Water quality assessment using comprehensive water quality index and modified Nemerow index method: A case study of Jinghui Canal, North China

Abstract

Groundwater is an essential part of water resources for human survival in irrigation regions. In this study, water quality of jinghui canal irrigation area were assessed using the comprehensive water quality index method (CWQI), normal Nemerow index assessment method (NNI) and modified Nemerow index assessment method (MNI). 47 groundwater samples were collected from unconfined aquifers through shallow well during November 2009. The results showed that groundwater quality in the area was poor due to the industrial and agricultural activities. Most of the groundwater samples were identified as Grade IV and Grade V by the comprehensive water quality index method. While majority of groundwater samples were assessed as Grade IV by both NNI and MNI. Besides, the water quality assessed by MNI was better than NNI and NNI was better than CWQI, which was caused by parameter value and weight value, so we should not only stick to a certain assessment method, but also need to comprehensively consider the purpose of evaluation.