Accessing Agulu Lake Through the Application of Remote Sensing and Geospatial Information Technology

Abstract

The widespread availability of satellite imagery makes it possible to access and map even an inaccessible area by looking at it from space. Agulu Lake, a natural feature has so many mysteries surrounding its existence which make effective ground-based research virtually impossible. The objective of this paper is to access Agulu Lake through the application of Remote Sensing. Mapping of Agulu Lake was carried out using IKONOS (2015) satellite image; the method adopted was digital image processing and cartographic procedures. The georeferenced and classified map was validated using Confusion Matrix Statistical tool after ground-truthing, acquisition of coordinates of selected Ground Control Points (GCPs) and field completion. It was also possible to map buildings and roads using the imagery and this was done to depict some development around the lake during the onscreen digitization. The acquired data were processed using ArcGIS 10.1 and ILWIS 3.3. The image classification was tested using Box Classifier and Minimum Distance Classifiers respectively and the Maximum Likelihood Classifiers result gave the best result with the Average Accuracy of 83.46 %, Average Reliability of 81.56 %, and Overall Accuracy of 86.49 %. The perimeter of the Lake is found to be 965,062.083 square metres and longest side of the Lake is 2,622.848 metres. The coordinate list of the lake perimeter was produced based on the WGS1984 UTM Zone 32N coordinate system. A buffer zone with a fixed distance 30 m which specifies a constant buffer distance was applied to the boundary line of the Lake and result showed that a building of the Idemili Cultural centre was the only infrastructure inside the buffer zone. The project recommends among others that the relevant institutions/government concerned, should use this information as a base map for monitoring the developments that affect the water quality and good tourism potentials of the lake and environs.