An Overview of the Assessment of Groundwater Quality for Irrigation

摘要

The assessment of water quality is one of the important tools for sustainable development and provides decisive information for water management. In identifying water availability for irrigation, knowledge is required on both the quantity and quality; nevertheless, quality need has often been neglected especially in developing countries. Quality should generalize how substantially a water supply fulfils the needs of the planned user and must be assessed based on its suitability for the proposed use. The quality of groundwater is determined by various physicochemical properties and chemical indices. Chemical properties of groundwater are controlled by natural geochemical processes and anthropogenic activities. Therefore, to monitor the quality of groundwater for irrigation purposes, in depth understanding of hydro geochemistry of the water is required since different ions in water have contrasting impacts on soil. The water having high sodium adsorption ratio (SAR) when used for irrigation heighten exchangeable sodium percentage (ESP) in the soil thereby adversely affecting the soil structure leading to decrease in infiltration, hydraulic conductivity, enhance surface runoff and erosion. Moreover, the poor-quality water causes impairment in crop growth as high salt concentration in irrigation water results in osmotic stress and ion toxicity in plants.