Analyzing Soil Erosion Of Haitan Island, Using RS And GIS

Soil erosion, a global hot topic, is the main reason of land deterioration. In our country, the protection of water and soil loss is an important part of land territories'prevention and treatment. Haitan Island, since established as integrated experimental site, has greatly pushed fundamental construction events. Its original zoology construction has been destroyed, which to some extent, triggers water and soil loss. This research which is made use of GIS and remote sensing image technologies, and based on RUSLE model, K-means algorithm, and exploratory spatial analysis to value the water and soil loss of Haitan Island. It mainly contains the following conclusions:(1)Using remote sensing image technologies to extract water and soil loss factors like land utilization, vegetation coverage, and soil moisture. The land utilization explaination, which is combined the algorithm of the largest minimum redundancy method and CART decision tree algorithm, can realize fast and automatic classification. By using the mixed pixel decomposing model to extract vegetation coverage, and according to the on-the-spot investigation's data to verify accuracy, the result showed that the vegetation coverage rate is above 85%. It also showed that the vegetation coverage rate is high in the relatively high altitude hilly areas, whereas it is low in the relatively low altitude and human activities'areas. By using the TVDI index to invert Haitan Island's soil moisture, the result accorded to the tendency of the vegetation coverage rate.(2)Based on RUSLE model to figure out water and soil loss erosion amount, it showed that in recent years, influenced by the engineering project, strong, tense and even violent rank of the water and soil loss areas expands. Strong, and even above ranks of water and soil loss mainly appear in above 15° areas. With the aggravation of loss degree, the vegetation coverage rate declines.(3)Using the exploratory spatial analysis to analyze Haitan Island's water and soil loss spatial distribution pattern. Local variance method confirmed the best analysis scale of Haitan Island's water and soil loss analysis is 300 meters. From 2009 to 2012, spatial autocorrelation analysis and Semi-variation function analysis showed positive correlation distribution in 6500 meters, and the distribution had isotropy feature. Soil erosion modules rate enhanced while the differency of spatial distribution expanded. In small range(within analysis scale), the correlation remarkably enhanced.(4)Construct Haitan Island's wind erosion hazard's evaluation index. Using K-means cluster solution, on-the-spot data and connected knowledge to judge Haitan Island's different wind erosion hazard types and classify them to 3 degree. It shows that Haitan Island's wind erosion hazard greatly influenced by vegetation coverage. The higher vegetation coverage rate, the stronger wind erosion resistant ability. Bare lowland areas had high wind erosion hazard rate.