CHAPTER IV
Results & Descussion
50
According to the graph (figure 33) we have the evolution of land use variables in the years
1990, 2000, 2010, 2010.
In the total surface of the wilaya agricultural lands, forest and vegetation areas show a
gradual decrease over the last three decades; secondly, urban areas and bare lands show a
gradual increase over the period. These trends imply that a considerable portion of
agricultural land, forest and vegetation were occupied by urban and bare lands in the study
area in the past 30 years. Another important cause of this remarkable decrease which present a
threat on the environment of the municipality is the changes in precipitation patterns resulting
from climate change led to increased rainfall in certain municipalities. This surplus of water
contribute to the formation or expansion of natural or artificial water bodies within noncoastal areas.
What can be clearly seen in coastal municipalities in (figure 33) is the steady decline of
agriculture area from 35000 Ha in 1990 to 5000 Ha in 2020. The area of forest experienced a
slight increase between 2000 and 2010, followed by a continual decrease to 60000 Ha in
2020. In contrast, there was a sharp decrease in the area of vegetation lands in 2000 from
52000 Ha in 1990 to 10000 Ha in 2000. The area of urban lands experienced a slight increase
in 2020.
Changes in land cover were also observed for all classes in non-coastal municipalities between
1990 and 2020. It is evident that the agriculture area, vegetation lands area, and forest area have
undergone a significant decline, with nearly half of their previous total areas being lost over the
course of the last three decades.
The urbanization of agricultural areas and the deforestation leads to decry the agricultural
capacity and loss of forests and their biodiversity. As cities expand, they encroach upon fertile
agricultural regions, reducing the available land for food production. This conversion disrupts
the agricultural supply chain, leading to a decrease in agricultural capacity. The loss of
biodiversity can disrupt natural processes, such as pollination and seed dispersal, which are
crucial for the functioning of ecosystems.
Results & Descussion
50
According to the graph (figure 33) we have the evolution of land use variables in the years
1990, 2000, 2010, 2010.
In the total surface of the wilaya agricultural lands, forest and vegetation areas show a
gradual decrease over the last three decades; secondly, urban areas and bare lands show a
gradual increase over the period. These trends imply that a considerable portion of
agricultural land, forest and vegetation were occupied by urban and bare lands in the study
area in the past 30 years. Another important cause of this remarkable decrease which present a
threat on the environment of the municipality is the changes in precipitation patterns resulting
from climate change led to increased rainfall in certain municipalities. This surplus of water
contribute to the formation or expansion of natural or artificial water bodies within noncoastal areas.
What can be clearly seen in coastal municipalities in (figure 33) is the steady decline of
agriculture area from 35000 Ha in 1990 to 5000 Ha in 2020. The area of forest experienced a
slight increase between 2000 and 2010, followed by a continual decrease to 60000 Ha in
2020. In contrast, there was a sharp decrease in the area of vegetation lands in 2000 from
52000 Ha in 1990 to 10000 Ha in 2000. The area of urban lands experienced a slight increase
in 2020.
Changes in land cover were also observed for all classes in non-coastal municipalities between
1990 and 2020. It is evident that the agriculture area, vegetation lands area, and forest area have
undergone a significant decline, with nearly half of their previous total areas being lost over the
course of the last three decades.
The urbanization of agricultural areas and the deforestation leads to decry the agricultural
capacity and loss of forests and their biodiversity. As cities expand, they encroach upon fertile
agricultural regions, reducing the available land for food production. This conversion disrupts
the agricultural supply chain, leading to a decrease in agricultural capacity. The loss of
biodiversity can disrupt natural processes, such as pollination and seed dispersal, which are
crucial for the functioning of ecosystems.