Assessment of groundwater quality for irrigation using a new customized irrigation water quality index

Angads plain, Northeastern Morocco This study aims to assess groundwater quality for irrigation purposes by introducing a new customized irrigation water quality index (CIWQI) to improve precision by adapting to local hydrochemical specificities using factorial analysis. The results reveal a high degree of variability in groundwater quality in the study area, influenced by both natural and anthropogenic factors. Some wells contain good quality water, suitable for irrigation without major restrictions, while others have high concentrations of dissolved salts, limiting their agricultural use. Conventional indices (SAR, Na%, KR and MH) did not show seasonal variations, but the CIWQI index showed that water quality is better during the wet period (53.3 % of samples classified as moderate to good quality) compared to the dry period (22.2 % moderate quality). This index, better adapted to local specificities, more accurately reflects seasonal variations. The study underlines that the use of indices adapted to the local environment enables a more accurate assessment of water quality. • Indices such as IWQI, SAR, Na%, KR, and MH was used. • New CIWQI was developed. • Combining CIWQI and GIS improves seasonal variation analysis.