Assessment of Land Use and Water Quality Changes on Anambra River in Otuocha Anambra State Nigeria: A Remote Sensing and Hydrochemical Apporach

This study investigated the impact of anthropogenic activities on Anambra River quality in Otuocha and environs, Anambra State, Southeastern Nigeria, where rapid urbanization and agricultural intensification have raised concerns about water quality degradation. Using remote sensing and hydrochemical techniques, Landsat satellite imageries from 1999 and 2023 were utilized to classify land use into three categories: Impervious surfaces, pervious surfaces, and water. A 24-year land use change assessment and prediction model were developed. Fifteen surface water samples were collected from various points along the Anambra River and Ezechi River, and analysed for physical, chemical, and microbiological parameters using various methods. Water quality indices, including Water Quality Index (WQI), Sodium Adsorption Ratio (SAR), Magnesium Adsorption Ratio (MAR), Integrated Water quality index (IWQI) and Degree of Contamination (Cd) were calculated to evaluate overall water quality and suitability for various uses. The integration of land use change assessment with water quality parameters revealed significant correlations between urban expansion, agricultural intensification, industrialization and declining water quality. Results indicate poor water quality for drinking without treatment, moderate suitability for irrigation with long-term risks, and widespread faecal contamination, indicating possible poor sanitation. This study provides valuable insights into the complex interactions between human activities and water resources, offering a basis for informed land use planning and water resource management strategies in the area.