Analysis of Land-Use and Land-Cover Changes in YongDeng County Using Remote Sensing and GIS

Abstract

The research is supported by the fundamental Research Funds of Gansu Provincial Natural Science Fund of “Research on Land Use and Ecological Security in Ecologically Vulnerable Areas” (Project No. GSAN-ZL-2015-045) and Research on the Coordination Relationship between Land Urbanization and Population Urbanization (Project No. GSAU-ZL-2015-046).

Abstract

To generate reliable data on the spatiotemporal changes in land use and land cover in YongDeng county over a period of 24 years (1993 -2017) that will provide a basis for land use management decisions and policy formulation, this study used RS and GIS to analyze Landsat images of 1993, 2001, 2009 and 2017 of the study area which were acquired from the Geospatial Data Cloud (Http/westdc.westgis.ac.cn). Using supervised classification based on maximum likelihood classification method in ArcGIS (version 10.3) to classify images of the various years, the computed land use and land cover classes indicate that over the period of 24 years, significant Land use and land cover changes have occurred in the study area and the dominant land-use types in the study area were found to be grassland, bare land woodland and cultivated land occupying 65 percent, 20 percent, 8 percent and 6 percent of the study area respectively. As the years pass by, urban sprawl, population growth, agricultural activities, and other socio-economic activities in the study area, have led to rapid land-use transfer and change intensity. The results revealed that about 4.5 km² of grassland, 3.21 km² of bare land, 2.51 km² of cultivated lands and 1.7 km² of woodland were changed to construction lands from 1993-2017, whiles Cultivated lands, on the other hand, made gains of 2.56 km² from Garden lands, 2.3 km² from bare land and 1.05 km² from woodland from 1993 to 2017. Whiles transport land, from 1993 to 2017 gained 3.3 km² from bare land, 2.42 km² from grassland, and 1.32 km² from cultivated. Cultivated land, transportation land, construction land and water area and conservation land showed significantly positive land-use change intensity index of 2.19%, 1.97%, 1.49% and 1.31% respectively. Garden Land and woodland, though not significant also showed positive land-use change intensity of 0.55% and 0.79% respectively. The study identified population growth, urbanization and policy orientation as the main drivers of land use/land cover change in the area. The results reveal there is an urgent need to put measures in place to reduce the overexploitation of land in order to protect the integrity of biodiversity and to also ensure a continuous supply of valuable ecosystem services.

Keywords: Land-use/land-cover change, remote sensing, geographical information system, dynamic change, YongDeng County.

DOI: 10.7176/JEES/10-6-15

Publication date:June 30^th 2020