An ecological study of some characteristics of water column in Derbendikhan reservoir

Abstract EN

Vertical profile from (surface to 21 meters) of Derbendikhan reservoir were focused for 4 sites (Zimkan, Tanjero, Arawan and Qashtee) and 7 days (1st to 7th March 2010).Daily water samples were analyzed in every meter depth for parameters of (Air and Water Temperatures, pH, EC, DO, Turbidity, PO-34, NO-2, NO-3, and Chlorophyll a) Results showed that there were a significant differences for different parameters among sites under study.

From the direct measurement in the field during the sampling periods at each site, air temperature was ranged between (17.8 - 19.0 C° ) for sites 2 and 3 as a minimum and maximum respectively and there was a significant differences between sites 2 and 3 as compare with other sites this may be due to the location, elevation and altitude.

While the water temperature was ranged from (13.6 -15.5 C°) at sites 4 and 2 respectively, in fact this site is more open with motorboats movement in addition to the discharge of water from the dam.

Statistical analysis shows that surface water temperature was significantly differ from the depths(p < 0.5) for sites 1, 2, and 3 this may be due to many environmental factors such as elevation, current velocity, water depth, bottom materials exposure to direct sun light and degree of shading or vegetation cover, evapotranspiration and wind speed.

PH was on alkaline sides of the neutrality (8.2-8.3) for studied sites and the significant differences (p < 0.5) was between sites 1, 2 with 3, 4.

while for the differences in depth, EC of the studied sites and different depths revealed that there was no significant differences in the water column, because EC is indirectly depend on the climate, temperature, soil erosion, geological formation and directly on ion content.

some parameters were decreased with increasing depth such as DO were the mean concentration was about 17 mg l-1 in the surface for most of sites, but this value was dropped to about less than 10 mg l-1, mean concentration of DO in site 1 was decreased from 3 mgl-1 down to the reservoir, because it contain sewage water come from Suleiman city.

Generally, results of Turbidity in site 2 was ranged from (5.67 – 12.05) NTU in both sites 3 and 4.

Mean PO-34 concentration of the studied sites were ranged from (7.11-14.79) μg at-P l-1 in sites 3 and 1 in respective.

NO2 was ranged from (31.78 -93.24) μg at-N l- at sites 1 and 2 with the significant differences among studied sites(p< 0.5), generally, the higher concentration was occurred in site 2., NO3 was ranged from (82.06-185.04 μg at-Nll-) for sites 4 and 2, recorded values for chlorophyll a were (11.12 μg at -ch-a l l-) in site 1 and (78.52 μg at -ch-a.

l l-) in site 2, and both sites of 1, 2 are significantly differ from other sites.

Turbidity, PO-34, NO-2, NO-3, and chlorophyll a with different depths revealed that there were no significant differences of the water column.