Assessment of Groundwater Potential and Quality using GIS and Remote Sensing Techniques: Case study of Kirundo Province, Burundi

Abstract

Although water is the most essential element for life, it is becoming increasingly scarce in different parts of the globe due to anthropogenic and/or climate change or variability. A number of African countries face the challenge of getting portable water from surface sources and rely mostly on groundwater. A case in point is Burundi where groundwater is almost the only source of drinking water for the entire population in rural areas. For many years, the population, particularly in the Northern region of the country, still faces a serious challenge related to water availability in terms of both quantity and quality which is accompanied by limited studies on groundwater resources in the region. Therefore, the sustainable and effective groundwater resources management, which requires a judicious understanding of the factors contributing to groundwater development and pollution, is highly needed. In this regard, the application of GIS and Remote Sensing techniques which have become essential and effective tools in water resources and particularly in groundwater studies in the last two decades were used in this study. This study investigated the groundwater potential zones and assessed its quality compared to the standards required for a safe usage for its various purposes. Different thematic features such as; elevation, slope, soil, drainage density, land use /land cover, lineament, fractional impervious surface and geology were utilized based on the relative contribution of each parameter to groundwater potential. The groundwater potential zones were delineated through the model development using the model builder tool of ArcGIS Pro with the help of the AHP method. Different indices were calculated for the assessment of the groundwater suitability to its main uses based on the results of physiochemical analysis of water samples from different boreholes/wells located in Kirundo province. The groundwater potential map revealed that 70.5 % of the province fall under very low and low groundwater potential whereas the medium, good and high groundwater potential have been respectively discovered in the extent of 10.8%, 8.9% and 1.2% of the study area. The water bodies occupy 8.6% of the province. It has been also noted that the groundwater of the province usually requires effective treatments for the safe usage except in some particularities where the groundwater quality has been judged as suitable before treatment. The results from the study will help the policy makers and water resources managers to make informed decisions in planning and management of water resources within Kirundo province.