MOJ Ecology & Environmental Science Water Quality Assessment Based on CWQI and NDWI Indices in Mariout Lake, Egypt Submit Manuscript | http://medcraveonline.com Abbreviations: NDWI: The Normalized Difference Water Index; CWQI: Candian Water Quality Index; WQIA: Water Quality Index, WQIM: Multiplicative Water Quality Index; WQIUA: Un-weighted Arithmetic Water Quality Index; WQIH: Harkins’ Water Quality Index Introduction Water Quality Index, a critical tool for water resources management, will be developed to evaluate and communicate the suitability of water bodies in Egypt for various uses such as drinking, irrigation, livestock, aquatic life, and recreation [1]. The CCME WQI provides a measure of the deviation of water quality from water quality guidelines. The CCME WQI model consists of three measures of variance from selected water quality objectives (Scope; Frequency; Amplitude). These three measures of variance combine to produce a value between 0 and 100 that represents the overall water quality. The CCME WQI values are then converted into rankings by using an index categorization schema that can be customized to reflect the expert opinion by users. The detailed formulation of the WQI is described in the Canadian Water Quality Index 1.0 – Technical Report (CCME 2001) [1]. Study Area and Methodology Study area Lake Mariout is a salt lake of about 250 square km in northern Egypt, lies between Latitude 31º 01’ 48” and 31 o 10’ 30” N and Longitude 29º 57’ 00” E along the Mediterranean coast of Egypt. It forms the southern boundary of the city of Alexandria. It is a closed lake with a surface area of 60 km2 and ranges in depth from 1-3 m. The lake is divided into 4 basins. These are the main (6000 acres), South West (5000 acres), North West (3000 acres), and aquaculture or fisheries (1000 acres). The lake is fed by canals from the Rosetta branch of the Nile. Several branches of these canals allow water flow from and to these basins. The main canals are al Kalaa drain, Omum drain and Nubaria canal. The water inflow to the lake came mainly from these sources plus those from a Wastewater treatment plant, the discharge from the west Nubaria drain and from the petrochemical area. Outflow from the lake is only released by El-Max pumping station. Domestic sewage is discharged from the wastewater treatment plant at the north and main basin and with the El-Kalaa drain to the lake body. Thus, the lake acts as a receptor for agricultural drainage and domestic Volume 2 Issue 5 - 2017 1 National Authority for Remote Sensing and Space Sciences (NARSS), Egypt 2 Institute of Environmental Studies and researches (ASU), New Zealand *Corresponding author: Sameh B El Kafrawy, National Authority for Remote Sensing and Space Sciences (NARSS), Egypt, Email: ; Received: June 15, 2017 | Published: August 08, 2017 Research Article MOJ Eco Environ Sci 2017, 2(5): 00039 Abstract Alexandria Governorate inhabited by 4 million people is located on the north western edge of the Nile Delta. It extends about 70 kilometers north-west of the Nile Delta. Lake Mariut, one of Egypt’s Northern Lakes facing the Mediterranean Sea, is located within the Alexandria Governorate Borders. Since the last four decades. Lake Mariut falls under enormous pressure of un-planned development, pollution and land reclamation. Now-a-day, Lake Mariut suffers from pollution, reduction of its surface area, un-planned development in a way that considerable part of the lake entered into possible irreversible processes. The purpose of this study is to assess the degree of pollution in the context of CWQI (Canadian Water Quality Index) in Mariut Lake by determining various physicochemical parameters, as the concentration, PH, DO, BOD, CHL-a, TSM, NH4, TP, and NO3 during from 2010 to 2014. Using CWQI found that the water quality of the studied Lake is found according to CWQIs model which indicates that water quality of this Lake is moderate and frequently impaired for determining water quality and its area constantly decreased according to NDWI. Results of this research showed that there are large variations in parameters in different sections, and these variations are affected by different factors. Such pressures deteriorated the Lake Mariut environmental resources quality, decreased it surface area and created problems to the Large Marine Ecosystem (Eastern Mediterranean Part). The study concluded that the area of the Lake Mariut was exposed to multiple stages of drying in order to create economic development activities for the community of Alexandria Governorate. The impact of sewage disposal to parts of the Lake basins was quite obvious too. Keywords: Water resource management; Water quality indexes; Water pollution; Mariout Lake; NDWI; Remote Sensing; GIS Applications