.

Key words: Poyang Lake Basin, Poyang Lake Basin, Runoff, NDVI(Normalized Difference Vegetation Index), Correlation analysis, Morlet wavelet analysis