基于MOD16的洞庭湖流域2000-2014年地表蒸散时空变化分析  

Analyzing spatio-temporal variations of evapotranspiration in Dongting Lake Basin during 2000-2014 based on MOD16

作　　者：张猛[1,2] 曾永年[1,2] 齐玥 Zhang Meng;Zeng Yongnian;Qi Yue(School of Geosciences and Info-physics,Central South University,Changsha 410083,China;Center for Geomatics and Regional Sustainable Development Research,Central South University,Changsha 410083,China)

机构地区：[1]中南大学地球科学与信息物理学院,长沙410083 [2]中南大学空间信息技术与可持续发展研究中心,长沙410083

出　　处：《农业工程学报》2018年第20期160-168,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(41171326;40771198);中南大学中央高校基本科研业务费专项资金(2016zzts087)

摘　　要：地表蒸散是决定土壤-植被-大气之间水循环与能量转换的关键因素,研究流域蒸散量的时空变化对水文、气象和农业等领域的治理和管理具有重要意义。该文基于时间序列MOD16数据集,分析了2000-2014年洞庭湖流域地表蒸散量时空变化,并利用多年降水量及气温数据,采用回归模型探讨了蒸散量与气候因子之间的相关性,以期为洞庭湖流域热量平衡和气候干湿状况评价提供数据支持。结果表明:1)MOD16地表蒸散量产品数据的精度满足洞庭湖流域蒸散量时空分布研究的需求;2)洞庭湖流域年蒸散量值具有较高的空间分异性,呈现出东北部低、西部和南部高的趋势。洞庭湖流域各年蒸散量多年年平均蒸散量值为636.83mm/a,多年年均蒸散量整体呈波动下降趋势;3)蒸散量的季节性变化明显,一年中夏季地表蒸散量平均值最高4)洞庭湖流域地表蒸散量年内分布显现为先增大后减小的单峰型分布趋势,蒸散量的高值区主要集中在5-9月,最高值出现在7月,最小值出现在12月;5)地表蒸散量值与降水量和气温的平均相关系数分别是0.67和0.41,表明地表蒸散量与降水量的相关性较高。基于已有的研究表明,总体而言,MOD16产品为全球变化研究提供了较为可靠的、长时间序列蒸散发产品,并可以用于全球范围地表蒸散研究。As an important part of ecological environment and water resources assessment,timely and accurate analysis of spatio-temporal characteristics of regional evapotranspiration and its relationship with climate factors,is of great significance to the regional weather,hydrology,water conservancy and agricultural fields.In this article,we analyzed the inter-annual variation and annual variation of surface evapotranspiration in the Dongting Lake Basin during 2000-2014 based on the time series MOD16 dataset.And the correlation between evapotranspiration and climate factors was discussed by using regression model based on the annual precipitation and temperature data of study area.The results show that:1)Based on the measured evapotranspiration of Taoyuan station,we validated the MOD16 dataset.The correlation coefficient between the measured evapotranspiration and surface evapotranspiration from MOD16 was 0.88,which met the needs of accuracy of the study on the spatial and temporal distribution of evapotranspiration in Dongting Lake Basin;2)The annual evapotranspiration value of Dongting Lake Basin has a strong spatial differentiation pattern,showing a trend of being low in the northeast area,and high in western and southern areas of the study area.During the study period,the average annual evapotranspiration in Dongting Lake Basin was 636.83 mm/a,which showed a downward trend with irregular fluctuations.The highest evapotranspiration value appeared in 2001,which was 669.19 mm/a,and the lowest evapotranspiration value was 613.62mm/a,which appeared in 2011.The change rate of annual surface evapotranspiration(θ)was-2.98%,which indicated that the evapotranspiration value showed a downward trend of Dongting Lake Basin.The spatial distribution of evapotranspiration was related to land cover types,which had effect on the evapotranspiration distribution in the Dongting Lake Basin,and the order of evapotranspiration intensity of different land cover types was forest>grassland>bare land>cultivated land>town.3)The seasonal variati

关 键 词：蒸散 气温 降水 时空变化 MOD16 洞庭湖流域 

分 类 号：TP79[自动化与计算机技术—检测技术与自动化装置] S127[自动化与计算机技术—控制科学与工程]