Remote sensing (RS) and GIS are important methods for land use assessment and land cover transition. In this study, land use/land cover changes in the Ago-Owu Forest Reserve, Osun State, Nigeria have been assessed. La...Remote sensing (RS) and GIS are important methods for land use assessment and land cover transition. In this study, land use/land cover changes in the Ago-Owu Forest Reserve, Osun State, Nigeria have been assessed. Landsat 5 TM, Landsat 7 ETM+ and Landsat 8 OLI were acquired for 1986, 2002 and 2017 respectively. The three scenes corresponded to path 190 and row 055 of WRS-2 (Worldwide Reference System). The processing of the imagery was preceded by the clipping of the study area from the satellite image. The boundary of the reserve was carefully digitized and used to clip the imagery to produce an image map of the forest reserve. Using the supervised image classification procedure, training sites were used to produce land use/land cover maps. The same classification scheme was used for the 1986, 2002 and 2017 images to facilitate the detection of change. The differences in the area covered by the different polygons between the three sets of images were measured in km2. The results show that during 1986 and 2017, there is a dramatic increase of build-up areas with a change of 55.65 km2 and sparse vegetation (farmland and grassland) with a change of 53.97 km2, while a dramatic decrease of dense vegetation (forest areas) with a change of 109.61 km2. The consequence of these results is that over the years, the population of people living in the forest reserve has increased and many of them are engaged in farming, leading to an increase in farmland. In addition, logging activities continued unabated in the forest reserve, as demonstrated by a sharp increase in the deforested area within the reserve. The maps produced in this study will serve as a planning tool for the Osun State Forestry Department to plan reforestation activities for the forest reserve.展开更多
In recent years, Web GIS has been widely applied in mapping and sharing spatial data. This paper introduces a Web GIS solution has been applied to establishing “The Mekong Delta Geographic Information Systems—MGIS”...In recent years, Web GIS has been widely applied in mapping and sharing spatial data. This paper introduces a Web GIS solution has been applied to establishing “The Mekong Delta Geographic Information Systems—MGIS”. The development and implementation of a web-based MGIS are a suitable technology for monitoring and managing the natural resources and environment that aims to achieve sustainable development in the Mekong Delta region. The proposed solution shows that Web GIS can be applied effective to for integrating and sharing data among administration agencies in order to provide fully integrated information of updated on the status of land cover changes and analyzing the trend of forest-cover changes in this region. Results of this study illustrate the MGIS’s applications in sharing of regional data that allows multiple users to use tools for displaying spatial distribution of forest-cover in the period from the year 1990 to 2015 and analyzing the trend of changes.展开更多
文摘Remote sensing (RS) and GIS are important methods for land use assessment and land cover transition. In this study, land use/land cover changes in the Ago-Owu Forest Reserve, Osun State, Nigeria have been assessed. Landsat 5 TM, Landsat 7 ETM+ and Landsat 8 OLI were acquired for 1986, 2002 and 2017 respectively. The three scenes corresponded to path 190 and row 055 of WRS-2 (Worldwide Reference System). The processing of the imagery was preceded by the clipping of the study area from the satellite image. The boundary of the reserve was carefully digitized and used to clip the imagery to produce an image map of the forest reserve. Using the supervised image classification procedure, training sites were used to produce land use/land cover maps. The same classification scheme was used for the 1986, 2002 and 2017 images to facilitate the detection of change. The differences in the area covered by the different polygons between the three sets of images were measured in km2. The results show that during 1986 and 2017, there is a dramatic increase of build-up areas with a change of 55.65 km2 and sparse vegetation (farmland and grassland) with a change of 53.97 km2, while a dramatic decrease of dense vegetation (forest areas) with a change of 109.61 km2. The consequence of these results is that over the years, the population of people living in the forest reserve has increased and many of them are engaged in farming, leading to an increase in farmland. In addition, logging activities continued unabated in the forest reserve, as demonstrated by a sharp increase in the deforested area within the reserve. The maps produced in this study will serve as a planning tool for the Osun State Forestry Department to plan reforestation activities for the forest reserve.
文摘In recent years, Web GIS has been widely applied in mapping and sharing spatial data. This paper introduces a Web GIS solution has been applied to establishing “The Mekong Delta Geographic Information Systems—MGIS”. The development and implementation of a web-based MGIS are a suitable technology for monitoring and managing the natural resources and environment that aims to achieve sustainable development in the Mekong Delta region. The proposed solution shows that Web GIS can be applied effective to for integrating and sharing data among administration agencies in order to provide fully integrated information of updated on the status of land cover changes and analyzing the trend of forest-cover changes in this region. Results of this study illustrate the MGIS’s applications in sharing of regional data that allows multiple users to use tools for displaying spatial distribution of forest-cover in the period from the year 1990 to 2015 and analyzing the trend of changes.
