Article Type: Research Article Article Citation: Faiza Khebour Allouche, Saida Hammami, Arwa Hamaideh, Emna Gatta, and Anas Khasawneh. (2021). ENVISIONING SUSTAINABLE LANDSCAPE
MANAGEMENT IN THE ENVIRONMENTALLY SENSITIVE AREAS OF KSOUR ESSEF, TUNISIA. International
Journal of Research -GRANTHAALAYAH, 9(1), 85-98. https://doi.org/10.29121/granthaalayah.v9.i1.2021.2715 Received Date: 11 December 2020
Accepted Date: 27 January 2021 Keywords: ESA Landscape Diagnosis Urban Natural
Park Each territory has distinctive features and landscape compositions that contribute to the creation of territorial identities. Natural parks are territories remarkable for their wealth of biodiversity, which in turn contribute to the development of sustainable socio-economic development through landscape enhancement. The main idea of this research is to test the combinaison of two concepts to propose a suitable management in a semi-arid environment. It is based on the use of the ESAs and landscape diagnosis concepts. The concept of ESAs is supported including the need to identify environnementally sensitive lands based on the hypotheses of MEDALUS project model. However, the landscape diagnosis is based on the combination of landscape potential and social requirements. Results aimed to create ecological and environmental models based on natural materials such as wood, light minerals and a diversified and multicoloured plant palette, including the logic of working with nature and preserving its particularity by promoting sustainable local development criteria and create a new green city. Â 1. INTRODUCTIONSince the early
19th century, forests have been the scene of urban growth and have sometimes
been transformed into green and wooded areas or urban forest parks. With the
evolution of large urban areas, the need for space for new construction has
caused problems following deforestation, fires and the
degradation of peri-urban natural areas. Today, despite these disadvantages,
several countries have become more aware of and respectful of peri-urban
forests through the development of fields of activity in these areas. Forests
are multifunctional spaces, offering both tangible and intangible services. In
Japan or Australia, the demand for recreational spaces has encouraged public
authorities and local authorities to invest in forests to benefit from their
environmental and social functions. In France, the social perception and
representation of forests are very closely linked to
leisure activities (Papillon,
2014). In
Tunisia, peri-urban forests were transformed into public parks in the summer
following the program of 100 parks that began in 1996. The objectives of
creating these parks are essentially to improve the living conditions of city
dwellers and to preserve the natural spaces adjacent to the cities. Among the
forests that have been transformed into public parks are (Nahli,
El Mourouj, Farhat Hached,
El Hmeda,...). Today, these forests converted into
peri-urban parks do not meet society's needs for a pleasant natural living
environment and also for leisure. Peri-urban forests
require new recognition and also a rethinking of their
future. The example of the Ksour Essef
peri-urban park is our study support, in order to
assess its current state and propose solutions that can remedy the
disadvantages and offer the target population a better living environment in
order to preserve natural resources while meeting the requirements of
sustainable development. Generally, landscaping projects are
based on landscape analysis, this research work consists in presenting a method
of evaluating the landscape features of a regional forest natural park which
has been developed in 2011 but has undergone a significant degradation of
natural and managed entities following the effect of climate change and
anthropogenic especially after the revolution. The status of sensitive
environmental areas will be assessed by applying the Medalus
method. Then, a landscape diagnosis is carried out on the ground. The
comparison of the results will enable to better manage the studied space and
propose a sustainable landscaping taking into account
the three pillars of sustainable development. 2. STUDY AREAThe park is located in the delegation Ksour Essef belongs to the
governorate of Mahdia and occupies an area of 16
hectares which implanted in a forest of an overall area of 50
hectares (Figure 1). This space was actually an old
stone quarry in the sixties, which after its closure in 2001, was promoted as a
green space. It occupies the highest point of the city whose altitude can reach
up to 66 m. This forest represents the green lung of the city, thus, it is
formed of an afforestation of Aleppo pine "Pinus Halepensis"
and Eucalyptus "Eucalyptus
Camaldulensis". The development of the park is part of the national
parks program that brings together 100 parks throughout Tunisia to improve the
living environment of the population and the protection of the environment. It
was open, according to the municipality of Ksour Essef, in 2002 and was valued as a forest park. Indeed, a wrought iron
fence was put in place to demarcate the park and protect it with an entrance
gate made by AUDEC (2002), with a sum of 28 thousand dinars. Inside the park, a
fitness trail was set up in 2011 with all the physical work equipment, a
refreshment bar, a play area, a "LABIB" pedestal and family rest
areas with benches. But since the Tunisian revolution, in 2011, the space was
destroyed and poorly maintained, therefore, it became non-functional and a wealth
of landscape was lost including the components of the course. The delegation of Ksour Essef
belongs to the governorate of Mahdia located
south-east of the Tunisian sahel, 200 km from the
capital Tunis and 12 km from the city of Mahdia with
an area of 40 Km² and 54 366 inhabitants in 2014. It is located
on a moderate hill, and encloses a coastal zone stretching 13 Km (Figure 1).
According to the National Meteorological Institute of Tunis (2017), the city of
Ksour Essef is known for a
warm, dry Mediterranean climate in summer, humid and temperate in winter with a
maximum average temperature of 31 ° C and a minimum average of 6 ° C. The city
is also known by winds on the east side in summer and on the west side in
winter, whose west winds are dominant and can reach up to 80 m/s. Potential
evapotranspiration (PET) varies from 1319 to 1321 mm / year in 2010. According
to the Regional Commissariat for Agricultural Development (CRDA, 2014), Ksour Essef contains the water
table "Melloulech", where 1446 water wells
produce 2.91 million m3/year with a variable salinity between 3 to
15 g/l. It belongs to the "Sahel Sfax" water table, consisting of 22
water wells, producing 3.15 million m3 of water. The Territorial
Extension Cell (CTV, 2002), has mentioned that the irrigated perimeters at Ksour
Essef occupy a total of 110 hectares spread over 152
farmers. It despites a water salinity of 4.3 g/l of
salt. However, Ksour Essef is
built on a succession of hills with altitudes that vary between 6 m and 30 m
and the neighboring altitude hills reaches 65 m.
Figure 1: Location
of Ksour Essef city, Tunisia The delegation of Ksour Essef is home to several types of soils, and the
predominance of low input soils, isohumic soils and raw mineral soils on the north
side. In the southern part, the soils are raw limestones, while in the center
there is a diversity such as halomorphic soils, rendzines and complex units.
The raw mineral soils are located on a steep slope where the surface layers are
constantly entrained thus preventing the formation of soil from which the
vegetation cover is very insignificant. This type of soil is mainly present in
the northern and north-eastern part of Ksour Essef, with a succession of hills
reachs 66 m. The poorly evolved soils are generally located in semi-arid areas,
characterized by a low degree of weathering, a humic horizon and a structure
that is often weak. Isohumic soils are characterized by a dominance of clays
found in the forest of Ksour Essef (Figure 2). The land use of the town of
Ksour Essef is subdivided into two parts: the coastal side presents a variety
of crops including cereals (barley and wheat), forage crops (sorghum, maize,
oats ...), market gardening (pepper, tomato, potato, zucchini, cucumber,
carrot, onion, melon, eggplant, pea, squash, watermelon, garlic ...), spices
(cumin, choriambe) and olive groves. Further, cereal crops persist in the west
one (Figure 3).
The commune of Ksour Essef, contains 12 green spaces with a total area of
353,950 m2 distributed as follows: ·
Habib Bourguiba Street Garden: 2500 m2 (under
redevelopment) ·
Hedi Chaker Street Garden: 1850 m2 (in
redevelopment study) ·
Ahmed Tlili Street Garden: 1,800 m2 (requires
maintenance) ·
Omar Karchoud Street Garden: 400 m2 (requires
maintenance) ·
Ali Bouzidi Street Garden: 2000 m2 (in
redevelopment study) ·
El Hmeda Park: 160 000 m2 (in redevelopment
study) ·
Garden Aziza Othmena street: 78 300 m2 (corner
bush) ·
Garden rue Salah Eddin El Ayoubi: 20 100 m2
(corner bushed) ·
Garden Bizerte street: 8200 m2 (bushed area) ·
Garden Jbal Khmir street: 78 400 m2 (corner
bush) ·
Garden Street 2 Mars: 300 m2 (in redevelopment
study) ·
Garden street Abdallah Chaweli: 100 m2 (corner
bush). The delegation of Ksour Essef has a population of 54,366 inhabitants in
2014. The economic development of the city of Ksour Essef is based on the trade
where there are more than 300 points of sale in detail. The participation rate
is 38.87 % while the unemployment rate is 9.83 %, which shows that despite the
reduction in the number of jobs in the city, agriculture and commerce provide a
lot of jobs (INS, 2014). During the last five years, the city has undergone
remarkable development especially in the administrative, health, educational,
sports, cultural, religious and commercial (Monoprix, Carrefour, etc.). 3. METHOD
Urban Natural
Parks are designed to preserve and improve the quality of the landscapes and
the living environment of the inhabitants. As a result, the need for green
spaces in cities is becoming a necessity, and city dwellers are looking for
moments of relaxation, rest, recreation, outdoor activities and sports where
nature is very calm. In this strategy
that the municipality of Ksour Essef has requested a proposal for the
redevelopment of the El Hmeda natural urban park, which is part of the
sustainable development project of Mahdia city.Â
In response to this request, the objective of this research is to
propose a landscaping redevelopment in this park. The methodological approach is based on the
ESA approach and the landscape analysis dealing with the different physical,
sensitive and natural aspects and the development proposal is based on the
concept "Treasure Hunt". In order to
understand and act effectively on the Ksour essef park, we opt for an
analytical approach based on diagnosis and evaluations, as shown in Figure 4,
different steps followed in the methodological approach.Two principal steps are
used the landscape diagnosis and the ESA assessment of park El Hmeda The
physical diagnosis is based on the use of Google earth, open street map and
some shapefiles. Google earth and field validation using GPS are done for
digitizing and mapping the spatial delimitation of the park, slope and altitude
variation for two transects, it’s land use cover and field description of some
stations. The park accessibility is mapped using Open street map tool and some
benchmarks are located. However, sensitive analysis is based on the visual
interpretation of the landscape structure (vertical and horizontal), noise, and
colors in order to evaluate its state. The survey conducted as part of this
research, aims to know the expectations of the resident population around the
forest of El Hmeda and visitors to approve our idea of design.
Ten questions in total were asked, out of 50 people, some are asked in a
socio-economic context such as age, sex, the budget devoted to leisure, the
distance between the park and the housing of the person surveyed. Others are
asked to better understand the strengths and weaknesses of the space, the
reasons for the visit, the preferred locations and the expectations of the new
landscaping. The use
of this diagnosis method is based on the hypotheses of MEDALUS project model
(Giordano et al., 2007). Three qualitative indexes are computed by applying an
average of a geometrical model. The following three quality indices were
computed; ·
Soil
Quality Index (SQI), ·
Vegetation
Quality Index (VQI) ·
Climatic
Quality Index (CQI) Administrative, land use
land cover and sol Mahdia vector layers are used to map and calculate indexes.
DEM raster layer was downloaded from https://glovis.usgs.gov/ and used to
retrieve the slopes and aspect gradients. The data (spatial resolution of 30 m).
The evaluation of
ESAs is based on a combination of the physical including soil, climate, and
vegetation qualities. A geodatabase and several thematic maps were prepared and
standardized with the same projection system and spatial resolution. The indicators
were grouped into four quality indices, namely, the soil quality index (SQI),
climate quality index (CQI), vegetation quality index (VQI), and MQI (Khebour Allouche and Gad, 2014). Each indicator was calculated
by means of sub-indicators, which were also classified. For each class, a
weight value was allocated. The values of the weights varied from 1 (least
sensitive to desertification), to 2 (most sensitive to desertification) (Gad
and Lotfi, 2008). Figure 4: The landscape diagnosis and the ESA assessment of park El
Hmeda, Tunisia 3. RESULTS AND
DISCUSSION
3.1. ASSESSMENT OF SENSITIVE
AREAS
A large part
of the park is located in a quaternary formation. The quaternary part includes
terraces of major bed, mobile sand, unconsolidated scree, low terraces,
dejection cones, and white limestones, probably lacustrine and often
conglomeratic. Furthermore, the Ordovician part contains sandstone, quartzites,
and claystone. Soils derived from different parent materials react differently
to erosion, absorbency and production of biomass: the presence of pebbles still
causes an increase in runoff and therefore improved safeguard from
desertification (Figure4). The influence of each class for each sub-indicator
constructs SQI that was weighted based the influence on desertification
process. More than 50% of the area is marked by less sensitive soils. A strip which
crosses this entity in the center of the forest area is marked by moderately
sensitive soils. These landscape conditions encourage sensitivity to land
degradation. Calculating
the vegetation quality index, on basis of the previous parameters reveal that
the 60 % of the vegetation cover is very weak and sensitive to desertification
(Figure5). The good vegetation index class which may resist desertification is represented
olive plots. The Hmeda park have an average of a precipitation of 283mm/a and
the PET is inferior to 1300 mm/an. So, the climatic quality index is inferior
to 0,217. That’s why all the field have a weak climatic index. Figure 6 show
the distribution of ESA’s. It is clear that most of the Hemeda park is
moderately sensitive to desertification (60 %) and the very sensitive area is
located in the east.
Through
the geographical evaluation of the park, in order to qualify the different
biotic (plant and soil) and abiotic (climate) components, it can be concluded
that the El Hmeda peri-urban park is a natural space whose distribution of
natural resources is not very equitable throughout the park, which leads to
rethink landscape development through conservation and remediation planning. In
this respect, a landscape analysis is essential to meet the requirements of a
functional and sustainable development. 3.2.  LANDSCAPE ANALYSIS
3.2.1. Â PHYSICAL ANALYSIS The
physical analysis is based on the description during field visits and the use of
digital media such as Google Earth, Google maps and QGIS 1.18. The park is accessible
from the Mahdia-Ksour Essef road via Rojich on the north side or on the west
side by the Salakta-Ksour Essef road. It is surrounded by three types of
landscapes: an urban landscape constituting the center of the city of Ksour
Essef, a peri-urban landscape formed by the extensions of the city and a wider
agrarian landscape formed by olive groves. The slope in the park to be
redeveloped is very specific which gives it a unique charm following the
variation of the slopes, the division of the land into three terraces and
rugged terrain. A longitudinal plot shown in Figure 7 shows that the park
represents a variation in altitude between 27 m and 58 m. While the transverse
plot of the same figure indicates a variation between 32 m and 61 m. |