江苏沿海滩涂围垦与社会经济发展的耦合关系

Abstract

沿海滩涂湿地是脆弱的生态敏感区，滩涂围垦是沿海国家和地区拓展土地资源的重要方式之一。近年，沿海地区快速城市化下的滩涂围垦导致了沿海湿地生态系统退化等一系列环境问题。基于环境库兹涅茨曲线（Environmental Kuznets Curve，EKC）模型，以江苏北部沿海湿地为研究区，结合遥感影像和社会经济数据，刻画滩涂围垦过程、强度及社会经济发展过程，揭示近40年江苏沿海滩涂围垦主要类型、阶段性变化特征，阐述滩涂围垦与社会经济发展的耦合关系。研究结果显示，养殖水体扩张是近40年江苏滩涂围垦利用的主要方式；相比养殖水体聚集发展的盐城市，以启东为典型代表的南通市经历了相对较完整的养殖水体的滩涂围垦过程，其养殖水体面积与区域渔业产值存在指数关系，即当人均地区产值达到约9.55万元时，区域渔业产值的增长不再以通过围垦增加养殖水体面积为主要途径；从江苏沿海滩涂围垦来看，滩涂围垦与社会经济发展之间存在典型倒U型曲线关系。苏北滩涂围垦可分为3个阶段，初期阶段（1980-2005年），滩涂围垦随着经济发展而急剧增加；中期（2005-2014年），当人均GDP约为3.64×10⁴元时滩涂围垦速度达最大；后期（2014-2018年），滩涂围垦随着经济发展呈现下降趋势。3个阶段中，单位滩涂围垦面积与人均GDP增长关系由4.11元/km²，17.08元/km²增加至60.77元/km²，呈显著增加的趋势。经济发展，农业和农村经济改革以及国家和地方各级政策均对滩涂围垦具有重要影响。严格的国家环境保护政策将是有效控制滩涂围垦、保护生态环境的重要手段。;Tidal flat wetland is one of the most sensitive and fragile ecosystems in the world, and tidal flat reclamation plays an essential role for coastal countries or regions to expand land. In recent years, with rapid urbanization, tidal flat reclamation in coastal areas has led to a series of environmental problems such as wetland ecosystem degradation. Taking coastal wetlands in northern Jiangsu as a research area, based on the Environmental Kuznets Curve (EKC) model, this study attempted to characterize the process of tidal flat reclamation and socio-economic development, and reveal the phase of reclamation over the past 40 years, and explain the coupling relationship between tidal flat reclamation and social economic development. The results showed that the expansion of aquaculture water has been the main characteristics of reclamation in Jiangsu tidal flats in the past 40 years. Compared with Yancheng City, where aquaculture water bodies are clustered developing, Nantong City, which is represented by Qidong, has experienced a relatively complete tidal flat reclamation process for aquaculture water bodies. An exponential relationship was observed between the area of aquaculture water bodies and the regional fishery output value in Qidong, that is, when the per capita regional output value reached approximately 95,500 Yuan, the increase of regional fishery output value no longer depended on increasing the aquaculture water area through reclamation. There was a typical inverted U curve relationship between tidal flat reclamation and economic development in north Jiangsu coastal area in the past 40 years. The process of reclamation in north Jiangsu coastal area can be divided into three phases. In the early phase (1980-2005), the reclamation increased sharply with economic growth. In the middle phase (2005-2014), the increasing trends of reclamation and economic growth continued, with a turning point appeared, when the per capita GDP was about 3.64×10⁴ Yuan, and the maximum reclamation appeared with the speed up to 146.34 km²/a. In the late phase (2014-2018), tidal flat reclamation showed a downward trend while the economy still increasing. In the three stages, the relationship between reclamation and per capita GDP growth increased from 4.11 Yuan/km² and 17.08 Yuan/km² to 60.77 Yuan/km², showing a significant growing trend. Economic development, agricultural and rural economic reforms, and national and local policies make important impacts on tidal flat reclamation. The strictly national environmental protection policies would be of great significance to effectively control tidal flat reclamation and protect the coastal ecological environment.