Study On Evaluation Index System Of Reserved Land Resources Suitable For Cultivation In Beijing

Under the guidance of the strategy of sustainable development, aiming at the special demand of Beijing, this paper put forward the principle of reserved land reclamation suitable for cultivation, the core of which is to pay preferential attention to ecology, synchronously to quantity and quality. In order to protect ecosystem services and keep dynamic balance of total amount of cultivated land in area, this paper set a suit of evaluation index system, which includes productivity index and protection index.Protection index was set by qualitative techniques; it includes 'Whether or not to be ecological-land-used area' and 'soil contamination'. The reserved land is regarded unsuitable ecologically if it does not meet one of the two criteria.On the practice of Beijing land reclamation evaluation, productivity index was set by correlation analysis and principal component analysis. It is composed of altitude, slope, soil depth and gravel content. Then productivity index was classified by cluster analysis. The result corrected by former result was to judge the land to be suitable for cultivation or not. In the end, productivity index threshold under different suitable-levels was determined by analyzing the frequency histograms distribution of 4 productivity index. The result shows that the productivity index criteria of reserved land in Beijing is that altitude≤800 m, slope≤ 15° , soil depth≥30 cm and gravel content≤ 15%. And the reserved land is unproductive if it does not meet anyone. As bottomland, soil depth and gavel content are not taken into account, altitude ≤800 m and slope ≤=5° are the criteria of unsuitable for cultivation temporarily.Based on the index system established, criteria for reserved land resources reclamation was confirmed in Beijing area and index system was enriched in the field of reserved land resources reclamation limited by ecological security.