| Land utilization/ conversion interacts with the water resource, and its type and extend of function depends on the synthetic effect of both the natural environment and the human factors in the field. Natural environment is the basic context of the water and land resource of the zone. To some degrees, the natural environment holds the domination. Human factors, take the society, economy, technology and policy for example, are the guiding factors, and play the role of leading to some extend. Land utilization conversion is one of the specific demonstration kinds of the function on the natural environment from human activity. It is an important component and the chief reason of the conversion of the global environment, also, one of the principal impulse elements of the hydrologic conversion. Human activity alter the spacial structure and process of the natural conversion of the hydrologic circle, through the approach of changing the land utilization/coverage conversion, at the same time, this enhances the complexity of the water resource formation and diversification. Land utilization/coverage conversion effects the quality and spacial distribution of the water resource, it is the major factor leading to the conversion of the water resource. Thus, it is beneficial for superizing the configuration of the water resource, the sustainable development of the social economy and the ecologic environmental protection to take out the research on the effect of land utilization/coverage conversion on the water resource environment. This paper builds up the database of the land utilization and the earth erosion in the middle of Jilin province, on the base of completing the research item of the water resource protection and utilization countermeasure policy. It involves the water resource investigation throughout the whole country, the ecologic environmental investigation relating to water, the remote sensing investigation of the earth erosion and the achievement of the national "95"technologic items, and selects the remote sensing impression as the major source of the information, making use of the GIS space analytical technology, quantitatively anatomizes the process and rate of the land utilization/coverage conversion in the year of 1988, 1995, 2000 and the ability of the nature and the social economy affection, calculates the effect of the land utilization/coverage conversion on the earth erosion, ecologic demands for the water resource, surface flow and water quality, groundwater resource, with the technology of remote sensing, hydrologic analytical method. Its chief content is as follows: 1. The building up of the resource environmental database of land utilization/coverage conversion in the middle of Jilin province, through the technology of remote sensing and GIS, including the graphic one and the property one, besides, the graphic database encompasses the remote-sensing data and the special graphic data; the property database encompasses the statistics data of various categories. 2. The quantitative research on the process of the land utilization/coverage conversion in the middle of Jilin province in the year of 1988, 1995, 2000, adopting the landscape ecologic index and spacial. The analysis on the intertransition among the land of various categories and the land utilization conversion impetus, the calculation of the rate of the land utilization conversion, with the graphic iterative method. 3. The analysis on the effect of land utilization/coverage conversion on the earth erosion in the middle of Jilin province on the base of graphic iterative method and the land type conversion, with the application of the combination of the remote sensing and GIS spacial analytical technology. 4. Analysis on the effect of land utilization/coverage conversion on the land outflow, adopting the hydrologic and statistic analytical method. Furthermore, we calculate the quantity of the land outflow, according to the land utilization/coverage conversion. 5. We calculate the burthen of the contamination of the non-point resource on the base of the investigation on it, and analyze the effect of the landutilization/coverage conversion on the surface water environment in hydrologic way. 6. With the support of GIS, we analyze the effect of the land utilization/ coverage conversion on the groundwater quality, involving the method of hydrogeologic technology and experimental analysis technology. Achievement of the research: 1. On the whole, the characteristics of spacial configuration of the land utilization in the middle of Jilin province are: the preferential type of the land in the middle of Jilin province is furrow, occupying over 70% of the total area, being the foundation of the landscape in the field. Timberland and watershed are the two followed, with the area of about 13% and 8% of the total field. Timberland, meadow, resident field, construction field, watershed and non-utilization land can be classified as the studded body of the furrow. Timberland, meadow, resident field, and non-utilization land hold great ratio of fragmentation, while furrow small. The augment of the furrow is obvious, while the number of the lumps which leads to the decrease of the average area. This indicates the spacial focus property of the field is becoming strong. 2. The extent of the land utilization is high in the middle of Jilin province. Natural factors limit the ways of land utilization, the land utilization/coverage conversion is in the charge of the human factors, such as the policies, social economic development, the increase in population and so on. During the year of 1988 and 1995, the area of furrow in the middle of Jilin province increased largely, in the influence of the innovation. And the year of 1995 and 2000, the area of the furrow decreased a little and the timberland increased a little, according to the policy of furrow protection and ecologic environmental policy. Relative stable space configuration came into being gradually. 3. The earth erosion in the middle of Jilin province takes on the trend of the decreasing area on the whole, which mainly due to the predominate furrow area rises according to the increase of the paddy field and the carrying out of the protection policy, more emphases people draw on the furrow this years. Though the erosion degree of the timberland, construction land enhanced, which leaded to the configuration of the whole trend down while local up. The earth erosion due to the land utilization conversion is in the state of becoming stronger. The prevention and cure of the earth erosion seems to be tough.4. The relationship between the land utilization/coverage conversion and the quantity of the river flow is complex, the river flow conversion due to the factor combination of the land utilization/coverage conversion of various types. The calculation indicates that: the decrease in the timberland, watershed area is benefit for the ground outflow. On the whole, the land utilization/coverage conversion in the middle of Jilin province is good for the formation of the ground outflow in the year of 1988, 1995, 2000, and is vulnerable for the flood. 5. Analyse the effect that land utilization/coverage conversion on surface stress flow exerting the method of stress flow curve exponent, analyse the effect that land utilization/coverage conversion on surface water source through contrasting quanity of natural stress flow with fact of it and chang of river stress flow between snaps mang years. Researches show that exploiting paddy field excessively is one of reasons that lessend of quantity of river. 6. Analyse the effect that changr of land utilization/coverage conversion on quantity and quality of surface water according investigation of non-point source , and the effect that contribution rate whith change of land utilization/coverage conversion on river quatity.The area of furrow and resident construction land increases largely in the middle of Jilin province. The quantity of the fertilizer and the pesticide increases all the time. The burthen of the non-point source contamination increase, especially in the buffer zone between the furrow and the river, which is bad for the prevention and cure of the contamination. The index of nitrogen and permanganate in the river takes on the upward trend, which indicates that the contamination is enhanced. contribution rate of COD is 42.6%, that of a-nitrogen is 45.4%,that of assemble nitrogen is 77.6%,that of assemble phosphor is 86.6%.Researches show that agro-production's non-point source contamination is leading factor of river quality polluted now. 7. The land utilization/coverage conversion in the middle of Jilin province leads to the drawdown of the groundwater ,stress folw and drainage in the area, the average drawdown is 3~5m. Firstly, the land utilization/coverage conversion makes the quantity of the water resource development. Secondly, it decreases the inflow recharge of the groundwater resource. It is result about decreases the inflow recharge of the groundwater resource and increase the exploitaion and utilizion due to change of the land utilization/coverage conversion.
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