Environmental Modelling of Surface Water Quality of Banas River using AQUATOX Simulation Model: A Case Study of Pollution River Stretches (PRS), North Gujarat, India

There are 14 major rivers, 44 medium rivers and 53 small rivers in India, the seat for setup of big cities and their educational, political and regional developments. Gujarat State is profusely endowed with number of perennial rivers such as Narmada, Tapi, Mahi and Sabarmati, used by people as a source of water to dispose sewage and industrial effluents, altering quality and ecology of water bodies, brings new challenges to both water resource managers and aquatic ecologists. Gujarat is one of the leading largest industrial states of the country, known for textile industries and engineering units, which produce chemicals, fertilizers, dyes, fibres, polymers, drugs, catalysts etc. These industries are major contributors to air, water and soil pollution at a great extent. Urban cities located along river banks cause significant negative impacts on water quality owing to unrestrained garbage dumping and discharge of untreated or partially treated effluents from adjacent industries. As a consequence, proximate rivers are getting deteriorated day by day. Looking into an urgent need of an hour, the present study was aimed to assess surface water quality from March 2014 to September 2014 with a view to predict hydro-chemical parameters for subsequent five years (2015-2019) using AQUATOX Simulation Model (EPA, Release 3.1) at Banas River, North Gujarat. For analysis of hydro-chemical parameters, surface water samples were collected from five permanent sampling stations (Upper Stream: US: Dantiwada Dam; Non-Control Point: NCP: Deesa; Middle Steam: MS: Deliyathara; Control Point: CP: Mota Jampur; Down Stream: DS: Totana) during Pre-Monsoon (March & April) and Post-Monsoon (August & September). Physico-chemical parameters such as NH3-NH4+, NO3, Total Soluble P (TSP), Oxygen, Total Suspended Solids (TSS), Temperature & pH, were analyzed using APHA (2012). Based on Biological Monitoring Working Party (BMWP) Score, pollution gradient was NCP>DS>MS>US>CP under ‘Moderately Polluted or Impacted’ River category. In case of NH3-NH4+, mean concentration (0.125026536), mean difference (0.625132675), and mean % increase (99.9999998) was observed from 2015 to 2019, that of NO3, mean concentration (2.612430993), mean difference (10.0590781), and mean % increase (94.36554743), that of TSP, mean concentration (1.687903404), mean difference (-0.007325245), and mean % decrease (-0.435496), that of Oxygen, mean concentration (7.798760987), mean difference (-0.011005071), and mean % decrease (-0.141272556), that of TSS, mean concentration (373.9252877), mean difference (0.032911562), and mean % increase (0.0088001022), that of Temperature, mean degree of centigrade (26.25641984), mean difference (0.000519778), and mean % increase (0.001979592), and that of pH, mean content (7.789118651), mean difference (8.49373), and mean % increase (0.001090452) was observed. Further research is warranted is in line for aquatic pollution abatement for environmental sustenance therein