| Land desertification was an important ecological environment problem which has always been a great importance to scholars both at home and abroad,was a complex frontier issues.Based on above,this article applied the regional comparative analysis method,which was represented by Duyangshan in Guangxi and Bashang area in Zhangjiakou.To analyzed the similarities and differences of desertification,and to reveal the dynamic characteristics and driving mechanism of desertification.Scientific and reasonable measures to prevent and control desertification are put forward.Firstly,the article takes full advantage of the MODIS remote sensing image as the data sources.It is proved that the NDVI-Albedo feature space with land surface albedo and vegetation index apply on typical desertification has a strong negative correlation,then establish the desertification graded index model,extract the classification of desertification level in the three periods of 2005,2010 and 2015.Based on the field investigation,the desertification degree was divided into four scales,including mild,moderate,severe and none desertification.Secondly,ArcGIS software was used to extract the desertification dynamic information from year 2005~2015,the study on the temporal and spatial variation characteristics of land desertification was then carried out.The results indicated that:(1)The area proportion of serious desertification area gradually decreased year by year in past 10 years;(2)Desertification land area in the study area showed a downward trend in past 10 years;(3)The desertification degrees in the northern study area grew worse,some areas continued to deteriorate.While the desertification degree in the southern study area were continuously decreased,ecological status is getting better.Thirdly,taking the two clues of time and space,the similarities and differences of the single factors of desertification in the typical area were compared,and the driving mechanism of the dynamic change of desertification land in 2005~2015 was revealed.Constructing evaluation index system on driving force in desertification which performed based on nine index as geomorphology,lithology,slope,annual average temperature,annual average precipitation,maximum daily precipitation,annual average wind speed,population,land use type.Spatial principal component analysis(PCA)was used to extract the main influencing factors in the study area.The results indicated that: the formation of land desertification in the study area was the result of both the natural and human factors,and the important influence included three as precipitation,precipitation,population and land use type.The main influencing factors were slope,precipitation,population,land use type and maximum daily precipitation in Southern study area.Among them,the slope was the greatest influence on the desertification degree.The main influencing factors were population,precipitation,land use type,geomorphology and lithology in northern study area.Among them,the population was the greatest influence on the desertification degree.Finally,according to the two typical areas of factors: population,land use type,rainfall,combining with the concept of local conditions,this article puts forward the control population,adjusting land use structure,reasonable exploitation and utilization of water resources the scientific and reasonable control measures.In addition,we must adhere to the "ecological" and "economic" win-win governance objectives and establish the basic countermeasures for sustainable development.Mobilize all forces to join hands in the face of desertification,so as to effectively deal with desertification and make efforts to write a new chapter on the roads of construction ecological civilization.The uniqueness of this paper was the first time in the study of desertification area comparison,which can be used as a reference index and model for the two regions and similar research. |
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