Water Quality Modeling for Faria Stream

Discussion Committee: 
Dr. Numan Mizyed / Supervisor
Dr. Abdel Fattah Hasan / Co-Supervisor
Prof. Marwan Haddad / Internal Examiner
Dr. Subhi Samhan / External Examiner
Dr. Numan Mizyed / Supervisor
Dr. Abdel Fattah Hasan / Co-Supervisor
Afaf Tayseer Abdu-Allah Alawneh
Assessment and modeling of water quality is essential for ecosystem management. Faria watershed has an area of 320 km2, its main land use is for agriculture with 70% irrigated crops. Faria stream through the watershed, is polluted mainly with untreated WW discharged from eastern Nablus and due to surface runoff from adjacent draining lands. Stream’s water quality modeling is needed for stream and watershed restoration. The stream was divided into five reaches through five sampling points. At each point several field measurements were conducted for stream velocity and flow, and water samples were collected monthly from December, 2010 to May, 2012, and analyzed for pH, EC, BOD, COD, TKN, and SOD. Water quality of the stream was modeled by QUAL2Kw. Modeling of water quality along the stream was performed for three current cases. These include; summer with maximum BOD, winter with minimum flow, and critical conditions of minimum DO with minimum flow. The model was calibrated for depth, flow, velocity, travel time, DO profile and SOD using measured values. Considerable changes were detected along the stream as DO changed due to aeration in natural stream from 0.55 mg/l upstream to DO level of 5.1 and 4.8 mg/l at the following two sampling points, and also due to natural treatment in the stream, average TKN changed from 233 mg/l at upstream to about 160 mg/l at the downstream, average TDS reduced from 2000 mg/l to 500 mg/l at downstream, and TSS also reduced from average 1604 at upstream to about 266 mg/l at downstream. Withdrawals were predicted at reaches 2-3, 3-4, from Badan area to AL Malaqi Bridge, withdrawals were estimated of about 3000-3450 m3/d and increased at summer to 8120 m3/d at reach 2-3, Badan area. Stream management and restoration techniques are recommended for Faria stream, this can be achieved first by the installation of WWTP at Nablus-outfall. Such solution is expected to improve stream quality by reducing SOD from 6.22 without treatment to 0.37 gO2/m2/day after treatment, and DO profile showed enhancement along the stream as it improved after treatment, from effluent DO of 2 mg/l at upstream to about 5.56 mg/l at distance of 7.77 km and DO of 8.6 mg/l at stream end. Other management and simple structural techniques can be used for Faria stream restoration such as: Waste Water Storage and Treatment Reservoir (WSTR), improving the sanitation conditions of communities around the stream, side armoring using riprap and gabions, stream aeration by using hydraulic structures such as weirs, waterfalls or ladders, and impoundment removal. Nonstructural techniques also can be effective in Faria stream restoration and management include: planting and establishment of buffer zones and riparian zones to reduce runoff pollution, pollution control legislations and administration of fertilizers application frequency, timing and types, in addition to controlling and maintaining human activities, and land use at the watershed.
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