Based On The Drought Areas Of The Temporal And Spatial Dynamic Ecological Environment Quality Evaluation

Human society faces the eco-environmental problem which is one of global issues nowadays, and which is one of the hot issues of environmental assessment. Environmental problems has become an obstacle to economic development in arid areas are facing major problems. The assessment environmental quality in arid areas is the purpose of the contradictions of the ecological environment and economic growth transfer into the unity, and it pursuits of the ecological balance in the economy, and economic development in arid areas coordinates with development of ecological protection, and it establishes a reasonable evaluation system of eco-environment quality.In this paper, RS technology is acted as the primary means of monitoring, and the use of GIS as a primary tool for spatial analysis and mapping methods. According to the characteristics of eco-environment, it is established an evaluation system of ecological environment quality which consists of meteorological factors, topographic factors, land and vegetation factor as a level factor index layer, and each level indicators is make of indicators. At the same time, it establishes the space-time dynamic model, including the transfer model of land-use, NDVI analysis model and the model of spatial and temporal changes rate of EQI. And information of the assessment of eco-environmental quality release to service based on Web Service, in order to achieve information sharing and utilization. In case of ShiYang River Basin in Gansu, evaluation system of ecological environment quality and space-time dynamic model is correct.Through the study, conclusions of this paper are elicited as follows:(1) Through the study of the ShiYang River Basin, the quality of ecological environment evaluation system and the space-time dynamic model is reasonable and correct.(2) The ecological environment of the ShiYang River Basin shows significant level differentiation, vertical differentiation and the spatial and temporal variation. In the horizontal direction, the ecological environment quality in the basin upstream of the best, followed by middle and lower reaches of the worst environmental quality higher degree of spatial fragmentation. From the administrative areas, Gulang County, YongDeng County, SuNan and TianZhu Tibetan Autonomous County of the ecological environment quality is good, however, since it's mountainous and less populated, relatively little changes in environmental quality. In addition to relatively continuous desert areas, the rest scattered like distribution were tested; in the vertical direction On the more obvious differences in the distribution, showing a normal change, from the region starting at the lowest point of 1180m to 3000m or so, and he rise of ecological environment quality, from 3000m upwards, environmental quality and show a downward trend, an inverted distribution pattern of "U" Shaped. Dynamics in space and time, mainly from the transfer of land use, NDVI temporal and spatial variation degrees, EQI of space-time rate of diversification.(3) From the perspective of the transfer of land use, changing area was mainly in the central region from year1990 to 2000, and mainly south-east from year2000 to 2004, and changing area from year 2004 to 2009, particularly in scattered broken, ecological Great impact of environmental damage; NDVI temporal and spatial variation degrees, it is similar in three periods, and changes higher degree of ecological damage occurred in central and southern, in 1990-2000 then in the 2000-2009 period the region; the rate of change of time and space from the EQI in 1990-2000 occurred in the areas of ecological damage in the period 2000-2004 to improve environmental quality, ecological damage occurred in 2000-2004, the region from 2004 to 2009, part of the ecological environment quality has improved, but the ecological damage from the western to the eastern region, and ecological destruction trend intensified significantly.(4) Geographic information database technology and spatial information services were integrated depth with business service system based on Web Service spatial information. And eco-environment quality in ShiYang river basin is released by Web Service spatial information technology, in order to accomplish the aim of sharing and utilization.