Extraction and analysis of abandoned farmland:A case study of Qingyun and Wudi counties in Shandong Province

摘要

Rapid urbanization and continuous loss of rural labor force has resulted in aba donme nt of large areas of farmland in some regi ons of China.Remote sen sing tech no logy can in directly help detect abandoned farmland size and qua ntity,which is of great significance for farmland protection and food security.This study took Qingyun and Wudi counties in Shandong Province as a study area and used CART decision tree classification to compile land use maps of 1990-2017 based on Landsat and HJ-1A data.We developed rules to identify aba ndoned farmla nd,and explored its spatial distributi on,du rati on,and reclamation.CART accuracy exceeded 85%from 1990-2017.The maximum abandoned farmland area was 5503.86 ha during 1992-2017,with the maximum rate being 5.37%.Farmland abandonment rate was the highest during 1996-1998,and abandonment trend decreased year by year after 2006.Maximum abandonment duration was 15 years(1992-2017),mostly within 4 years and only a few exceeded 10 years.From 1993-2017,the maximum reclaimed aban?doned farmland was 2022.3 ha,and the minimum^20 ha.The maximum reclamation rate was 67.44%m,with annual average rate being 31.83%.This study will help analyze farmland aband onment drivi ng forces in the study area and also provide ref ere nces to ide ntify abandoned farmland in other areas.