Suitability Evaluation On Land Reclamation Of Mining Areas In Jilin City Based On GIS

In the era of rapid development in China, many land deterioration issues (e.g. soilcontamination, surface subsidence, crack and landslide) have been caused in the processof mining explorations. All of these issues lead to the destruction of ecologicalenvironment, the changes of landscape and the decline of soil quality around the miningareas. In order to achieve the goal of sustainable land use, it is imperative to takeappropriate land reclamation measures to improve and restore the land use condition.Therefore, researches on suitability evaluation of land reclamation have become a hotfield all over the academic world.On the basis of previous study cases and research actualities at home and abroad,this thesis combines GIS technologies with traditional land suitability evaluationindicator system in order to build a creative evaluation scheme which counts on GIStechnologies and statistical models for different land suitability classes. The foundationof evaluation indicator system is the key step of this thesis, the selected indicators shouldnot only completely and accurately reflect the natural and social-economic characteristicsof research area, but accord with the demand of GIS spatial recognition and analysis.Expert selection method and previous study cases were used as tools to select8evaluation indicators in4aspects (landform, soil, hydrology and social-economicconditions), and then evaluation indicator systems and score standards were built fordifferent orientation in agriculture, forestry and graziery. The thesis adopted AHP todetermine the weights of indicators, took every village’s land that to be reclaimed as theevaluation unit, to recognize the attribute data in each unit by spatial analysis and to calculate the scores of them. Finally, single-indicator maps were produced in these threedirections, and then weighted overlay model was applied to get the comprehensiveresults of suitability evaluation.Applying the evaluation indicator system that has been built above, this thesisselected Jilin City as the case study region to conduct the suitability evaluation of landreclamation. The results are as follows:1) The total area of damaged land in case study region is5165.64Ha, and PanshiCity occupies the biggest percentage, followed by Jiaohe City and Huadian City. Thesethree cities mentioned above take up for over50%.2) The suitability degree for arable land presents obvious geographical features, andthe most suitable regions for agricultural land use are located in central urban areas,north-western of Shulan City and west Yongji County; as for quantitative structure,general-suitable region occupies the largest area at over50%.3) Forestry-oriented and graziery-oriented use for land reclamation both have highsuitability degrees, which are due to the low demand for soil quality and landformcondition in these two directions. Besides, these two land-use types both present thesame spatial characteristic, which is the suitability degree gradually decreased from thenorth-western to the south-eastern.4) The determination of land reclamation direction should follow the principle of“focused on agriculture, supplemented by forestry and graziery”, this thesis identified thenorth-western region of Jilin City should be primarily reclaimed to arable land, andgrassland and forest land should be focused on the south-eastern part. On the other hand,the other areas should take land use planning and surrounded land use conditions intoconsiderations to determine the direction of land reclamation.