干旱区生态环境知识资源中心(Arid): 夏季黑河中游绿洲样带蒸散量遥感估算

Arid

	夏季黑河中游绿洲样带蒸散量遥感估算
其他题名	Evapotranspiration estimation for oasis transect in middle reach of Heihe river basin based on remote sensing
	连晋姣 1; 黄明斌 2; 李杏鲜 1; 刘文娟 3
来源期刊	农业工程学报
ISSN	1002-6819
出版年	2014
卷号	30 期号:15 页码:120-129
中文摘要	黑河中游绿洲集中了全流域95%的耕地,利用了全流域68%的水资源,绿洲农田蒸散是水资源的主要支出项。为了解绿洲生态系统不同景观单元的耗水规律,高效管理区域水资源,该文利用2011年6-8月的7期Landsat TM影像,结合地面气象、物候数据和土地覆盖类型,基于SEBAL-METRIC模型估算了夏季黑河中游样带尺度不同土地覆盖类型蒸散量,并利用涡度观测数据对卫星过境日模型估算的蒸散量进行验证,发现遥感估算值与实测值具有较好的一致性。结果表明:由于土地覆盖类型和灌溉的差异,黑河中游样带尺度内蒸散量空间变化较大,6-8月农田平均总蒸散量是340 mm,林地是328 mm,草地的平均值是214 mm,荒漠区只有97 mm;夏季不同土地覆盖类型蒸散量均保持在较高水平,农田日蒸散量在6月底达到最大值,荒漠日蒸散量于7月中旬达到最大值,草地6月和7月平均日蒸散值较8月大,林地蒸散量月际变化较小。另外,荒漠与绿洲土壤类型差异较大,在荒漠区与绿洲区分别选取"热点"可有效提高模型估算精度。研究对于干旱半干旱区域水资源利用与管理有参考价值。
英文摘要	The Heihe River Basin is the second largest inland river basin in the arid area of Northwestern China, and the oasis in its middle reach has 95% of the total arable land and uses 68% of the total water resources in whole basin. Because evapotranspiration (ET) from the oasis is one of the most important components in water consumption, it is very important to study the ET in various land uses for water resource management and allocation in whole basin. The objective of this study was to estimate ET values for different land uses at a spatial scale of 16 km * 20 km in the middle reach oasis of Heihe river basin using remote sensing method. The main challenge of this study was to find a method to extrapolate instant ET values, which were estimated from the remote images, to monthly or seasonal actual ET (AET) values. In this study, a representative transect was selected to analyze the spatial distribution and temporal change of ET for different land cover types in the middle reach of the Heihe river basin. Seven qualified Landsat TM images for the studied transect were obtained during June to August in 2011. The surface energy balance model of SEBAL-METRIC and meteorological data were used to calculate the transient ET and daily reference ET (ET0) when the Landsat passed the studied region. The ratio of instant ET/ET0 was extrapolated to daily value using a sinusoidal function, while the daily ratio of ET/ET0 was assumed to be constant for a short period of 5 to 24 days for estimating a cumulative ET for different land uses in the transect. The comparison of daily ET values obtained by an eddy covariance system and remote sensing method showed the SEBAL-METRIC model combined with Landsat TM image and ET0 can provide reliable estimation of ET for different land cover types with an average relative error of 10.2%. The ET values varied from different land cover types and different irrigation schedules, with the high ET values in water area, farmland and forest, in contrast to low ET values in grassland and desert. The average ET values for farmland and forest during the studied period were 340 mm and 328 mm, respectively. They were higher than that for grassland of 214 mm and desert of 97 mm. ET variation for farmland was closely related to crop growth, and the highest ET value appeared on June 27th when both maize and wheat needed a large amount of water. By contrast, the ET values for desert were greatly influenced by the occurrence of precipitation events, as the vegetation was sparse and the most important limitation factor for evapotranspiration in this area was the low soil water content. Besides, the ET values of forest did not change significantly (p>0.05) during this period, with approximately 4 mm/d in sunny days. This study showed that METRIC hold substantial promise to estimate ET values for different land cover types in the middle reach of the Heihe river basin throughout plant growing periods. Besides, the accuracy of ET estimation in the oasis of Heihe middle reach could be improved when the hot extreme pixels in arable land and desert were respectively chosen due to different soil types.
中文关键词	遥感 ; 蒸散 ; 模型 ; 黑河中游绿洲 ; 夏季
英文关键词	SEBAL METRIC remote sensing evapotranspiration models the middle reach oasis of Heihe River Basin summer SEBAL METRIC
语种	中文
国家	中国
收录类别	CSCD
WOS类目	AGRICULTURE MULTIDISCIPLINARY
WOS研究方向	Agriculture
CSCD记录号	CSCD:5207919
来源机构	西北农林科技大学 ; 宁夏大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/231480
作者单位	1.西北农林科技大学资源环境学院, 黄土高原土壤侵蚀与旱地农业国家重点实验室, 杨凌, 712100; 2.西北农林科技大学, 黄土高原土壤侵蚀与旱地农业国家重点实验室, 杨凌, 712100; 3.宁夏大学农学院, 银川, 宁夏 750021, 中国
推荐引用方式 GB/T 7714	连晋姣,黄明斌,李杏鲜,等. 夏季黑河中游绿洲样带蒸散量遥感估算[J]. 西北农林科技大学, 宁夏大学,2014,30(15):120-129.
APA	连晋姣,黄明斌,李杏鲜,&刘文娟.(2014).夏季黑河中游绿洲样带蒸散量遥感估算.农业工程学报,30(15),120-129.
MLA	连晋姣,et al."夏季黑河中游绿洲样带蒸散量遥感估算".农业工程学报 30.15(2014):120-129.