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

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.