| Farmland resource is one of the economic resources in nation. It is the basis production data. It endures the need pressure with the increase of the population and the improvement of the economic. In the china with high speed increase of economic, land resource, especially of farmland resource, the need pressure is changed with utilize way and quality.The paper propose a method, using the RS and GIS technology ,based on the land using and dynamic change datum through the RS survey and Chinese DEM datu, Chinese weather datuiru Chinese landscape ecology index datum, analyze the dynamic change of Chinese farmland .Farmland is parted the dry land and paddy land to separately analyze, meanwhile the dynamic is parted the increase and decrease .the increase is indicate the other land using types conversed to farmland, the decrease is indicate the farmland conversed to other land using types. The content of the paper is followed:First, according to the farmland changed model:S0 is the farmland total area of survey sample region in start time, ds; i the changed area between the farmland and the i of the type land using ii the all of the survey time; t is the segment of the time; S is the changec degree of the sample region comparison to the t segment of the time.Unit with the Kilometer gridding , form the near the last decade changed charts, including Chinese paddy land increasing degree distributed chart > Chinese paddy land decreasing degree distributed chart, Chinese dry land increasing degree distributed char, Chinese dry land decreasing distributed char. This four charts clearly show the space distribute of the Chinese farm greatly dynamic change in the last decade .The mostly paddy land increasing regions are the three provinces in northeast and NingXia province, involves southeast area of HeiLongJiang province , mid area of JiLin province , mid area of LiaoNing and north area of NingXia; The mostly paddy land decreasing regions involves north-mid area of LiaoNing province and south area of JiangSu province and nearly of the delta of the ChangJiang river and ZhuJiang river. The mostly dry land increased regions are the three provinces in northeast and inner Mongolia province, it involves southwest and northeast of the HeiLongJiang province, northwest of the LiaoNing province and the borderline of the sourtheast of the inner Mongolia province; The mostly dry land decreasing regions are the three provinces in northeast and Beijing city, it involves northeast and southwest of the HeiLongJiang province, west of the JiLin province, west of the LiaoNing and the Beijing citySecondly, based on the elevation classification slope classification rainfallclassification -, dryness classification ., yearly average temperature classification, gradually analyze the Chinese farm land dynamic change in the differ background. The last decade increased Chinese paddy land area mostly under the 200m elevation, the decreasing Chinese paddy land area mostly under the 100m elevation, it's proportion is achieve to 50%, and with the elevation higher the decreased paddy land area is litter; The rang of the increased dry land is abroad, under the 1500m elevation is the mostly. The decreased dry land is mostly under the 100m elevation. The last decade Chinese farm land dynamic change is mostly in 0~3 degree of the slope degree, and 400~800mm rainfall regions, 0.5-1 and 1-1.5 dryness range, 0~5 and 5~10 average temperature areas.Finally, based on the Chinese landscape index approach, I analyze the last decade Chinese farm land dynamic change. Selecting the landscape variety index ., landscape advantage degree index, landscape uniformity index landscape crash index, apply to analyze about the farm land dynamic change-analyze about index of the farm change type . Through the result of the experiments, the characteristic distribute of the four type index is approximately homology, the differ is consist in the distribute amount; The landscape variety index of the farm change is lower, it's distribute accords to the normal;... |
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