The Ecological Restoration Eesearch Of The Severest Disaster Area Of Wenchuan Earthquake

The Wenchuan Earthquake of8.0magnitude at Richter scale hit large region ofSichuan, China on May12,2008. Not only did it cause huge death, injuries andeconomy losses, but it ruined the local eco-environment badly, which damaged thefarmlands, destroyed the vegetation, blocked the rivers, broken the habitat of the rareanimals. The severest disaster area of Wenchuan earthquake located at the transitionzone from the northwest of the Sichuan Basin to the east of Tibet Plateau, there arecomplex geology structure, various geomorphology types, fully fragileeco-environment. At the same time, the region’s physical geography elements endowthe severest disaster area with ecological service function such as water and soilconservation, water conservation, Biodiversity and so on. It is one of the importantareas for ecological defenses of the upstream area of Yangtze River. It plays anirreplaceable role in protect biodiversity and ensure the safety of water consumptionof the Chengdu Plain. Therefore, researching and analyzing the ecological damageand the ecological restoration situations of the severest disaster area has veryimportant meaning to promote the restoration of the damaged ecosystem effectivelyand scientifically.In this study, from the perspective of landscape ecology, the classificationstatistics has been used to count the landscape ecological types of the severest disasterarea before and after the earthquake with RS and GIS techniques. The author masteredthe landscape pattern, regular rules and the impact factors by using the landscapeindex and transformation matrix. Based on the theory and technology restorationecology, the recovery suggests of the damaged ecosystem of the severest disaster areahave been proposed.The main conclusions drawn in this research include:(1) The study of landscape pattern transformation. Based on the multi-phaseremote sensing data, by means of RS and GIS, landscape classify and index wereselected to contrast the landscape pattern, study the temporal and spatial pattern oflandscape and regular rules of the severest disaster area before and after theearthquake. The result shows that the landscape fragmatation of the severest disasterarea became aggravated, the shape of the ecosystem became complex after the earthquake. After three years restoration, the landscape shape at the patch level getsbetter than before, the area of the filed, woolland and glassland raise, the area and theaggregation of utilized land decline, but the pattern of the whole landscape stay thesame.(2) The influence factors of the ecological restoration study. Considering thephysical features and the terrain condition of the severest disaster area, classify theslope and the elevation of the severest disaster area, study the temporal and spatialcharacteristic of vegetation fraction on the basis of different grade partition. Theresult shows that the vegetation areas were distributed mainly at the gradient10°-20°region, and the elevation1000m-3000m region. At the low elevation and thelow slope region, the vegetation fraction hasn’t change so much at all time, because ithas been influenced by human. Except the low elevation and the low slope region, therestoration effect become bad when the slope and the elevation raise. According to thefield survey and information collection, the main factors of man-made contains felling,quarrying and grazing that seriously retardant the ecosystem restoration.(3) The restoration suggestions were proposed. According to the restorationcondition of the severest disaster area, the author suggested the representativephysical features should be considered when the recovery measures were carried out.On the basis of the significance and the restorability of the damaged eco-environment,the most important area should be recovered first. Emulate the idea “governanceunless it can’t” from Japan, eliminate the geology damage that avoid the ecosystemdamaged over and over again. Establish the ecology restoration monitor net of theseverest disaster area, master the regular pattern of the damaged ecosystem by collectthe data from the restoration fields regularly, supply theory direction and technicalassistance to the subsequent restoration of the study area or other earthquakes.