摘要
蒸散是地表能量平衡与水量平衡的重要组成部分,研究松嫩平原生长季蒸散量时空格局及影响因素对该区农作物生长环境评价、水资源高效利用具有重要意义。本研究以MODIS产品为主要数据源,通过陆面能量平衡算法SEBAL及Penman-Monteith方程估算了松嫩平原2000年-2008年生长季(5月-9月)的陆面实际蒸散量,分析了蒸散量的空间分布特征及时间变化趋势,并在月时间尺度上通过基于像元的相关分析法探讨了蒸散量与主要气候因子(降水量、平均气温、平均相对湿度、平均风速、日照时数)相关性。结果表明:①除水体、沼泽湿地等高蒸散特性地物外,松嫩平原生长季蒸散量具有从西南部向东部、东北部逐渐增加的变化趋势,呈明显阶梯状变化,松嫩平原2000年-2008年生长季蒸散量的区域平均值呈明显下降趋势(P<0.05),多年平均值为612.63mm,最大值(669.31mm)出现在2000年,最小值(570.79mm)出现在2005年;②受气候条件、土壤供水状态及植被覆盖度等因素影响,松嫩平原生长季各月蒸散量差异明显,7月蒸散最强烈,高达141.60mm,9月由于降水减少、气温降低,月蒸散量仅81.35mm;③对蒸散量与主要气候因子进行基于像元的相关分析得知蒸散量与降水量、平均气温的正相关性极其明显,而蒸散量与平均相对湿度的相关性在林地、水体分布区以负相关为主,在其他区域则以正相关为主,蒸散量与平均风速、日照时数的相关性相对较弱。
Evapotranspiration（ET）is a critical component of the land surface energy balance system and hydrologic processes.Analysis of spatiotemporal variations and influencing factors of ET in the growing season is of great importance to evaluate the growing environment for crops and to effectively use water resources across the Songnen Plain,a critical base for grain production in China.The authors made use of the Surface Energy Balance Algorithm for Land（SEBAL）and the Penman-Monteith equation（P-M）in conjunction with Moderate-resolution Imaging Spectroradiometer（MODIS）products（i.e.,MOD11A1,MOD11A2,MOD13A2,MOD43B3,and MCD43B3）to estimate land surface actual ET in the growing season generally from May to September during the period 2000-2008.Furthermore,spatial patterns and temporal trends in the ET estimates were comprehensively analyzed,with investigating correlation of five key climatic factors（i.e.,precipitation,air temperature,relative humidity,wind speed,and sunshine hours）with ET estimates.In addition to large water bodies and wetlands,the average ET in the growing season from 2000 to 2008 changed obviously,increasing gradually from the southwest to the east and northeast of the study region.It was suggested that the average ET of the whole Songnen Plain exhibited a significant decreasing trend during the period 2000-2008,with a maximum ET value of 669.31 mm occurring in 2000 and a minimum ET value of 570.79 mm in 2005.The mean annual ET was found to be roughly 612.63 mm.Under a combined effect of weather conditions,soil water supply status,and fractional vegetation cover,the monthly ET from May to September showed a marked spatiotemporal variation,with a maximum monthly ET value of 141.60 mm in July and a minimum ET value of 81.35 mm in September.This could be ascribed largely to relatively less precipitation and lower air temperatures.By examining responses of the ET estimates to climatic variables,it was found that ET was positively correlated with precipitation and average air temperature
出处
《资源科学》
CSSCI
CSCD
北大核心
2010年第12期2305-2315,共11页
Resources Science
基金
中国科学院知识创新工程重要方向项目:"东北亚地区自然资源现状与生态环境变化趋势分析"(编号:KZCX2-YW-341)
国家自然科学基金项目:"定量区分气候变化与人类活动对草地生产力的影响"(编号:40871187)
