A Study On RS-based Assessment Of Eco-environment Effects Caused By Land Use In Qiqihar City

With the rapid development of economy,the increasing of population, land use and land cover changes in the pattern of depth,breadth and speed showed a trend of dramatically increasing and contradiction between economic development and ecological environment has become increasingl y prominent. Land use change not only causes the climate,hydrology,soil,biological geochemistry circulation as well as biodiversity changes,but also affects the ecological environment of regional and even global,affecting the social and economic sustainable development of the region. So the re-search of land use cover change and its ecological effect,for the understanding of the regional and global environment change has important theoretical significance,but also can p rovide a scientific basis for regional sustainable land use and ecological environment construction.This study takes Qiqihar city as the research object,using the interpretation data of Qiqihar city in 1989,2002 and 2014 remote sensing data,combined with statistical analysis,based on the analysis of the land use cover change,the number of land use change.In this paper,the quantitative analysis and description of the change of land use,land use degree and transformation mode are quantitatively analyzed and described. By using the method of principal component analysis,the driving mechanism of land use change in Qiqihar city was analyzed; Based on the concept of pressure-state-response model,This study builds an index system and a weighted composite function evaluation model.And by means of GIS spatial analysis functions,ecological environmental effect of land use of Qiqihar city in the temporal variation characteristics are analyzed,in order to the sustainable use of land in the area and the ecological enviro nment sustainable development an-d economic growth to provide reference.The study results figure that:(1)During the period of 25 years,the land use change in Qiqihar City is intense. And land use types are mainly composed of cultivated land.The change of cultivated land is mainly focused on the period from 1989 to 2002.Woodland area increased year by year,which the main source of were the cultivated land,grassland and water.Grassland area first increased and then decreased.These changes are mainly concentrated in the 2002-2014 year time period.During the period,area has dec-reased by 3.05×104 hm2.Water area reduced significantly,which were decreased by 24.26×104hm2 from 1989 to 2014.And the area reduced,mainly concentrated in the 1985 to 2002.In this period of time,the area has been reduced by 24.61 x 104 hm2. The most part converted to cultivated land.Con-struction land area is increasing year by year,when was in the time period 2002-2014.Unused land increased first and then decreased,most of which transformed into cultivated la nd,grassland and w-ater.(2)In 1989-2014,the land use comprehensive level of Qiqihar city continues to increase. The main influencing factors: annual accumulated temperature,population,population density,urbanizat-ion level,GDP,grain production,agricultural fertilizer application amount,agricultural plastic film usage,the use of pesticides,rural per capita net income,agricultural machinery gross power,agricult-ural machinery total power,etc.(3)Volatility change of ecological environment of Qiqihar city appears.The ecological environment index showed the first decline after rising trend. The ecological environment of Qiqihar city changed from the general situation to the poor situation,the ecological environment index of which fell to 0.39 from 0.51. The ecosystem function showed the state of degradation. Until 2014,the ecological environment index rose from 0.39 to 0.43. The ecological environment was slightly better.(4)In 1989-2014,the ecological environment in Qiqihar City as a whole showed det erioration, especially in 1989-2002 the decline trend of urban and Nehe City was the most obvious. In 1989,t he ecological environment of Urban District,Nehe City,Longjiang County,Yi’an County,Keshan County,Tailai county and Gannan county was relatively better,followed by Fuyu Cou nty,Baiquan County and Kedong County,the ecological environment was poor. The ecological environment of Baiquan county was the worst.In 2002,in addition to Gannan county to maintain the general situati on.the ecological environment of the rest of the counties changed more strongly,showed signs of deterioration,but the ecological environment of Tailai county was the most serious situation. In 20-14,Urban District and Nehe city continued to maintain the trend of deterioration,the ecological en vironment of which was still in poor situation,especially Nehe city,the ecological environment wa-s the worst. The ecological environment of Gannan county changed significantly. Although Longj-iang County,Yi’an County,Fuyu County,Baiquan County,Keshan County,Kedong County and Taila-i county were slightly better,the same was still in poor condition,and the ecological environment i-ndex showed an increasing tendency in different degrees.