*3.9. Land Use/Land Cover*

Land use/land cover involves several elements, including soils, human settlements, vegetation cover, waste lands, etc. [112]. The settlement in an area affects the groundwater due to the human-made structures. The land vegetation covering is one of the major groundwater factors used for retaining water [65]. Depending upon the porosity and permeability, the soil conditions of an area also control groundwater seepage through the surface. RS and GIS usage for land mapping has gained popularity recently [6,104]. With the help of land use/land cover, a similar study has linked the best and most abundant agricultural practices with groundwater availability over the study region [109]. For Islamabad, the regions should be studied based on their demand for groundwater, thereby necessitating the inclusion of land use/land cover in this study.

#### *3.10. Soil*

Soil is one of the most important factors for groundwater recharge since groundwater movement through the surface is controlled by soil type and properties [65]. Accordingly, parameters such as porosity and permeability are of utmost importance and are crucial to groundwater flow [72]. Moreover, the soil is also responsible for the filtering or buffering activities between the atmosphere and the groundwater in the biosphere [65]. Therefore, it is considered one of the prime influencing factors in groundwater recharge analysis. Considering that soil properties vary in each region, large-scale test data of the soil type might be required. In previous research consisting of a variable soil type for groundwater recharge, higher weightage has been allocated to the soil as a contributing factor. Accordingly, it has been declared as one of the high IF [109,111]. Furthermore, greater variations of the soil types were seen influencing the groundwater recharge potential in relevant studies [108]. In the current study area, the terrain has high soil variation; the northern outskirts are predominant with mountainous soil, and the southern outskirts are predominant with loamy soils. Thus, soil type is selected as a key factor in this study.

#### *3.11. Lithology*

Lithology refers to the physical appearance of rocks. Rock characteristics impact the movement of water beneath the surface [105]. In smaller rocks, the water finds more passage for movement and vice versa. If the grains are arranged in a well-graded manner, there is no passageway for water and vice versa [65]. Lithology plays an important part in dictating groundwater flow via channels, permeability, and occurrence [104]. This factor has been considered in a similar groundwater recharge study outlining the influence of rock type, soil type, and the higher permeability on groundwater movement and occurrence [105,109]. Several other factors may influence the lithological characterization and its impact on groundwater recharge. However, this research is limited to lithological information and does not have permeability, porosity, or grain size information. Further, it is based on a literature review for assigning weightages of lithologies. The terrain is composed of various rock types in our study area, including tertiary sandstone, limestone, and alluvial deposits [84]. Lithology contributes to groundwater flow and is included in the current study [105].
