Analyzing the impacts of Discharges from coastal outfalls on water quality of Kuwait Bay via Landsat monitoring

Abstract

Monitoring water resources plays an important role in water pollution control. Taking Samples of the whole water body is limited in practice for many reasons such as time-consuming, cost constraints, and the situation of topography. So, the remote sensing method has been used as it provides a reasonable and feasible approach to providing water quality data. In this study, Nitrates and phosphates were assessed along Kuwait's territorial water using data from Bands reflection that was taken from remote sensing images to improve the prediction of Nitrate and Phosphate concentrations in waterbodies. The predicting algorithms have been subjected to calibration and validation by using the in-site data measured in the field from the KEPA Monitor stations. All the algorithms produced a good performance in estimating the concentration of nitrate and phosphate at the outfall sites, but the nitrate algorithms had superior performance over the phosphate algorithms. The Relative Error of the Nitrate and Phosphate Algorithm was 16.851% and 37.793%, respectively. One of the accuracy requirements for estimating the quality of water for the satellite imagery method is that the Relative Error should not be more than 30%, and the accuracy of the nitrate prediction algorithms is more accepted than phosphate prediction algorithms. At last, Nitrate and phosphate were estimated at the outfall’s sites using Landsat 8 OLI imagery. The retrieval models result showed that all the Nitrate and Phosphate concentrations were above the KEPA ambient seawater quality criteria standard values which are for the Nitrate (NO3-) is equal to 0.095 milligrams per liter, and equal to 0.035 milligrams per liter for the Phosphate (PO43-). Although this case study is a particular study, the modeling procedures related to the Nitrate and Phosphate retrieval model can provide others the ability when they use the technology of satellite imagery to predict Nitrate and Phosphate for identical or different water bodies.