Delineation of Surface Water Potential Zones and Identification of Sites in Mahanadi River Basin, Odisha, India, Using GIS: Fid-Bau Portal

Delineation of Surface Water Potential Zones and Identification of Sites in Mahanadi River Basin, Odisha, India, Using GIS

Das, Abhijeet

Abstract

One of the most crucial stages for developing surface water resources for drinking water use is assessing the water quality (WQ). So, agriculture and human health are seriously threatened by the geogenic and anthropogenic variables that affect surface water quality. It is obvious that the current water shortage in the area has necessitated a review of the river's water quality. Water samples from 19 locations were taken in 2018–2023, to test 20 physicochemical parameters in the selected sampling sites in Mahanadi River Basin (MRB), Odisha. This study has spotlighted an evaluation of surface water quality for drinking purposes by integrated use of Stepwise Weight Assessment Ratio Analysis (SWARA/S)-based WQI, with reliability-based multi-criteria decision-making (MCDMs) such as Simple Additive Weighting (SAW) that has been employed. The substantial engineering feature used in the study, which incorporates temporal large and contextual data based on the specific period, leads it distinctiveness. Geographical Information System (GIS) techniques were used to create surface maps of river water attributes, and sampling-broad analysis utilizing GPS was found to be a potentially effective tool. In addition, the geospatial approaches such as Inverted Distance Weighted (IDW) are used to anticipate for an unobserved place utilising nearby known qualities and interpolate the spatial variability of point attributes, and it is represented in the form of maps using ArcGIS 10.5 software. The result obtained from the research portray that the river water is alkaline in nature and the pH value ranges between 7.74 to 7.91, respectively. The spatial distribution results showed that the higher values of coliform, TKN, chloride and sulphate were recorded in the places close to the coastline, indicating the occurrence of sea water intrusion and salinization. Further, the S-WQI revealed that 10.53% (sites MP-8 and MP-19) and 5.26% (site MP-9) of samples belong to poor/very poor water quality while 84.21% of sites come under the zone of excellent water. It revealed that the main cause could be deterioration of domestic water, illegally dumped municipal solid waste and agricultural runoff were the leading sources causing adulteration of the river’s water quality. Despite being a crucial component for grading overused water stations, WQI involves sensitive issues. As a consequence, MCDM models, such as SAW, were implemented to resolve discrepancies, incorporating WQI index and evaluating the model’s performance based on factors such as uncertainty, sensitivity, and reliability. The final ranking was calculated by taking the factor weights and field data into consideration. The proposed approaches depicted by MP-9, was perhaps the most filthy/contaminated, when compared to other places, followed by MP-(8) and MP-(19) respectively. This was apparent from the high S-WQI levels in this vicinity. It also accompanied with high values of TC, TKN, EC, SAR, TDS, TH, Cl⁻, SO₄²⁻ and Fe²⁺, which were highest among all the areas and also more abundant than their desired concentration. However, it was pertinent that the pollution level at these stations was associated more with increasing and diverse anthropogenic activities like overexploitation of water, fertiliser influences and agricultural return flow and industrial presence within and around the river course. The resultant WQI model significantly contributes to sustainable surface water resource management in the studied areas and generates improved prediction precision with fewer input parameters. Hence, the current work determines that we are unable to use the surface water at MP-(8), (9) and (19), directly without treatment, and for this resource to be used sustainably, strict management procedures must be put in place. So, it is recommended that river water can be utilised for residential purposes and, after disinfection, can be consumed.