基于生态用地约束的土地利用数量结构优化

Optimization of Land Use Quantity Structure Based on Ecological Land Constraints

引入生态优先理念,采用碳氧平衡法分析规划目标年区域生态用地约束,以经济效益最大化为目标,构建基于生态用地约束的土地利用数量结构优化模型,并以南通市为例进行案例研究。研究结果显示,从区域低碳经济发展及远期预留的角度出发,到2020年南通市需65.66万hm2标准生态用地。土地利用结构优化后,目标年南通市耕地与林地面积分别增加27 256.59 hm2和6 640.08hm2,园地、城镇工矿及交通水利用地也有不同程度增加;而其他土地减少44 034.20 hm2,其他建设用地、农村居民点及牧草地等也有所减少。结果表明,优化后南通市2020年土地利用经济效益可达8 414.73亿元,折算后的标准生态用地面积达89.01万hm2,比2007年减少1.90万hm2,但其综合固碳释氧能力满足区域碳氧平衡的需要,可保障区域生态安全。

By introducing the concept of ecology priority and the method of carbon-oxygen balance, the paper analyzes the constraints of regional ecological land in the target year of land use planning. Then, an optimization model of land use structure is built based on the ecological land constraints and the objective of maximizing land use economic benefit, and a case study in Nantong was taken. The result shows that 656 600 hm^2 of standard ecological land is required in 2020 while considering development of regional low-carbon economy and long-term ecological reservation. After optimization of land use structure, the area of arable land and woodland in 2020 will increase to 27 256.59 hm^2 and 6 640.08 hm^2 respectively, and area increase will also occur on orchard and perennial plantations, urban land and land for mining and industry, land for transportation and water-control structures. However, the area of other land will decrease to 44 034.20 hm^2 , and the area of other constructed land, rural settlement area and grazing land will decrease too. The study also shows that economic benefit of land use will rise to RMB 841. 473 billion in 2020, and the area of standard ecological land after optimization is 890 100 hm^2 ,which is 19 000 hm^2 lower than that in 2007, while it could meet the needs of the regional balance of carbon and oxygen well, and the regional ecological security could be assured.