The Analysis Of Dynamics Changes And Influencing Factors About Changbai Mountains Forest Landscape Since 1990's

This work investigates the land usage in the region of Changbai moutains and the environment protection issues.By virtual of an object oriented method,dynamic picture of land usage can be obtained as TM remote sensing images.Based on it and together with other natural and social factors,the structure of the land usage in the region of Changbai mountains during past 20 years can be examined.Analysis of forestation and underlying effective natural,social and economical influences can be carried out.Also,quantitative results of the impact of the land usage on the ecological system can be mined.We finally make efforts to predict the land usage in 2020 utilizing the Markov model,which backbones the decision making for a regional sustainable development.The research outline and the conclusions are as following:(1)Medium resolution remote sensing images information data,so called the TM remote sensing of the land usage data,are captured via an object-oriented method.By also taking into account auxiliary information such as the DEM,multi-temporal,expertise and historical data,three-epoch(1990,2000 and 2010)images of the land usage are more effectively extracted.All the images well pass the classification accuracy tests implemented by sampling verification.The classification accuracy for the three epochs are respectively 88.79%,89.91%and 88.39%.(2)The landscape pattern variations in the Changbai mountains region during the 20 years from 1990 to 2010 are interpreted by means of landscape index.The corresponding ground coverage information in the three epochs is obtained as a consequence.Through the constructions of transferring matrices,the dynamic models and center of gravity model,we are able to track the quantity,rate and trend of transformation among various land features.As a result,we are further aware of the essential transformation between forests and other features.It is demonstrated that in Changbai mountains region,during the 20 years,the overall loss of the area of forests is 344.85 km2,implying an annual deforestation rate of 17.24 km2.The transformation from forests to arable land,amounting 476.83 km2,accounts for the largest percentage of such deforestation.24.2%of the area of arable land in 2010 is attributed to this origin.Reverse conversion from arable land to forests added 2%of the area of forests,which takes 264.60km2.Forests tend to be more concentrated to the northeast region.(3)The driving force of the time variations of forests in the Changbai mountains region is unveiled from both aspects of natural and social factors.There is a negative correlation between the population and the area of forests.Meanwhile,forests are affected by terrain,leading to a vertical distribution.The variations of forests at high altitude are less significant.The combined effects of the natural reserve boundary and the population distribution cause minor variations of forests within the 15 km range from the natural reserve,maximum variations at 30-45 km range and fading variations beyond the maximum.