Abstract

Generally speaking, there has been a consensus on the primary drivers of anthropogenically induced environmental degradation. However, little progress has been made in determining the magnitude of these impacts, particularly in developing countries. The aim of this study therefore, is to ascertain, the degree of anthropogenically induced environmental impacts on the Niger river in high Guinea. The results show that only three variables; population, anarchistic exploitation and urbanization were statistically significant and that the regression model accounts for 60% of the variation in the environmental impacts. Moreover, the degradation of water quality is a significant problem for the Niger river in high Guinea. The growth of large cities along the river’s banks has not been accompanied by development of wastewater collection and treatment plants, be it for domestic or industrial wastewater. We established, a water sampling protocol for the soil and climate conditions found in high Guinea that would allow us to analyze concentrations (parts billion^-1) of trace elements and TSS in the waters of the Niger river. The enrichment factor calculated for these trace elements compared with international standards allows a preliminary estimate of contamination from anthropogenic sources. The primary causes of degradation are to be sought in a strong entropic pressure on the anarchistic exploitation of the renewable and non-renewable natural resources, which have been worsened by the past 25 years of dryness. Mining, fishing, animal husbandry and other aspects of agriculture, appear among the main causes of environmental degradation.

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INTRODUCTION

The idea that population growth affects environmental resources and human welfare is as old as civilization. Population has been recognized as one of the key driving forces of environmental change bringing along economic activities such as, technology, politics and economic institutions, as well as varied attitudes and beliefs (Dietz and Rosa, 1994).

There is no doubt that population development and environmental quality are interconnected. This fact is expressed by a fundamental identity formulated by Ehrlich et al. (1971), who stated that the number of people living in an area determines the level of environmental degradation, due to such factors as their anarchistic exploitation of resources and the implementation of technology. This implies that the magnitude of the human induced threat to the ecosystem and banks of the Niger river is linked to human population size and resource use per person. In turn, resource degradation is accelerated by population growth due to rising levels of per capita income, consumption habits, technological development, social organization and resource management (Nwafor, 2006; Ignatius, 2009). As aptly put by Rosa et al. (2004), an unintended consequence of industrial development and the simultaneous rapid growth in both population and economic out put per capita has caused the unprecedented growth in global environmental impacts.

Environmental damage threatens all humanity although, people living in developing countries are often the most vulnerable to its effects. This is due to the fact that a large proportion of the population is directly dependent on primary economic activities for their survival and well being. In Niger river Basin for instance, is known for its rapid population growth and concentration of people in few localities. This has strained the traditional system of: agriculture, hunting and fishing anarchistic, bust fires, mining and brick production, resulting in environmental degradation. Furthermore in the attempt to diversify the economy, rapid industrialization has taken place in the country without adequate consideration given to environmental concerns (Nwafor, 2006). There has also, been a concentration of both population and economic activities in some states at the expense of others with the former experiencing pressure on environmental resources. These account for the linkages between population density, anarchistic exploitation of resources and environmental degradation on the Niger river (Sadoff and Grey, 2002).

There is evidence to show that some aspects of human well being can be improved with minimal environmental impacts. For instance, Dietz et al. (2007) has shown that although urbanization, economic structure, age distribution and life expectancy are among the anthropogenic drivers of environmental impacts, they have little or no effect on environmental degradation. This, according to them is because findings suggest that while, increasing affluence does drive impacts, it is possible to improve on other aspects of human well being without adverse environmental effects. A pertinent issue therefore is whether, this situation is the same in Guinea and other developing countries. A doubt has however been raised in this regard by Rosa et al. (2004), who argued that despite the pivotal role human factors play in environmental degradation, uncertainties and contradictions about them persist. Against the foregoing, the aim of this research is to determine the strength and direction of anthropogenic drivers of environmental change on the Niger River in high Guinea. This is necessary because as noted by Dietz et al. (2001), although, there appears to be scientific consensus on the primary drivers of anthropogenic environmental degradation for well over a decade, little progress has been made in determining the precise relationship between drivers and impacts.

This creates a gap in knowledge, which constitutes a significant barrier in identifying policies that have the most potential for reducing human impacts on the environment. According to Nwafor (2006), the filling up of such a knowledge gap will enable policy makers, project proponents, environmental authorities and other stakeholders to fully appreciate environmental concerns and give them due weight. More importantly, the study is significant because it elucidates the applicability of environmental impact.

MATERIALS AND METHODS

The data for this study were obtained from three sources. The population data were obtained from the general census of the total population and distribution by sex: estimate 2007, while the data for the water flow in the basin, average height of water per day and TSS were obtained by researchers documented calculations. Finally, the data for the number of industrial establishments were obtained by using the following apparatuses: GPS Magellan, Apparatus of photography, Dictaphone and surveys through closed questionnaires (2007). It should be noted that the Niger River Basin in high Guinea is divided into 7 prefectures. Accordingly, the data were all aggregated for the 7 prefectures and the capital Conakry. The altitude, the heights and the instantaneous flows of certain tributaries were determined, as well as the number of brick production furnaces and all these data were reported by means of tables. In short, the localization was carried out each time after a documentary exploitation near the prefectural, communal authorities and the local community. The characteristics of banks and of modern and artisanal mining along the rivers above made it possible to confirm their current level of degradation.

RESULTS AND DISCUSSION

The Niger River Basin area in high Guinea, stretching from the highlands of Guinea down to the delta in Nigeria, represents about 4% of the total area of the basin (Fig. 1). However, the basin is a spinal column for the economy of Guinea. Communities living within and around the basin are heavily reliant on the environmental products and services provided by the river, which also supports 243 fish species (including 20 endemic species) and provides vital stop-over sites for millions of migratory birds.

Major environmental degradation in the Niger River Basin results from either natural or anthropogenic causes. Natural causes relate to climatic variability and change, in particular the decrease in rainfall in the basin since, the late 1970s. The major anthropogenic cause is land degradation via deforestation, which has taken place in the watershed in large part because of increased demographic pressure (Andersen et al., 2005).

Four principal environmental issues; land degradation, water degradation, deforestation and biodiversity loss have a synergistic effect on water resources in the basin. Land degradation in the form of erosion results from inappropriate agricultural practices, such as bush fires also termed slash and burn in an attempt to clear fields for rice paddies and other extensive cultivation as well as overgrazing, which leads to the reduction of wetlands through drainage (Table 1a and b). Water degradation, mainly the deterioration of water quality, results from point-sources such as pesticides and fertilizers used in agriculture and from non-point-sources such as urban pollution generally through lack of sanitation infrastructure (sewerage). Deforestation is the result of increased needs for energy and limited access to electricity; people in the Basin use wood and charcoal for domestic purposes (which also, contributes to land degradation). Biodiversity loss is caused by habitat destruction and a subsequent increase of invasive species, which are in turn caused by inappropriate fishing practices, deforestation and land conversion for agriculture.

 

Fig. 1:	The Niger River Basin in high Guinea

 

 

Table 1a:	Agricultural production 2000

 

 

Table 1b:	Agricultural production 2001

 

It is necessary to also, note the mining, which may attack the ground, under ground and vegetable cover, the aggression of the banks and the heads of sources (Fig. 2-4).

This thorough degradation of the ecosystems of the catchment area of Niger River led to the disappearance or reduction of certain animal and vegetable species.

 

Fig. 2:	Diamond mining site from Foulifimba (Sonaferiya) Banankoro to Kerouane; lack of rehabilitation of the grounds has contributed to the vast level of soil erosion

 

This has affected the quality, the quantity and the availability of the biological diversity of these ecosystems to be preserved.

 

Fig. 3:	The depredated banks of the Milo river

 

 

Fig. 4:	Mud tank of Slams Dam, Factory DMS AREDOR on the new banks of the new bed of baoule (Milo) several times moved for the industrial exploitation of diamond to Gbenko, Korean Detruisant thus of the watery ecosystemand and decreasing the flow of water in the river

 

These reductions and disappearances also caused problems of poverty to the communities who are the users of these resources (Koranteng, 2001).

The booming population growth is the main cause of the environmental degradation, due to human activities such as: the construction of houses and factories and agricultural activities (York et al., 2003). Therefore, a combination of human population growth (on average 3% year^-1), unsustainable resource use and development and decertification is threatening the Niger River’s ecosystems ability to supply critically needed natural resources to the people of Niger Basin in high Guinea. River flow in the basin is decreasing and fishing pressure is increasing, leading to drastic declines in production of fisheries. Deforestation and farming of fragile soils contribute to erosion through sedimentation in river channels. Waterborne diseases have increased and invasive aquatic species have spread, choking river channels.

Indeed, this situation resulted in a generalized and accelerated impoverishment of bordering populations. In our investigation concerning the brick production evaluation, we found that the Niger River basin experienced population increase of >50% between 1990 from 1,286,000, 000 inhabitants to 2,242,718 inhabitants in 2007 (Table 2).

 

Fig. 5:	Average annual flow rate of Niger River: four main branches in 1990 and 2007

 

During recent decades, civil war and unrest in several countries that border the Niger Basin have made it the recipient of large numbers of people displaced by violent conflict, adding pressures and stresses to already fragile lands. For example, in 2003 >25,000 refugees settled in the Fouta Djallon and Mount Nimba regions of Guinea. This led to increased degradation of the highlands, with rapid deforestation and associated land degradation, soil erosion, gullying and loss of productive lands. Loss of absorption capacity causes rapid runoff, with the consequences downstream of high sedimentation, siltation of existing infrastructure, floods and changes in river flows (Gans and Jost, 2005).

The anarchistic exploitation of the resources of the basin slopes and the effect of the natural phenomena led to a trend in reduction flows, heights and instantaneous speeds of these rivers. This is why nowadays the majority of these rivers tare for the period of low water level contributing to the total degradation of the quality of the hydrous resources, principal resource of provisioning of the populations of drinking water and resources holidic (Fig. 5 and Table 3-7).

Thus, one observed on Syncaryon this case of rather significant variations of flow over a period of approximately 20 years. The annual average, which was of 340 m³ sec^-1 (1973-1980) has gone down to 190 m³ sec^-1 (1980-1989) which indicates a reduction of about 50% of the total flow (Bamba et al., 1996).

Figure 2 shows, the variation of the number of brick furnaces within the 7 various prefectures of the Niger Basin in high Guinea. This economic activity has a very disastrous impact on the current state of the degradation of the river’s banks. Collected statistics of this activity give us an idea of the width by area. It is also, at the base of the widening of the beds of the rivers by the loam pits open on the banks whose widening reaches 10-15 m place^-1. It contributes to the destruction of the forest by the wood cut for the cooking of bricks (Fig. 6-8).

The results also, show that at any of the stations of the upper basin, titanium, aluminum, iron, zirconium, other yttrium, strontium, lead, uranium and vanadium can be considered as earth elements, coming from the weathering of silicate rocks. These elements are correlated to one and to Total Suspended Solids (TSS) (Andersen et al., 2005). According to Ahearn et al. (2005), population density also contributed to TSS loading, which has an impact on water quality.

 

Fig. 6:	Furnaces with brick (cooked) number Variation from 1990-2007

 

 

Table 2:	Total population and distribution by sex: estimate 2007
These data are drawn from the general census of the population and the habitat (1996)

 

 

Table 3:	Results of attitude, hight evarge per day and flow of catchment area

 

 

Table 4:	Contains the monthly average values of the flow of the tributary rivers of the catchments area of Niger in the 2007
Author’s research

 

 

Table 5:	Mean monthly flows at the four main branches of the Niger River in Guinea (cubic m sec-1)
Andersen et al. (2005)

 

 

Table 6:	Monthly and annual flow of the Milo at Kankan (high Guinea) from 1947-2000 (cubic m sec-1)
Andersen et al. (2005)

 

Indeed, enrichment factors for strontium are very significant at Banankoro (Table 8).

Fertilizers used have an impact on water quality as nitrate contaminate water. The impact of cotton farming in high Guinea on wells, pasture and surface water in the Syncaryon, Milo, Niger, Niandan, Tinkisso watershed was studied. Traces of pesticides were found, but not in significant amounts. Nitrates, nitrites, phosphates and ammonia were consistently present at several sites, sometimes over the maximum allowed limits. Thus, it is becoming acknowledged that water is likely to be the most pressing environmental concern of the next century (Wolf et al., 1999).

In the past 20 years, Guinea has experienced intense exploitation of its gold resources and currently produces tonnages per year in Siguiri, Kouroussa and Mandiana.

 

Table 7:	Niger River monthly and annual flow at siguiri (high Guinea) from 1950-1999 (cubic m sec-1)
Andersen et al. (2005)

 

 

Table 8:	Annual discharge of TSS in the Niger to Banankoro (high Guinea)
Andersen et al. (2005), TS (transport specifique) is the annual discharge of TSS divided by the basin area

 

Gold development has contributed to several environmental problems and in particular those pertaining to water resources. In the gold mines these environmental problems are usually caused by accidental pollution and by illegal siphoning. Studies have indicated that >1 million litters of cyanide have been spilled into the environment (Fig. 9). In addition to gold development; the exploitation of other mineral resources is an environmental threat in the basin.

 

Fig. 7:	Bricks production (cooked) of the banks of Milo contributing to the river environmental pollution and the stranding of Niger and its affluents to Kankan

 

 

Fig. 8:	Loam pit for bricks at the edge of the Milo River in Kankan widening the bed of the river

 

 

Fig. 9:	Sight of the basin of leaching in heap by cyanide of the industrial exploitation of gold often overflowed on the banks of koba with Koron by the SAG with Siguiri (Destroying the ecosystems in the Niger River)

 

CONCLUSION

This study has firmly established that population and anarchistic exploitation of resources are the most important drivers of environmental impacts on Niger River Basin in high Guinea.

It has also shown that urbanization influences environmental change in Guinea on the Niger River although its effect is negative; implying that modernization, which is associated with it brings about a reduction on environmental impacts. The negative influence of urbanization in Kankan and Siguiri, the more urbanized prefectures in the Niger Basin were found to have higher environmental impacts because of the cumulative effects of other drivers of environmental change namely population, anarchistic exploitation of resources, which captures the effect of population density as well as the technological impact.

The implication of the findings on the environment sustain ability on the Niger River in high Guinea is that appropriate measures should be put in place to reduce the impacts of the anthropogenic drivers on the environment. In addition, the substantial amount of the technological impact on the environment requires that urgent attention be paid on the measures to improve on the efficiency exploitation of gold in Guinea. This will help reduce the deterioration of the water quality in the Niger Basin.

Within sight of these degradations and taking into account the fact that among the rivers, some are trans-border it is time to make provisions allowing a rational and durable exploitation of these basins slopes and their resources in the interest of all the generations.

How to cite this article:

Ibrahima Sory Cisse and Jiwen Ge. Anthropogenic Impacts on Niger River Basin Environment in High Guinea.
DOI: https://doi.org/10.36478/erj.2009.127.135
URL: https://www.makhillpublications.co/view-article/1994-5396/erj.2009.127.135