| The black soil region is China’s major grain producing areas and major grain production base, to maintain the production of safe food has a very important role. But a long time ago, the people building large-scale production, excessive reclamation of arable land, coupled with unreasonable land use, scientific farming methods, resulting in a very serious soil erosion. The erosion gully widely distributed in Northeast Black Soil area, gully erosion is a very important part in the local soil erosion. With the development of erosion gully, it swallowed arable land, topsoil erosion, lower soil fertility, reduce food production.With the development and application of 3S technology, research methods of erosion gully also made progress, they can conduct large scale and longer time span positioning research and quantitative research. The data source of this study is Corona image in 1965, and SPOT5 image in 2005 and some of China image, The use of artificial interpretation and field investigation method combining extracted three periods of erosion gully information. Erosion gully interpretation heavy workload and complex environmental conditions, We need some people completed to finish this work. In order to get true, accurate results, we have established erosion gully interpretation signs, determining erosion gully extraction methods and procedures, We have finally been able to reflect the actual situation of erosion gully interpret results.Digitized the natural environment factors, and comparative analysis of three land use information, slope and erosion gully number information and distribution of information, research erosion development contact with the environment factors. Through regression analysis of various factors, establish erosion gully risk zoning within the study area, and proposed classification urgency erosion gully harnessing this study obtained results are as follows:1. In 1965 the erosion gully number is 2463 in the study area, In 2005 the erosion gully number is 11052, In 2012 the erosion gully number is 12381. After nearly 50 years of development and evolution,2012, the number of erosion gully is 5.03 times that of 1965. Gully density in that area in1965 was 620.36 m2/km2, in 2005 was 3718.49 m2/km2, in 2012 was 4723.10 m2/km2, Gully density in 2005 was 7.61 times more than 1965’s. As can be seen from the evolution of distribution of erosion gully, in 1965, the gully density is sparsed, only slightly concentrated in the central, southeastern. In 2005, the max gully density was 2.79 times more than 1965’s, and develop rapidly all in the research area, with focus on the development of contiguous signs. In 2012, the max gully density have a little down, but overall intensity values continue to increase, the erosion gully has formed a contiguous focus of trends.2. Gully erosion in black soil region is controlled by multiple factors such as topography, soil, lithology, climate, land cover and human activity, and results of other natural environmental factors. By analyzing individual factors, It can be found in the development of erosion fissure increases with increasing rainfall erosivity, have a good correlation, Through analysis of topography. First, the degree of erosion fissure was found with increasing slope increases when the degree of slope erosion fissure is 3-4° at the highest, and then with increasing slope gradually reduced, in two directions, erosion fissure on the western slope and southwest slope of the highest. Erosion fissure degree slope-shaped gap is not obvious. Four kinds of soil is mainly distributed in the study area, a high degree of erosion fissure is black soil and meadow soil. There are nine kinds of strata in the study area, Basalt and Alluvial rock in the highest degree of erosion fissure. The arable land is the most important areas for the gully development. Distance from the settlements to the same erosion fissure value and has a good correlation. As can be seen by human activities have a significant effect on the erosion gully. Correlation Analysis erosion fissure degree of each factor in 1965,2005 and 2012. Results show the rain erosivity(R)correlation in three different periods is a significant correlation, and have the most relevant. This shows the degree of erosion fissure have the most prominent with rainfall erosivity (R)effects in the study area. From 2005 to 2012, erosion gully developed rapidly, need for effective control measures as soon as possible. Erosion gully value of average annual growth of 143.51m2/km2.3. In this study, the various effects of erosion gully elements regression analysis, superimposed on the five factors have a significant impact, Create erosion gully risk zoning map of the study area. analysis erosion fissure distribution, Proposed erosion gully control the urgency of the study area. Classification of urgency. This is for the local government to better understand the status of erosion gully development in the region, the rational use of limited funds be better erosion gully harnessing provide a scientific basis.4. Innovative content of this study is the first time with erosion gully three remote sensing images and interpretation of data in typical black soil area, Study on the development of 50 years erosion gully. By superimposing the major factor impact of erosion gully develop, Create erosion gully risk zoning map of the study area.Through these innovative achievements, Local governance can be provide technical support and scientific basis for control the erosion gully in this region. |
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