الفهرس | Only 14 pages are availabe for public view |
Abstract Irrigation canals not only pass across fields but also go through residential areas in some situations, where they are affected by the bad habits of users. Surface water quality was not the only problem; there was the surface water problem of quantity, where amounts of surface water in the irrigation network lost by evaporation and by infiltration to the shallow aquifer, while the pipelines had no seepage losses. So, the decision makers adopted the solution of irrigation canals covering. It was important to make an environmental impact assessment for this solution. Environmental Impact Assessment (EIA) was done for surface water quality, groundwater levels, groundwater quality, and Quality of Life (QOL) for the residents. It was done through three main measurements. The first measurement was for evaluating surface water quality, through collecting five samples from three canals, which were for The Reference Point Upstream (R.P.US.), the Point of Inlet (P.l.), the Point ef Manhole (P.M.), the Point of Outlet (P.O.) and the Reference Point Downstream (R.P.DS.). The samples were analyzed in the laboratory. The results proved that covering of irrigation canals was affected water quality and construction material in bad way, however HC03, decreased in manholes, while TA (total alkalinity), TDS (total dissolved solids), Na, Cl, S04, ... etc increased in manholes. Comparisons were performed between the parameters of water before and after covering. These comparisons were regards to .he upstream reference points. The comparisons results were that irrigation canals covering affected water quality negatively. They also discovered that point of inlet is a dangerous point, due to the existing of mesh at this point. In this regard, dimensional analysis method used to get relations between water quality parameters and the hydraulic parameters of canals. Two types of efforts were done to get these relations. One of these efforts was for the relation of water quality parameters with all effective hydraulic parameters of canals. This concluded to sixteen equations for PH, HC03, TA, TDS, Ca, Mg, Cl, N03, P04, Co, Cu, Mn, Ni, Sr, Zn, and V. The other type of efforts was for the relation of water quality parameters with Fr (froud number) and Re (Reynolds numbers). It proved that only PH has a strong relation. |