| Erosion of soil is one of the most common and significant phenomenon of environmental lapse. At the mean time for hμman society it is the most active and sensitive factor which result in environmental disaster. Among the global ecology and resources and environment issue, erosion of soil is the most common and significant one. Basin of Wu Yuer river which is representative region of chernozem region of northeast China was choosed as the study area. The whole study was based on science of soil erosion and landscape ecology theory. The spatial analysis method based on remote sensing and geographic information system theory was applied to study spatial-temporal pattern and evolutionary processes of soil erosion from 1980 to 2010 by dviding the whole process into four periods. The main diven facor espically the comprehensive management activity in the river basin which was constituted of agricultural land was analysed. The effection of landscape structure to chernozem rosion was discussed to provide the reference for the land use plan and management activity in the similar area.The main research conclusions includes :(1) By using revised universal soil loss equation(RUSLE) generally analyzed the all kinds of nature environment factor’s effect for soil erosion under the watershed scale. Then the main erosion factor which include rainfall erosion factors(R), soil erosion factor(K), slope length factor(LS), vegetation cover and management factor(C), the factor of soil and water conservation measures(P).Finally the database of erosion factor was built by using geographic information software ArcGIS 9.3 for 1980,1995,2010.(2) The spatial- temporal change pattern of soil erosion last for 30 years in the study area was studied from the aspect of transition probability matrix. The result indicated that a high degree of intensity of soil erosion appeared in 1980. The intensity was decreased from 1980 to 1995 where reflected in erosion area under different Erosion intensity level tend to decrease. But from 1995-2010 the intensity, area,volμme of erosion increased obviously on different levels.(3) The erosion was studied from aspect of different environmental context and aspect of different division of river basin. The result came from overlay analysis of factors like elevation, terrain slope, land cover types showed that the most severe soil erosion area existed in non-irrigated farmland which located in elevation from 150 to 200 meters and slope from 5 to 15 degree.(4) The relation between soil grades and soil erosion index was analyzed which indicated that they have negative correlation when soil grades in scope of 35-220μm and positive correlation in scope of 220-2000μm. The analysis of relation between landscape patterns and soil erosion index indicated that paddy field, forest land, grassland, marsh had a positive effect on erosion control,but there was a positive correlation between non-irrigated farmland, unused land which included saline-alkali soil and soil erosion index. The analysis of relation between landscape index and soil erosion index indicated that there was a negative correlation between fragmentation and soil erosion index which was same to relation between diversity indices and soil erosion index. But there was a positive correlation between degree of aggregation and soil erosion index. |
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