Integrated Management Approach in River Quality Simulations

Uneven spatial distribution of water resources, discrepancies in their temporal distribution and demographic pressures are main causes of stress on water quantity whilst decrease of quality poses as a looming factor. Sefid-Rud river in the north of Iran, where a large population depend on for their livelihoods, was chosen here as a case study. Pollution parameters namely DO, BOD, COD. NO3 and Coliform were considered for investigation. QUAL2KW software was adopted for simulation of quality parameters in two representative months of June and August when the river has the highest and lowest flows respectively. A number of probable conditions were considered for concentration of pollution sources ranging from -40% to +100% at 20% intervals. Self cleansing conditions were obtained as a result of investigation of different circumstances comprising natural river condition and each of pollution concentration conditions. Management scenarios were identified for sustainable development of the river basin based on development factors in the form of increase in population, agricultural activities and industrial development. Associated implications of each factor on individual pollution parameters were evaluated. Management scenarios were then ranked in a multi criteria decision support model based on integrated management principles specifically focused on environmental and socio-economical indicators. The MCDM software adopted for this was DEFINITE 2 where a series of possible scenarios affecting river water quality were considered and ranked. The scenario with the least adverse effect on river quality was identified as the highest rank and thus the best integrated solution assisting water quality stability and river basin development.