本文選題：科爾沁沙地 + 蒸散發(fā)�。� 參考：《內(nèi)蒙古農(nóng)業(yè)大學(xué)》2017年碩士論文

【摘要】：本文以科爾沁沙地典型區(qū)為研究對象,運用Landsat遙感影像和氣象數(shù)據(jù),基于METRIC模型對2013年-2016年生長季5月-9月的地表特征參數(shù)(地表溫度Ts、土壤熱通量G、反照率Albedo、葉面積指數(shù)LAI、植被指數(shù)NDVI)及蒸散發(fā)(ET)進行估算,利用試驗站點的渦度相關(guān)系統(tǒng)實測數(shù)據(jù)對反演結(jié)果進行驗證,在此基礎(chǔ)上分析了地表參數(shù)、ET的時空變化,并分析地表參數(shù)和氣象因子對ET的響應(yīng)關(guān)系。通過研究得到如下的主要結(jié)論:1.地表特征參數(shù)和ET估算值與渦度實測值的擬合結(jié)果均為良好,其中日ET的擬合系數(shù)為0.815,均方根誤差為1.084mm。通過對METRIC模型輸入數(shù)據(jù)的敏感性分析可知,草甸和農(nóng)田區(qū)ET對地表參數(shù)的敏感程度排序為:TsAlbedoLAINDVI;沙丘區(qū)ET對地表參數(shù)的敏感程度排序為:AlbedoTsNDVILAI,而且對NDVI和Ts的敏感程度小于草甸和農(nóng)田。2.研究區(qū)下墊面地表特征參數(shù)和ET的時空分布情況為:各年地表參數(shù)和ET在年內(nèi)基本呈現(xiàn)相同的分布趨勢,一般7-8月ET和各地表參數(shù)達到了峰值;空間分布表現(xiàn)為草甸和農(nóng)田的LAI、NDVI和Rn比沙丘地區(qū)的大,相反沙丘地區(qū)的Albedo和Ts比草甸和農(nóng)田大,最終導(dǎo)致草甸和農(nóng)田的ET比沙丘地大。三年生長季平均ET草甸、農(nóng)田集中在308mm-592mm;沙丘主要集中在400mm以下。2016年生長季沙丘總ET較大,這是由于2016年的平均氣溫較高,且降雨較多。3.草甸和沙丘的各年的凈輻射、風(fēng)速、空氣溫度對ET的影響均呈極顯著正相關(guān)關(guān)系,而與相對濕度均呈負相關(guān)關(guān)系。氣象因子對ET貢獻率的大小排序為:凈輻射風(fēng)速空氣溫度土壤溫度相對濕度。當(dāng)凈輻射≤179.19W/m2時,ET主要受空氣溫度和相對濕度的影響,當(dāng)空氣溫度在22.99℃時,ET主要受風(fēng)速和土壤溫度的制約。ET與Ts、G、Albedo等地表參數(shù)呈極顯著負相關(guān)關(guān)系,而與LAI和NDVI呈極顯著正相關(guān)關(guān)系。草甸和沙丘的地表特征參數(shù)對ET貢獻率大小排序為:NDVIAlbedoLAITsG.
[Abstract]:This paper takes the typical area of Horqin Sandy Land as the research object, using Landsat remote sensing image and meteorological data. Based on METRIC model, the surface characteristic parameters (surface temperature T _ s, soil heat flux G, albedo Albedo, leaf area index Lai, vegetation index NDVI) and evapotranspiration (et) of the growth season from 2013 to 2016 were estimated. The inversion results are verified by the measured data of vorticity correlation system of the test station. Based on this, the temporal and spatial variation of surface parameters and the response of surface parameters and meteorological factors to et are analyzed. The main conclusions are as follows: 1. The fitting results of the surface characteristic parameters and the estimated values of et and the measured vorticity values are all good. The fitting coefficient of daily et is 0.815, and the root mean square error is 1.084 mm. According to the sensitivity analysis of METRIC model, the sensitivity of et to surface parameters in meadow and farmland is in the order of: TsAlbedo LAINDVI, and in sand dunes et is in the order of: Albedo TsNDVILAII, and the sensitivity to NDVI and ts is less than that of meadow and farmland. The temporal and spatial distribution of surface characteristic parameters and et on the underlying surface of the studied area are as follows: the distribution trend of surface parameters and et in each year is basically the same, and the peak value of et and surface parameters is reached in July-August; The spatial distribution of LAIN NDVI and rn in meadow and farmland is larger than that in sand dune area, on the contrary, the Albedo and ts in sand dune area are larger than that in meadow and farmland, which leads to the et of meadow and farmland being larger than that of sand dune area. The average et meadow in three years growing season, the farmland is 308mm-592mm, the sand dune is mainly below 400mm. The total et of sand dune is larger in 2016 growth season, which is due to the higher average temperature in 2016 and the more rainfall. 3. The net radiation, wind speed and air temperature of meadow and sand dunes were positively correlated with et and negatively correlated with relative humidity. The order of contribution of meteorological factors to et is net radiation wind speed, air temperature, soil temperature and relative humidity. When net radiation 鈮，

本文編號：2104727