Statistical approach of factors controlling drainage network patterns in arid areas. Application to the Eastern Anti Atlas (Morocco)

Dimension Reduction and Analysis of a 10-Year Physicochemical and Biological Water Database Applied to Water Resources Intended for Human Consumption in the Provence-Alpes-Côte d’Azur Region, France

“…Principal components furnish macro parameters, i.e., synthetic data that convey strong and significant information and, therefore, are particularly suitable and relevant for time monitoring or digital mapping and spatial analysis, just like original parameters [14,[23][24][25]. The scores of the samples along the principal components were used for the mapping of the main sources of variation in water quality identified in the study.…”

Drainage Network Patterns Determinism: A Comparison in Arid, Semi-Arid and Semi-Humid Area of Morocco Using Multifactorial Approach

“…On the other hand, the dendritic, pinnate, parallel, trellis, and rectangular patterns are patterns of low relief, that is to say of a weakly eroded zone associated with a weak tectonic activity, as is the case in the Central Anti Atlas [14]. The correlation between PC1 and the geological parameters "Line-Dens" and "Rock-type" is linked to the local structural control, highlighted by the presence of drainage network patterns (rectangular, trellis, herringbone, and barbed) whose development is mainly controlled by geological structuring [4,5,7,19,23,43].…”

“…They are orthogonal to each other and therefore represent independent sources of variability, i.e., independent associated processes. Taking into account the main PCs makes it possible to concentrate the information in a reduced number of factorial axis while losing a minimum of the information contained in the dataset, which constitutes a dimensional reduction of the data hyper-space [7,9]. To determine the impact of climate differences on the factors that control the variability in drainage network patterns, PCA was first applied to the entire dataset (318 basins) and then individually to each sector.…”

“…The first group consists of patterns controlled by rugged relief and strong structural control (barbed, herringbone, rectangular, and trellis) (Figure 8d-g). These patterns develop in structural areas with a high density of geological lineaments and deformations due to intense uplift tectonic activity [7,[42][43][44]. The uprising concerns the Intrarif, the Mesorif, and the internal Prerif in the External Rif sector, and the folded and tabular Middle Atlas, central Morocco, the Paleozoic bedrock in the Middle Atlas sector, and the Saghro, Bou Azzer, Siroua, and Agdez massifs in the central Anti-Atlas sector (Figure 11).…”

“…These works lead to hypotheses and a classification of the drainage network patterns on the basis of findings, careful observations, and uni-factorial descriptions. However, the links between the physical properties of the environment and the type of drainage networks are neither ranked by importance nor strictly demonstrated, probably because this link is partial, as the determinism of the drainage network pattern can be more complex than a causal link based on a single parameter [7]. In particular, the relief parameters, climate aridity, and vegetation cover affect the extent of the dissection of the drainage basins.…”