**2. Study area and data analysis**

The study area is located in the east of Algeria and the south of Setif (**Figure 1**). It is characterized by intensive agricultural and human activities. The climate of this area is semi-arid, with a mean annual temperature and precipitation of 15.2°C and 296 mm/year, respectively [6].

In the current study, 18 wells were collected (**Figure 1**) and 11 parameters (T, pH, EC, Al, Cd, Cu, F, Fe, Pb, Si and Zn) were analyzed using standard procedures [7]. The electrical conductivity (EC), pH and the temperature (T) were measured by multi-parameter WTW (P3 MultiLine pH/LF-SET). The concentrations of heavy metals were determined by Graphite Furnace Atomic Absorption Spectrophotometer (Perkin-Elmer AAnalyst 700).

In the present study, factor analysis (FA) and cluster analysis (CA) were used to evaluate the

Assessment of Heavy Metals Contamination in Groundwater: A Case Study of the South of Setif…

http://dx.doi.org/10.5772/intechopen.75734

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Factor analysis was employed to find and interpret the structure of the underlying data set through a reduced new set of orthogonal (non-correlated) variables (principal components, PCs), arranged in decreasing order of importance. Besides considerable data reduction, PCs can explain the entire multidimensional data set variability without losing much original information. FA with Varimax rotation of standardized component loadings was conducted for extracting and deriving factors, respectively, and those PCs with eigenvalue >1 were retained [8–10]. The distribution manner of individual association of element in groundwater was determined by principal component method (results are shown in **Table 3**). Statistical treatment of these data indicates their association and grouping with three factors explained most of the variability (total variance explained was about 75.69% variance for the groundwater data). The relations among the heavy metals based on the first three factors are illustrated in **Figure 2** in three-dimensional space.

concentrations of heavy elements in groundwater samples.

**Figure 1.** Location of the study area and the samples.

**3.1. Factor analysis**
