Development of an Integrated Irrigation Water Quality Index (IIWQIndex) model

Abstract

There are many irrigation water quality indices used to assess water suitability, despite some of their limitations. Hence, it is imperative to develop a water quality index to evaluate the irrigation water more accurately. This study has aimed to emerge an Integrated Irrigation Water Quality Index (IIWQIndex) using the sub-index and aggregated equations. This proposed index model was considered to be improved and updated in four aspects: the verified desirable and permissible value of parameters, maximum hazard class, used a modified rating system of parameters, and diversified parameters were considered. The proposed IIWQIndex model classified irrigation water into five categories, i.e., rejection, poor, moderate, good, and excellent. This model assessed two types of water to justify the model by categorizing the irrigation waters. The calculated results showed that the index values were 75.77 and 36.51, and the water category fell under ‘good’ and ‘rejected’ for the calcite (Ca-HCO3) and sodic (Na-Cl) water, respectively. Besides, this index model satisfactorily evaluated different types of water datasets of eight geographic locations in the world. The study illustrated that the IIWQIndex evaluated values and water categories were rational and exhaustive to predict the suitability of irrigation water.

Comparison of classical and developed indexing methods for assessing the groundwater suitability for irrigation

“…The cationic and anionic concentrations in water samples follow the order, respectively as Ca 2+ >Mg 2+ >Na + >K + , and HCO 3 − >Cl − >SO 4 2− >NO 3 − >PO 4 3− . Except for Ca, HCO 3 − , total hardness, Mn, and Fe; the rest of the parameters are in standard ranges of irrigation suitability (Islam & Mostafa, 2021d). For the determination of the water type of samples, Piper's and Chadha's diagrams are plotted (Chadha, 1999; Piper, 1944).…”

“…For instance, one model exhibited the water quality status of a water sample as ‘good’ but, the model showed it is ‘poor’ for the same. On the other hand, several studies considered the lower rating value of parameters as 1 (Ayers & Westcot, 1985; Islam & Mostafa, 2021d; Simsek & Gunduz, 2007), but this is the wrong concept as the total index value can be affected by the rejected category of the parameters at the lowest‐scoring point. The lowermost value of the parameter's score in rejection ranges should be zero.…”

“…It is impossible fact to completely assess the quality of that water through a single index model. Many IWQ indices and guidelines for the proper justification of irrigation water suitability were recognized worldwide by some researchers (e.g., Arslan, 2017; Ashraf et al, 2011; Ayers & Westcot, 1985; Bauder et al, 2011; Bozdag, 2016; Hussain et al, 2012; Islam & Mostafa, 2021d; Meireles et al, 2010; Simsek & Gunduz, 2007; Zaman et al, 2018). For instance, Simsek and Gunduz (2007) recognized a geographical information system (GIS)‐based IWQ index by the amalgamation of predictable five geochemical hazards (salinity hazard, permeability hazard, ion toxicity, trace metal toxicity and miscellaneous) to evaluate the IWQ of the Simav Plain, Turkey.…”

“…We have followed US-APHA (2005) methods in every stage of all the above quantitative investigations.5 | RESULTS AND DISCUSSION5.1 | Water characteristicsThe statistical records of the physical, geochemical, and trace metal parameters of groundwater samples of both PRM and POM periods are shown in Table5. The result showed that the most important cations and anions in the samples are Ca 2+ , Mg 2+ , and HCO 3 The cationic and anionic concentrations in water samples follow the order, respectively as Ca 2+ >Mg 2+ >Na + >K + , and HCO 3 , Mn, and Fe; the rest of the parameters are in standard ranges of irrigation suitability(Islam & Mostafa, 2021d).…”

Identification of Sources and Mobilization of Trace Elements in Shallow Groundwater of the Upper Ganges River Basin

“…These two ions may be invented from similar sources. Thus, dissolution or weathering is the geogenic geochemical process controlled by the salt load along the groundwater flow path [54].…”