Contribution of GIS and Remote Sensing in the Physical and Geomorphological Characterization of the Addouz Watershed, a Tributary of the Chichaoua River, to Enhance the Management of Hydrological Risks, Morocco

Abstract

The analysis of various physical and geomorphological characteristics of the watershed aims at a quantitative evaluation of its shape, slope, orientation, relief, as well as the quantity and arrangement of the hydrographic network. A thorough understanding of these aspects will lead to a better grasp of the factors responsible for variations in hydrological regimes, thus contributing to the genesis of natural hazards and their temporal and spatial variability. Given the high frequency of flood risks in the Tensift basin, especially in its mountainous part, this study focuses on a comprehensive analysis of the ADDOUZ watershed. The objective is to determine the physical and morphological characteristics of the basin, a crucial step in understanding flow patterns and constituting a fundamental element before implementing flood protection projects. The results indicate that the Addouz river has a small watershed, with an estimated perimeter of 61.47 kilometers and an area of 69.34 square kilometers. Physical characteristics show an elongated shape with an equivalent rectangle of 24.90 km in length and 5.79 km in width. Hypsometric and slope analysis reveals flow oriented towards the north of the basin along the Addouz river valley. As for morphological parameters, they are used to understand flow and sedimentation patterns: depressional areas slow down flow, thus promoting deposition, while open slope areas act as catalysts for the risk of water erosion. The outcome of this characterization can guide hydrological stimulation efforts and assist decision-makers in choosing appropriate interventions for the development of flood-prone and erosion-sensitive areas. It provides an overall understanding of the behavior of the Addouz river during peak flow exceedances for given return periods.

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Uluslararası İleri Doğa
Bilimleri ve Mühendislik
Araştırmaları Dergisi
Sayı 7, S. 485-494, 11, 2023
© Telif hakkı IJANSER’e aittir
Araştırma Makalesi
https://alls-academy.com/index.php/ijanser
ISSN: 2980-0811
International Journal of Advanced
Natural Sciences and Engineering
Researches
Volume 7, pp. 485-494, 11, 2023
Copyright © 2023 IJANSER
Research Article
485
Contribution of GIS and Remote Sensing in the Physical and
Geomorphological Characterization of the Addouz Watershed, a
Tributary of the Chichaoua River, to Enhance the Management of
Hydrological Risks, Morocco.
Khadija Lamrani*, Ahmed Algouti 1, Abdelhalim Tabit 1, Fatiha Hadach2, Kaouthar Majdouli1,
Mohammed Lakhlili 1, Yahia Laadimi 1, Naji Jdaba2, Khadija Oudour1 and Imane El kihal1,
1 Laboratory: Geosciences, Geotourism, Natural Hazards and Remote Sensing. /Faculty of sciences Semlalia/ University Cadi
Ayyad, Morocco
2 Laboratory: Geosciences, Environnement, And Geomatic / Faculty of sciences Ibno Zohr Agadir / Morocco
*1kaouthar.majdouli@edu.uca.ma
(Received: 23 December 2023, Accepted: 25 December 2023)
(3rd International Conference on Scientific and Academic Research ICSAR 2023, December 25-26, 2023)
ATIF/REFERENCE: Lamrani, K., Algouti, A., Tabit, A., Hadach, F., Majdouli, K., Lakhlili, M., Laadimi, Y., Jdaba, N.,
Oudour, K. & Imane, E. K. (2023). Contribution of GIS and Remote Sensing in the Physical and Geomorphological
Characterization of the Addouz Watershed, a Tributary of the Chichaoua River, to Enhance the Management of Hydrological
Risks, Morocco. International Journal of Advanced Natural Sciences and Engineering Researches, 7(11), 485-494.
Abstract – The analysis of various physical and geomorphological characteristics of the watershed aims at
a quantitative evaluation of its shape, slope, orientation, relief, as well as the quantity and arrangement of
the hydrographic network. A thorough understanding of these aspects will lead to a better grasp of the
factors responsible for variations in hydrological regimes, thus contributing to the genesis of natural hazards
and their temporal and spatial variability.
Given the high frequency of flood risks in the Tensift basin, especially in its mountainous part, this study
focuses on a comprehensive analysis of the ADDOUZ watershed. The objective is to determine the physical
and morphological characteristics of the basin, a crucial step in understanding flow patterns and constituting
a fundamental element before implementing flood protection projects.
The results indicate that the Addouz river has a small watershed, with an estimated perimeter of 61.47
kilometers and an area of 69.34 square kilometers. Physical characteristics show an elongated shape with
an equivalent rectangle of 24.90 km in length and 5.79 km in width. Hypsometric and slope analysis reveals
flow oriented towards the north of the basin along the Addouz river valley.
As for morphological parameters, they are used to understand flow and sedimentation patterns: depressional
areas slow down flow, thus promoting deposition, while open slope areas act as catalysts for the risk of
water erosion.
The outcome of this characterization can guide hydrological stimulation efforts and assist decision-makers
in choosing appropriate interventions for the development of flood-prone and erosion-sensitive areas. It
provides an overall understanding of the behavior of the Addouz river during peak flow exceedances for
given return periods.
Keywords – Watershed Analysis, Hydrological Regimes, Addouz Rive, Flood Risks, Morphological Characteristic

International Journal of Advanced Natural Sciences and Engineering Researches
486
I. INTRODUCTION
Surface hydrology, a science dedicated to the
qualitative and quantitative analysis of flows on the
Earth's surface, is of crucial importance in
predicting water flows and volumes. This interest is
particularly evident in the in-depth study of
watersheds, considered as fundamental entities for
understanding the water cycle. Indeed, watersheds
represent the essential foundation on which all
hydrological investigations are based.
In Mediterranean regions, characterized by climates
ranging from humid to arid, wadis are characterized
by their frequent propensity to trigger floods. With
this in mind, the main objective of this research
project is to explore the hydrology of the Addouz
watershed, one of the tributaries of the Oued
Chichaoua, a Moroccan river that flows into the left
bank of the Tensift in the Marrakech-Safi region.
This study aims to unravel the influence of the
various elements contributing to the genesis of
runoff in this watershed.
This project will have two distinct components.
Firstly, an exhaustive presentation of the study area
will focus on its geographical, geological and
climatic context. These parameters, recognized for
their significant impact on the hydrological regime
of watersheds, will be dissected to provide a
comprehensive framework for analysis. Secondly,
particular attention will be paid to determining the
basin's morphological and physiographic
parameters, crucial elements in understanding
future hydrological mechanisms in this specific
area. By combining these two aspects, this study
aims to shed light on the hydrological dynamics of
the Addouz watershed, thereby contributing to a
better understanding of runoff phenomena in this
region.
II. PRESENTATION OF THE STUDY AREA
1. geographical context
Addouz is a village in the province of Chichaoua,
part of the Marrakech-Tensift-Al Haouz region in
Morocco. It lies some 76 kilometers southwest of
Marrakech, at the foot of the High Atlas Mountains,
at an altitude of 1,451 meters. Nestled in the High
Atlas Mountains, Addouz rises in this mountain
range before emptying into the Tensift River.
The village's geographical coordinates are
latitude 31° 7' 34" north and longitude 8° 15' 57"
west.
2. The climate context
Addouz enjoys a warm Mediterranean climate
characterized by dry summers, according to the
Köppen-Geiger classification. The average annual
temperature in Addouz is 19.7°C, while average
rainfall is around 290.6 mm.
3. Geological context
The main objective of the geological study is to
identify, delineate and incline the various
lithological strata, whether permeable or
impermeable. In addition, it aims to locate and
determine the orientation of zones with strong
fracturing, such as fault networks, as well as highly
fissured terrains conducive to increased water
circulation. Aquifers subject to intense tectonic
activity can generate several sources of water.
In the specific context of the Addouz basin, the
use of the Imi-n-Tanout geological map has
provided valuable information on the geology of
this watershed. The approach consists of
georeferencing the Imi-n-Tanout map using
Geographic Information System (GIS) software,
then overlaying the study basin in shapefile form. It
is essential that both maps have the same
cartographic projection to ensure correct
integration.
The Addouz sub-watershed, located in the
southern part of Imintanout. Geologically, our
watershed is essentially made up of Upper
Cretaceous formations of Cenomano-turonian age,
consisting of grey and red marls with anhydrite and
limestones with
Astrart seguenzae, topped by yellow marly-sandy
phosphates and Eocene limestones, marly
limestones, marly-sandy phosphates and marls with
siliceous levels. All this is deposited on Upper
Jurassic formations of greenish clayey

International Journal of Advanced Natural Sciences and Engineering Researches
487
conglomerates and sandstones. Towards the base,
the Hercynian basement spreads over most of the
basin, characterized by NNE-SSW folds and
extensive metamorphism, resulting in the deposition
of granitoids.
Figure 1: location of the Addouz watershed
Figure 2: geological map of addouz watershed

International Journal of Advanced Natural Sciences and Engineering Researches
488
4. Geomorphological context
The geomorphological history and lithological
nature of the terrain are at the origin of the
organization of a watershed's hydrographic
network.
That's why it's also necessary to examine the
geomorphology of our watershed.
After analysis and interpretation of the map, the
basin can be subdivided into three major
morphological units:
❖ Sectors where the river does not interact
with alluvium (high valleys, gorges), where
the river has a steep gradient;
❖ Middle sectors where the river interacts
with alluvial deposits and has a regular
gradient;
❖ Naturally rising areas where rivers have a
very low gradient, depressions and flat areas
(which favour sediment deposition).
III. METHODS AND MATERIALS
1. METHODS
In order to characterize the geometry and physics of
the Addouz watershed, our study is based on the
analysis of several factors that reveal its
characteristics. This analysis is based primarily on
the use of the Digital Terrain Model (DTM) of our
study area, a digital representation of the relief that
provides valuable indications of slopes, exposure,
topography and the hydrographic network. In
addition, the integration of satellite images plays an
essential role in the creation of maps, providing
further information on the structure of the basin. In
parallel, we are examining the development of
vegetation in the region, using in particular the
normalized difference vegetation index (NDVI).
This holistic approach aims to gain an in-depth
understanding of the geomorphology, vegetation
cover and hydrographic characteristics of the
Addouz basin.
2. Materials
❖ Arcgis
To perform a physical and morphometric
characterization of our basin, we utilized the
ArcGIS software. As a geographic information
system, ArcGIS offers an integrated approach for
the analysis and visualization of complex
geographic data, facilitating the understanding of
topographical, hydrological, and environmental
aspects of a given area.
Using this software, we generated several essential
maps for our study. Firstly, the slope map provides
information about variations in terrain inclination,
offering crucial insights into local topography.
Secondly, the hypsometric map offers a graphical
representation of altitudes in the region, enabling a
detailed understanding of the relief configuration.
Furthermore, the creation of the hydrographic
network map allowed us to chart watercourses,
rivers, and other hydrological elements present in
the basin. Finally, the use of the Normalized
Difference Vegetation Index (NDVI) helped assess
the health and density of vegetation in the study area
❖ Saga Gis
This program enabled us to delimit our watershed
and identify its outlet. This delineation provided us
with essential information on the key parameters of
our basin, such as surface area, perimeter, elevation,
KG shape index and so on.
Map design using Saga GIS involves several crucial
steps, including the creation of visual
representations such as NDVI (Normalized
Difference Vegetation Index), convergence index,
cover plane and curvature profile
Figure 3: Geomorphological map of Addouz watershed

International Journal of Advanced Natural Sciences and Engineering Researches
489
IV. RESULTS AND DISCUSSION
1. Geometric features
Tableau 1: Morphological parameters of the ADDOUZ
watershed
KC : Compactness index
L: Length of equivalent rectangle
l: Width of equivalent rectangle
Once the surface area and perimeter are known, it's
essential to calculate the compactness index KC to
determine the shape of our pond. With KC = 2.03,
which is greater than 1, we conclude that the basin
has a relatively elongated shape. This configuration
favors reduced peak flows due to a high time of
concentration.
2. The hydrographic network of the ADDOUZ
basin
Oued Addouz is one of the convergence points of
the Tensift. Its watershed is made up of a varied
network of watercourses, the main one being around
20.41 kilometers long.
a) Hydrographic network classification
b) Drainage density
Drainage density depends on a number of factors,
including lithology, tectonics, exposure, vegetation
cover, slopes and climate.
Generally speaking, low drainage densities are
characteristic of regions where the soil and subsoil
are highly resistant or permeable, where vegetation
cover is dense and relief is low. In the opposite
conditions, very high densities are most often
encountered.
Area
(Km2)
Perimeter
(km)
KC
L
(Km)
l
(Km)
67.34
59.55
2.03
27.2784
2.4686
Figure 4: The hydrographic network of the ADDOUZ basin
Figure 5: strahler hydrographic network classification
Figure 6: Drainage density map of Addouz watershed

International Journal of Advanced Natural Sciences and Engineering Researches
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Drainage density, introduced by Horton, is the total
length of the drainage network per unit area of
catchment:
Dd: drainage density [km/km2];
Li: stream length [km];
A: watershed area [km2].
Drainage density in the Addouz basin is of the order
of 1.89 km/km2
This means that the basin as a whole has a
permeable geological formation, with limited,
centralized runoff and increased infiltration.
3. Topographical features
1. hypsometric map
The hypsometric map illustrates the spatial
variation of altitude bands in relation to surface
area. Altitude ranges from 1900 to 2079 are the
most dominant.
The Addouz basin is characterized by a maximum
altitude of 2077 m, and a minimum altitude of 825
m, giving it a vertical drop of around 1252 m and an
average altitude of 1451 m. The majority of the
basin's surface is occupied by terrain at altitudes
ranging from 1900 m to 2079 m.
2. The slope
The slope map illustrates the distribution of
different slope values in the basin. Slopes range
from 0° to 31.06°. It can be seen that steep slopes
are distributed in the southern part of the basin,
where there are high altitudes. Weaker slopes are
found in the northern part of the basin.
4. Morphological features of the basin
1. Basin convergence index
The convergence index is a terrain parameter that
shows the relief structure as a set of converging
Figure 7: hypsometric map of addouz watershed
Figure 8: Map of the Addouz watershed slope
Figure 9: Convergence index map of the haouz watershed

International Journal of Advanced Natural Sciences and Engineering Researches
491
zones (channels) and diverging zones (ridges). It
represents the concordance of the direction of
aspect of the surrounding cells with the theoretical
direction of the matrix.
Based on the results obtained by processing
satellite images, we were able to determine the
convergence index distribution in our study basin.
2. Profile curvature and plan curvature
Profile curvature affects flow acceleration and
deceleration, and consequently influences erosion
and deposition. In-plane curvature influences flow
convergence and divergence. Considering both in-
plane curvature and profile curvature enables us to
understand flow over a surface more precisely.
The plan view curvature function found in the
SAGA toolbox is also important for work aimed at
understanding variations in man-made and natural
terrain. This tool can be used in fields such as safety,
monitoring and tracking of massive erosion
phenomena, and watershed mapping.
It can be described as the curvature of the
hypothetical contour line passing through a specific
cell. In-plane curvature can be used to differentiate
ridges from valleys.
In-plane curvature is positive for cells with concave
contours and negative for cells with convex
contours.
Profile curvature is the curvature of the surface in
the direction of steepest slope (in the vertical plane
of a flow line). Profile curvature influences erosion
and deposition.
Where profile curvature is convex and takes on
negative values, erosion will prevail, and where
curvature is concave and therefore positive, it
automatically corresponds to deposition zones.
5. MRVBF and MRRTF parameters
1. Multi-resolution valley bottom flatness
index (MRVBF)
Figure 10: plan curvature map of Addouz watershed
Figure 11:Addouz watershed profile curvature map
Figure 12: MRVBF parameter map of Addouz watershed

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MrVBF is a topographic index designed to
identify areas of material deposition in flat valley
bottoms, based on the observation of the flatness of
valley bottoms in relation to their surroundings,
given that large valley bottoms are flatter than small
ones.
Zero values indicate eroding ground, with values
of 1 and above indicating increasingly large areas
of deposition. MrVBF values seem to correlate with
the depth of deposited material.
2. Multi-resolution peak flatness index
MRRTF, Multi-resolution Ridge Top Flatness is
a topographic index designed to identify elevated
flat areas at a range of scales. Unlike the MRVBF
index, the MRRTF index has no clear link to
landform processes, but it has proved a useful
complement to the MRVBF index in landform
classification.
Zero values indicate steep or low-lying areas, with
values of 1 and above indicating progressively
larger areas of flat, elevated terrain.
6. Topographical moisture index
TWI, or topographic wetness index, is an index
commonly used in hydrological analysis to describe
the tendency of an area to accumulate water.
Essentially, it tells us how likely an area is to be wet.
As you can see, it's important for identifying
wetlands.
The index is strongly correlated with several soil
attributes such as horizon depth, silt percentage,
organic matter content and phosphorus.
Areas with higher topographic moisture index
values are likely to be wetter than areas with lower
values.
7. NDVI: Normalized Difference Vegetation
Index
Vegetation plays an important role in slope
stability through hydrological and mechanical
processes and mechanical processes. Tall vegetation
has good soil properties, for example, organic
matter and greater accumulation, leading to greater
infiltration capacity.
NDVI is an indicator of vegetation health. It is a
combination of the centered, visible red (Red) and
near infrared (NIR) bands and indicates the general
greenness vegetation or photosynthetically active
vegetation
Figure 13: MRRTF parameter map of Addouz watershed
Figure 14: Addouz watershed topographie moisture index map

International Journal of Advanced Natural Sciences and Engineering Researches
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The NDVI map is based on Landsat 8 satellite
images for the year 2020. It shows moderately
developed vegetation in the south-eastern part of the
watershed.
V. CONCLUSION
The geometric and physical approach to our study
has enabled us to assess the importance of
characterizing the watershed. Knowledge of its
characteristics provides us with valuable
information on the basin's morphology and
associated risks.
Geomorphologically, the Addouz basin is a small
one, with an estimated perimeter of 59.55
kilometers and an area of 67.34 square kilometers.
Physically, it has an elongated shape, equivalent to
a rectangle 27.2784 km long and 2.4686 km wide.
Hypsometric and slope analysis reveals a northward
flow direction along the Addouz valley.
Vegetation analysis also revealed a particularly
marked vegetation development in the south-eastern
part of the basin. This additional information
enriches our understanding of the watershed's
environmental dynamics
ACKNOWLEDGMENT
The authors express their deep gratitude to the
Director of the Laboratory of Geosciences,
Geotourism, Natural Hazards and Remote Sensing
at the Semlalia Faculty of Sciences, Marrakech,
Cadi Ayyad University, Morocco, for his constant
support and encouragement throughout this study.
VI. REFERENCE
[1] Agoussine M. 2003. Les divers aspects de l'hydrologie en
régions arides et semi arides - cas du sud-est marocain.
Terre & Vie, Rabat, 70
[2] Algouti Ahmed, Algouti Abdelah, Hadach Fatiha, Farah
Abdelouahed, Ali Aydda (2022) - Upper Cretaceous
deposits on the Northern side of the High Atlas Range of
Marrakesh(Morocco): tectonics, sequence stratigraphy
andpaleogeographic evolution, Boletin de la Sociedad
GeologicaMexicana 74(1):1-18 (Web of Sciences)
(2002) The IEEE website
[3] Aquino, D. et al (2018). Use of remote sensing to
identify areas at risk of degradation in the semi-arid
region
[4] Beven, K. J., & Kirkby, M. J. (1979). A physically based,
variable contributing area model of basin hydrology/Un
modèle à base physique de zone d'appel variable de
l'hydrologie du bassin versant. Hydrological sciences
journal, 24(1), 43-69.
[5] Chaponnière, A. (2014). Fonctionnement hydrologique
d'un bassin versant montagneux semi-aride: cas du bassin
versant du Rehraya (Haut Atlas marocain). Presses
Académiques Francophones.
[6] El Myr, A., Algouti, A., Tabit, A., Hadach, F.,
Guernouche, M., Aadaj, J., ... & Oudour, K. (2023). The
contribution of remonte sensing in the mapping, land
cover and hydrology of the ouled Abdoun basin. AS-
Proceedings, 1(4), 305-308.
[7] El Mimouni, A., Daoudi, L., Saidi, M. E., & Baiddah, A.
(2010). Comportement hydrologique et dynamique d’un
bassin versant en milieu semi-aride: exemple du bassin
versant du Ksob (Haut Atlas occidental, Maroc). Rev. C.
& G, 24(1-2), 99-112.
[8] Hanane, Toudamrini, et al. "Sedimentological and
Mineralogical Caracterisation to Assess the Erodability
of the Chichaoua Watershed (Morocco)." AS-
Proceedings 1.6 (2023): 642-645.
[9] Lamrani, K., Algouti, A., Tabit, A., Hadach, F., Jdaba,
N., Mjdouli, K., ... & Oudour, K. (2023).
Characterization of meteorological droughts in thHaouz
plain in Morocco: an analysis over the period 1984-
2023. AS-Proceedings, 1(4), 282-286.
[10] Majdouli, K., Algouti, A., Tabit, A., Hadach, F.,
Lamrani, K., Lakhlili, M., ... & Elhamdi, S. B. (2023).
Exploring the Links between Climate Change and
Meteorological Drought in the Draa Basin. AS-
Proceedings, 1(6), 517-521.
[11] Khadija, O., Ahmed, A., Abdelhalim, T., Addine, A. K.,
Hadach, F., Mohamed, L., ... & El hamdi Sabah, B.
(2023). Study of the vulnerability of the Bouregreg basin
to the risk of water erosion. AS-Proceedings, 1(4), 338-
342.
[12] Saidi, M. E. M., Boukrim, S., Fniguire, F., & Ramromi,
A. (2012). Les écoulements superficiels sur le Haut Atlas
de Marrakech cas des débits extrêmes. LARHYSS
Journal P-ISSN 1112-3680/E-ISSN 2521-9782, (10).
Figure 15 : Normalized Difference Vegetation Index

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494
[13] Saidi, M. E. M., Daoudi, L., Aresmouk, M. E., & Blali,
A. (2003). Rôle du milieu physique dans l’amplification
des crues en milieu montagnard, exemple de la crue du
17 août 1995 dans la vallée de l’Ourika (Haut Atlas,
Maroc). Sécheresse, 14(2), 1-8.