## 2 Materials and Methods
### Preliminary Investigations  
After obtaining insight into the available parameters, the second phase was initiated by marking preliminary data acquisition stations on the map in a mesh grid pattern. The tentative coordinates of  
Figure 1: (**a**) Digital Elevation Model of the Study Area; (**b**) Field Reconnaissance Sites; (**c**) Locator Map of the Study Area. the marked points were acquired from Google Maps. The coordinates were entered into a Garmin GPS unit, and the reconnaissance phase started for the physical examination of the testing sites. The field reconnaissance survey information sheet was developed to allow field personnel to provide basic information about each site such as the visual soil classification, soil color, general geological setting, selection of suitable drilling equipment, accessibility to the testing point, nearby water bodies, and layout of testing points. The purpose-built reconnaissance survey information sheet is shown in Table 1.  
Tentative groundwater tables were assessed from the nearby wells. Interviews with residents were also conducted to collect information that was useful for subsequent mapping such as precipitation patterns, groundwater conditions, surface runoff storage, and landslide incidents. The locations of sampling stations are shown in Figure 1b. The locator map of the study area is presented in Figure 1c. Geotechnical exploration included drilling, standard penetration testing, and collection of soil samples at an interval of 1.5 m; hence, the samples were collected from 1.5-, 3.0-, and 4.5-m depths and tested at a soil mechanics laboratory to determine their properties. The field reconnaissance survey and laboratory testing aimed to obtain the index and engineering properties of the soil. During the selection of field survey, testing, and sample collection sites, it was ensured that the sites were located on natural soil deposits and representative of the general setting of the area. The sites are shown in Figure 1.  
In total, 75 field survey sites were marked and distributed in the mesh grid pattern throughout the region. Standard penetration tests (SPT) were performed at 1.5-, 3.0-, and 4.5-m depth at each site. Samples were extracted for gradation, Atterberg's limits, moisture content, subgrade rating, and engineering soil classification. In total, 450 SPT tests were performed in the field, and the same number of disturbed samples was collected for laboratory testing. The collected soil samples were properly preserved and transported to the laboratory for testing in a systematic manner. In total, 1800 laboratory tests were performed, including 450 tests for moisture content, 450 tests for Grain Size Distribution (GSD), and 900 tests for Atterberg's limits (Plastic Limit (PLs) and Liquid Limit (LLs). GSD is an indicator of engineering properties such as compressibility and shear strength of the soil, and it is an integral part of the engineering classification of soil. Moreover, it is also essential for selecting a suitable fill material for backfills, highway embankments, and earthen dams. In addition, GSD is required for the design of seepage filters and groundwater drainage works. The standard penetration test is the most widely used test for the determination of bearing capacity of the \begin{table}
\begin{tabular}{c c c} \hline \hline Site ID- & & \\ \hline (N) & (E) & (Z) \\ \hline Site Address: - & & \\ District & Tehsil & UC \\ General Topography of the Area: & & \\ Visual Soil Classification & & \\ Soil Color & & \\ General Geological Setting & & \\ Vehicular Excess Source & & \\ Nearest River & & \\ Nearby Water Body: & & \\ Tentative Ground Water Table: & & \\ Elevation from the Road Level & & \\ Nature of Ground Surface & Plain & Rolling & Irregular \\ Type of Built Structures (if any) & Residential & Commercial \\ Visible Soil Problems & & \\ Noticeable Soil Problems (if any) & & \\ Other Notable information & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Reconnaissance Survey Information Sheet.