Land Use Policy 101 (2021) 105145 Contents lists available at ScienceDirect Land Use Policy journal homepage: www.elsevier.com/locate/landusepol Delineation of a basic farmland protection zone based on spatial connectivity and comprehensive quality evaluation: A case study of Changsha City, China Yanming Chen a,b, Mengru Yao c, Qiqi Zhao a,b, Zhenjie Chen a,b, Penghui Jiang a,b, Manchun Li a,b,*, Dong Chen a,b a Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources, School of Geography and Ocean Science, Nanjing University, Nanjing, Jiangsu 210023, China b Collaborative Innovation Center of South China Sea Studies, Nanjing, Jiangsu 210023, China c Guangdong Urban & Rural Planning and Design Institute, Guangzhou, Guangdong 510200, China ARTICLE INFO ABSTRACT Keywords: The continuous reduction of farmland poses a serious threat to national food security. Delineating essential basic Farmland delimitation farmland for special protection is urgently needed in China and is an important measure to stabilize food pro­ Spatial connectivity duction capacity and ensure regional food security. Currently, research on basic farmland delineation is mostly Comprehensive quality based on the evaluation of the characteristics of the farmland and lacks the integration of multiple factors such as Changsha City spatial connectivity and scale constraints. Solving these issues will help improve the rationality and scientificity of basic farmland delineation. This study performed a case study of Changsha City based on land use, spatial planning, economic and social factors, natural geography, and other multi-source data. The index method and the food demand method were used to predict the scale of basic farmland protection to determine the basic farmland scale thresholds. Buffer analysis method is used to measure the spatial connectivity of farmland. This study implemented the LESA evaluation system to construct a comprehensive quality evaluation index system for farmland. Finally, based on the technical framework of basic farmland delimitation of “serial priority, quality screening, and scale constraint,” the basic farmland scale was determined to be 23,104,701 ha. 1. Introduction Ministry of Agriculture and Rural Affairs signaled the need to consoli­ date the results of permanent basic farmland delineation and to coor­ Farmland is the land resource on which humans depend for survival dinate ecological construction and farmland protection. Many countries and development and has become a global and strategic issue affecting across the world have made various efforts to protect increasingly economic and social development. Since the Chinese economic reform precious farmland resources. and its opening up to trade, industrialization and urbanization at the In the rapidly urbanizing United States, a large amount of high- expense of farmland resources have made the reversal of the non- quality and high-yield farmland was converted to urban land. The agriculturalization trend difficult in some areas (Liu et al., 2014). In government subsequently drafted a series of public land management recent years, the continuous reduction of farmland area has limited the regulations to curb the spread of cities and to protect farmland (Smith, potential for further grain production, which seriously threatens na­ 2002; Furuseth, 2006). Additionally, the U.S. Soil Administration had tional food security (Liu, 2018). In 2016, the Ministry of Natural Re­ proposed a “Land Evaluation and Site Assessment” (LESA) system, sources and the Ministry of Agriculture and Rural Affairs jointly issued a collaborating with the state governments to determine the type and report requiring all the localities to implement a permanent basic scope of farmland protection (Wright, Zitzmann et al. 1983; Brabec and farmland demarcation and to strengthen the protection of permanent Smith, 2002). Japan had formulated and implemented a number of laws basic farmlands. In 2019, the Ministry of Natural Resources and the and regulations to protect land and resources and to solve the current * Corresponding author at: Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Key Laboratory for Land Satellite Remote Sensing Applications of Ministry of Natural Resources, School of Geography and Ocean Science, Nanjing University, Nanjing, Jiangsu 210023, China. E-mail address: [email protected] (M. Li). https://doi.org/10.1016/j.landusepol.2020.105145 Received 1 February 2020; Received in revised form 2 September 2020; Accepted 4 October 2020 Available online 3 November 2020 0264-8377/© 2020 Elsevier Ltd. All rights reserved. Y. Chen et al. Land Use Policy 101 (2021) 105145 land shortage issue to protect farmland and to improve the utilization section focuses on the evaluation of the socio-economic conditions of rate of resources (Sorensen, 2000a; Aizaki, Sato et al. 2006). Japanese agricultural land (Steiner et al., 1987; Dung and Sugumaran, 2005; laws stipulate that farmland must be contiguous and prohibit converting Braun et al., 2019). Owing to the recent development of research theory farmland to non-farmland (Sorensen, 2000b). The British government and technical resources, the evaluation index has been further encourages industry to occupy wasteland and prohibits the industrial expanded, and economic benefits( Zeng et al., 2017), ecological quality use of high-quality farmland. Thus, different levels of farmland protec­ (Han et al., 2019), agricultural natural risk (Ren et al., 2018), landscape tion prevent industry from occupying large amounts of cultivated land aesthetic function (Guo et al., 2014), and other factors are considered for (Pretty et al., 2000; Robinson and Sutherland, 2002). the evaluation of farmland quality. Scientists in China and abroad have extensively researched basic It is essential for all the countries to further develop the techniques, farmland delineation and more diversified approaches have been methods, and scientific basis required for basic farmland delimitation. developed with a quantitative and spatial focus, thereby establishing a The LESA system has become the most widely used evaluation system. solid theoretical foundation for basic farmland delimitation. Although this system has certain advantages, it does not consider the A demarcation model of permanent basic farmland has been pro­ ecological value of farmland. Research on the delimitation of basic posed by constructing a systematic classification model to analyze the farmland is mostly based on one or more farmland attributes, and the continuity and fragmentation of the farmland from a perspective of work needed before and after the evaluation is seldom discussed. In this spatial continuity and high productivity (Cheng et al., 2017). A GIS grid context, a “combined” basic farmland comprehensive delineation search–based analysis system of farmland continuity was developed to method system must be constructed by linking a feature evaluation with rapidly identify contiguous areas of high-quality farmland (Guo and spatial optimization and scale constraints to provide a clearer farmland Yang, 2010). Huang et al. analyzed the farmland contiguousness of the delineation definition. Guangxi Zhuang autonomous region using the spatial aggregation We performed a case study on Changsha City based on the current function of the ArcGIS software (Haizhou and Yong, 2018). Some re­ state of land use in 2016. The index and the grain demand methods are searchers rely on the LESA system to conduct comprehensive evalua­ used to predict the scale of basic farmland in the study area and to tions of farmland, which takes into account the natural quality and land determine the basic farmland scale threshold. The spatial connectivity conditions (Feng et al., 2014; Nosrati and Collins, 2019). This system and comprehensive quality of farmland were coupled to the basic consists of two segments: 1) land evaluation (LE) and 2) site analysis farmland delimitation, and the technical framework for basic farmland (SA). LE focuses on the natural conditions of agricultural land. The SA delimitation of "serial priority, quality screening, and scale constraint" Fig. 1. Study area. 2 Y. Chen et al. Land Use Policy 101 (2021) 105145 was designed and executed. This study formulates basic farmland 100.08 %. Based on spatial distribution characteristics, the basic farm­ delineation rules, delineates basic farmland protection patches, analyzes land of Changsha City is primarily distributed in Yuelu, Wangcheng, the basic farmland spatial distribution and landscape pattern charac­ Changsha, Ningxiang, and Liuyang. teristics, and provides guidance and reference for basic farmland delineation in China and other countries. 2.2. Data sources 2. Materials and methods The data used in this study primarily involves four categories, i.e., land use data (vector data), spatial planning data (vector data), natural 2.1. Study area geographic data (raster data), and economic and social data (raster and vector data). Table 1 summarizes the data sources and uses. Changsha City is located in the northeast Hunan Province, in the lower reaches of the Xiangjiang River and the western edge of the ◦ 0 ◦ 0 2.3. Research methodology Changliu Basin (Fig. 1). Its geographical range is 111 53 ~114 15 E, ◦ 0 ◦ 0 27 51 ~28 41 N. The land area covered by the city is 11,815.96 km2. We set 2035 as the target year to correspond to