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American Journal of   
Environment and Climate (AJEC)

Deterioration of  Plant Resources in Contact with Nigerian Refugees, Returnees and 
Internal Displaced Chadians in Kaya, Lake Region, Western Chad

Bayang Sirbele1*

Volume 2 Issue 3, Year 2023
ISSN: 2832-403X (Online) 

DOI: https://doi.org/10.54536/ajec.v2i3.1848
https://journals.e-palli.com/home/index.php/ajec

Article Information ABSTRACT

Received: June 30, 2023

Accepted: July 28, 2023

Published: August 28, 2023

Chad in general and Kaya in particular, hosts a large number of  refugees, returnees and 
internally displaced persons. Wars, inter-community conflicts and the nebulous Boko Haram 
sect are the causes of  massive displacement of  populations from neighboring countries to 
Chad and Kaya. The arrival of  Nigerian and Nigerian refugees, returnees and internally 
displaced Chadians has increased the population and the need for energy, especially firewood 
and charcoal. Moreover, to meet their food and financial needs, these migrants are forced to 
destroy the plant resources of  the region and of  Kaya in order to survive. This is damaging 
the natural environment and the economy of  the Lac and Kaya region. Thus, 25 refugees, 
returnees and displaced persons were studied and empirical data collected in order to 
determine their responsibility in the degradation of  vegetation in Kaya. Then, 3 people in 
charge of  the environment in Bagassola were interviewed to gather their opinions on the 
role played by refugees, returnees and IDPs in Kaya in the environmental degradation in this 
area. Five interviews were held with NGOs in Bagassola to find out the underlying reasons 
that lead refugees, returnees and IDPs to destroy nature.

Keywords
Deterioration, Refugees, Plant 
Resources, Kaya, Lake Region, 
Chad

1 Department of  Geography, Higher Teachers’ Training College, N’Djamena, Chad
* Corresponding author’s e-mail: bayangsirbele@gmail.com

INTRODUCTION
The Chadian Sahel covers an area of  553,590 km2 or 
43.11% of  the country (Baohoutou, 2007). The Lake 
region, on the other hand, covers an area of  22,320 km2.  
The vegetation in this part of  the country is steppe-like 
(Cabot and Bouquet, 1978). Indeed, the Chadian Sahel 
in general, and Kaya in particular, abounds in plant 
resources that have been subjected to unprecedented 
degradation in recent decades by local populations (4th 
National Report on Biological Diversity, 2009). 
Recurrent droughts, especially those of  1972 and 2007 
(DREM, 2008), which have occurred in the Lake region, 
on the one hand, and human actions on the other, have 
contributed to the degradation of  the plant cover (field 
surveys, 2021; Bayang, 2023). 
Among human actions, it should be noted that for almost 
a decade, in 2015, where 32,000 Chadians and other 

internally displaced people fled attacks by the nebulous 
Boko Haram sect. This is because the sect has committed 
atrocities in Nigeria and Niger, forcing people from 
neighboring countries, returnees and displaced Chadians 
to take refuge on the Lake in general and in Kaya in 
particular. The flow of  displaced people is compromising 
the survival of  the environment in general and plant 
resources in particular in this part of  Chad (United 
Nations Communication Group, 2014; OCHA, 2021). 
It is well known that the impact of  this degradation of  
plant resources is enormous, and is felt at several levels in 
the Lac and Kaya regions. The sectors most affected by 
this phenomenon are agriculture and livestock breeding. 

Materials and methods 
Study Area    
Kaya, the study area, is located in western Chad. It is 

Figure 1: Situation and location of  Baqassola



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located some 400 km from the Chadian capital and is part 
of  the Lac region. The department of  Kaya comprises the 
cantons of  Nguéléa 1, Nguéléa 2 and Boudouma Dallah, 
whose respective chief  towns are Nguéléa, Bagassola and 
Ngouboua. Kayac comprises 171 villages and covers an 
area of  1,302 km². Bordered to the north by the Liwa sub-
prefecture, to the south by the Kangallam sub-prefecture, 
and to the east and west by the Bol sub-prefecture (Figure 
2), the two cantons have an estimated population of  
45,000. Nguéléa 2, which is the subject of  this study, has a 
population mainly made up of  farmers and herders, who 
play an important role in the environmental degradation 
of  the Lac region through their activities. Refugees, 
returnees and internally displaced persons also have a 
negative impact on Bagassola’s plant resources.
In the Lake region in Figure 1, Bagassola, chief  town 
of  Nguéléa 2 canton, is bordered by two main towns on 
the lake, Bol and Liwa, and by Nigeria, a giant African 
country. Bagassola is home to a large number of  Nigerian 
refugees, returnees and internally displaced people.

Methodological Approach 
Several methods were combined in this study: 
• Fieldwork: this involved collecting data on the 

degradation of  plant resources from public and private 
officials in the environmental field with group interview 
guides;
• Surveys were carried out and empirical data collected 

on anthropogenic actions of  encroachment from 
Nigerian refugees, returnees and internally displaced 
people in Bagassola with a survey sheet;
• Using GPS, the geographical coordinates of  refugee, 

returnee and IDP sites, viewpoints and other points 

relating to the degradation of  Bagassola’s plant resources 
were recorded. 

RESULTS
Steppe Vegetation Formation of  the Lake in Perpetual 
Anthropic Degradation
The vegetation of  the Lac region in general, and Kaya in 
particular, belongs to the Sahelian domain, with a steppe 
formation characterized by thorny acacias, but others 
such as calotropis procera are not.

Steppe Characterized by a Shrubby Landscape
This landscape features a diversity of  shrub species 
at Kaya that differs from one environment to another. 
Around the natron valleys, the most common species are 
doum palms, roasting palms, leptadenia pyrotechnica, 
calotropis procera and Ka-you . Here, in this environment, 
it should be noted that these species are spread along the 
sides of  the valleys. In the villages of  the natron areas, a 
category of  ligneous trees is found. These include soap 
trees (balanites aegyptiaca) and neem trees (as in the 
village of  Kaya). In the bush, leptadenia pyrotechnica, 
acacia and soap trees predominate. It should also be 
noted that plant species such as acacia albida, jujube, 
gum tree, etc. are found in the natron valley zone (field 
survey, 2021, table 1). Table 1 shows a plant society in 
the natron area. This plant society is defined by a group 
of  plants living together in a common habitat and subject 
to the same living conditions. The dunes and the plant 
colonies are arranged jointly in a process referred to as a 
perfectly predictable “symbiotic partnership”. Calotropis 
procera is one of  the most widespread plant species in 
the natron area (Figure 2).

Table 1: Plant species at Bagassola in the Lake District
Geographical unit Plant species

Scientific name  Name in local Arabic Name in Kanembou
Around villages and water points Leptadenia pyrotechnica Rtem Kalemo

Acacia seyal Kitir/Asharat Koloul
Balanites aegyptiaca Hidjilid
Ziziphus mauritiana Nabak Kongue
Acacia sieberiana Kouk Keringa
Calotropis procera Atchoro Kaya
Acacia raddiana ou Tortilis Talha Kidile
Acacia albida/faidherbia2 Haraz Kouroulou
Acacia nilotica Garate
Prosopis juliflora Soubsoubane Kangar,komé

Around the natron valleys Calotropis procera Atchoro Kaya
Hhyphaena thebaïca Dom Soullou
Leptadenia pyrotechnica Kalemo
Borassus aethiopum Kourtou mdina
Salvadora Persica Arak Kayou

At the bottom of  natron Without tree Without trees
Source: Field survey, July 2021



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Figure 2: View of  calotropis procera in Kaya
(Photo: Bayang Sirbélé, 2023) Andja, January 31, 2023 
(N13°41’0.09’’; E 14°16’29.1’’)

Figure 3: View of  a fenced field in Dar Salam (Bagassola)
Photo: Bayang Sirbélé, 2023) Dar Salam, January 31, 2023 (N 
13°32’9.3’’ and E 14°18’49.6’’)

Figure 2 shows calotropis procera growing on the sand 
dune at Kaya. Calotropis procera is most commonly 
found in the brown zone. This species (Figure 2) 
preferentially colonizes well-depleted soils. It has become 
the indicator of  tired, infertile soils, known in Arabic as 
naga. It is protected to prevent silting-up of  the valleys.
It should be noted that, depending on the geomorphology 
of  the terrain, certain dominant species are found around 
the natron valleys and in the villages. These include 
calotropis procera and leptadenia pyrotechnica.

Grass-Dominated Lake Vegetation
Grasses populate the sand dunes of  the Lake region. They 
include: aristida pallida, aristida funiculata, cymbopogon 
giganteus, andropogo gayanus, etc. (Cabot et Bouquet, 
1974, 1978 and field survey, 2021).

Vegetation Destroyed by Salt
Trees don’t grow at the bottom of  valleys because of  
their salinity. Because the lowest parts of  natron valleys 
are barren, they are devoid of  all vegetation (Pias, 1970). 
Prosopis juliflora or prosopis chilensis is bushy and 
therefore tolerates these salty, highly acidic soils. It is a 
species of  American origin, but has become pan tropical. 
It is an evergreen plant.
Vegetation in the Lake region and in Kaya is nowadays 
experiencing a high mortality rate of  certain species due 
to the effects of  climate change (field survey, 2021). This 
degradation is due to agricultural, pastoral and logging 
activities in the region and in Kaya. 
In fact, the degradation of  nature is the result of  human 
action, with agriculture using thorn fences. The over-
exploitation of  woody vegetation is explained by the need 
to protect fields (korelo) with thorn fences or kalyi, to 
combat the incursions of  the region’s relatively large herd. 
Penicillary millet is grown on the dunes. To fence their 
fields, farmers and refugees generally use thorny acacia 
trees such as acacia seyal, acacia nilotica, etc. (Figure 3).
Figure 3 shows that the penicillium fields in Dar Salam 
are fenced. The fences are made of  branches of  acacia 

nilotica and other shrubs. In addition, dune fields 
are found on the outskirts of  villages. This type of  
cultivation contributes significantly to the degradation of  
the ecosystem in the Lac and Kaya regions.

Demographic Growth of  the Lac Population
In human terms, the population of  the Lac, like that of  
other attractive regions of  Chad, is constantly increasing. 
This is due to the natural potential of  the Lake region. As 
a result, many Chadians refer to the Lake as one of  the 
breadbaskets of  Chad. 
Its approximate population was 88,911 in 1962. In 1968, 
an administrative survey put the population at 92,801. In 
1989, the population was 127,974. With the 1st General 
Census of  Population and Housing (RGPH1), which 
took place in Chad in April 1993 and lasted 6 months, the 
population of  the Lake was 248,226. This was the largest 
census in Chad’s history, carried out by the BCR (Bureau 
Central du Recensement). Sixteen (16) years after the 1st 
census, i.e. in 2009, the 2nd census was carried out. At 
this latest census, the population of  the Lake was 451,369. 
From 1993 to 2009, the population of  Le Lake almost 
doubled. From 248,226 to 451,369 souls. The population 
almost doubled from 2009 to 2021. From 451,369 to 
804,165. This is what draws attention to the fact that the 
population of  Le Lac is indeed evolving. It is made up of  
sedentary and nomadic populations. The Kanembou and 
Boudouma are in the majority in the region.

Migrant Population at the Lake 
The Lac is a cosmopolitan region, as its population 
includes several African nationalities (Senegalese, 
Malians, Nigerians, Cameroonians, Beninese, Ghanaians, 
etc.) (Figure 12). Nigerians are the most numerous and 
the most mobile. The Fricans who live in the region are 
attracted by the fishing opportunities on Lake Chad. They 
are concentrated on islands such as Kinaserom, Tetoua, 
Fitiné, Koulfoua, Tchongolé and others. 
As Youssouf  Mbodou Mbami, Bol Township Chief, 
explains: “The islands are heavily exploited by foreigners 



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who engage in intensive fishing and export their products 
to Nigeria. But with fishing no longer profitable, some 
of  the foreign islanders are growing sugar cane and 
potatoes. Others have become lumberjacks. These are 
the returnees and refugees. This foreign population also 
includes Chadians from other regions (figure 4).

The site reserved mainly for Nigerian refugees is located 
12 km from Bagassola, in a locality called Dar Salam. 
According to CNARR, there will be 18,247 people in this 
camp by 2023.
The majority are Haoussa, followed by other ethnic 
groups including Peul, Kanouri, Peul, Boudouma, Arab, 
Kanembou, Margui and Gousa. They have come from 
Baga Kawa in Nigeria and Karaga in Niger. They have 
been in the Dar Salam camp since 2014(Figure 5).

Figure 4: Percentage distribution of  the Lake’s population
Source: Laoro, 2001 and OCHA (2021)

Figure 4 shows that natives account for over 87.98%. 
Other ethnic groups from Chad to the Lake are 
representative at 7.3% and expatriates are at 4.72%.
The population of  the Lac region increased in 2015 with 
the arrival of  refugees, returnees and displaced persons 
(table 2) due to the Boko Haram sect.

Table 2: New migrants in Lake
Migrants Number/Year

2021 2023
Refugees (Dar 
Salam camp)

16 277 18 247

Refugees outside 
camp

12 120

Returnees 30 356
Total 46 633 30 367

Source : OCHA, 2021 and CNARR , 2023

Table 2 shows the number of  new migrants to Lac. 
There are 16,277 refugees. There are 30,356 returnees. 
This gives a total population of  46,633 in 2021, according 
to OCHA. Updated statistics for 2023, according to 
CNARR, give a total of  18,247 refugees in the Dra Salam 
camp and 12,120 refugees outside the camp. This makes 
a total of  30,367 people.
Given Chad’s population growth rate of  3.23% and 
the number of  refugees and returnees to the Lake, the 
population of  the Lake region in 2021 will be 804,165. This 
population has almost doubled in the 20 years between 
2009 and 2021. The growth of  the Lac population has a 
very strong influence on the plant resources of  the Lac 
and Kaya regions.

Characteristics of  Refugee, Returnee and IDP Sites 
and Shelters in Kaya
Three sites shelter refugees, returnees and internally 
displaced persons (IDPs) in Kaya in the Lac region. 

Figure 5: View of  a refugee dwelling and tents at Dar 
Salam (Bagassola)
(Photo: Bayang Sirbélé, 2023) Dar Salam, February 01, 2023 
2021 (N 13°3730.8’’ and E 14°17’50.7’’)

Figure 5 shows, from left to right, a refugee shelter in the 
Dar Salam camp. The shelter is made from a tarpaulin 
and fenced with an aquatic plant from Lake Chad, known 
in the local language as kaye. Opposite this habitat, tented 
houses have been set up in the camp, with financial 
support from the HCR.  
On the other hand, 30,356 returnees and 45,951 internally 
displaced persons are housed in shelters in a village 2 
km west of  Bagassola called Kousseri 1, 2, 3. Most of  
them are Boudouma. They live in dwellings built by 
international NGOs (Figure 6).
Photo 1 of  Figure 6 shows the makeshift shelters 
in Kousseri 3. These shelters are made of  kaye, an 
aquatic grass found in Lake Chad, with a tin roof. The 
shelters were built with funding from the UNHCR and 
implemented by the Chad Red Cross (CRT). Photo 2 
of  Figure 6 shows shelters in Kousseri 2. These shelters 
are still made by kaye with financial assistance from the 
Luxembourg Red Cross, and the project was carried out 
by Boudouma women.
There is an elementary school in the Dar Salam camp. 
The school has a total of  3,055 pupils from CP1 to CM2, 
of  whom 1,625 are refugee children. The school was 
created by the Foulbé community of  Dar Salam in 2010, 
and became official on February 03, 2015. The school is 
run by Mahamat Abakar Adam and 18 other community 
teachers supported by UNHCR. The WFP provides food 
for the children, while UNICEF donates school supplies 
(Figure 7).



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Figure 7 shows the Dar Salam elementary school. It 
shows classrooms and a schoolyard with pupils running 
around and a teacher in a white coat at recess.

Outside the Dar Salam camp, in Kousseri 1, there is also 
a full-cycle elementary school from CP1 to CM2, called 
the “Ecole de la Paix”, with 1,038 pupils, including 
359 children of  displaced persons and 205 children of  
returnees.  The school is run by Mahamat Tchari Ali and 
has 11 teachers (Figure 8).
Figure 8 shows the Peace elementary school in Kousseri 
1. Classrooms are visible, as well as pupils are running 
and others playing soccer during recess.
The three categories of  displaced persons in Lac and 
Kaya, namely returnees, internally displaced persons 
(IDPs) and third-country nationals (TCNs), are mobile 
( DTM , 2019). They have a negative impact on plant 
resources in the Lac and Kaya regions, causing enormous 
damage to these resources.

Degradation of  Plant Resources by Refugees, Returnees 
and IDPs in Kaya
The gradual destruction of  plant resources in the Lac 
and Kaya areas is nothing new, as it is not a recent 
phenomenon. Plant damage is generally caused by 
farmers, herders, etc. in Lac and Kaya. Refugees, returnees 
and displaced persons have now been added to the list of  
people damaging plant resources in Lac and Kaya. The 
most deforested plant species is acaca nilotica, known in 
local Arabic as garate (table 1).
Indeed, given the precarious living conditions endured by 
these vulnerable people and the poor care they receive, 
the activities (farming and livestock rearing) carried out 
by mobile people force them to degrade the vegetation. 
Many of  the refugees, returnees and displaced persons 
have integrated into the socio-economic life of  Kaya by 
growing small millet and beans. Others, on the other hand, 
raise goats and sheep. Both of  these activities contribute 
negatively to the degradation of  vegetation (Figure 3). 
In addition, men, women and children in and outside the 
Dar Salam camp are engaged in the massive destruction 
of  plant resources all around the sites some 1 or 2 km 
away (Figure 9).
Figure 9 shows the cleared area at Kousseri 3. The area 

Figure 6: Returnee and IDP shelters in Kousseri 3 and 2
(Photo: Bayang Sirbélé, 2023), Photo 1: Kousseri 3, February 01, 2023 (N 13°31’35.3’’; E 14°17’35.7’’), Photo 2: Kousseri 2, 
February 01, 2023 (N 13°31’37.3’’; E 14°17’48.0’’)

Figure 7: View of  the pri (school in Dar Salam (Bagassola)
Photo: Bayang Sirbélé, 2023) Dar Salam, February 01, 2023 
2021 (N 13°37’24.4’’ and E 14°17’34.4’’)

Figure 8: View of  the primary school la Paix in Kousseri 
1 (Bagassola)
(Photo: Bayang Sirbélé, 2023) Dar Salam, February 01, 2023 
2021 (N 13°31’57.2’’ and E 14°18’21.7’’)

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Figure 10: View of  bags of  charcoal and firewood at Bagassola market
(Photo: Bayang Sirbélé, 2023) Photo 1. Bagassola market, February 01, 2023 (N 13°32’8.22’’; E 14°18’35.2’’) Photo 2. Bagassola 
market, February 01, 2023 (N 13°32’8.37’’; E 14°18’38.3’’)

shows trees cleared in the vicinity of  the makeshift 
shelters at Kousseri 3. A few trees are still visible in this 
area and have not been cut down.  
Trees are felled to provide firewood, charcoal and 
wood for building sheds (Figure 10). The principal of  
the peace school said that parents use their children to 
degrade the environment, and a refugee at the Dar Salam 
site admitted that during the vacations, children cut 
wood for their parents. The environmental inspector in 
Bagassola reported that migrants play a major role in the 
destruction of  vegetation in Kaya, and urged that their 
living conditions be improved so that they can limit their 
“massacring of  nature” (field survey, 2023).
Photo 1 of  Figure 10 provides information on charcoal. A 
koro of  charcoal costs 300 FCFA and a bag 5,000 FCFA, 
while the photo 2 on Figure 10 shows that firewood is 
still being moved to the Bagassola market by Boudouma 

Figure 9: View of  a cleared area at Kousseri 3 (Bagassola)
(Photo: Bayang Sirbélé, 2023) Kousseri 3, February 01, 2023 
2021 (N 13°31’57.2’’ and E 14°18’21.7’’)

women. A heap of  this wood is sold for 1,250 FCFA.  
International and national NGOs such as HCR, CRT, etc. 
have contributed to the deterioration of  plant resources 
in Kaya by helping to finance the construction of  
shelters for refugees, returnees and internally displaced 
persons. These buildings are generally made from kaye, 
a herbaceous plant that grows in Lake Chad. As a result, 
many people have taken to cutting down these kayes in 
order to raise money. Hence the massive deterioration of  
the kayes in Kaya.

Consequences of  the Degradation of  Plant Resources 
by Refugees, Returnees and IDPs
Disappearance of  Plant and Wildlife Species 
Degradation of  plant resources has had a considerable 
impact, as many plant species have disappeared. In 
addition, there are empty spaces. Trees have been cleared, 
so no agricultural activities are carried out on these 
deforested areas (Figure 11).
Figure 11 shows the deforested area at Kousseri 3. No 
trees can be seen in the vicinity of  the makeshift shelters 
at Kousseri 3. This is because the area is devoid of  trees 

Figure 11: View of  a cleared area at Kousseri 3 (Bagassola)
(Photo: Bayang Sirbélé, 2023) Kousseri 3, February 01, 2023 
2021 (N 13°31’35.4’’ and E 14°17’35.7’’)

due to the deforestation carried out by the returnees and 
displaced persons. 
The deterioration of  the vegetation is forcing the animals 

Photo:1 Photo: 2



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to disappear. They no longer have habitats in which to 
hide. As a result, they are threatened and attacked by 
hunters. As a result, they are forced to flee and migrate to 
areas where they can survive.
Aquatic plants such as the kayes of  Lake Chad should 
provide shelter and breeding grounds for the fish and 
other aquatic animals that frequent the lake’s littoral zone. 
They also provide food for certain aquatic organisms. 
Unfortunately, we have to admit that these organisms will 
no longer have shelter and food, as the kayes have been 
destroyed for humanitarian purposes.

Soil Stripping 
The Lake District boasts a variety of  soils. These soils are 
known as brown or red-brown soils, brown steppic sandy 
soils and salty soils. They are poor and erodible. 
In the Lake District, we can also distinguish between 
soils such as naga (Arabic for sterile), modern polders, 
semi-modern polders, traditional polders or false polders, 
sandy soils and sub-arid brown soils. 
The soils are increasingly bare and degraded today, 
and erodible by the wind as a result of  natural and 
anthropogenic actions.

Agro Pastoral Impacts
As far as human activities are concerned, the effects of  the 
degradation of  the vegetation cover are visible and real. 
Village dwellings are scattered and visible from a distance 
due to the absence of  vegetation. The soil is bare, which 
leads farmers in general and refugees, returnees and internally 
displaced persons to have dune fields on the outskirts of  
villages due to the destruction of  vegetation. This reduces 
the productivity of  cereals and market garden produce. 
Livestock farming is also suffering a fatal blow from the 
degradation of  plant resources. Animals are finding it 
extremely difficult to feed themselves. As a result, they have 
to fall back on dried calotropis procera leaves for food.

DISCUSSION OF RESULTS
Recurrent Droughts at the Lake
Everywhere else, rainfall is the determining factor in 
human activities, as it is an indispensable link in the Sahel 
in general and in the natron area in particular. Rainfall is 
very poorly distributed in the Lake region. Rainfall and 
its intensity are irregular and low. Most of  the time, it 
comes late, leading to droughts (Beauvilain, 1995, p. 8; 
Koumbaye, 1996, p. 19).    

Figure 12: Low rainfall at Ngouri
Source: Climatology Division, DGM/N’djamena, 2018

Figure 13: Low rainfall at Bol
Source: Climatology Division, DGM/N’djamena, 2018

Droughts are frequent in CILSS member countries. In 
the Lac, they are present because the region experiences 
rainfall deficits almost every ten years. In Chad in general, 

and in the Lake region in particular, the drought years 
of  1972 and 1984 justify this. These periods of  drought 
have attracted the attention of  many researchers and 



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governments. To better understand the phenomenon 
of  drought in the Lake region, we can observe the low 
rainfall in Bol and Ngouri to understand the intervals 
of  drought. Rainfall records for 1972, 1987, 1982, 1998, 
2007, etc. at Bol and 1972, 1984, 1987, 1989, 2004, etc. at 
Ngouri are clearly deficient (figures 11 and 12).
Figure 12 shows data covering the period from 1960 to 
2007. This range of  years shows that the lowest rainfall 
was recorded in 1972 (78.6 mm). Low and irregular 
rainfall was also observed in 1984 (114.4 mm), 
1987 (141.5 mm), 1989 (154.5 mm), 2004 (155.1 mm) and 
1996 (161.7 mm). It can be seen that 11972 and 1984 were 
years of  low precipitation. Figure 12 also gives an idea of  
the eight-year low rainfall in the period 1960-2007, with 
an average of  145 mm.
Figure 13, on the other hand, shows the case of  the Bol 
station (1960-2007), with the lowest rainfall in 1972 (62.0 
mm) compared with Ngouri (Figure 12). Low rainfall was 
also recorded in 2007 (80.1 mm), 1987 (102.8 mm) and 
1982 (113.4 mm). The average low rainfall over thirteen 
(13) years is 141.3 mm (figure 13). The irregular rainfall 
observed at Ngouri is also found at Bol. The low rainfall 
in the region has a negative impact on production.

Increasingly Dry and Violent Winds in the Lake Region
Generally speaking, the intertropical zone is the domain 
of  trade winds, including the harmattan or boreal trade 
wind. This is a dry wind that considerably dries out nature. 
It then transports fine particles (sand, silt, etc.), giving rise 
to dry mists. It comes from the Saharan anticyclone. It 
carries winds from the east and north-west of  the Sahara 
to the south-west, and dominates during the dry season. 
According to natron operators, the wind generally blows 
from November to February or March. 
Another type of  wind that prevails in the Lake region is 
the so-called monsoon. This is a moisture-laden maritime 
wind. It moves in the opposite direction to the harmattan. 
of  these two air masses, harmattan is the main cause of  
silting in the natron valleys at Le Lac (table 3).
Table 3 shows that the average wind speed at Mao varies 
from season to season. The average maximum wind speed 
oscillates between 1.6 m/s and 1.9 m/s. The absolute 
maximum wind speed recorded at Mao was 4.7 m/s in 
November 1989. 
Due to the lack of  wind speed data in the Lac region, the 
Mao data were collected in the Kanem region, adjacent 
to the Lac region. In addition, the old data on rainfall 

Table 3: Average wind speed (m/s) for Mao
Année J F M A M J J A S O N D T
1970 2,1 2,5 2,3 2,3 2,0 2,0 2,0 1,6 1,9 2,3 2,5 2,6 2,2
1971 2,4 2,4 2,3 2,3 2,2 2,3 2,2 1,6 1,7 2,3 2,6 2,7 2,3
1972 2,2 2,7 2,7 2,0 1,9 1,9 1,9 2,1 1,9 2,1 2,8 2,5 2,2
1973 2,5 2,5 2,7 2,4 2,4 2,1 2,3 1,7 1,9 2,3 2,9 2,5 2,4
1974 3,1 2,8 2,8 2,1 2,3 2,3 2,1 1,7 1,8 2,0 2,6 2,7 2,4
1975 2,6 2,3 2,4 2,1 2,0 2,2 1,9 2,0 1,8 2,1 2,2 2,6 2,2
1976 2,3 2,5 2,2 2,3 2,0 2,1 2,2 2,0 1,6 1,8 2,1 2,2 2,1
1977 2,3 2,8 3,2 2,4 2,0 2,1 2,3 1,6 1,6 2,2 2,1 2,4 2,3
1978 2,2 2,1 2,4 1,9 1,8 2,1 2,1 1,6 1,6 1,5 2,1 2,1 2,0
1985 3,0 3,2 3,5 3,0 2,9 2,2 1,9 2,1 1,8 2,0 2,1 1,9 2,5
1989 3,1 3,3 3,9 2,2 2,2 2,7 2,7 2,4 1,8 3,6 4,7 3,8 3,0

Source : DGM of  N’Djamena (2019)

and temperature are due to the lack of  data data available 
from the General Directorate of  Meteorology.

CONCLUSION 
Ultimately, the study concludes that the destruction of  
the ecosystem is generally caused by man and by Nigerian 
refugees, Nigeriens, returnees and internally displaced 
Chadians, who are directly involved in modifying the 
plant landscapes of  the Lac and Kaya in a very significant 
way. This is to harvest firewood, charcoal, etc., leading 
to deforestation associated with human settlements and 
their expansion.
However, as this ecosystem is degraded, the consequences 
for mankind are far-reaching. For farmers and shepherds 
in Lac and Kaya, this degradation of  plant resources has 
a considerable impact on cereal and pastoral production.

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