Bathymetric Information and Shoreline Delineation along Anyaogologo River, Rivers State, Nigeria

• Main Authors: eke, stanley Nwaudo, Jonah, IYOWUNA benjamin
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2022
• Subjects: Eagle Island
• Online Access: https://zenodo.org/record/6787747; https://doi.org/10.5281/zenodo.6787747

Shoreline mapping, determination of itsdeterioration and bathymetry overtime resulting from the socio-economic activities are of high importance. Satellite remote sensing offers an alternative to conventional topographic mapping and hydrographic surveys for measuring the extent of Land Use-Land cover changes and water depth, with the advantage of low cost and large area coverage. The use of multi –spectral image of Spot-5 and Landsat ETM7+ with high resolution provides possibility for shoreline variation and bathymetry mapping. This study mapped and analyzed variations along the Eagle Island Shoreline from the year 1986 to 2015 using Landsat ETM-7+ and Spot-5 imageries. The images were preprocessed and classified using ENVI 4.5 software and ArcGIS 10.0 software, while Surfer 10.0 was used for the 3-D modeling of the Echo sounding in situ measurement. The Midas Echo sounder was used for in situ measurement of the depth of the study area. The result showed a shoreline decrease of 1000 square meters from 2,745,000 square meters in 1986 to 1,457,731 square meters in 2015. The area occupied by water body decreased from 594,900 square meters to 440,918.75 square meters that’s an increase of 400,000 square meters that is 40%, the built-up area increased from 1,001,700 square meters in 1986 to 1,401,575 square meters in 2015. The lengths of the shoreline for the various years were found to be 3.761 kilometer in 1986, 3.832 kilometers in 2000, and 3.743 kilometers in 2015, showing a decrease of 18m in 30 years. The study demonstrated the relevance of satellite imagery in mapping shoreline changes and the use of echo sounding technique in determining depth useful for navigational decision making. Regular shoreline mapping is recommended to avoid costly structure placement along shorelines, shoreline mapping aids in better boundary definition among communities near shorelines, and better-quality images free of cloud cover and haze would allow for a more accurate assessment of bathymetry, potentially removing the majority ...