Research On Security Of Land Ecological Environment In The West Of Jilin Province

Ecological security is a new international environmental research field in the nineties of last century. It has become the main component of nation security and social stability. It is the prerequisite and foundation of sustainable development. In recent years, a lot of domestic and international scholars have carried on much research in the ecological risk and ecological health. But generally, the research level of regional ecological security evaluation is relatively less, especially the evaluation of regional ecological environment security and its'academic research results are seldom. There are very few reports about regional land ecological environment security study. At present, there are some problems in the ecological security research field, which were embodied in three respects mainly. Firstly, the foundation of special research on regional land ecological environmental security is weakness; And secondly, the construction of the database and index system lack standardization and consistency; Last, research approach and technology of ecological security need to improve. Research on security process and evolutional mechanism are more and more important with the constant aggravation of globe change and the human disturbance intensity. So, deeper (evaluation, precaution, control) and more extensive (different levels, types eco-environment system) research on ecological security need to improve. Land is the basic natural resource that is the foundation of human subsistence and development. Land cover has been changed by unreasonable exploitation and utilization of land resource. During the land eco-environmental evolution, the land system balance has been destroyed seriously, and ecological function slacked up gradually, which induced the crisis of land eco-environmental security. The western of Jilin province is in the east of the farming-grazing transitional zone in north China, where the sensitivity of ecosystem is high, the disturbance resistant performances and capability of natural regeneration are low. In recent 50 years, with the global warming aggravation, climate of west is becoming aridity. Under the simultaneous action of nature and human, land use and land cover have been changed, and the land system balance has been destroyed seriously. Soil desertification, land salinization and soil deterioration are more serious increasingly. Maladjustment of ecosystem structure and debasement make the situation of land eco-environmental security flinty. It has restricted the sustainable development of the regional economy, and also threatened the human living environment. At present, the west has already become one of the most fragile and the most seriously destroyed ecological environment areas in Jilin province, and even the northeast China. Researching on security of soil ecological environment in this area is urgency. On the basis of mentor's subject, the land ecological environment in the west of Jilin province was selected as the research object. Several research aspects were carried on by means of theories and methods of ecological security. Land use/land cover information in the west of Jilin province was drawn with 3S integrated technology. Space position was offered with GPS real-timely; GIS was the basic platform, it was used to manage and analyze space-time data; Space information was offered with RS, and the datum to GIS was updated in time. On the basis of drawing information and defining current situation of the land ecological environment in the west of Jilin province, the administrative county (city) units were chosen as the unit for the data statistics. According to the models of land use dynamic change, the research on the dynamic change on land use quantity, space structure and land use degree were carried during 1989 and 2001. The results of the research indicated that the area of cultivated land and saline land increased, and the area of meadow, water areas and wetland reduced within 12 years; The variety ratio of cultivated land, meadow, water areas and saline land changed relatively great; and variety ratio of forestland, land used for resident, industrial and mining changed more steady; The land use degree presented a reducible tendency. The analysis of land ecological environment sensitivity is the foundation of carrying on security evaluation. The result of land ecological environment sensitivity analyze indicated that land salin-alkalization was more sensitive than land degradation. It was the main sensitive problem of ecological environment ofland. The most sensitive areas distributed at Zhenlai county, Tongyu county, Da'an city and Qian'an county, Fuyu county, Qiangu county, and Changling county; non-sensitive areas were mainly distributed in southeast of the west of Jilin province and Baichen city. During the evaluation of land ecological environment security, with the aid of the space analyses function of GIS, territory range (47,011km2) of the west of Jilin province was divided into 47,114 bar 1×1km2 evaluation units. From the viewpoint of systematic pressure, state and response, the index system was design according to AHP. With the model of gray relevancy evaluation, the evaluation of land ecological environmental security in the west of Jilin province in 2001 was carried on through VB software program. The result of evaluation was represented in the form of digital picture. The result indicated that the land ecological environment in the west of Jilin was in the unsafe state generally. The area of risk grade and worsen grade was 34.37% accounted for whole western, which could show the land ecological environment security was bad. Among them, the land ecological environment security of Da'an city was in the most abominable state, secondly was Zhenlai county and Tongyu county. Songyuan city and Fuyu county were safe. Finally, according to the result of land ecological environment sensitivity evaluation and security evaluation, Da'an city was chosen to carry on the land ecological environment precaution research. According to the principle and course of precaution, on the basis of analyzing current land ecological environment situation of Da'an, the precaution research of land ecological environment in 2010 was carried on by using the artificial neural network and grey prediction models. The research contained five parts: defining the meaning of alert, looking for the alert source, analyzing the indication of alert, predicting alert degree and getting rid of the hidden trouble. The result indicated that land ecological environment of Da'an city had already in the dangerous state in 2010. The area of risk grade and worsen grade were over half of the whole city, which were mainly distributed in the southeast and the south, it was the tendency to spread to the north. To this variation tendency, the concrete guarantee measures of the land ecological environment security were proposed. The innovation and characteristic of the thesis are in these aspects: the...