Studies And Applications Of Land Surface Parameters Retrieval With NOAA/AVHRR Data

Today, in the twenty-first century, the contradiction between thedevelopment of the society and resource, environment and economybecomes a serious issue. The deterioration of the eco-environment hasseverely restricted the advancement of society and the development ofeconomy, at the same time, threatened the survival of human life. Theland-surface parameters are major components which affect the globalclimatologic change. They are also important indexes in the study oneco-environmental system. Precise land-surface parameters retrieval playsan important role in the synthetic study and the quantitative prediction of theeco-environmental system. Because of the friability of eco-environment, theproblem of land degradation is very serious, which has been the primaryfactor to restrict severely the development of economy in Jilin province.Therefore, chosing western Jilin Province as the study area is veryrepresentative .Land surface is an entity in which land, ocean, atmosphere, biosphereinteract on each other. Virtually, the process of interaction between landsurface and atmosphere is the process of exchange between energy,momentum and mass. Because of the variety and diversity of land surface,meanwhile,the characteristics of land surface and the physical property ofunderlying surfaces in the time and space distribution are different,whichinfluence greatly on the distribution of energy, momentum and mass.Therefore, the energy re-distributes, which influences climatologic changelocally and even globally. In order to describe the process of exchangebetween energy, momentum and mass quantitatively. Firstly, we need toretrieve the land-surface parameters (Albedo, emissivity, land-surfacetemperature, NDVI, soil moisture and thermal inertia and other physicalcharacteristic parameters) precisely. We make use of Interactive DataLanguage to develop a new module that extends the function of ENVI.Based on the SEBS,a program module written by professor WAN Li fromChina University of Geosciences, we made some modifications so to enablethe SEBS module properly applied to the study area.Retrieving the land-surface parameters from satellite remote sensedmultispectral data has particular advantages. The NOAA/AVHRR data hasbeen intensively applied to the study on land-surface parameters retrievaland land-surface evaportranspiration estimation because of its high timeresolution, large area coverage and low cost. In this paper theparameterization model of land-surface was established for NOAA/AVHRRdata. The land-surface parameters, such as temperature, emissivity, Albedoand NDVI, were then calculated from the AVHRR data of July 5 , 2000 overthe study area of the west of Jilin Province. The spatial distributingcharacteristics and rationality of the parameters were analyzed with thereference from the landuse data of the same year. Meanwhile, on the basis ofcomparative analyses of 4 conventional split window algorithms for surfacetemperature retrieval, Coll and Caselles algorithm gives the best temperatureestimation. The results are essential to the evaportranspiration estimation.Making use of the land-surface parameters what has been calculated, basedon the surface energy balance theory and in association with the real worlddata from the west of Jilin Province, we established a remote sensing modelfor estimating evapotranspiration for the study area, and then the dailyevaporation and month mean evaporation were calculated. Furthermore thewe have proved the validity of the remote sensing model using datameasured on sites by weather observatories and stations. And we madecomparative analysis between calculated value and empiric value. At thesame time, we analysed qualitatively the correlation between theland-surface parameters, which prove the rationality of the model.The land-surface parameters retrieval and estimation ofevapotranspiration provide a new approach for studying eco-environmentalchanges in the west of Jilin Province. And it also provides new informationfor understanding regionally the eco-environmental problems, which willaid us in taking measures to stop the eco-environmental deteriorations in thestudy area and impulse sustainable development in the west of JilinProvince. Meanwhile, it develops a new range of application forNOAA/AVHRR data for eco-environment study. The models described canbe valuable to other arid and semi-arid regions in China.