新时代广州市耕地多功能评价及时空演变分析

Multi-functional evaluation of cultivated land and an analysis of the temporal and spatial evolution of Guangzhou in the new era

在新时代城乡融合发展背景下,基于耕地多功能理论,构建耕地多功能评价指标体系,选取2000—2018年面板数据,运用改进的CRITIC-熵权法组合权重模型与TOPSIS模型,定量评价和分析广州市耕地多功能水平及时空变化。结果表明:高度城市化地区耕地内涵不断丰富,从传统农业生产功能逐渐衍生出农地价值显化后的经济贡献功能、三权分置后对农户仍重要的社会保障功能、与全体国民休戚相关的生态安全维持功能、促进城乡融合的景观游憩功能及后疫情时代的社会安定维护功能。总体变化上,2000—2018年广州市耕地综合功能小幅波动但总体平稳趋势,功能水平稳定在0.442左右。农业生产功能、经济贡献功能保持在较弱等级,社会保障功能呈下降趋势,生态安全维持功能逐步上升并稳定为较强等级,社会安定维护功能呈现"一般-较弱-一般"特征,景观游憩功能呈先小幅下降后大幅上升趋势。总体结构上,生态安全维持、社会安定维护和景观游憩功能为广州市占比较高的三类功能。区域层面上,荔湾区经济贡献、生态安全维持及景观游憩功能为其主导功能,海珠区、天河区、黄埔区和番禺区的主导功能为生态安全维持功能,白云区和增城区的主导功能为农业生产功能,南沙区的主导功能为社会保障、生态安全维持、社会安定维护及景观游憩功能,花都区、从化区的主导功能为生态安全维持功能。子功能时空演变上,2000—2018年广州市农业生产功能空间分布情况较为稳定,经济贡献、社会保障、社会安定维护和景观游憩功能表现出中心老城区地带向外围呈近似圈层结构逐渐递增特征,生态安全维持功能在中心城区、近郊及远郊呈现"低-低-高"分布特点。未来各区可根据耕地主导功能的不同因地制宜地利用耕地,以提高耕地利用多功能水平。

Given the fact that integration of urban and rural development in the new era is based on the theory of arable land multifunctionality,we developed a multifunctional evaluation index system for arable land using panel data from 2000 to 2018.We aimed to improve the CRITIC-entropy weighted TOPSIS evaluation model used to quantitatively evaluate and analyze the multi-functional application of arable land in Guangzhou and map the changes in time and space.Our results showed that the connotation of cultivated land in highly urbanized areas continued to be enriched.Except for the traditional agricultural production,land function for the economic contribution had become more apparent as value of agricultural land gradually increased.In addition,the arable land function for social safety,ecological safety,social stability maintenance,and landscape recreation associated with the integration of urban and rural areas would become increasingly important.There were very small changes in the overall function of cultivated land in Guangzhou between 2000 and 2018,stabilizing at around 0.442.Both agricultural production and economic contribution remained weak in this area while social security showed a downward trend.Ecological safety gradually rose and stabilized at a fairly strong level while social stability presented as"general-weak-general".Landscape recreation demonstrated a slight decline and then a sharp rise over the same time period.In terms of overall structure,ecological safety,social stability and landscape recreation were the most prevalent functions for land in Guangzhou.However at the regional level,Liwan District presented with more significant use of land for economic,ecological,and landscape recreation functions while the Haizhu,Tianhe,Huangpu and Panyu districts all prioritized ecological safety.Baiyun and Zengcheng were shown to focus on agricultural production while Nansha District prioritized land for social security,ecological safety,social stability and landscape recreation.The Huadu and Conghua districts also focused on ecological safety.When we evaluated the temporal and spatial evolution of these sub-functions,we found that the spatial distribution of agricultural production remained relatively stable between 2000 and 2018.The economic contribution,social security,social stability,and landscape recreational functions demonstrated incremental change in distribution from the central portion of the old city with these areas adopting an approximately circular structure toward the periphery.Ecological security maintenance presented with a"low-low-high"distribution in these areas.In order to improve the multi-functional use of cultivated land in the future,each district should evaluate the dominant function and local needs of each area and assign land accordingly.