Limited access to safe drinking water constitutes a significant challenge for residents of Ede North Local Government Area. A considerable proportion of the rural population does not have access to the minimum recommended quantity of 30 litres per capita per day of drinking water from safe sources. As a result, many residents depend on streams, rivers, and unprotected wells to meet their daily drinking water requirements. Reliance on these potentially unsafe sources has contributed to the premature loss of lives through diseases associated with inadequate water supply and poor water quality. Despite interventions by governments at different levels, development partners, non-governmental organizations, religious institutions, and philanthropic organizations in the provision of water supply schemes in Ede North LGA, access to safe drinking water remains inadequate (FMWR, 2007).

The persistent inadequacy of water supply in the study area has been attributed partly to insufficient data and information for effective planning and management, alongside low levels of capital investment and a lack of coordination in the development of water supply infrastructure. Furthermore, decisions concerning the location of water supply schemes are often influenced by political considerations rather than the actual needs of communities and appropriate technical assessments. This practice may result in the establishment of facilities in locations that are unsuitable for meeting the water requirements of the intended beneficiaries.

The quality of groundwater consumed by rural residents is also largely inadequately monitored. Groundwater quality deterioration within the study area may result from the infiltration of contaminated surface water, the leaching of chemical fertilizers into groundwater systems, and bacterial contamination of boreholes associated with poor sanitation practices. In 2014, a report on drinking water sources in parts of the LGA indicated that concentrations of toxic metals, including lead (Pb), ranging from 0.01 to 0.03; mercury (Hg), ranging from not detected (Nd) to 0.03; arsenic (As), ranging from Nd to 0.03; and cadmium (Cd), ranging from Nd to 0.04, exceeded the safe limits established by the World Health Organization (WHO). These findings suggest that the affected water sources could pose serious risks to human health (Odebunmi et al., 2014).

The rural population in the study area consists predominantly of farmers engaged in subsistence agriculture and poultry production. Waste generated from poultry farming represents a potential source of groundwater contamination. Similarly, the cultivation of cash crops, such as cocoa, and various annual crops commonly involves the application of pesticides and fertilizers to maintain agricultural productivity. These agricultural practices increase the possibility of contaminants entering groundwater systems and consequently place the groundwater resources of the area at risk of pollution.

In view of these challenges, there is a need for a systematic assessment of groundwater potential, groundwater pollution vulnerability, climatic variation, and the spatial distribution of existing rural water supply schemes. The application of Geographic Information System and Remote Sensing techniques can provide essential spatial information for identifying suitable locations for water supply infrastructure, recognizing areas vulnerable to contamination, and supporting more effective groundwater resource planning and management in Ede North Local Government Area.

1.3 Aim and Objectives of the Study

The principal aim of this study is to employ Geographic Information System (GIS) techniques to assess groundwater resources for rural water supply schemes, with the intention of providing effective tools and reliable spatial information for the planning, development, and management of such schemes.

Specifically, the objectives of the study are to:

a. Identify and delineate groundwater potential zones within the study area.

b. Determine groundwater pollution potential zones within the study area.

c. Assess climatic variations through trend analysis.

d. Map the locations of rural water supply schemes and establish their spatial distribution patterns.

1.4 Justification of the Study

The human right to water is recognized in international legal instruments, which emphasize the need to ensure that every individual has access to water that is sufficient, safe, acceptable, physically accessible, and affordable. According to Kofi Annan (2011), the former Secretary-General of the United Nations (UN), “Access to safe water is a fundamental human need and therefore a basic human right.” Access to safe water is an essential component of the fundamental rights of every human being. However, the realization of this right remains an unfulfilled promise for many inhabitants of Ede North Local Government Area, particularly those residing in rural communities.

Every year, a considerable number of people, many of whom are children, die from diseases associated with inadequate access to water. Water scarcity and poor water quality also have adverse consequences for food security, livelihood opportunities, and educational prospects, particularly among economically disadvantaged families. These challenges demonstrate the need for effective water resource assessment, planning, and management to ensure that communities have access to safe and adequate water supplies.

Furthermore, the primary objective of managing any natural resource, including water, is to establish conditions that guarantee its long-term sustainability. The acquisition, organization, and maintenance of a reliable and functional database containing groundwater information and the geographical coordinates of water supply schemes provide an essential foundation for sustainable resource management. Such a database can support informed decision-making, facilitate the monitoring of water supply infrastructure, and help prevent the excessive exploitation of groundwater resources within the study area.

The significance of this research lies in its potential to provide spatial information and practical tools for improving rural water supply planning, groundwater protection, and resource management. Specifically, the expected benefits of the study include the following:

e. The study will produce maps showing the locations and distribution of various rural water supply schemes within the study area.

f. It will delineate groundwater potential zones and groundwater pollution vulnerability zones, thereby making it easier to identify and monitor areas that are particularly susceptible to contamination.

g. It will examine changes in land use within the study area to provide information on the relationship between land-use patterns and groundwater resources.

h. The findings will support informed, appropriate, and timely decision-making by policymakers, planners, and other relevant stakeholders involved in water resource development and management.

i. The study will help address inconsistencies in the actual records of existing water supply facilities by providing a more systematic and coordinated approach to the management of facility-related data.

j. The outcomes of the research will contribute to efforts aimed at realizing the human right to water by supporting improved access to safe and sustainable water supply systems.

Overall, the study is justified by the need to strengthen the planning and management of rural water supply schemes, improve knowledge of groundwater availability and vulnerability, and promote the sustainable utilization of groundwater resources in Ede North Local Government Area.

1.5 Research Scope and Limitations

The scope of this research encompasses the identification and delineation of groundwater potential zones and the assessment of groundwater pollution risks within the study area. The study is not intended to identify specific sources of contamination. Rather, it focuses on examining the characteristics and environmental factors that influence groundwater potential and contamination zones. It also involves the production of maps illustrating areas suitable for the location of water supply facilities and identifying zones that are more susceptible to groundwater contamination.

In addition, the research covers the estimation of mean annual groundwater potential, the assessment of climatic variations, the mapping of existing water supply schemes, and the identification of gaps that need to be addressed to support the achievement of the Sustainable Development Goals (SDGs) relating to water supply. Through these assessments, the study seeks to generate useful spatial information that can inform the planning, location, distribution, and management of rural water supply infrastructure.

Despite its intended scope, the research encountered several limitations arising from inadequate rainfall measurement instruments within the study area, the absence of groundwater-level monitoring data from wells, and the unavailability of river-flow data. These limitations restricted the availability of certain hydrological and climatic information required for a more comprehensive assessment of groundwater resources and their relationship with environmental conditions.

Furthermore, the assessment of water supply schemes was restricted to public water points. Consequently, the findings and maps produced do not necessarily represent all existing water supply facilities within the study area. The reliability and accuracy of the maps are also dependent on the quality, completeness, and extent of the information available and utilized during the research. Therefore, the results should be interpreted in relation to the limitations of the underlying data and the specific scope of the investigation.