Mapping and evaluating cultivated land fallow in Southwest China using multisource data

Kaifang Shi; Qingyuan Yang; Yuanqing Li; Xiufeng Sun

doi:10.1016/j.scitotenv.2018.11.172

Mapping and evaluating cultivated land fallow in Southwest China using multisource data

Sci Total Environ. 2019 Mar 1:654:987-999. doi: 10.1016/j.scitotenv.2018.11.172. Epub 2018 Nov 13.

Authors

Kaifang Shi¹, Qingyuan Yang², Yuanqing Li³, Xiufeng Sun⁴

Affiliations

¹ Chongqing Engineering Research Centre for Remote Sensing Big Data Application, School of Geographical Sciences, Southwest University, 2 Tiansheng Rd, Chongqing 400715, China; Research Base of Karst Eco-environments at Nanchuan in Chongqing, Ministry of Nature Resources, School of Geographical Sciences, Southwest University, 2 Tiansheng Rd, Chongqing 400715, China.
² Research Base of Karst Eco-environments at Nanchuan in Chongqing, Ministry of Nature Resources, School of Geographical Sciences, Southwest University, 2 Tiansheng Rd, Chongqing 400715, China; Chongqing Key Laboratory of Karst Environment, School of Geographical Sciences, Southwest University, Chongqing 400715, China. Electronic address: yizyang@swu.edu.cn.
³ Research Base of Karst Eco-environments at Nanchuan in Chongqing, Ministry of Nature Resources, School of Geographical Sciences, Southwest University, 2 Tiansheng Rd, Chongqing 400715, China; Chongqing Key Laboratory of Karst Environment, School of Geographical Sciences, Southwest University, Chongqing 400715, China.
⁴ College of Horticulture and Landscape Architecture, Southwest University, 2 Tiansheng Rd, Chongqing 400715, China.

PMID: 30453268
DOI: 10.1016/j.scitotenv.2018.11.172

Abstract

Accurately and effectively mapping and evaluating cultivated land fallow has already become an important issue that has received much attention in China. However, systematically analysing regional cultivated land fallow remains inadequate because current studies have mainly focused on quantifying cultivated land fallow using statistical data based on administrative units or a single aspect of cultivated land fallow using high or medium spatial resolution images at the local or regional scales. Against the existing shortcomings, this study first developed an integrated index of cultivated land fallow (ILF) for mapping and evaluating cultivated land fallow in Southwest China using multisource spatial data. The performance of the ILF was validated by comparing its results with Google Earth images and ecological carrying capacity of cultivated land (TEC). And the spatial distribution of cultivated land fallow in Southwest China was evaluated at the regional, provincial and metropolitan scales. The results revealed that the ILF provided a reliable evaluation of cultivated land fallow in Southwest China. Compared to the Google earth images, the pixel with the high ILF value was the cultivated land that was found to prioritize fallow. There was also a significant correlation between ILF and TEC at the prefectural level in Sichuan, with an R² value >0.65. In Southwest China, the cultivated land related to highly appropriate fallow (HAF) accounted for 5.73% of the total cultivated land in 2010. The cultivated land related to inappropriate fallow (IF) accounted for 53.26% and 37.36% in Sichuan and Chongqing but only comprised 22.90% and 19.72% in Yunnan and Guizhou, respectively. Special attention needs to be paid to Guiyang and Kunming, where the HAF made up 25.38% and 17.48% of their total cultivated land, respectively. Human activities have been found to already become the most important impact factors for cultivated land fallow in Southwest China. This study is especially valuable for providing a scientific basis for policy-making on viable cultivated land fallow policy in Southwest China.

Keywords: Cultivated land fallow; Multiple scale analysis; Multisource data; Southwest China; Spatial distribution.