Water Quality Assessment Based on CWQI and NDWI Indices in Mariout Lake, Egypt

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.

Water quality assessment and phosphorus budget of a lake (Mariut, Egypt) after diversion of wastewaters effluents

“…Widely variable concentrations of TP were recorded previously but remarkably lower than our values (Alnagaawy et al, 2018;El Zokm et al 2018). El Kafrawy et al (2017) recorded up to 3.47 mg TP from 2010 to 2014.…”

“…It is noted that the DO in our results appeared to be extremely higher than those given in previous studies (Ali et al 2017;Alnagaawy et al, 2018;El Zokm et al 2018). During the period of 2010-2014, El Kafrawy et al (2017) recoded the conditions of oxygen depletion as well as high levels, up to 15.8 mg/l.…”

“…The proper agricultural UD us waters were noticeably enriched with the oxidized N forms, mainly due to the use of agrochemicals containing NO 3 (as fertilizers) by landlords. The present study recorded a remarkably lower concentration of ammonia than those reported previously (El Kafrawy et al, 2017;El Zokm et al 2018;Alnagaawy et al 2018).…”

“…Ali et al (2017) recorded a pronouncedly smaller range of BOD (12.5-83 mg O 2 /l), and Alnagaawy et al (2018) reported up to 34.97 mg O 2 /l in the lake. In contrast, El Kafrawy et al (2017) observed great variation in BOD (1.7-620.48 mg O 2 /l) during the period 2010-2014 throughout the lake.…”

“…4 Diurnal variations of dissolved oxygen (DO) concentration (mg/l) at surface and bottom waters (1 m depth) at station II in LMMB during 5-6 May, 2013 et al 2018). El Kafrawy et al (2017) observed great variation of 1.26-347.86 mg/m 3 within the period from 2010 to 2014.…”