根据2010 年遥感反演得到的黑河流域蒸散发量以及土地利用数据进行土地利用重分类, 运用最邻近法对蒸 散数据进行了重采样, 统计了额济纳三角洲各土地利用类型各月以及年蒸散发量, 并分析了其时空分异特征。结果 表明: 额济纳三角洲遥感分析面积为8 0731 6 km2 , 依据水分耗散和补给特征, 土地利用类型可分为水域、农田、裸 地、建设用地和林草绿洲等五类, 年蒸散发量大小排序为水域( 8151 9 mm) > 农田( 1421 8 mm ) > 林草绿洲( 1031 3 mm) > 建设用地( 611 6 mm) > 裸地( 551 6 mm) 。2010 年蒸散水量为51 39 亿m3 , 裸地、林草绿洲、水域依次占 711 6%、181 5%、61 9%。水域、农田、裸地、建设用地和林草绿洲的月最大蒸散发量分别出现在6 月、8 月、6 月、6 月、6 月, 最小分别出现在11 月、1 月、1 月、1 月、1 月, 极值比的最大、最小值分别为2231 5( 农田) 、431 5( 水域) 。 6 月- 9 月各地类蒸散发量之和占全年的比例在61. 3%( 水域) ~ 83. 9%( 农田) ; 11 月- 次年3 月蒸散发量之和占 全年的比例在2. 7%( 农田) ~ 7. 7%( 水域) 。同一土地利用类型的蒸散发量空间变异性也很显著, 各土地利用类型 所属像元年蒸散发量极值比、标准差、变异系数的最大值分别为301 3、5111 5、01 63( 水域像元) , 水域年蒸散发量空 间分异性最大。

The land use was r eclassified based on the evapotr anspir atio n ( ET ) and land use dat a in 2010 obtained f rom remot e sensing r etrievals in the H eihe Water shed, the ET data w ere resampled using the nearest neig hbor s mEThod, t he mo nthly and yearly ET of each land use w ere calculated, and the char act eristics of its tempo ral and spatial distr ibut ion wer e finally analyzed. The results showed t hat ( 1) the remote sensing analysis area of Ejina Delta is 8 073. 6 km2 ; ( 2) accor ding t o the characterist ics of moist ur e dissipatio n and recharg e, the land use can be reclassified into water , farmland, bar e land, construction land, and for2 est2o asis land, and the o rder of annual E T in each land use t ype in 2010 is water ( 815. 9 mm) > farmland ( 142. 8 mm) > for2 est2o asis land ( 103. 3 mm) > co nstr uction land ( 61. 6 mm) > bar e land ( 55. 6 mm) ; ( 3) the to tal ET o f Ejina Delta is 5. 39@ 108 m3 in 2010, and the ET of bar e land, fo rest2oasis land, and water accounts for 71. 6%, 18. 5%, and 6. 9% of the tota l E T, re2 spect ively; ( 4) the maximum mo nthly ET of w ater, farmland, bare land, co nstr uctio n land, and for est2oasis land occur s in June, Aug ust, June, June, and June, respect ively, w hile t he minimum occurs in No vember, January , January, Januar y, and January , re2 spect ively. The ratio n o f max imum and minimum ex tr eme v alues is 223. 5 ( farmland) and 43. 5 ( w ater) ; ( 5) the to tal ET from June t o September accounts f rom 61. 3% ( water ) to 83. 9% ( fa rmland) , while the to tal ET fr om No vember to Mar ch o f next year accounts from 2. 7% ( farmland) to 7. 7% ( w ater) of the annual E T; and ( 6) the spatial va riability of ET o f one land use type is remarkable. The max imum of ex tremes ratio , standar d deviat ion, and coefficient o f v ariation of pix el of all land use types are 30. 3 ( w ater) , 511. 5 ( w ater ) , 0. 63 ( w ater ) , r espectively, indicating that the spatial va riability o f annual ET fo r land use type of w ater is the g reatest.

国家自然科学基金项目( 41271049, 41371059)