Quantification of anthropogenic factors affecting Iran’s groundwater quality: Application of method of moments quantile regression

Document Type : Research Paper


1 Department of Agricultural Economics, Faculty of Agriculture, University of Tehran, Karaj, Iran.

2 Department of Water, Wastewater and Environmental Engineering, Faculty of Civil, Water and Environmental Engineering, Shahid Beheshti University, Tehran, Iran.



Until now, various studies have been conducted regarding the quality of groundwater resources in Iran, however, few researchers have paid attention to the assessment of the role of different anthropogenic factors in the decrease of the quality of these resources. In this study, in order to fill this gap, the groundwater quality index was first calculated for all provinces of Iran between 2013 to 2019, and then by using a novel approach in estimating quantile regression, the influences of anthropogenic factors on the quality index were measured. Furthermore, to investigate the role and impact of sewage infrastructures on the quality of groundwater, two composite indices for the development of sewage treatment and collection infrastructures have been calculated by Entropy method. The findings of the study illustrate that in areas with high quality groundwater, the main factor affecting the quality of groundwater is the population, so that one percent growth in it increases the quality index by 0.71 percent. In places with medium and low-quality groundwater, the main factor in the quality decline of these resources is the economic growth of the agricultural sector. In fact, each percent growth in the economy of the agricultural sector amplifies the quality index by more than 2.5 percent. Other influential factors in these areas are population growth and economic growth of industry and mining sector. One percent growth in the composite indicators of the development of sewage treatment and collection infrastructure has also lessened the quality index by 0.05 and 0.01 percent on average. According to the results of the study, reducing input intensity in the agricultural sector and upgrading the sewage infrastructure are the main possible solutions regarding the quality management of groundwater resources in Iran.