Evapotranspiration (ET) and its response to global change are one of the focuses of global change research and study on variations in evapotranspiration can provide credible data for regional water resources planning and ecological environment improvement. Based on MODIS-ET data, spatial-temporal variation patterns of evapotranspiration in the Loess Plateau in Shaanxi-Gansu-Ningxia Region during 2000-2012 were analyzed. Meanwhile, the influencing factors of the ET's variations in the Loess Plateau in Shaanxi-Gansu-Ningxia Region were analyzed by observation data of the meteorological stations and correlation coefficients calculation of ET to climate elements. The results showed that: (1) The average of ET in the Loess Plateau in Shaanxi-Gansu-Ningxia Region increased rapidly in 2000-2002 and peaked in 2003(378.6mm), and there was a downward trends in evapotranspiration in 2003-2006, after 2006 evapotranspiration showed a slow upward trend. (2)The spatial distribution pattern of annual ET was apparently various. ET increased gradually from the northwest to the southeast, and ET of southern forest regions, such as Liupanshan Mountain, Ziwuling Mountain and Huanglong Mountain were higher than that in other parts of the Loess Plateau in Shaanxi-Gansu-Ningxia Region. The maximum seasonal value of the ET lay in summer, then followed by spring, and the lest ET was in autumn and winter; the spatial distribution pattern of seasonal ET was basically the same as annual pattern. (3) Different land use/cover types had different contribution to the ET distribution in the Loess Plateau in Shaanxi-Gansu-Ningxia Region. The highest contribution rates were made by grasslands and croplands, closely followed by closed shrubland and open shrubland, while the evergreen needle leaf forest and woody savannas contributed less for ET distribution. (4) The influencing factors of ET were as the following: ET in main part was positively correlated with forceful factor, wind speed affected the ET significantly. The thermodynamical factor mainly negatively correlated with ET changes. The air temperature was negatively correlated with ET in most areas whereas sunshine hours in the less region with negative correspondence with ET than air temperature. Besides, it can be found that moisture condition like precipitation and relative humidityboth had strong positive effect on the ET.
[1] 丛振涛,杨大文,倪广恒.蒸发原理与应用[M].北京:科学出版社,2013.
[2] Chahine M T.The hydrological cycle and its influence on climate[J].Nature,1996,359(6349):373-380.
[3] 潘志强,刘高焕,周成虎.基于遥感的黄河三角洲农作物需水时空分析[J].水科学进展,2005,16(1):62-68.
[4] 刘昌明,张丹.中国地表潜在蒸散发敏感性的时空变化特征分析[J].地理学报,2011,66(5):579-588.
[5] 蒋冲,王飞,穆兴民,等.秦岭南北潜在蒸散量时空变化及突变特征分析[J].长江流域资源与环境,2013,22(5):573-581.
[6] 王鹏涛,延军平,蒋冲,等.华北平原参考作物蒸散量时空变化及其主要影响因素[J].生态学报,2014,34(19):1723-1730.
[7] 段春锋,缪启龙,曹雯.塔克拉玛干沙漠周边地区潜在蒸散时空演变特征及其主要影响因素[J].中国沙漠,2012,32(6):1723-1730.
[8] 王素萍.近40 a江河源区潜在蒸散量变化特征及影响因子分析[J].中国沙漠,2009,29(5):960-965.
[9] 邱新法,曾燕,刘昌明.陆面实际蒸散研究[J].地理科学进展,2003,22(2):118-124.
[10] 张晓涛,康绍忠,王鹏新,等.估算区域蒸发蒸腾量的遥感模型对比分析[J].农业工程学报,2006,22(7):6-13.
[11] 张长春,魏加华,王光谦,等.区域蒸发量的遥感研究现状及发展趋势[J].水土保持学报,2004,18(2):174-177,182.
[12] 刘志武,雷志栋,党安荣,等.遥感技术和SEBAL模型在干旱区腾发量估算中的应用[J].清华大学学报(自然科学版),2004,44(3):421-424.
[13] Lin W J,Su Z B,Dong H,et al.Regional evapotranspiration estimation based on MODIS products and surface energy balance system(SEBS) in Hebei Plain,Northeastern China[J].Journal of Remote Sensing,2008,12(4):663-672.
[14] 李贺,王红,孔岩,等.基于TSEB模型的黄河三角洲蒸散量估算[J].遥感技术与应用,2012,27(1):58-67.
[15] Mu Q Z,Heinsch F A,Zhao M S,et al.Development of a global evapotranspiration algorithm based on MODIS and global meteorology data[J].Remote Sensing of Environment,2007,111:519-536.
[16] Mu Q Z,Zhao M S,Running S W.Improvements to a MODIS global terrestrial evapotranspiration algorithm[J].Remote Sensing of Environment,2011,115:1781-1800.
[17] 李超凡,罗格平,李均力,等.近20 a中亚净初级生产力与实际蒸散发特征分析[J].干旱区地理,2012,35(6):919-927.
[18] 吴桂平,刘元波,赵晓松,等.基于MOD16产品的鄱阳湖流域地表蒸散量时空分布特征[J].地理研究,2013,32(4):617-627.
[19] 延军平,严艳.陕甘宁边区生态购买设计与操作途径[J].地理学报,2002,57(3):343-353.
[20] 吴绍洪,尹云鹤,郑度,等.近30年中国陆地表层干湿状况研究[J].中国科学(D辑:地球科学),2005,35(3):276-283.
[21] 施雅风,沈永平,胡汝骥.西北气候由暖干向暖湿转型的信号、影响和前景初步探讨[J].冰川冻土,2002,24(3):219-226.
[22] 王鹏涛,延军平,蒋冲,等.三北防护林工程区气候变化分析[J].水土保持通报,2014,34(1):273-278.
[23] 蒋冲,王文丽,陈爱芳,等.近52年渭河流域气候变化对植被净第一性生产力的影响[J].中国沙漠,2013,33(3):952-957.
[24] 邱新法,曾燕,缪启龙,等.用常规气象资料计算陆面年实际蒸散量[J].中国科学(D辑:地球科学),2003,33(3):281-288.
[25] 孙睿,刘昌明,李小文.利用累积NDVI估算黄河流域年蒸散量[J].自然资源学报,2003,18(2):155-160,259.
[26] 李双双,延军平,万佳.近10年陕甘宁黄土高原区植被覆盖时空变化特征[J].地理学报,2012,67(7):960-970.
[27] 韦振锋,王德光,张翀,等.1999-2010年中国西北地区植被覆盖对气候变化和人类活动的响应[J].中国沙漠,2014,34(6):1665-1670
[28] 张勃,张调风.1961-2010年黄土高原地区参考作物蒸散量对气候变化的响应及未来趋势预估[J].生态学杂志,2013,32(3):733-740.
[29] 刘敏,沈彦俊,曾燕,等.近50年中国蒸发皿蒸发量变化趋势及原因[J].地理学报,2009,64(3):259-269.
