Remote Sensing Application for Water Quality Assessment in Lake Timsah, Suez Canal, Egypt

Abstract

Lake Timsah lies along the middle section of Suez Canal in Egypt, and is the backbone of the tourism and fishing industry in Ismailia City, providing a significant portion to its income. In recent years, however, Lake Timsah has been subjected to significant environmental changes caused by various anthropogenic activities. Remote sensing and biological monitoring program were integrated for assessing its water quality. Sixteen sites were selected throughout the lake for in situ measurements and collecting water samples which were subsequently analysed. The analysed water parameters were regressed against calibrated radiance values extracted from a high resolution WorldView-2 image. The regression analysis resulted in six unique models with high determination coefficient (R 2 ) and probability (P) at 95% confidence level. These models were then applied to the WV-2 image to produce six unique water quality maps for the entire Lake Timsah. These maps were subsequently used to select the appropriate sites for collecting aquatic macro-invertebrates that serve as good bio-indicators for assessing the water quality of Lake Timsah. This collected biota was used to calculate the Hilsenhoff Biotic Index (HBI) which is an indirect measure of pollution tolerance. The HBI scores indicate the water quality of Lake Timsah ranged from poor to fairly poor. KeywordsWater Samples Analysis; Optical Satellite Data; Regression Analysis; Biotic Index; Water Evaluation; Lake Timsah Egypt