天山北坡三工河流域高时空分辨率气温与地表反照率数据构建与分析

	天山北坡三工河流域高时空分辨率气温与地表反照率数据构建与分析
	王新新
Subtype	硕士
Thesis Advisor	罗格平
	2017-05-01
Degree Grantor	中国科学院大学
Place of Conferral	新疆乌鲁木齐
Degree Discipline	理学硕士
Keyword	日均气温土地利用/土地覆被变化地表反照率绿洲-荒漠区三工河流域 Daily mean air temperature Land-use and land-cover change(LUCC) Land surface albedo Oasis-desert region Sangong River Basin
Abstract	Currently, the spatial resolutions of available temperature datasets such as ClimaticResearch Unit(CRU) 、 The Climate Forecast System Reanalysis(CFSR) 、 ModerateResolution Imaging Spectroradiometer(MODIS) are too coarse to efficiently characterizethe difference of heterogeneous hydrothermal pattern in medium-scale oasis-desertecosystem in arid regions. Therefore, the construction of mean air temperature dataset withhigh spatial and temporal resolution is crucial for investigating ecological interactionsbetween oasis and desert ecosystems. The human-induced land-use/land-cover changes areregarded as one of the main factors in affecting surface albedo and albedo affects the nearsurface air temperature through influencing the hydrothermal circulation between the landand atmosphere. Nowadays, studing the interactions between albedo and air temperature isbecoming a hot topic in the context of global climate change. Thus, the Sangong riverbasin which comprises a typical Mountains-Oasis-Desert System is selected as the studyarea. Based on Landsat TM/OLI images、meteorological datas and land use/land coverdatas, the relative change rates of air temperature (R-Rates) for different land-covers andthe daily mean air temperature dataset were retrieved. Moreover, the albedo datas withhigh spatial resulotion in August of year 1989、1998、2004、2014 were retrieved and alsoanalysed the land cover change features during the 25 years. Then the interactions betweenalbedo and air temperature were analysed. Results show that:(1) The regression coefficient between the instantaneous air temperature and daily meanair temperature perfomed well, R2=0.96，p<0.01 and the mean RMSE=1.54℃. TheR-Rates of sandy desert, soil desert, built-up areas, cropland and hills was 1.12, 1.03, 0.97, 0.80 and 0.76, respectively, compared with reference station. Estimated dailymean air temperature and observed values in different weather stations showed asignificant linear correlation , R2>0.90, RMSE=2.34℃,p<0.05.(2) The method of retrieving albedo data had high accuration, the absolute error wassmaller than 0.05 and it agreed well with MCD43B3 datasets, R2=0.8173. Differentland-covers had different albedo, the albedo of sandy desert, hills, soil desert, built-up,cropland and water was 0.33, 0.30, 0.29, 0.27, 022 and 0.11, respectively. The spatialdifferences becomed weaker from 1989 to 2014.(3) The mean air temperature had apparent heterogeneity which caused by different landcovers. The mean air temperature of sandy desert > soil desert > built-up> cropland >hill and the mean air temperature of oasis had a high fluctuation. The main factorwhich affects the interannual difference of albedo is land-cover change and affects theannual variance is the vegetation cover condition. The mean albedo and mean airtemperature of growing season had positive correlation, R2= 0.3, p < 0.01.
Other Abstract	现有的温度数据集（CRU、MERRY、CFSR等），空间分辨率普遍大于10km，而MODIS地表温度产品为1km，且时间序列较短，均无法满足绿洲－荒漠相互作用研究的百米级精度要求。因此，获取绿洲－荒漠区高时空分辨率的气温数据集成为绿洲－荒漠相互作用研究的关键环节。人类活动导致的土地利用/土地覆被变化（LUCC）被认为是影响地表反照率(Albedo)的关键因素之一，且Albedo又通过影响地-气系统水热循环从而影响近地表气温，因此在全球气候变化的背景下，研究LUCC影响的Albedo与气温的相互作用已逐渐成为全球尤其是生态系统脆弱的干旱区研究的热点之一。本文以天山北坡三工河流域为研究区，以Landsat TM/OLI系列影像为数据源，并基于气象站观测数据和土地利用/土地覆被数据，反演卫星过境日期日均气温，定义―气温相对变化速率‖,据此估算卫星非过境日期日均气温，从而构建得到三工河流域1989年-2014年（冬季除外）逐日日均气温空间数据集。基于1989年、1998年、2004年和2014年8月（天气状况相似）的Landsat影像反演高空间分辨率Albedo数据和土地利用覆被数据，分析研究区Albedo空间分布特征及近25年土地覆被变化特征，并以此分析LUCC影响下的Albedo对近地表气温的影响。主要结论如下：（1）通过建立瞬时气温与日均气温回归方程估算三工河流域卫星过境日期日均气温的方法精度较好，R2=0.96，p<0.01，RMSE=1.54℃。基于日均气温影像定义了不同覆被类型不同季节（春、夏、秋三季）的―气温相对变化速率‖，沙质荒漠（1.12）>土质荒漠（1.03）>参考站点（1.00）>建设用地（0.97）>农田（0.80）>低山丘陵（0.76），卫星非过境日期日均气温计算值与气象站实测数据具有较好的相关性，R2>0.90，总RMSE=2.34℃，p<0.05。（2）本研究基于 Landsat 系列影像估算研究区高空间分辨率（30m）Albedo 的精度较高，绝对误差在 0.05 以内，且具有明显的空间差异性：Albedo 平均值北部沙质荒漠区（0.33）>南部低山丘陵区（0.30）>土质荒漠区（0.29）>建设用地（0.27）>农田（0.22）>水体（0.11），空间差异性（研究区内 albedo 最高与最低值的差值）由1989 年至 2014 年逐渐减弱。（3）土地覆被变化是 Albedo 年际差异性的主要影响因素，而植被覆盖状况则是其年内变化的主要影响因素。Albedo 的改变又通过影响地-气系统的能量交换从而影响近地表气温，Albedo 与生长季平均气温具有显著的正相关性，R2= 0.3，p < 0.01。基于生态模型及气候模式的三者之间机理层面的相互作用研究还有待进一步研究与讨论。
Subject Area	地图学与地理信息系统
Language	中文
Document Type	学位论文
Identifier	http://ir.xjlas.org/handle/365004/14902
Collection	研究系统_空间对地观测与系统模拟研究室
Affiliation	中国科学院新疆生态与地理研究所
First Author Affilication	中国科学院新疆生态与地理研究所
Recommended Citation GB/T 7714	王新新. 天山北坡三工河流域高时空分辨率气温与地表反照率数据构建与分析[D]. 新疆乌鲁木齐. 中国科学院大学,2017.

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