Hybrid objective model (IDOCRIW-CoCoSo) optimizes groundwater potential

Published:


Description

Published work - Cleaner Water (2026). Link


Highlights

  • Integrated Determination of Objective Criteria Weights-Combined Compromise Solution (IDOCRIW-CoCoSo) multi-criteria decision-making approach have been employed to model groundwater potential of the area.

  • Integration of Remote sensing and geophysical datasets proved effective for the modelling.

  • Comparative analysis with objective models (CRITIC-CoCoSo, and Mean Weighted CoCoSo) ensured confidence in the adopted approach.


Abstract

Groundwater is a valuable asset in both urban and rural areas, where the demand for alternate water sources is increasing—a vital resource for agriculture, industry, and domestic. Assessment of this resource becomes paramount globally and especially in areas where fresh water demand is rising despite falling within a multi-faceted geologic environment—rendering its sustainable management a pressing concern. To address this issue, an Integrated Determination of Objective CRIteria weights–Combined Compromise Solution (IDOCRIW-CoCoSo) was developed by integrating five groundwater potential influencing factors sourced from remote sensing and geophysical datasets. This will increase the prospect of finding productive aquifers and maximize the choice of drilling sites. The results were contrasted with two other hybrid objective modelling approaches, including CRiteria Importance Through Intercriteria Correlation–Combined Compromise Solution (CRITIC-CoCoSo), and Mean Weighted (MW) - CoCoSo. The groundwater potential map produced, classified into five classes, showed that 6% (113 km²), 26% (486 km²), 32% (603 km²), 26% (473 km²), and 10% (192 km²) fall into very low, low, medium, medium high, and high potentiality, respectively. The obtained results were confirmed using the receiver operating characteristic (ROC) curve and sensitivity analysis. According to the area under the ROC curve, the IDOCRIW-CoCoSo had a success rate of 83%, compared to MW- CoCoSo with an area under the curve (AUC) of 75% and CRITIC-CoCoSo (69%). The findings demonstrate IDOCRIW-CoCoSo’s higher accuracy in predicting groundwater potential zones. For the sustained development and management of water-scarce areas, this study offers scientific perspective into the sustainability, distribution and governance of groundwater assets.


Methodology

Conditioning factors maps have been generated using ArcGIS 10.8.2 software. Python programming coded objective models were applied to the groundwater potential decision matrix gotten through fishnet points extraction of pixel values from the factors maps. Interpolation technique was used to create groundwater potential maps of the study area taking groundwater potential indices from models as input. Several reliability and comparative analysis iincluding sensitivity analysis as well as multicollinearity testing were adopted.

Methodology Flowchart
Methodology Flowchart

Findings

The produced groundwater potential map (IDOCRIW-CoCoSo) is advantageous in meeting SDG 6.1 goals in the study area

Study area location map
Study area map
Groundwater potential map (IDOCRIW-CoCoSo
Groundwater Potential Map (IDOCRIW-CoCoSo)

IDOCRIW-CoCoSo showed impressive AUC-score compared to CRITIC and Mean Weighted CoCoSo

ROC-Curve for IDOCRIW-CoCoSo
ROC-Curve for IDOCRIW-CoCoSo
ROC-Curve for CRITIC-CoCoSo
ROC-Curve for CRITIC-CoCoSo
ROC-Curve for Mean Weighted-CoCoSo
ROC-Curve for Mean Weighted-CoCoSo

Comparative and hydrogeological analysis further elaborated the supremacy and efficacy of IDOCRIW-CoCoSo model for groundwater potential mapping

Bootstrapped AUC result of the models
Bootstrapped AUC result used as a form of computational efficiency assessment of the models
Sensitivity analysis of IDOCRIW-CoCoSo
Sensitivity analysis of IDOCRIW-CoCoSo
Heatmap of IDOCRIW-CoCoSo model
Heatmap of IDOCRIW-CoCoSo model demonstrating the stability of its outputs across the fishnet locations during scenario analysis
IDOCRIW-CoCoSo groundwater potential map indicating correlating regions with overburden thickness map
IDOCRIW-CoCoSo groundwater potential map indicating correlating regions (black circle) with overburden thickness map
Overburden thickness map showing correlating regions with IDOCRIW-CoCoSo groundwater potential map
Overburden thickness map showing correlating regions (black circles) with IDOCRIW-CoCoSo groundwater potential map