Abstract
Understanding farmland changes and their mechanisms is important for food security and sustainable development. This study assesses the farmland changes and their drivers within the Tumen River of China and the Tuman River within the Democratic People’s Republic of Korea (DPR Korea) from 1991 to 2016 (1991–2000, 2000–2010, and 2010–2016). Farmland surfaces in Tumen/Tuman River Basin (TRB) for each of the years were mapped from satellite imagery using an object-based image segmentation and a support vector machine (SVM) approach. A logistic regression was applied to discern the mechanisms underlying farmland changes. Results indicate that cultivated surfaces changes within the two regions were characterized by large differences during the three time periods. The decreases of cultivated surface of −15.55 km2 (i.e., 0.55% of total cultivated surface area in 2000) and −23.61 km2 (i.e., 0.83% of total cultivated surface area in 2016) occurred in China between 1991 and 2000 and between 2010 and 2016, respectively; while an increase of 30.98 km2 (i.e., 1.09% of total cultivated surface area in 2010) was seen between 2000 and 2010. Cultivated surfaces increased within DPR Korea side over the three time periods; a marked increase, in particular, was seen between 1991 and 2000 by 443.93 km2 (i.e., 23.43% of total cultivated surface area in 2000), while farmland increased by 140.87 km2 (i.e., 6.92% of total cultivated surface area in 2010) and 180.86 km2 (i.e., 1.78% of total cultivated surface area in 2016), respectively, between 2000 and 2010 and between 2010 and 2016. We also found that expansions and contractions in farmland within both regions of the TRB were mainly influenced by topographic, soil, climatic, and distance factors, which had different importance degrees. Among these significant forces, the temperatures in the two regions were paramount positive factors on farmland changes during 1991–2016 and slope in China and precipitation in DPR Korea were the paramount negative factors affecting farmland changes, respectively. Additionally, except for between 2000 and 2010 in DPR Korea TRB region, most of the factors significantly influencing the farmland changes revealed the same positive or negative effects in different periods, because of mountainous topography. This study allows enhancing understanding of the mechanisms underlying farmland changes in the TRB.
Highlights
Land is the most basic natural resource and it provides the means for human survival and development [1,2]
Data show that the farmland area within the DPR Korea Tuman River Basin (TRB) region has mainly increased over time; expansion of farmland has been greater than its contraction throughout this analysis
Farmland contractions within the Chinese TRB region have been more marked than those seen in DPR Korea TRB region; areas of farmland decreased between 1991 and 2000 and between 2010 and 2016, because of an overall lower expansion rate compared to the contracted areas
Summary
Land is the most basic natural resource and it provides the means for human survival and development [1,2]. Understanding land use and cover change (LUCC) is critically important for assessing global environmental variation and sustainable development [3,4]; these factors significantly influence local, regional, and global climate change, ecosystems [5,6], and human welfare [7]. Cultivated land is the most essential component of this overall resource in the context of food security, but faces competition from land use demands for industrialization, urbanization, and ecological environmental construction [8]. General changes to farmland over time include expansion and contraction, both the result of reclamation by cultivate activities [9], farmland abandonment because of rural-to-urban population migration [10], and conversions associated with urbanization, industrialization, and ecological rehabilitation projects [11,12]. The area of farmland in mountainous areas of Europe and Japan has continuously contracted since the late 1980s because of abandonment [10]; large areas of cropland across some regions of China have contracted over the last 20 years, mainly converted to built-up areas, forests, and grassland via urbanization activities and ecological restoration projects [14]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
