Ecological Restoration And Reconstruction In Open Pit Area Based On Landscape Pattern Changes

The exploitation of opening-pit coal mine brings a series of social economics, and ecological problems with its destruction and occupation of numerious lands, local water system, damaging living chain, degeneration of ecology and pollution of environment. Ecological restoration work in mine area has already aroused widespread attention and be one of relatively active research topic.It is researched the second phase of mining of Xiao Longtan in this thesis, by using the satellite images taken in 1992,2000 and 2006, and applying to "3S" technologies to study and analysis the dynamic change of the land's usage and landscape pattern. At the same time, the methods for analyzing agricultural soil was used to test the chemical characters of the soil in the stripped area. On the basis of careful study and analysis of the ecological restoration technology and engineering measures taken in open-pit coal mine at home and broad, measures to restore the ecology in these areas are brought out with local conditions. The main conclusions are:(1) By analyzing the change of the quantity, the structure and the speed in land use of study area, the results that the style and area of land use change a lot from 1992 to 2006. This include the area of some industrial and mining lands are increasing, such as mined zone, waste dump of open pit coal mine, and shrubbery lands, while that of farmlands on which residents rely and waters are decreasing gradually about by 80% in 15 years, the increase on the style of land use are followed as waste dump> mined zone>stripping zone>shrubby lands>residential areas>wasteful grassland, and the rate are 7.86%,2.92%, 1.89%,1.57%,0.85% and 0.7% respectively, of which waste dump growing fast and wasteful grassland and residential are slower comparisionly, while dry land, paddy field and waters reduce. The rate of paddy field reduct rapidly reaching 4.9%. Waters are followed by 3.36%. The trends in landscape pattern changes reflects the mine's construction is based on pressed accounts on farmlands.(2) Through the establishment of landuse transition matrix, getting the process of land use in study area. Mining, waste dump and stripping zones are transferred from the dry land and paddy fields. Because a large number of farmlands become industrial and mining land and shrubbery land, the level of land use decrease, agricultural productivity goes down.(3) According to the theory of landscape ecology, selecting and calculating the three landscape level indexes of different periods with Fragstate 3.3 software, the characteristics of landscape pattern changes in different periods have been obtained. In 15 years, with the reduction of farmlands, industrial and mining lands increase, the landscape has also been changed a lot. All in all, humans' mining activities have been resulting in the increase of landscape fragmentation, the reduction of biodiversity.(4) Using agricultural experimental methods to analyse soil physically and chemically characters and composition of soil in stripping zones, the results showed that:affected by mining, the effects of soil, such as organic matter, nitrogen, phosphorus, potassium was low, and then the soil was barred. Also referring to the Card-Qing Gaussian soil texture classification criteria, determination of composition of soil texture found the basic structure of the soil profile in the study area has not changed. Only to improve soil fertility, crop cultivation can be carried out.(5) Through comparative analysing the changes in landscape pattern and various reclamation models of the study area since it has been open up, the appropriate soil amelioration and vegetation configuration, ecological restoration measures was put forward, and the intensive agro-ecological model was selected. As a result of exploitation of a larger volume of the earth would not be enough to restore into a terrace. Xiao Longtan open-pit coal mine and dam cloth marsh area planted in the earth after the plantation. It promotes regional eco-environment to be restored, and realized the economic harmonization of the ecological and social effectively and efficiently.The research achievements mentioned above, deepen the understanding and awareness of environment impact in Xiao Longtan open-pit coal mining. It not only provide theory and technical support for ecological restoration of mining areas in the region, but also provide a theoretical basis and reference for conducting ecological restoration in other mining areas in Yunnan Province and realizing the regional eco-environment-coordinated development of socio-economic system. So it has an important reference role and practical significance.