期刊:
2010 The 2nd Conference on Environmental Science and Information Application Technology,2010年3:401-405
作者机构:
[Hao Liu; Ling-ling Tian; Ying Dong; Xiao-shi Shi; Can-can Xiang] College of Urban and Environmental Science, Central China Normal University, Wuhan, China
摘要:
Urban wetlands play a significant role in the sustainable development. But the effect of human action on urban wetlands has been expanded in greater scope and depth, which may cause the accelerated degeneration of urban wetlands seriously. Based on the historical data of land using maps, topographic maps and TM images of Wuhan from 1930s to 2005, which were through the Man-Machine Interaction in ArcGIS System and ERDAS IMAGINE, and the field data through the fieldwork and questionnaire research in 2009 and 2010, the urban wetland database from 1930s to 2005 in Wuhan had been established. Then, the spatio-temporal evolution of urban wetlands was quantitatively and qualitatively analyzed. Urban wetlands have been degenerating seriously, and the tendency of its degeneration is all but irreversible. The results showed that: (1) the area of natural urban wetlands decreased: lake wetlands decreased by 55% from 1930s to 2005; (2) pollution state of urban wetlands worsened: no lakes reached Grade I, and the remaining 65.4% exceeded Grade V; (3) decline in biodiversity had been becoming worse and worse; (4) the urban wetland landscape fragmentation had augmented a lot. Based on the statistic data of socio-economic factors from 1930s to 2005, we analyzed dynamic changes of urban wetlands, and by making use of the correlation analysis of SPSS, analyzed the direct factors consisting of agriculture-inning, engineering construction, resource utilization and biological invasion, and the basic factors consisting of population explosion, urbanization, industrialization, mass consciousness and public policy.
摘要:
The purpose of this study is to identify and classify the ecological risks in land consolidation, and to develop a framework of the theory and method to assess the change of ecological risk degree before and after land consolidation. Environmental impacts and ecological risks of land consolidation have recently drawn much attention, and there are two opposing viewpoints to assess these impacts and risks in the academia of China. Both viewpoints result from the bias of assessment anticipation. Land consolidation includes four main engineering aspects in China, and ecological succession from start of land consolidation to ecosystem stabilization should pass three phases. Different ecological impacts and risks of land consolidation rise from different phases of ecological successions. According to the climax theory of ecology. we developed a framework of the ecological risk assessment based on the anticipation of ecosystem stabilization (ERABAES) for land consolidation. We applied analytical hierarchical processing (AHP) method to the data resources from the land consolidation project in Southern China to allocate weightings to the indices of ecological risk (ER), and to set up an integrated index system for the ecological risk identification. This integrated index system encompasses the ecological risks with three factors (water, soil and biology) and 14 indices. The results of the project show: (1) The ER is reduced from 58.02 to 28.8 after land consolidation and the degree of ecological risk is down from Degree III to Degree IV. (2) According to the element analysis, the water ER is reduced from 21.53 to 6.16, its contribution to reduce the ecological risk is 53%; the reduced ERs of soil and biology are respectively 12.79 and 1.06, their contribution of ecological risk reduce is lower than water. (C) 2009 Elsevier Ltd. All rights reserved.