Study On The Comprehensive Evaluation Of Cultivated Land Quality And Its Spatial Division In LongNan City

Using the local spatial autocorrelation method,The paper try to build the LongNan farmland natural quality and utilize condition evaluation model by means of GIS.It is analyzed the space distribution features of the LongNan farmland natural quality and utilize condition, and divided the LongNan city into eight comprehensive regions of cultivated land protection, puts forward the measures of the corresponding cultivated land protection. The results showed that:(1)The seven levels of the farmland natural quality in the LongNan city: the area of the first grade is 52.47 km~2,accounting for 0.94% of the cultivated land area in the LongNan city; the area of the second grade is 185.86 km~2,accounting for 3.34% of the cultivated land area in the LongNan city; the area of the third grade is 954.96 km~2,accounting for 17.14% of the cultivated land area in the LongNan city; the area of the fourth grade is 2625.92 km~2,accounting for 47.14% of the cultivated land area in the LongNan city; the area of the fifth grade is 1476.62km~2,accounting for 26.51% of the cultivated land area in the LongNan city; the area of the sixth grade is 274.64km~2,accounting for 4.93% of the cultivated land area in the LongNan city; the area of the seventh grade is 0.22 km~2,accounting for 0.01% of the cultivated land area in the LongNan city.The nine levels of the farmland utilization quality in the LongNan city: he area of the first grade is 304.13 km~2,accounting for 5.46% of the cultivated land area in the LongNan city; the area of the second grade is 690.34 km~2,accounting for 12.39% of the cultivated land area in the LongNan city; the area of the third grade is1021.81km~2,accounting for 18.34% of the cultivated land area in the LongNan city; the area of the fourth grade is 1124.47 km~2,accounting for 20.19% of the cultivated land area in the LongNan city; the area of the fifth grade is 1063km~2,accounting for 19.08% of the cultivated land area in the LongNan city; the sixth grade and the largest area is 1131.41km~2,accounting for 20.31% of the cultivated land area in the LongNan city; the area of the seventh grade is 203.44km~2,accounting for 3.65% of the cultivated land area in the LongNan city; the area of the eighth grade is 24.3km~2,accounting for 0.44% of the cultivated land area in the LongNan city; the area of the ninth grade is 7.78km~2,accounting for 0.14% of the cultivated land area in the LongNan city;(2)The cultivated land quality show a certain regular in the research area. In terms of farmland natural quality, the high score of cultivated land are mainly distributed in the southeast of LongNan area, relatively flat terrain and water is abundant. The low score of cultivated land are mainly distributed in LI county and TanChang county, the high altitude and the relative lack of water resources, In addition, the positive correlation of the farmland natural quality index(HH and LL type) show that the clustering is stronger, the negative correlation type(HL and LH type) show that the no obvious distribution and scatter distribution.In terms of farmland using condition, the high score of cultivated land are mainly distributed in the some part of XiHe county,Li county, Cheng county and Hui county: The cultivated land concentrated degree is high and the advantage of arable land is taken lessin the surrounding of the town. In addition, it is similar to farmland natural quality index of spatial autocorrelation: the positive correlation of the cultivated land utilization level index(HH and LL type) show that the clustering is stronger, the negative correlation type(HL and LH type) show that the no obvious distribution and scatter distribution.(3)It is analysing local spatial autocorrelation using the utilization level of farmland natural quality index and index, on the basis, the LongNan city is divided into eight comprehensive regional of cultivated land protection: the integrated demonstration area(HH-HH type),key development area(HH-LL type), moderate development and consolidation area(HH-F type), appropriate non-agricultural looks remarkably(F-HH type), comprehensive improvement area(HL-F type), moderate improvement area(F-LH type), non-agricultural looks remarkably(LL-F type) and farmland to forest(F-LL type).At the last, The corresponding protection measures are put forward.