Study On Temporal-spatial Change Of Vegetation Coverage In Earthquake Zone-Lushan

The ecological environment is so intertwined with the survival anddevelopment of human society, is related to the sustainable development of societyand economy. Vegetation system is the biggest component of the terrestrial ecosystem,and the change of the vegetation ecosystem is an important factor of the change of theworld. Vegetation damage by the earthquake is of great importance to the research ofecological damage. Lushan County has a vast virgin forest and rich vegetationresources. Reveal the regularity and characteristics by space and time of the change isof great significance to the recovery of ecological system and the development ofsocial economy.In this paper, we explain the concept of the vegetation coverage on the basis ofreading a large number of domestic and foreign literature, summarize the methods ofvegetation coverage estimation and sums up the principles, applicability andreliability of the various methods. This study considers the operability of variousmethods and data availability, this study considers the operability of various methodsand availability of data, choose the dimidiate pixel model to estimate the vegetationcoverage and verifiy the accuracy of results. At last, do a temporal-spatial changeanalysis and driving factor analysis of the vegetation coverage.This study collect TM data of year2001and2009,ETM data of year2005and2013, use the dimidiate pixel model to estimate the vegetation coverage of LushanCounty from nearly12years ago and verify the results of the estimation of year2013by high marks aerial photo data. Estimation accuracy is about82%.Analyse the temporal-spatial change and carried on the qualitative and quantitative analysis of thedriving factor.The results showed that: from2001to2013, the overall coverage from72.5%in2001to66.97%by2005, to rise to75.47%in2009, the last fall to70.22%by2013, adownward-growth-downward trend.We analyze the change according to each levelof vegetation coverage and analyze its change by the time period.the paper reveal thecoverage internal transformation relationship exists between the high coverage andmedium coverage through transfer matrix.At the same time, we combine the data ofdem, slope aspect, meteorological data and the earthquake factor to describe thequantitative characterization of the vegetation coverage change,analyzed the relationbetween each factor and its changes.Finally we explain the influence of humanactivities on the vegetation coverage change combining with the social and economicfactors. By studying the dynamic changes about vegetation coverage, revealing theearthquake damage to the vegetation condition and providing decision-making for therestoration in the disaster area of ecological.