الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 198 |  |  |
| | | from | 198 | | |
Abstract
The study aims to evaluate the surface water quality of the Nile River in the Damietta branch beside the inlet of drinking water purification plants in Damietta governorate, using 2 different methods; first by calculating the water quality index(WQI), the second by recording and monitoring some living benthic invertebrates, which are used as a biological indicator to determine water quality.
Environmental physicochemical parameters have been measured for surface water such as temperature, turbidity, pH, total dissolved solids, electrical conductivity, dissolved oxygen, biochemical oxygen demand, chlorides, alkalinity, total hardness, , ammonia, nitrite, nitrate, phosphates, silica, and heavy metals then compared with Egyptian standard regulations followed by calculation of (WQI).
The results showed that surface water was in a medium-quality condition with an annual average of 56.44%-66.70%, the sampling sites (9th/1rd/8th) were recorded the best locations while the sites (2nd/4th/3rd) were the worst based on annual average, the 9th site was the highest percentage of 66.70%, while the 3rd site was the lowest with an average of 42.97%. .
-Recording living invertebrates in sediment act as biological indicator, which describe the quality condition, in a relation to the physicochemical factors, to assess the impact of these results on the structure of the benthic communities in statistical correlation and by calculation of diversity indicators such as ; Equality index and Biodiversity index as evidence of the viability and quality of the aquatic environment, providing an assessment of the diversity and benthic invertebrate communities and seasonal changes, with a relation to surface water environmental factors.
-20 species benthic invertebrates were recorded relative to 16 families and represented in 3 phyla; Arthropods, Annelida, and Mollusca, whereas the latter phylum includes gastropod(11 species) and bivalves (6 species) while Annelida was represented by only 2 species .the annual average of the regional distribution of benthic invertebrate’s communities indicated that total abundance ranged from 905 to 2435 ind./m2 with an annual average of 1730 ind./m2. The 3rd site was record the low denisty of living benthic organisms due to high level of water pollution and it is compatable with environmental physicochemical results reported in WQI. of water pollution and indicates that the quality of water and sediments are bad.