The Santa-Babadjou Corridor, located in the Western and North-Western regions of Cameroon, spans approximately 34 km north to south and 38 km west to east, covering a total area of about 1292 square kilometers. This region is defined by a diverse physical landscape that includes mountains, valleys, forests, springs, crop fields, and clustered farming communities. Its physical environment is shaped by a Guinea-type climate, with annual rainfall ranging between 2000 and 3000 mm and temperatures fluctuating between 15˚C and 25˚C. These climatic conditions directly influence water availability, crop growth, and overall agricultural activity. The corridor’s relief is characterized by scenic hills and plateaux of varying sizes and slopes, with elevations ranging from 1300 meters in Bali-Gham and Awing to 2703 meters near the Wabane boundary. Mt. Lefo in Awing, standing at 2300 meters, is the second-highest peak in the North West Region. Numerous valleys, shaped by the erosive action of flowing streams, enhance drainage and support farming. The drainage system is complex, dominated by the Santa Stream and its numerous tributaries, which create a dense hydrological network crucial for water supply and irrigation. Soil types across the corridor also vary significantly, influencing agricultural potential. Fertile alluvial soils dominate the floodplains and lowlands areas of Maforbe, Matazen, and Kombou, enriched by seasonal sediment deposits. In highland areas such as Akum, Baba, Mbu, and Awing, modified orthic soils offer good drainage, reducing waterlogging. Meanwhile, parts of Santa contain humic or black soils rich in organic matter, which retain moisture effectively. Together, these interconnected climatic, topographic, hydrological, and soil features create a dynamic environment that supports diverse agricultural systems and shapes water resource availability across the Santa-Babadjou Corridor (; Mfonka et al., 2025 ; Momo et al., 2020 ; Azinwi Tamfuh et al., 2020 ; Yasmine et al., 2024 ).

The methodological framework illustrated in Figure 2 was systematically followed. Remotely sensed data were utilized to develop a series of thematic layers, which were subsequently integrated to generate the GWPZ map. To ensure the reliability of the GWPZ outputs, field verification and validation as shown in Table 1 were carried out using a combination of existing spring locations and static groundwater level measurements. In this regard, Field validation was conducted using a total of 33 ground-truth points, consisting of 14 springs, 12 boreholes, and 7 static groundwater level measurement points, spatially distributed across the Santa-Babadjou Corridor. These validation points were overlaid on the final Groundwater Potential Zone (GWPZ) map to assess model accuracy. Results indicate that 28 out of the 33 validation points (equivalent to 84.8%) fall within zones classified as moderate to very high groundwater potential. The various phases of this approach are elaborated in the subsequent sections. Phase (1) involved, the identification and mapping of surface factors that influence groundwater recharge, runoff, occurrence, and storage; Phase (2) involved, the reclassification of each of these factors based on their relative impact on recharge potential; and Phase (3) focused on assigning appropriate weights to each thematic layer to reflect its significance in contributing to groundwater availability. A rank and weight were assigned to each factor based on its relative importance to groundwater recharge. Finally, all thematic maps were integrated in ArcGIS 10.5 using the weighted overlay analysis method to generate the GWPZ map.

In this study, five key factors were considered: lithology, slope, relief, drainage density, and land use. The slope and drainage density maps were derived from Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) data with a 30-meter spatial resolution (SRTM1N04E009V3) using ArcGIS 10.5. Relief and Land Use thematic layers were generated from Band 7 of Landsat 8 OLI imagery (LC08_L1TP_187057_20170507_20170515_01_T1), which covers the entire Santa-Babadjou Corridor. The slope, drainage, and Relief maps were created using the Spatial Analyst tools, while the land use map was developed using the supervised maximum likelihood classification tools in ArcGIS 10.5. Lithological data were also incorporated as a crucial factor influencing groundwater movement and storage within the study area.

The lithology map was reproduced from the Multi-Source Satellite Imagery and Machine Learning for Detecting Geological Formations in Cameroon’s Western Highlands by ().

The five thematic layers of lithology, slope, relief, drainage density, and land use/land cover (LULC) were selected for this study based on their direct influence on groundwater recharge and storage dynamics in the Santa-Babadjou Corridor, as well as the availability of reliable spatial data.

Lithology was prioritized because fractured and porous geological formations such as Late Tectonic Granites and alluviums significantly influence infiltration and aquifer storage capacity. Slope was included due to its control over surface runoff and infiltration, where gentler slopes promote groundwater recharge, especially in the steep terrains of the corridor. Relief reflects elevation differences that affect surface water accumulation, with low-lying areas enhancing recharge. Drainage density was used to indicate runoff potential; lower densities allow more time for water to percolate into the ground. LULC was considered to assess how different land covers affect infiltration, with farmlands and grasslands promoting recharge while built-up areas hinder it.

While theoretically important for recharge modeling, we faced significant administrative challenges in obtaining reliable, community-level rainfall data from local meteorological authorities due to data-sharing restrictions and sparse monitoring station coverage across the corridor. Given these constraints and the region’s relatively uniform annual rainfall distribution (2000 - 3000 mm/yr), we prioritized more readily available and spatially variable factors (lithology, slope) that better discriminate recharge potential at our study scale. Soil texture was excluded because of the low resolution of regional maps and because lithology and slope have greater control over infiltration in volcanic terrains like the corridor. Lineament density was not included because, its effects are partially captured through the lithology and slope layers which indirectly account for structural controls.

This focused selection ensured a parsimonious model while accounting for over 90% of recharge variability, as confirmed by field validation, with a consistency ratio (CR) of 1.84%.

To minimize errors and maintain the geometric integrity of the imagery, all thematic layers were standardized and projected onto a common Universal Transverse Mercator (UTM) coordinate system (WGS84 Zone 32N) with a spatial resolution of 30 meters. The five thematic maps generated through this process served as key input factors for producing the GWPZ map using the AHP. AHP is a multi-criteria decision-making method developed by Thomas ( Saaty, 1984 ), which involves calculating weights by determining the dominant right eigenvector of a positive reciprocal decision matrix. This matrix is constructed from pairwise comparisons, using a fundamental scale of values to express relative importance. This was achieved using the Analytic Hierarchy Process Software developed by Klaus Goepel (2024), the five criteria (factors) were subjected to pairwise comparisons, as shown on equations 1 and 2 below.

$pwc=\left(a_1,a_2,\cdots ,a_{np}c\right)/\left(x_1,x_2,\cdots ,x_{np}c\right)$ (1)

Each integer a_i falls within the range [0, 1], while x_i ranges from [1, M], where M = 9 and i = 1, 2, …, npc, with npc representing the number of pairwise comparisons. For n criteria, a corresponding n × n decision matrix is constructed and populated using the values from the pairwise comparison (pwc) vector (equations 2)

$npc=\left(N^2-N\right)/2$ (2)

The five influencing factors, along with their assigned weights, were geoprocessed using the Weighted Overlay tool under the Spatial Analyst Tools in ArcGIS 10.5 to produce the GWPZ map. Prior to analysis, all input criteria were reclassified into integer rasters. A scale of 1 to 5 was applied, where 1 denotes the least favorable and 5 the most favorable conditions for groundwater recharge and occurrence. This scale was set through the Evaluation Scale parameter to guide the assignment of relative suitability scores during overlay analysis.

The geological structure of the Santa-Babadjou Corridor plays a fundamental role in determining the potential for groundwater recharge and subsurface water flow. Among all influencing factors, lithology stands out as the most critical in controlling both the occurrence and movement of groundwater in the corridor ( Table 2 ). Effective groundwater recharge relies on the presence of suitable geological formations that allow for the infiltration and storage of water in aquifers. As illustrated in Figure 3 , the corridor is characterized by a diverse assemblage of rock types, each with varying implications for infiltration, porosity, and water retention.

Source: Generated from AHP-OS.

The Late Tectonic Granites dominate the area, covering approximately 29.4% of the corridor. These granitic formations, found predominantly in the Centre, North, Northwest, and Eastern zones, are generally fractured and moderately permeable, offering fair potential for groundwater recharge through secondary porosity developed in joints and cracks. Biotite and Amphibole Gneisses make up 24.6% of the corridor and are located mainly in the Central and Northeastern parts. These metamorphic rocks typically exhibit low primary porosity, but when highly weathered or fractured, support limited groundwater movement and storage. Ignimbrites, occupying about 21.5%, are concentrated on the western flanks of the corridor, particularly along the slopes of the Bamboutos Mountain. These pyroclastic volcanic rocks often exhibit variable permeability, with their recharge potential heavily dependent on the extent of weathering and fracturing. In more fractured zones, they form effective aquifers. Anatoxite Granite, covers approximately 15.3% of the area and distributed across the Northern and Northeastern sectors, also contributes to groundwater dynamics. Though generally less permeable due to its crystalline structure, localized fracturing can enhance infiltration in some parts. Alluviums account for 9.2% of the corridor and are mainly concentrated along wetland zones and stream channels in the Southern and Southwestern parts. These unconsolidated sediments possess high porosity and permeability, making them the most effective geological medium for groundwater recharge in the corridor. The heterogeneity of these geological formations results in spatial variation in groundwater recharge potential across the Santa-Babadjou Corridor. Hence, regions underlain by alluvium and fractured granitic rocks are more favorable for recharge, while areas dominated by unfractured crystalline and metamorphic rocks show relatively lower infiltration capacity. Understanding this geological framework is crucial for guiding water resource management and planning within the corridor.

The Slope of the corridor also plays a crucial role in groundwater recharge potential, as it influences both surface water infiltration and the velocity of runoff. As illustrated in Table 2 , slope ranks as the second most influential factor in determining recharge potential, with a calculated weight of 29.9. The slope map of the corridor, in Figure 4 , reveals considerable variations in terrain, ranging from flat low laying regions to steep mountainous areas. The slope across the region is classified into five gradient categories consistent with those used in Table 3 . These classes were reclassified to reflect their recharge potential, with very gentle and gentle slopes being most favourable due to longer residence time and higher infiltration capacity, while very steep slopes encourage rapid runoff and minimal infiltration. According to Table 3 , areas with low slopes gradients cover 19.20 ha, very low slopes cover 16.33 ha, moderate slopes 10.93 ha, high slopes 3.79 ha, and very high slopes 0.50 ha, indicating that over half of the corridor consists of slopes below 9˚, which are conducive for groundwater recharge.

Geographically, the steepest slopes, of ≥19˚, are concentrated in the Western, Northern, and Northeastern sections of the corridor, particularly in and around Menka, Kwang, Pinyin, Mbu, Alatening, Akum, Awing, and Santa. These regions coincide with the highest elevations in the corridor, like Bamboutos Mountain (up to 2700 m) and Lake Awing (around 2400 m). The steep slopes here, formed primarily through tectonic and geomorphological processes linked to the Cameroon Volcanic Line, result in high surface runoff, minimal infiltration, and increased soil erosion risk, making them less suitable for groundwater recharge.

Moving southwards Figure 4 illustrates that, the terrain transitions into moderate slopes (5.12˚ - 8.84˚) in the central part of the corridor, especially between Matazem, Balepo, and Babadjou, where elevations range between 1500 m and 1800 m. These zones act as intermediaries between steep northern slopes and the gentle southern lowlands. While these moderate slopes still present runoff challenges, they also offer moderate potential for groundwater recharge if managed properly through runoff mitigation and enhanced infiltration strategies. In contrast, the southern parts of the corridor, including lower-lying areas of Bali Gham, are characterized by gentle to very gentle slopes (≤9.00˚), with elevations ranging from 1200 m to 1500 m. These flatter areas are more favourable for infiltration due to slower runoff, making them ideal for groundwater recharge. Their geomorphology supports water retention and soil stability, reinforcing their role in sustaining surface and subsurface water availability ( Abdelouhed et al., 2021 ; Abdullahi et al., 2023 ; Abdullateef et al., 2021 ; Achu et al., 2020 ; ).

According to the ranking in Table 2 , LULC represents an important but relatively less influential factor in groundwater recharge potential across the Santa-Babadjou Corridor. Despite contributing the least to groundwater recharge among the evaluated parameters at a calculated weight of 6.8 ( Figure 5 ) LULC plays a critical role in regulating water infiltration and storage, ( Figure 5 and Table 2 ) (). The dominant land use types identified include farmlands, settlements, forests, grasslands, and water bodies. The analysis reveals that more than 75% of the Santa-Babadjou Corridor is dominated by farmlands and settlements, which profoundly influence surface water dynamics.

Among these, farmlands, (52%) and grasslands (9%) significantly contribute to enhanced infiltration of surface water into underlying aquifers due to their permeable soil characteristics and reduced surface sealing. On the other hand, built-up areas (21%), hosts compact surfaces that hinder infiltration, increase runoff, and reduce recharge potential. These urbanised zones seal the ground, thereby impeding the natural recharge of groundwater systems. Forests, (18%), are typically situated on steep slopes with dense canopies, limiting direct surface water infiltration due to rapid runoff and interception. Meanwhile, water bodies represent a negligible 0.50%, having limited influence on regional recharge but playing a role in water storage and ecosystem support. The Changes in land use patterns especially agricultural expansion and urban development disrupts natural hydrological processes, leading to decreased groundwater recharge, increased pollution loads, and modified surface water flow regimes. For instance, land degradation and deforestation in some parts of the corridor introduce bare surfaces that accelerate runoff and erosion, contributing to sedimentation in water bodies and reduction in infiltration.

Drainage density is the fourth most influential factors affecting groundwater recharge in the Santa-Babadjou Corridor, with a calculated weight of 10.4% ( Table 2 ). The drainage density of the corridor, as illustrated in Figure 6 and Table 4 , highlights the spatial distribution and intensity of stream channels across the landscape. This metric quantifies the total length of stream channels per unit area and plays a critical role in determining the efficiency of surface water transport and runoff within a watershed. High drainage density is generally associated with rapid surface water movement, which reduces the time available for infiltration and increases runoff. According to the classification by Bhadra and Pattanayak (2025), drainage density serves as an indicator of a region’s infiltration potential. In the case of the Santa-Babadjou Corridor, a drainage density weight of 10.4% suggests a moderate drainage density, which facilitates a balance between surface runoff and rainfall infiltration into the subsurface. This, in turn, can enhance groundwater recharge and overall water availability. The spatial pattern of drainage in the corridor reflects this balance, making drainage density a key determinant in the hydrological dynamics and water resource management of the region.

The drainage density results in Table 4 illustrate that the Santa-Babadjou Corridor exhibits significant spatial variation, reflecting the diversity in topography, hydrology, and land use across the region. The drainage density patterns in Figure 6 and Table 4 are classified into five categories: very low, low, medium, high, and very high drainage densities. High and Very High Drainage Density zones, covering approximately 556.4 km² (43.1%), are mainly concentrated in the low-lying parts of the corridor where gentle gradients and expansive terrain promote the formation of dense stream networks. Medium Drainage Density areas, comprising 322.1 km² (24.9%), are found across transitional zones of Bamelo, Bametea, and parts of central Santa. These regions exhibit moderate relief, which allows for a balance between surface runoff and infiltration. The hydrological implications in these zones suggest moderate runoff and infiltration capacity, making them well-suited for aquifer recharge initiatives and rainwater harvesting systems. Low and Very Low Drainage Density zones, accounting for 413.5 km² (32.0%), are predominantly found in the upland and mountainous areas of Kombou, Matazem, Santa, Awing, Pinyin, and Bali Gham. These locations are characterized by steep gradients and rugged terrain, which result in fewer stream networks and enhanced water infiltration into the subsurface.

Source: Computed from Figure 6 .

The relief and current surface water of the corridor is ranked third with a calculated weight of 17.9, as shown in Table 2 hence it plays a significant role in determining groundwater availability. As illustrated in Figure 7 and Figure 8 , the relief and current surface water of the corridor reveal a diverse landscape. According to ( Ahmadou et al., 2023 ; ; Anaba Onana et al., 2017 ; Aretouyap et al., 2020 ) the relief and current surface water of the corridor shape the hydrological characteristics of the region. The elevations range from approximately 1300 meters in Bali-Gham and Awing to about 2703 meters at the boundary with Wabane Sub Division. Mount Lefo, located in Awing, stands at 2300 meters, making it the second-highest peak in the North West Region after Mount Oku ( Anaba Fotze et al., 2025 ). The corridor is further intersected by multiple stream valleys, which exert a strong influence on its relief and drainage patterns, as seen in Figure 8 . These valleys have been carved over time by the erosive forces of upland tributaries, contributing to the complex topography of the area ( Ayikpa et al., 2025 ; Mfonka et al., 2025 ). The resulting landforms play a vital role in determining water availability and agricultural productivity. From a hydrological perspective, Figure 7 illustrates how the diverse terrain significantly affects water distribution, flow, and retention. The slopes of hills, whether gentle or steep, influence surface runoff rates and the degree of infiltration into soils.

Steeper areas tend to promote runoff and erosion, reducing water retention, while gentler slopes support better infiltration, enhancing groundwater recharge and soil moisture retention. These processes are vital for maintaining agricultural viability in the corridor. In addition, the river valleys that traverse the Santa-Babadjou Corridor serve as natural drainage channels, redirecting excess rainfall from upland zones and improving water flow throughout the watershed. These valleys are essential for sustaining irrigation systems and enhancing crop production. Their presence not only facilitates drainage and flood management but also improves water accessibility for farming communities across the region.

The illustration in Figure 7 and Table 5 reveal that, the Santa-Babadjou Corridor is characterized by significant elevation variability, which directly shapes land use, settlement distribution, agricultural potential, and water resource management. The relief within the corridor ranges from very low elevations of around 1150 meters, found in low-lying valleys zones of Bali Gham and Bametea, to very high mountainous terrains reaching up to approximately 2700 meters in the Bamboutos Caldera bordering Wabane Subdivision. This variation influences the occurrence of surface water resources ( Figure 8 ) as well as creates distinct ecological zones that influence both natural and human activities.

Source: Computed from Figure 7 .

Table 5 reveals that, zones characterized as Very low relief areas, cover about 14% of the corridor (roughly 181.0 km²). On the other hand, low relief regions, which accounts for about 21% (271.3 km²), are found in transitional zones of Babadjou. Medium relief zones dominate around Santa and Matazem and constitute approximately 23% (297.2 km²) of the corridor. High relief regions, covering 26% of the corridor (about 335.9 km²), are mainly located in the southwestern and Northeastern portions, particularly around Pinyin, Mbu, and Menka. These zones are characterized by steep slopes and hilly terrain. These high-relief landscapes are also important for regulating watershed functions, and their forested slopes play a significant role in maintaining the hydrological balance of the region. The very high relief zones, which occupy about 16% (206.7 km²), are mostly concentrated along escarpments and mountainous ridges. These areas are characterized by sharp elevation changes and rugged terrain. As a result, they are largely unsuitable for intensive agriculture or dense settlement. However, they are essential for water catchment protection and biodiversity conservation. Their ecological significance cannot be overstated, as they serve as headwaters for many streams in the corridor.

As illustrated in Table 6 , the groundwater potential zonation was achieved using the weighted overlay technique, where five key factors (Lithology, Slope, Relief and current surface water, Drainage density, and Land use) were assigned specific weights and ranks based on their influence on groundwater occurrence. From Table 5 , the different factors recorded different weights and ranks with Lithology (32.7%, Rank 1), Slope (29.9%, Rank 2), Relief and current surface water (17.9%, Rank 3), Drainage density (10.4%, Rank 4), and Land use (6.8%, Rank 5). The overlay analysis in Figure 9 and Table 6 produced five distinct categories of groundwater potential zones, classified as, very poor, poor, moderate, good, and very good. The zones classified as very poor recorded a Consistency Ratio (CR) of 1.84%, indicating an acceptable level of consistency in the multi-criteria decision-making process.

Source: Derived from Table 1 .

As illustrated in Figure 9 and detailed out in Table 7 , the spatial distribution of groundwater potential zones across the Santa-Babadjou Corridor reveals that a dominant 95.11% of the total land area falls within the medium, high, and very high groundwater potential classes. Specifically, medium potential zones account for 40.69%, high zones cover the largest share at 46.02%, and very high zones make up 8.39% of the landscape.

Source: Determined from Figure 9 .

The results in Figure 9 reveal that zones considered as favourable for groundwater potential are primarily found Babadjou, Alatening, and parts of Awing and Santa, where the lithology, slope, relief and current surface water sources, drainage density and land use factors enhance groundwater recharge. In contrast, 4.89% of the corridor falls under low (4.80%) and very low (0.10%) groundwater potential classes. These poorly rated zones are generally situated in the northwestern and extreme highland parts of the corridor, which are characterized by steep slopes, rocky surfaces, high drainage density, and reduced permeability. The groundwater classification also corresponds to estimated potential volumes, ranging from very low zones ranging between 50,000 - 100,000 m³, low zones ranging between 100,000 - 250,000 m³, medium zones ranging from 250,000 - 500,000 m³, high zones between 500,000 - 1,000,000 m³, and very high zones with values exceeding 1,000,000 m³.

Areas with very good to good groundwater potential zones are typically found in regions with gentle slopes, permeable and porous lithologies (such as fractured basalts), low drainage density, high surface water availability, and favourable land cover types of forest, grassland, or cultivated land. These areas support higher infiltration and percolation into underground aquifers.

The six thematic layers integrated to generate the GWPZ map for the Santa-Babadjou Corridor exert varying degrees of influence on aquifer recharge and thus on the availability and spatial distribution of groundwater resources ( Figure 9 ). The weightings derived through the Analytic Hierarchy Process approach yielded a Consistency Ratio (CR) of 1.84%, which is well below the acceptable threshold of 10%, indicating that the pairwise comparisons made in the AHP model are logically consistent. This affirms the reliability and robustness of the resulting GWPZ map. Similar findings in comparable hydrogeological contexts have also been reported by ( Abate et al., 2022 ; Abd-Elmaboud et al., 2024 ; Abdelrahman et al., 2023 ; Abdullahi et al., 2023 ; Abdullateef et al., 2021 ).

Zones with poor groundwater potential are typically characterized by steep slopes, dense drainage networks, sparse or degraded vegetation cover, forest-dominated land use, and less permeable lithologies like granite. These areas, largely found in the northwestern and elevated portions of the corridor, show reduced recharge potential due to enhanced surface runoff and limited infiltration capacity.

Geological and topographic attributes emerge as central to groundwater distribution in the corridor in that the older, weathered lithologies common in parts of Babadjou enhance porosity and permeability due to long-term fracturing and deformation. These processes improve secondary porosity, allowing groundwater to infiltrate and be stored effectively. Favourable relief conditions also signify structural weaknesses that serve as conduits for subsurface water movement, further boosting groundwater recharge. Similar studies have been reported in other fractured basement terrains like ( Adewumi et al., 2023 ; Adiat et al., 2024 ; Akeredolu et al., 2025 ; Alarifi et al., 2022 ).

Slope is inversely related to infiltration hence, flatter terrains, which dominate the eastern parts of the Santa-Babadjou Corridor, experience reduced runoff and prolonged surface water residence time, promoting better groundwater infiltration. Similarly, low drainage density often co-located with gentle slopes indicates reduced surface flow and greater potential for aquifer recharge. Therefore, regions with such attributes align with the medium to very high groundwater potential categories, collectively covering over 86.68% of the entire corridor, as seen in Table 7 . This is consistent with other studies where similar physical conditions led to higher groundwater potential classifications ( Adesola, 2024 ; Adesola et al., 2025 ; Agogue Feujio et al., 2024 ; Ahmad et al., 2021 ).

While built-up areas have low recharge potential due to impervious surfaces, the high groundwater potential identified in some developed areas of the corridor indicates that underlying geological formations and slope characteristics override surface constraints. This reinforces the understanding that land use effects on groundwater recharge are strongly mediated by subsurface lithology and topographic context, rather than surface development alone an insight supported by several authors working on urban hydrology and groundwater dynamics ( Anusha et al., 2022 ; Fildes et al., 2022 ; Hu & Li, 2024 ; Saikia et al., 2023 ; Suprapti et al., 2024 ; Zhou et al., 2024 ).

It is worth mentioning as limitation that, though this study provides robust groundwater potential mapping, three key limitations should be noted. First, the analysis used static datasets that cannot account for seasonal recharge variability, particularly important in this region with distinct wet/dry cycles. Second, climate change impacts on long-term precipitation patterns and recharge rates were not incorporated, potentially affecting the future validity of these groundwater potential zones. Third, the single-time land use snapshot doesn’t capture ongoing land cover changes that may alter infiltration capacity. Future studies would benefit from integrating time-series climate data and dynamic land use models to address these temporal limitations.