Study On Eco-environment Vulnerability In Black Soil Area In Songliao Plain

The black soil area in Songliao Plain is famous for the valuable of black soil resources, and one of China's main grain producing area and largest commodity grain bases, it is honored as China's"North Granary","Grain Storage"and China's grain security"Regulator".However, in the background of global climate change and regional economic development, with the increasing of reclaimed years, under the integration of natural factors and human factors, the problems of ecological environment was appeared in black soil area, such as soil erosion, land productivity reduction, farmland pollution and natural hazard aggravation, especially, the quantity of typical black soil is sharply reduction and quality deterioration, posing a serious threat to China's grain security.The study on eco-environment vulnerability in black soil area, is to analyze evolution history, status of eco-environmental and impact of the stress from the external factors, at the same time, use vulnerability degree to quantify the eco-environment vulnerability evaluation and classification, understand the temporal and spatial distribution and characteristics of vulnerability in black soil area, provide reference to protecting black soil, ameliorating and renewing ecological environment.In recent years, the status of soil degradation and eco-environment deterioration in the black soil area has attracted widespread attention.The previous studies on the black soil area were mainly about the status survey, impact analysis of soil degradation and soil erosion and so on.On the basis of remote sensing data and non-remote sensing data, vulnerable ecological environment, landscape ecology and sustainable development theory as the guidance, RS and GIS for technical support, this paper studied the ecological environment vulnerability in black soil area from driving force, pressure, state, impact and response. The author aimed at eco-environment vulnerability in black soil area, firstly, using the results of visual interpretation of TM, ETM images to study the change of land use, then analyzing characteristics and rules of land use change from 1990 to 2000; sorting out, mining, extracting and testing the DEM data and statistics data in black soil area, using ArcGIS, MapGIS software to extract elements of the eco-environment; integrating with the methods of landscape ecology, selecting 10 landscape indices and analyzing the change of landscape pattern from patch type level and landscape level from 1990 to 2000; using comprehensive evaluation methods, taking county as an evaluation unit, integrating with DPSIR framework model, on this basis, establishes vulnerability evaluation system for eco-environment in black soil area, then analyzes eco-environment vulnerability degree, spatial distribution and characteristics in 1990 and 2000, respectively; according to sustainable development theory and the characteristic of black soil in the area, finally, puts forward sustainable development proposals in black soil area.The vulnerability of eco-environment in black soil area was caused by the integration of original vulnerability in natural conditions and human activities.Natural factors are the basis of vulnerability, and human activities breaching the objective laws speed up the eco-environment vulnerability in black soil area.The conclusions of this paper are as follows:1.The results of land use change shows that: in the past 10 years from 1990 to 2000, the area of farmland decreased by 7.23%, construction land and others increased by 23.05% and 23.16%, respectively, the construction land and the others increasing, and cultivated land reducing formed reverse consistency; since the black soil was reclaimed, the form for land use change is from others decrease to cultivated land increase to construction land increase to cultivated land decrease to others increase.2.Landscape pattern analysis shows that: the black soil area as typical patch-corridor-matrix agricultural landscape, with cultivated land as the background, construction land and water area for the mosaic patch, the others as the corridor; cultivated land related with human activities relatively large; Most cities (counties) existes landscape fragmented trend.3.According to the results of vulnerability evaluation in 1990 and 2000: eco-environment vulnerability presents worsening trend in past ten years; The west of black soil area vulnerability is low, the cities around Changchun and Harbin cities are high vulnerability.4.From the research results, adopted evaluation model, evaluation methods and process method for evaluation indicators in this paper, which play an important role in the research of eco-environment vulnerability in the black soil area.This study certainly has some practical significance, but there is also existing the inadequacies: the land use data obtained by visual interpretation interfered by human factors largely; Some statistical data is close to matching with the remote sensing data, and accuracy is not enough; The indicator system is not perfect, certain impact factors of eco-environment were substitute by other factors; Using AHP to empower the indicator, with a certain degree of subjectivity; In view of sustainable development proposals against eco-environment vulnerability in black soil area, the author does not consider the application and implementation feasibility in their legal and social aspects.