关键词: 潜在蒸发量, 水分盈亏, 时空变化, 鄱阳湖流域

Abstract: Based on the meteorological data of 13 stations in Poyang lake watershed from 1960 to 2014, the spatial and temporal variation characteristics of seasonal and annual water budget and its influential meteorological factors were analyzed with Penman-Monteith equation recommended by FAO, Mann-Kendall statistical method and correlational analysis method. The results show that the annual average water surplus is 565.88 mm, which shows a gradually increasing distribution from southwest to northeast and northwest to northeast; in the annual scale, the water budget is deficit in autumn and surplus in other seasons, especially, the seasonal water surplus value showing a descending order of spring, summer, winter, and autumn. The water surplus quantity increases in the watershed throughout the study period, however, the seasonal water surpluses have some differences. In particular, water surplus displays a slight downward trend in spring and autumn and there is a significantly upward trend in summer and winter (p< 0.05). The relationship between water budget and rainfall, sunshine hours, daily maximum temperature are very close. The increasing cause of annual water surplus is the increase of summer and winter rainfall and the decrease of sunshine hours and wind speed.

Key words: potential evaporation, water budget, spatial and temporal variation, Poyang Lake watershed