A Dynamic Study Of Sandy Desertification Land In North-China Based On Sandy Desertification Land Information System

The changing of sandy desertification land in north China is a slow and complex process. A spatio-temporal study based on investigation to its distribution regularities as well as dynamic regularities is of critical importance to understand its distribution characteristics, changing process, developing trend and changing reasons. An effective combination of remote sensing, GPS and GIS will be greatly helpful in research of sandy desertification land in north China timely and accurately.This paper firstly gives a brief introduction on the objective, significance and research situation in this aspect. Then, a constructive design of Sandy Desertification Land Information System was puts forward, in which "3S" technology was comprehensively applied. That is, acquiring basic data by processing and interpreting the satellite image, assisted by ground investigation using GPS and other investigation method; establishing attribute database and spatial database of sandy desertification land in north China by using FoxPro and Arc\info software respectively; establishing SDLIS by joining attribute database and spatial database through Arc view GIS platform.This paper analyses spatial distribution regularity and dynamic characteristic by means of applying SDLIS and comparing the developingcharacteristic of partial regions of sandy desertification land in north China by selecting sample plot while analyzing the overall developing trend. The result shows as follows: coinciding with the climate pattern, the area of sandy desertification land in north China increases gradually from the west to the east. The area of sandy desertification land in north China shrinks partially but expands generally with the passage of time, specifically speaking, the extending speed of sandy desertification land is faster in the middle, second in the east and slower in the west of north China. The analysis to sandy desertification land types shows that the moving sand dune decreases, semi-fixed sand dune and fixed sand dune increase.