Abstract

• Pyawbwe-Nyaungyan-Payangazu area is located in the southeastern part of Dry Zone, between 20° 31´ 12˝ to 20° 45´ 54˝ North latitude and 95° 53´ 24˝ and 96° 14´ 24˝ East Longitude. This area spreads over an area of 995.52 sq. km falling within the semiarid region and frequently facing water scarcity as well as quality problems. The major sources of employment are agriculture, horticulture and animal husbandry, engaging almost 80% of the workforce. On the basis of geological conditions and stratigraphic position, three types of aquifers are recognized in the study area, viz;- alluvial, Irrawaddian and Peguan. In accordance with their morphological characteristics and occurrence, alluvial aquifers are subdivided into those of compound alluvial fans, alluvial unit I and II. Water samples are collected from 140 wells and were subjected to analysis for chemical characteristics. The water samples from the compound alluvial fan aquifer is clustered in Ca2+ -Mg2+ Cl- -SO4 2- dominant section and minor water types identified is Na+ -K + Cl- - SO4 2- types. Most of the groundwater samples from alluvial unit I are mostly fall in Na+ -K + -Cl- - SO4 2- water types and some are fall in Ca2+ -Mg2+ -Cl- -SO4 2- type. In alluvial unit II the groundwater samples fall in Cl- -Na+ water types and SO4 2- -Na+ water types. The Irrawaddian aquifer, water are fresh and slightly saline Na+ -K + Cl- -SO4 2- water type. The groundwater quality of the area is moderately hard to very hard, fresh to slightly alkaline in nature. Most of the water samples were found to be within in WHO guideline value. The suitability of groundwater for irrigation was assessed from (TDS, EC, SAR, MAR, Na% or RSC). Most of the groundwater samples in this area fall in the suitable range for irrigation purpose either from EC and MAR values.