三峡生态屏障区耕地承载力与人口生态转移

三峡工程生态屏障区的建设是三峡工程后续工作规划的关键内容,对于保护三峡水库的水质和生态环境起着重要作用。然而,库区内极其脆弱的生态环境和尖锐的人地矛盾,给生态屏障区的建设任务造成了很大的困难。为了减少屏障区内人类活动频繁、过度地对区域生态环境的干扰,人口生态转移势在必行。为此,本文在分析三峡工程生态屏障区土地利用现状的基础上,分别从耕地数量和产量的角度出发,分别以人均耕地需求和人均粮食需求为度量计算了生态屏障区内15个区县的耕地现有承载力,并预测了造林规划实施完成后区内耕地承载力。研究表明:①三峡生态屏障区域内耕地承载力严重不足。现状耕地数量承载力(CLCCa)盈亏高达117.01万人,耕地产量承载力(CLCCp)盈亏值也达94.93万人。而通过预测区域2020年CLCCa盈亏更是达到127.39万人。②区域需要进行人口生态转移,其转移对象主要为农村人口,转出重点区域主要是东北翼的区县,而位于"一圈"与东南翼的区县耕地数量承载力略有盈余,可作为迁入区。③除了实施人口生态迁移,还要从保护耕地数量动态平衡和促进其质量提升2个方面提高区域耕地承载力,以实现区域内经济发展、社会稳定、生态安全的多重目标。

Cultivated land carrying capacity and population migration in ecological barrier zone of the Three Gorges Reservoir

An ecological barrier zone project in the Three Gorges Reservoir is an important follow-up of the Three Gorges Project for protecting water quality and ecological environment, reducing population pressure on the Three Gorges Reservoir environment. Nonetheless, numerous project building difficulties have been caused by excessive human activity and sharp contradictions between population and available land. It was imperative to transfer congested residential in the region in order to relieve ecological pressure. Relevant consideration was the ecological carrying capacities of current and post-aforestation of cultivated lands. Based on "status-quo" state analysis, this study calculated the existing carrying capacities of cultivated lands (CLCC) in 15 districts in Chongqing. The study area is along the Three Gorges Reservoir and both the area and yield of cultivated lands were analyzed through calculation of per cap. demand for cultivated land and grain. The study also forecasted the CLCC after afforestation construction. The result showed that population carrying capacity of cultivated lands in the study area was severely inadequate. Deficit in the "status-quo" carrying capacity of cultivated lands for area (CLCCa) was 117.01 million people and that in the carrying capacity of cultivated land for production (CLCCp) was 94.93 million people. Moreover, regional deficit in terms of the CLCCa in 2020 was 127.39 million people. It was necessary to enhance an ecological migration of people in the region based on congestion trend in CLCC. Rural population migration was required with the key emigration and immigration areas being the northeast and southeast regions, respectively, according to distributions of CLCC and population in the study area. Added to migration implementation, it was the enhancement of CLCC to maintain dynamic balance of the area, and enhance the quantity of cultivated land. This was good for economic development, social stability and ecological security in the study area.