At present, there is a little well-established irrigation water quality index (IWQI)
for surface water in arid and semi-arid regions. Thus, the current work focused on
establishing since-based weights of parameters adopted by FAO 29 guideline to develop
IWQI based on the National Sanitation Foundation Water Quality Index (NSFWQI). The
new index was then applied in Kafr El-Sheikh Governorate, Egypt as a case study. Fortyfive
geo-referenced water samples were collected from canals and drains during winter,
spring, summer, and autumn of 2018 and analyzed for twenty-two parameters. Data
were subjected to correlation analysis, principal component analysis (PCA), and factor
analysis (FA). Weights were assigned for initial parameters based on PCA and FA to
calculate IWQI-1 and IWQI-2, respectively. The two models resulted in similar trend and
showed low to good water quality, with IWQI-2 being more recommended. The initial
input parameters were reduced to finally shortlisted seven ones, including Na+, Zn, pH,
HCO−
3 , As, NO−
3 , and B. These parameters showed better performance in representing
water quality their when weights were derived from PCA rather than FA. Integrated use
of PCA/FA and IWQI would make water quality control rapid, low-cost, less biased and
more objective to form a base of sustainable development programs in the studied area.