Study On The Change Of Soil Erosion In Upstream Mountain Area Of Huaihe Basin Based On "3S" Technology

The soil erosion of Huaihe basin has been the Main issue which the Huaihe basin harnessing has to face up to since 1980.From the latest 20 years,the conservation of water and soil in Huaihe basin has obtained the remarkable achievements,however,the issue of water and soil loss in Huaihe basin was not improved fundamentally.The soil and water conservation is a very difficult task all the same.The mountainous region in upstream of Huaihe river comprise the Dabie mountain area and Tongbai mountain area in the upstream of the mainstream of the Huai River.It has functions that can conserve water resources and regulate river runoff.This region is the barrier that can maintain ecological balance in the whole area of Huaihe basin.But in recent years,the incongruous use of the land induces the serious man-made water and soil loss.The issue of water and soil loss in the mountainous region in upstream of Huaihe river has been the most serious in Huaihe basin.Therefore,the study on the change of soil erosion in this region, exploration to the influence that the change of land use has exert the intension of soil erosion, have significance to search after more efficient methods of water and soil conservation in the mountainous region in upstream of Huaihe river.This research studied on the dynamic change of space and time quantificationally in the mountainous region in upstream of Huaihe river based on the land use and soil erosion data in the year of 1995 and 2000 in virtue of "3S" technology.On this basis,focuses on the analysis of the dynamic change of soil erosion among 5 years and the character of change of soil erosion in cities and counties and the influence that the change of land use has exert the intension of soil erosion.The results indicated that:The intensity and the area of soil erosion in the mountainous region in upstream of Huaihe river have had an impressive alleviation from the year of 1995 to 2000.Among this 5 years,it had biggish area changing from low-grade and moderate water soil erosion to mired water soil erosion.The changing areas were 937.61 km~2 and 291.46 km~2.In 2000,the area of above the low-grade water soil erosion in this region was 6208 km~2,it made up 23.44%of the whole region.The phenomena of water and soil loss was very serious all the same in the region.Among this 5 years,the soil erosion composite index number in the county of Jinzhai and Huoshan had an impressive decline in the studying region.It represented a decline of 0.28.The water and soil conservation engineering of important county in Huaihe basin has achieved remarkable results.From the year of 1995 to 2000,the tendency of the change of land use was the area of arable land fell off rapidly,however,the area of forest land and land used for building increased rapidly.Among this 5 years,the net decrease of the arable land was 1061.34km~2,but the net increase of the forest land and land used for building was 837.87km~2 and 274.62km~2.In 2000,with regard to soil erosion in different kinds of land use,in forest land,the erodibility of shrub land and open forest land was most serious.The erosion rate was 36.64% and 32.37%.In grassplot,the erodibility of the moderate degree of coverage grassplot was most serious.The erosion rate was up to 70.02%.In Arable Land,the erodibility of dry land and paddy field in low-relief terrain was most serious.The erosion rate was 71.95%and 48.07%. The inconsequence exploitation to the land resource and management operating system may bring about the serious result to water and soil conservation.This research discussed the relations between the change of land use and soil erosion in the mountainous region of upstream of the Huaihe fiver from the year of 1995 to 2000.The regions where the intensity of soil erosion have changed in mainly occurs in these four types of land use,such as the paddy field,the dry land,the forest land,the grassplot.Among these four kinds of land use,the intensity of soil erosion had a drop obviously in the type of the forest land. The area of the changing from low-grade,moderate and deep water soil erosion to mired water soil erosion were 325.31km~2,156.89 km~2 and 25.15 km~2.The area of the change from moderate water soil erosion to low-grade water soil erosion was 90.67 km~2.The transformation among different types of land use had influence to the changness of soil erosion.The influence mainly reflected in the reduction of the soil erosion which the transformation that the type of farming land became the type forest land and the construction land lead to.In the kind of land use where the low-grade water soil erosion change to the mired water soil erosion occur in,the area of the change from arable land to forest land was 21.96km~2.The area of the change from arable land to land used for building was 3.14 km~2.This indicated that the returning land for farming to forestry was an effective measure of soil and water conservation.This kind of change to land use was propitious to the alleviation of soil erosion.