1. Introduction
Groundwater is an essential natural resource, especially in regions where surface water is limited. Although water covers 71% of the Earth’s surface, only 2.5% of it is freshwater suitable for human consumption [
1,
2]. Aquifers provide around 98.7% of global freshwater, and about a quarter of the world population relies on groundwater for their requirements [
3,
4]. From 1950 to 2000, global water withdrawals increased by more than three times, rising from 1382 km
3 per annum to 3973 km
3 per annum. Predictions indicate that this figure could reach 5235 km
3 per annum by 2030 [
5,
6]. In the last decade, over 2 billion people have been residing in water-stressed areas because of over-extraction rates and climate change [
7]. Demand for groundwater as a source of freshwater is rising progressively, particularly for domestic and commercial use [
8,
9,
10,
11].
Previous studies have shown that groundwater accounts for around one-sixth of freshwater globally [
12,
13,
14], forming a significant source of water not only for humans but also for aquatic ecosystems [
15,
16]. Furthermore, intensive farming practices and exponential population growth rates have increased demand for groundwater, resulting in over-extraction [
17,
18,
19]. Groundwater is critical for supporting urbanization and sustaining population growth [
14,
20]. Nonetheless, there is a significant lack of information and research-based findings regarding the likelihood of ensuring an adequate supply of water [
21,
22]. This shows the importance of groundwater modeling as a method for addressing current water resource challenges [
9,
20,
23]. Groundwater levels have been declining globally in recent years due to climate change and excessive groundwater use for a variety of purposes [
24,
25]. Additionally, climate change has led to higher evapotranspiration and less rainfall, further undermining the ability of some places to restore their water tables [
7,
26,
27].
About 60–70 percent of the people in Pakistan use groundwater either directly or indirectly for their needs [
28,
29]. Consequently, the nation’s economic growth, public health, and environmental stability are directly related to better access to fresh water and sustainable groundwater resource management [
16,
30]. However, the water management system of Pakistan has yet to reach its potential despite its artificial groundwater recharge systems such as the Indus Basin Irrigation System [
31]
The excessive use, contamination, and inadequacy of abstraction techniques have a significant impact on the survival of this essential resource [
32,
33,
34]. A balance between efficient use and sustainability is necessary to continue being an adequate source of drinking water and agricultural support in groundwater [
17]. However, Pakistan faces numerous hurdles in achieving this, including a weak groundwater policy and a lack of information about groundwater processes [
35]. These issues must be resolved to preserve this valuable resource for future generations.
Excessive pumping and the effects of climate change have depleted groundwater supplies, a critical problem particularly in Dera Ismail Khan, one of the districts of Khyber Pakhtunkhwa (KP) province, Pakistan [
29,
36]. The semi-arid climate of this area has left it mostly dependent on groundwater for crop irrigation and other purposes [
22]. The amount of groundwater available continues to be pressured by increased demand for available water supplies created by population density, as well as urban and agricultural expansion. In such areas, groundwater quality plays an important role in meeting the needs of the people for population as well as industrial and agricultural needs and for drinking water purposes [
16,
30,
36]. The growing demand for water in agriculture, domestic use, and industrial activities poses a challenge that must be addressed; we chose to map the groundwater potential zone in the study area as a main step in sustainable water resource management.
The parameters used for groundwater potential zone mapping in this study include rainfall, elevation, drainage density, soil, slope, road density, LULC, NDVI, NDBI, MSI, WVWI, and LST. These parameters have been commonly used in many research studies due to their important roles in defining the factors affecting the groundwater recharge and potential zone mapping [
37,
38,
39]. This study integrated the AHP to draw weightages for parameters directly into the GIS environment to develop the evaluation of the potential zones. This approach seeks to offer a thorough comprehension of groundwater resources so that well-informed decisions may be made for sustainable water management [
4,
14,
40]. Furthermore, this research holds significant value in enhancing water supply and ensuring the efficient use of sustainable water resources.
In fact, conventional methods of groundwater assessment such as field surveys, manual well sampling, and hydrogeological mapping are often constrained by high implementation costs, sampling errors, labor intensity, and limited spatial coverage, which can lead to oversimplified interpretations of groundwater dynamics [
41,
42]. As this leads to limitations, researchers have sought innovative ways to explore these methods to improve efficiency and spatial accuracy in analyzing groundwater resources. RS and GIS have proven to be powerful tools for delineating groundwater potential zones over large areas with greater precision and temporal consistency [
28,
43,
44]. Building upon these capabilities, recent studies have integrated RS and GIS with multi-criteria decision-making and machine learning techniques such as the AHP [
37,
45], Weighted Overlay Method [
38], Frequency Ratio [
19,
46], Principal Component Analysis (PCA) [
15], Decision Tree Models [
1], and ensemble classifiers like Random Forest, Quick Unbiased Efficient Statistical Tree, and Support Vector Machines [
47,
48,
49] to further enhance accuracy and predictive robustness. These integrative methods not only overcome the inherent drawbacks of traditional techniques but also provide the ability to incorporate diverse hydrogeological, environmental, and socio-economic variables, thereby offering more comprehensive solutions for groundwater resource assessment and sustainable management.
To address the increasing problems with groundwater usage in semi-arid areas such as Dera Ismail Khan, this work presents a novel way to integrate the AHP with GIS and remote sensing methods to identify possible groundwater zones. In contrast to traditional techniques, our method uses a hierarchical, expert-validated framework that incorporates twelve important parameters covering climatic, topographic, hydrological, land cover, and human aspects. The originality of this study is found in its robust multi-criteria assessment framework, which is improved by spatial modeling and ratio consistency checks. This framework increases the precision of defining both surface and subsurface recharge potential zones. This integrated methodology offers a scalable, data-driven approach to sustainable groundwater management, with practical benefits for policymakers, water resource managers, and planners in water-stressed areas.
3. Results
Groundwater potential zoning was assessed using twelve factors, including LULC, rainfall, drainage density, soil type, slope, road density, NDVI, NDBI, MSI, WVWI, and LST. These factors were analyzed with GIS-based AHP to determine their relative significance for groundwater recharge potential (
Figure 4).
The analysis revealed the following trends in recharge potential based on various factors.
LST showed that very high recharge potential was found in cooler areas (2.00%, 20–24 °C), while higher temperatures were associated with progressively lower recharge potential, ranging from high (19.09%, 25-28 °C) to very low (28.02%, 37–39 °C) potential (
Figure 4A). In terms of
water depth, the study found that shallow depths (7.08%, 20–94 m) exhibited the highest recharge potential, with moderate to very low potential increasing at greater depths (up to 33.37% at 203–318 m) (
Figure 4B). The
MSI analysis revealed that high-soil-moisture zones (11.43%, 0.533–0.783 MSI) provided very high recharge potential, but as moisture stress increased, recharge potential decreased, with very-low-moisture zones showing 38.12% at 1.105–1.653 MSI (
Figure 4C). For
NDBI, highly built-up areas (48.21%, 0.042–0.246 NDBI) showed very low groundwater recharge potential, while less built-up zones exhibited varying degrees of recharge potential, from low (22.47%) to very high (8.29%, −0.304 to −0.141) (
Figure 4D).
Drainage density analysis revealed that areas with dense drainage (0.001–10.416) had very high recharge potential (59.25%), with less dense areas showing moderate to low recharge potential (4.3% at >41.666) (
Figure 4E). The
land cover analysis demonstrated that water bodies (11.16%) had very high recharge potential, whereas barren land (59.47%) had very low recharge potential. Also, the built-up areas (14.49%) showed low recharge due to impervious surfaces, but vegetated areas (14.88%) supported high recharge potential (
Figure 4F).
Figure 4G shows the spatial and temporal distribution of NDVI in the study area. The result revealed that decreasing vegetation cover corresponds to reduced recharge potential, with moderate (22.07%), high (10.14%), low (56.47%), and very low vegetation cover (3.32%, −0.195–0.018) exhibiting progressively lower recharge potential. However, areas with dense vegetation (8.00%, 0.261–0.505 NDVI) were found to have very high recharge potential. In terms of
slope, flat terrain (90.14%, 0–2.471°) had the highest recharge potential, followed by moderate (2.89%), low (1.69%), and extremely low (0.58%, >22°) slope zones (
Figure 4H).
The spatial pattern of
Rainfall showed that very rainy areas (16.63%) had the greatest recharge potential, with progressively lower recharge potential in areas with moderate (22.06%), low (19.09%), and very low (17.56%, 356.918–387.328 mm) rainfall. Areas with very high rainfall (16.66%, 480.791–532.958 mm) provided optimal conditions for groundwater recharge (
Figure 4I). The
WVWI analysis revealed that areas with very high surface wetness (2.50%, −0.089 to 0.267 WVWI) exhibited high recharge potential, with decreasing potential in areas of high (3.83%), moderate (7.48%), low (37.71%), and very low (48.48%, −0.431 to −0.166) wetness (
Figure 4J). Regarding
Road distance, areas closer to roads (53.14%, 0–0.5 km) had low recharge potential, which improved with increasing distance from roads, reaching very high recharge potential at 3–5 km (2.23%) (
Figure 4K). Lastly, as shown in
Figure 4L,
Soil type analysis revealed that Haplic soil dominated the area, covering 80.43%, while Lithosol and Calcaric soils were present in smaller proportions (0.92% and 17.61%, respectively). These findings thus demonstrate the various ways in which environmental interactions impact the groundwater resource recharge process. Therefore, at various study scales, it is shown that important characteristics such as drainage density, slope, vegetation cover, and water depth relief have a substantial impact on recharging chances.
3.1. Development of Groundwater Potential Zoning
The distribution of groundwater potential zones (GWPZs) in the Dera Ismail Khan district is determined by climatic and geographic factors (
Table 8). The zone of very good potential, which covers only 2% of the district, is found in areas with high soil permeability and drainage density, typically along the eastern edge of the Indus River. The zone of good potential, making up 17% of the district, is in regions with dense vegetation, shallow water tables, and favorable recharge conditions, such as parts of Kulachi Tehsil and the Indus River floodplain. The moderate-potential zone, covering 47% of the area, is concentrated in the central region, including some built-up and agricultural areas with gentle slopes. The poor-potential zone, making up 33% of the district, is characterized by arid, barren land with scarce vegetation, particularly in the southwest region of the study area. The very-low-potential zone, which makes up 1% of the district, is confined to isolated, hilly regions in the west, characterized by steep slopes and deep-water tables (
Figure 5). These findings highlight the district’s varied groundwater recharge potential, with limited capacity in arid and hilly regions and better recharge suitability in areas near the Indus River and vegetated zones.
3.2. Validation of Groundwater Potential Zones and Accuracy Assessment
Out of the 83 observations of water table depths, 79 were accurately classified according to their respective groundwater potential zones, while 4 exhibited discrepancies (
Figure 6). The overall accuracy of the groundwater potential zoning map was calculated as follows:
The overall accuracy of the groundwater potential zoning was 95.18%, indicating strong agreement between predicted and observed values. The observed water depths varied greatly in terms of groundwater availability, ranging from 20 m to more than 320 m. Sample accuracy numbers are presented in
Table 9.
In Kappa analysis, the Percentage Correct Agreement with Observed Values is the proportion of correct samples for each class. Pe can be calculated as the sum of the expected proportion of each class being correctly classified by chance (
Table 10).
The Kappa coefficient (K) is then calculated as follows:
The Kappa value is 0.93, which indicates that agreement is almost perfect, meaning groundwater potential zoning classification is highly accurate and reliable. The agreement between predicted and observed values is almost perfect.
4. Discussion
This study utilized GIS, remote sensing, and AHP techniques to assess groundwater recharge potential in Dera Ismail Khan, Pakistan. Previous research in Dera Ismail Khan as well as other arid to semi-arid regions [
22,
29,
36] has centered around the analysis and management of groundwater quality. Most of these studies used standard GIS-based weighted overlay methods. Integrated assessments of groundwater potential lack effective multi-criteria decision-making methodologies. Our research fills this methodological gap through the application of a detailed AHP which works together with geospatial techniques. The hierarchical multi-criteria evaluation framework structures the model to achieve internal consistency through ratio consistency checks and expert judgment validation. The methodological design enhances both reliability and scientific rigor throughout the analysis. Our model stands apart from earlier studies because it includes twelve parameters that have been thoroughly justified and combines remote sensing indices like NDVI, MSI, and WVWI with topographic characteristics and land cover alongside hydro-climatic variables. The combination of different indicators for surface and subsurface recharge improves groundwater potential mapping accuracy in semi-arid regions. Our method shows better methodological progress than similar GIS–AHP-based research carried out in areas with similar climatic conditions, including Meki Catchment in Ethiopia [
4], Vaigai Upper Basin in Tamil Nadu [
10], the Semi-Arid Lower Ravi River Basin in Pakistan [
28], Kohat District in KP Pakistan [
35], Habawnah Basin in Saudi Arabia [
37], the northern Nile region in Egypt [
38], and the Jinan Karst Spring Basin in China [
65]. The classification accuracy of our model reached 95.18% with a Kappa coefficient of 0.93, which exceeds the typical accuracy range of 74–85% found in previously reported studies. The results highlight our combined AHP–GIS approach as a precise method for mapping groundwater recharge areas.
The results indicate that factors such as topography, hydrology, vegetation, and built-up environment play a complex role in groundwater recharge dynamics. Areas with mild slopes (0–2.471°), which make up 90.14% of the study region, were identified as highly conducive to infiltration and aquifer recharge. These findings align with global trends, while steeper slopes (>22°), covering only 0.58% of the area, predominantly promote runoff rather than recharge [
43]. Furthermore, the aquifer depth also plays a critical role in groundwater recharge, with zones at depths of 20–94 m, representing 7.08% of the study area, showing active recharge. In contrast, deeper zones (>203 m) show limited recharge potential due to some geological factors [
32,
36]. In addition, vegetation density emphasizes the impact of land use on groundwater recharge. Dense vegetation areas, covering 8% of the region, correspond to high recharge potential. Conversely, scrub and arid zones (56.47%) demonstrate low recharge potential, highlighting the need for afforestation to enhance water retention.
The challenges of groundwater recharge are exacerbated by urbanization, with built-up areas covering 48.21% of the study region and exhibiting a low recharge index due to the inaccessibility of infiltrative surfaces. This finding aligns with Sharp’s [
68] research, which links urban sprawl to negative impacts on groundwater quality and quantity. Additionally, the distribution of annual rainfall influences recharge potential; areas with precipitation between 480 and 533 mm show favorable recharge conditions. In contrast, areas receiving less rainfall require alternative management strategies, such as rainwater harvesting and moisture retention, to support recharge [
54,
56].
Moreover, the Land Surface Temperature (LST) dataset reveals significant thermal effects on groundwater recharge. Only 2% of areas with low LST (20–24 °C) demonstrate a higher recharge potential, whereas regions with high LST (37–39 °C), which cover an area of 28.02%, negatively impact recharge due to increased evapotranspiration. These findings align with global studies indicating that elevated temperatures can substantially reduce infiltration and soil water content [
60].
Our analysis revealed that approximately 1428 km
2 (comprising 148 km
2 of very-good-potential and 1280 km
2 of good-potential zones) has been identified as a groundwater recharge area, accounting for 19% of the total 7325 km
2 area of Dera Ismail Khan district. These zones are predominantly located along the Indus River floodplain, primarily within Dera Ismail Khan and Paharpur Tehsils, where conditions such as shallow water tables, gentle slopes, high drainage density, and vegetated land cover favor recharge. Based on the spatial distribution of population and recharge zones, an estimated 347,664 individuals—approximately 19% of the district’s total population of 1,829,811—reside in or near these recharge areas [
50]. These populations are expected to directly benefit through improved groundwater availability for domestic, agricultural, and municipal water supply. Additionally, the delineation of these zones provides a scientifically grounded foundation for sustainable groundwater management and targeted recharge interventions across the district.
Currently, the region exhibits moderate to poor potential for groundwater recharge, but there are several ways to enhance this potential. First, high recharge areas with low slopes, shallow water tables, and high vegetation should be considered for protection first. It is possible to further utilize these areas for recharging basins and rehabilitation of infiltration rates through afforestation. Furthermore, targeted measures are needed to mitigate natural recharge processes in the urban areas, where the substantial impermeable surfaces substantially hinder recharge. The implementation of permeable pavements, green roofs, and increased urban green spaces can significantly enhance groundwater recharge by allowing rainwater to percolate into the ground. Furthermore, policies promoting rainwater harvesting and the construction of check dams in the surrounding areas could also support the replenishment of the aquifer. Future development plans for study area should integrate these strategies into urban planning, ensuring that both urban growth and groundwater recharge are balanced for long-term sustainability.
The use of GIS, remote sensing, and AHP in this study offers valuable insights and could be further refined by incorporating additional variables, such as aquifer transmissivity and sustainable hydrological studies. By promoting these methodologies, this research provides a strong foundation for addressing water scarcity in arid and semi-arid regions through enhanced groundwater resource management. The study provides valuable insights into groundwater potential zones in Dera Ismail Khan using recent geospatial techniques; however, certain limitations must be acknowledged.
The use of moderate-resolution satellite data (30 m) may overlook finer-scale variability, and static environmental parameters fail to account for temporal changes, such as seasonal variabilities or climate change impacts. Key hydrological and geological factors, such as aquifer transmissivity, were not included due to data limitations, and reliance on expert judgments in AHP may introduce biases. The limited ground validation and reliance on a single-year dataset (e.g., 2022) constrain the robustness of the results. Additionally, anthropogenic influences like groundwater extraction were not explicitly modeled. Finally, while the methodology applies well to semi-arid regions, there may be certain components of the methodology that may require adaptation for a wider application. To increase the accuracy and generalizability of the results, future studies could fill in these gaps.
5. Conclusions
The present study effectively identified groundwater potential zones (GWPZs) in Dera Ismail Khan, Pakistan, utilizing GIS, RS, and the AHP model. A comprehensive evaluation of groundwater recharge capacity was conducted, considering key factors such as land surface temperature, drainage density, LULC, water depth, NDVI, slope, soil, road density, NDBI, WVWI, MSI, and rainfall. The findings reveal that 47% of the area falls within the moderate-recharge-potential zone, while 17% and 2% are classified in the good-and very-good-potential zones, respectively. However, 33% of the region is categorized as poor and 1% as very poor, highlighting significant challenges in water resource management.
This study makes a significant contribution to advancing scientific understanding by demonstrating how GIS, RS, and AHP can be integrated to create a robust framework for mapping groundwater recharge zones in semi-arid regions. The inclusion of innovative remote sensing indices (NDVI, NDBI, MSI, and WVWI), alongside traditional factors, enhances the methodological rigor and provides a reproducible model for similar studies in other regions. By highlighting the role of meteorological conditions and human activities, such as road density and LST, the analysis is further strengthened. The findings have critical implications for sustainable groundwater management, addressing issues like urban sprawl and over-extraction in low-potential areas and providing a scientific basis for prioritizing high-potential zones for conservation, afforestation, and recharge basin development.
The sustainable management of water resources to ensure long-term availability is emphasized in Sustainable Development Goal 6 (Clean Water and Sanitation), which is in line with this study. This study supports Target 6.4, which focuses on boosting sustainable withdrawals and improving water use efficiency to prevent water scarcity, by identifying groundwater potential zones using GIS and AHP. The results herein will give policy makers a solid scientific foundation on which to build groundwater conservation plans, maximize agricultural water use, and protect supplies of drinking water. In semi-arid areas such as Dera Ismail Khan, where groundwater serves as the primary source of water for domestic and agricultural use, the implementation of this strategy is particularly critical. Future research may enhance this methodology by integrating aquifer transmissivity and temporal datasets to better account for evolving hydrological systems.