Water Resources Mapping along the Jilango /Shabel-Dulla Areas of Laghdera Subcounty in Northern Kenya

Abstract

The Jilango and Shabel-Dulla areas are located in the Laghdera Sub- County of Garissa County, in North Eastern Kenya, on the fringes of the distal Merti aquifer. Water scarcity has been the number one factor contributing to the immense levels of poverty in the pastoralist centre. The resident inhabitants are of the nomadic-pastoralist lifestyles, raising livestock such as camels, goats and cows, for upkeep. The settlements are six kilometers apart and this is a deliberate effort by the villagers to live near the seasonal River Jilango, within whose beds the residents have sunk several sand wells to get water for their domestic use, and also, on a limited extent, to get little water for their livestock, mainly the sheep and goats. The water resources quality, ease of availability and priority ranking in the study area were undertaken using field traverse along the river channels and also via geophysical mapping in the selected sites in the neighborhood of the riverbed. Priority ranking was pegged upon the ready availability and cost effective way of getting water into the villages for use, for both domestic- and livestock- watering purposes. In areas where groundwater potential was inferred using Geophysical mapping, it became paramount that the study gets to estimate the water quality expected from the yet-to-be-drilled proposed well points. Groundwater potential estimation was also undertaken using field geophysics and GIS, as well as the Decision Tree algorithms in R software packages. Precision and sensitivity analysis of the data was also undertaken using the python Softwares and returned favorable results for the techniques employed. Feasibility for Wells, Earthpans, Springs and piped water from Baraki Centre were all considered, in terms of how much each option would cost to the community. This involved physical transects and meetings with members of the public in the proposed locality. From the table so prepared, it was decided to rank groundwater as number two priority source, mainly for use by r livestock and an earthpan as number one for human domestic usages, based on water quality and other factors considered. The study shows the priority ranking of water resources in the study area as well as the fact that predicted groundwater quality is of inferior order, and recommends the designing and construction of a big storage dam to aid domestic water supply. This shall complement the available aquifer water which, though saline and of low discharge, can be tolerated by the livestock. Equally deduced from the study is the fact the decision tree algorithm is a useful hydrological assessment tool, as it was used to a degree of over 90 percent precision levels, in predicting the water quality that will be encountered in the locality, once the new well water is drilled.