1961年至2007年东北地区水分盈亏变化趋势及其影响与响应

Changes of Water Budget and Their Effects and Responses in Northeastern China from 1961 to 2007

利用1961年—2007年东北地区124个气象站的气候资料,采用Penman-Monteith模型计算参考蒸散量,进而计算水分盈亏量,对水分盈亏量时空演变特征及其影响与响应进行分析。研究表明:东北地区10年际全年、春季、秋季和冬季水分盈亏量以亏缺为主,夏季以盈余为主,东北地区全年、夏季、秋季和冬季水分盈亏量都呈先减少后增加的趋势,但总体上呈减少趋势,速率分别为-4.2mm/10a、-3.4mm/10a、-2.2mm/10a、-0.7mm/10a;春季呈弱增多趋势,其速率为7.5mm/10a,东北地区有逐渐变干的趋势。从地域分布看,有2/3的地区呈下降趋势,1/3的地区呈上升趋势。对各气象因子与水分盈亏量的相关分析表明,影响水分盈亏量变化的主要因子是降水量,其次是温度。当温度变化时,各季节水分盈亏量变化:冬季>秋季>夏季>春季;当降水量变化时,各季节水分盈亏量变化:夏季>秋季>春季>冬季。由此可见,温度的变化对冬季的水分盈亏量影响最大,降水的变化对夏季水分盈亏量影响最大。受水分亏缺影响,干旱频率增加、区域扩大,粮食生产不稳定性增加。

Northeastern China is one of regions showing the most serious water shortages in China and highly seasonal and regional variations in water resources distribution.Demands for water resources are increasing due to rapid industrialization,urbanization and socioeconomic development,causing an increasing gap between water supply and demand.Water shortage has become a major constraint on economic development.On the other hand,in the context of global climate change,studying changes in water budget and their impact factors would be conducive to an in-depth understanding of climate change impacts on the water cycle and water resources.Based on observations of temperature,precipitation,wind,vapor pressure and sunshine hours collected from 124 weather stations during 1961-2007 and the Penman-Monteith equation,the potential evapotranspiration（ET）and water budget across Northeastern China were calculated and analyzed in this paper.Spatial-temporal characteristics of water budget and their effects and responses in Northeastern China were evaluated by spatial and time series analysis methods.Results showed that the decade-average water budget during the whole study period and in spring,autumn and winter in Northeastern China was insufficient but surplus in summer season.The amount of water deficit showed a generally decreasing trend before the 1980s and were increasing thereafter.There was a slight increase in the amount of water deficit in the 1990s.It was also found that the mean annual,summer,autumn and winter water budget in Northeastern China decreased at a rate of-4.2 mm/10a,-3.4 mm/10a,-2.2 mm/10a,and-0.7 mm/10a during recent 47 years,respectively,and the mean seasonal water budget in spring increased at a rate of 7.5 mm/10a,which showed a generally drying trend in Northeastern China.As for spatial distribution characteristics of the mean annual water budget,around two thirds of the regions showed a decreasing trend especially over the southeast of Liaoning Province at a rate of（20-51）mm/10a.Moreover,around one third of the region displayed a increasing trend especially over the west of Liaoning Province,the northeast of Jilin Province and the southwest of Heilongjiang Province at a rate of（1-23）mm/10a.This basically indicated a drying trend occurring in spring,summer and autumn over the most regions of Northeastern China.Correlation analysis between water budget and meteorological variables indicated that the water budget was determined most by precipitation and the next by temperature. The water budget for each season varied greatly with meteorological variables,showing winter autumnsummerspring as temperature changed and summer〉autumn〉spring〉winter as precipitation changed.This demonstrated the water budget in winter and summer were affected most by temperature and precipitation.As a consequence of water deficit,the probabilities and affected areas of droughts over the study regions will probably increase,which would cause an unstable crop production.