The principle applied courses and results of new algorithm of pixel slope in the GIS are introduced and the applied results of existent seven algorithms are also discussed. New algorithm is more reasonable,more reliable and has better adaptability and it is more suita- ble than existent algorithms in monitoring soil annual loss by remote sensing and GIS.Al- though fitting algorithm of nine point to curved plane in existent algorithms in more suitable,its run amount is bigger and not more .
The procedures on soil-erosion investigation in laterite area at scale of 1:200000 with remote sensing are concluded in this paper.The study strategy,weighted model by experts and discrimination condition to be developed are available for the estimation of soil erosion intensity in other laterite terrain.It is suggested in the paper that the colour composite image with the Landsat TM bands 3,4 and 7 to be acquired in March and April is key for the in- terpretation and identification of the affect factors.In the estimation of erosion area,the “unerosion area coefficents” can be obtained through the interpretation of larger scale airphoto and then the accuracy of the area estimation is largely increased by unerosion area eliminated.
Estimation large area near-surface soil water content has great value.The relations among surface soil diurnal temperature difference,soil thermal intertia and soil water con- tent are theoretically analysed in this paper.The method of calculating soil water content from soil thermal intertia and calculating soil thermal intertia from surface soil diurnal tem- perature difference are researched.The model of soil water content Monitoring by Thermal Infrared Remote Sensing is established.The model has certain precision in accordance with test of the observed data.The proposed model is used to obtain the near-surface soil water content map of Liaoning Province on August 11,1988.
The process procedure of the data-convertion translated CCT tape of TM image into microcomputer disk by making use of minicomputer or microcomputer and display of remote sensing image reading from the data of remote sensing image with common microcomputer is mainly introduced in the paper.
Quadtree,the image data structure,has been drawing more and more attention of researchers in recent years.GIS is an important field where the structure is applied.On the base of the research of some theory and methodology,this paper describes two facets of ap- plying 2DRE quadtree and some converting algorithms in GIS,and the way of achieving them:one is to construct the attribute distributing database;the other is to query about at- tributes.Then the complexities of time and space of the applying algorithms are discussed.
