Spatio-temporal analysis of land surface temperature variations in the rapidly developing Akure and its environs, southwestern Nigeria using Landsat data

The study attempted to assess land surface temperature (LST) variations in Akure, a millennium development city, and its environs, in Nigeria. The importance of LST as a vital component in global climate change cannot be over emphasized because as the greenhouse gases in the atmosphere increases, the LST also increases. Spatio-temporal assessment of LST variation is therefore becoming imperative to identify the contributing factors and the corresponding magnitude of contributions to the variation using remote sensing and GIS techniques. Landsat TM image of 1991, Landsat ETM+ image of 2002 and Landsat OLI/TIRS of 2015 were used and processed using ArcGIS 10.1, IDRISI and Erdas imagine 9.3 to generate indices such as Normalized Difference Vegetation Index NDVI, Land Use Land Cover (LULC) and Land Surface Temperature (LST). The finding showed that the changes, both spatial and temporal within the land uses influenced the temperature variations in the study area. The built-up, rock outcrops, farmland and vegetation land uses recorded mean temperature change of 4.91±0.7, 3.53±0.3, 3.14±0.2 and 1.87±0.3 respectively, with their respective yearly temperature increase estimated at 0.21°C, 0.15°C, 0.14°C and 0.08°C between 1991 and 2015. The study concludes that the observed increasing variations in LST in all the land uses has been precipitated by rapid land use conversion and modification that may have strong tendency to usher in climate related problems such as flood, human discomfort and other associated environmental hazards. An effective land use policy is therefore suggested to complement Federal Government ‘green policy’ urban environment.Keywords:  LST variation, Land Use Land Cover, NDVI, GIS, Remote sensing technique, Nigeri

Analysis of land use/land cover of Girei, Yola North and South Local Government Areas of Adamawa State, Nigeria using satellite imagery

This research demonstrated the use of satellite imagery in detecting changes in land use/ land cover on the fringes of urban areas. Satellite data of the same geographical area, recorded over a decade, were used to identify changes in the pattern of land use/land cover. The study used multi date satellite imageries namely, Landsat MSS 1978 and SPOT5 2007. The images were separately classified and then compared using ILWIS 3.3 and Erdas Imagine 9.3 Versions. The land use/land cover statistics results obtained from the two classifications process showed that built-up areas, sand, water bodies, and open/barren land were found to have been increasing at alarming rate while agricultural land and scrubs were encroached upon by other land use/land cover types. The study showed that land use/land cover change was better captured and monitored through the use of satellite imagery that served as a means of efficiently updating digital databases as shown in the research.Keywords: Remote sensing, GIS, Urban-rural interaction, Planning, Land use, Satellite imagery, Change detectio

Remote sensing and gis applications in determining shoreline and surface water quality changes in Bayelsa state, Nigeria

The study of shoreline changes is essential for updating the changes in shoreline maps and management of natural resources as the shoreline is one of the most important features on the earth’s surface. Shorelines are the key element in coastal GIS that provide information on coastal landform dynamics. The purpose of this paper is to investigate shoreline changes in the study area and how it affects surface water quality using Landsat imagery from 1987 to 2016. The image processing techniques adopted involves supervised classification, object-based image analysis, shoreline extraction and image enhancement. The data obtained was analyzed and maps were generated and then integrated in a GIS environment. The results indicate that LULC changes in wetland areas increases rapidly during the years (1987-2016) from 34.83 to 38.96%, vegetation cover reduces drastically through the year which range from 30% to 20%. Polluted surface water was observed to have decreased from 30% to 20% during 1984-2010 and reduced by about 3% in 2016. In addition, the result revealed the highest level of erosion from 1987 to 2016 which is -49.60% against the highest level of accretion of 13.39% EPR and NSM -1400 erosion against 350 accretions. It was also observed that variations in shoreline changes affect the quality of surface water possibly due to shoreline movement hinterland. This study has demonstrated that through satellite remote sensing and GIS techniques, the Nigerian coastline can adequately be monitored for various changes that have taken place over the years.Key Words: Shoreline, Remote Sensing, Erosion, Accretion, GIS