Impact of Climat Change and Human Activity on Water Quality of Babar Dam, Algeria
Aissam G* and Abderrahmane B
Laboratory of Applied Research in Hydraulics, University of Batna, Algeria
Submission: February 13, 2018;Published: June 26, 2018
*Corresponding Author: Aissam G, Laboratory of Applied Research in Hydraulics, University of Batna 2, 05 078. Fesdis-Batna, Algeria,
How to cite this article: Aissam G, Abderrahmane B. Impact of Climat Change and Human Activity on Water Quality of Babar Dam, Algeria. Civil Eng
Res J. 2018; 5(4): 555669. DOI:10.19080/CERJ.2018.05.555669
The quality of surface water has in recent years, a deterioration largely due to a climate change. The objective of this study was to evaluate the impact of a long drought and human activities on water quality in a dam of eastern Algeria, the Babar. To achieve this, a study of the composition of the waters of the dam using the method of trends was performed. The results show that the water has a calcium-magnesium-sulfated facies. They show that most parameters follow negative trends, with the exception of K (41.56%), NO2 (5%) and NO3 (35.62%). The use of potash fertilizers and the discharge spills of village waste directly into the dam basin without any prior treatment leads to an increase in K. The increase in NO3 is mainly due to fertilizer and nitrification of ammonium (-61%), which was accompanied by a decrease in the levels of dissolved oxygen (-7.5%). The decrease in the orthophosphate content (-80%) is due to its low mobility on the one hand, and to the removal of phosphorus on the other hand by the processes of mechanical erosion from the adsorption of the latter by the soil colloids. This approach has shown that drought and anthropogenic activity have a negative impact on the quality of surface water.
In the face of climate change that has hit the world in recent years, The quality of surface water has also been a major deterioration due to agricultural, urban and industrial development. Many water quality variables are subject to large fluctuations in space and time and understanding these fluctuations in the environment can be a difficult task . The factors of natural influence may be due to changes in precipitation, erosion, alteration of the materials of the earth’s crust or else they are due to anthropogenic action such as urban, industrial and agricultural activities as well as excessive exploitation of water resources . These factors work together to create a type of water whose chemical composition varies in space and time . In addition, in river monitoring, it is often necessary to determine whether a variable should be attributed to natural or anthropogenic causes . According to Hamzaoui-Azaza et al. , knowledge of the geochemical evolution of water quality could lead to effective management of water resources. Thus, the quality of the water is just as important as the quantity. Several studies around the world [6-17] and in Algeria [18-30] are reported on the effects of agricultural, industrial and urban effluents on the quality of surface water. Wadi El Arab controlled by Babar Dam, was built for the supply of potable water and the supply of industrial water and irrigation. The water stored in the basin of this dam is deteriorating in quality due to different types
of pollution, in addition to the natural processes of erosion and leaching of various toxic elements. A physicochemical analysis program which has made it possible to build a data bank, which should be analyzed, and to detect significant trends. This study therefore presents details of the fluctuations in the chemical composition of the water of the Babar dam between January 2013 and March 2016. This work makes it possible to understand the hydro chemical behavior of the surface waters of the dam. The trend analysis applied here is determined by linear regression, using the least squares method following the time series of the water quality parameters, it is a simple and easy method to implement.
The study area is located in the south-east of Algeria, in the eastern confines of the Saharan Atlas and precisely in the mountain range of Djebel Djehfa belonging to the Nememcha Mountains. Most of the inhabitants (more than 20,000 inhabitants) are concentrated in the city of Babar. The surface of the subwatershed is 567km2, the dam of Babar has a capacity of 42Mm3, built to retain the waters of Oued Tamagra in the West and Oued El Htiba in the East. The Babar Dam is located at 35° 10 ‘10’’N and 7° 01’41’’E and the town of Babar is located at 35° 10’4’’N and 7° 06’7’’E (Figure 1). An increase in the population and inadequate domestic sewer
systems have potential to influence the water quality of the dam.
The Wadi El Arab provides water for nearby cities and irrigates
thousands of hectares of farmland. The increase in water demand
at the development stage, including agriculture, could lead to a
bleak future for the water quality of the dam.
The trend method was applied to the physicochemical data of
the surface waters of the Babar dam during the 39-month period
from January 2013 to March 2016. This method allows to acquire
representative data on the spatial and temporal variability of the
surface water quality of the Babar Dam on Oued El Arab. For this,
we used the data of physico-chemical analyses, carried out by the
National Water Resources Agency (ANRH) of Constantine. The
measured parameters are determined by the ANRH such as: PH,
suspended matter (MES), electrical conductivity of water (CE),
surface water temperature of Babar Dam reservoir (T), turbidity
(crude), organic matter (MO), calcium (Ca2+), magnesium (Mg2+),
sodium (Na+), potassium (K+), chlorides (Cl-), sulphate (SO4 2-), bicarbonate (HCO3
-), nitrate (NO3 -), nitrite (NO2 -), ammonium (NH4 +), Orthophosphate (PO4
3-), biological oxygen demand in Five days (DBO5), chemical oxygen demand (DCO), dissolved oxygen
(O2 dis), variation of the water reserve at the deduction level (VR).
This technique was applied to the instantaneous monthly physicochemical
data of the Babar Dam, during the period from January
2013 to March 2016 using the Excel 2007. And which constitute
a chronological series of 39 analyses and 21 variables (Table 1).
In this study, we will effectively present trends in physicochemical
parameters using a linear regression method. It is a
model based on linear least squares equations. Whatever the
case, three trend classes have been defined: ‘+’ if a positive trend is
detected; ‘0’ if no significant trend is detected; and ‘-’ if a negative
trend is observed. The use of this technique thus makes it possible
to highlight the possible effects of anthropogenic pollution in the
long term. . This goal is also achieved using the moving average
that allows a smoothing that eliminates seasonality and minimizes
background noise . The method consists in calculating the
moving averages by choosing as length, the period of seasonal
variations, so as to make them disappear.
An examination of the standard deviation and coefficient of
variation shows that (Table 1):
• Water, pH, DCO, NO2, NO3, HCO3, Ca and O2 dis have a small variation (<20%);
• MES, MO, DBO5, NH4, SO4, Cl and Na show a variation around the average oscillated between 20 and 40%;
• The rest of the elements (Turbidity, CE, PO4, Mg and K)
show a strong variation around the average (>40%).
These strong variations resulting from the effluents and the
leaching of the grounds following torrential precipitations, badly
distributed especially in the time.
The examination of these data also shows that the
concentrations of the various elements are below Algerian
standards with the exception of:
• SO4 where 66.6% of the data exceed the standard during the study period;
• NO2 where 5.12% of the data exceed the standard.
• Turbidity where 36.46% of the data exceed the standard.
With maximum values recorded during the year 2013.
• MES where 35.89% of the data exceed the standard. It
has a similar evolution as turbidity.
The Piper diagram for these waters shows that the samples
have a sulfated-calcium to magnesium facies (Figure 2). The first
of the things we noticed between the first campaign (October 2007
to April 2008) and the second campaign (January 2013 to March
2016), no changes were made to the chemical characteristics of the
dam’s waters. According to Faurie  and Durand , calcium
can come from inputs of nitrogen fertilizers that participate in the
dissolution of carbonates according to the equations 1 and 2 .
NH4+ + 202↔ N03- + 2H+ + H20 (1)
CaC03 + H+↔ Ca24 + HC034 (2)
The global equation (3) can be written in the following way:
According to the relationship (3), the molar ratio between Ca2+ and HC03- when nitrification is 1, Whereas, according to equation (4), the molar ratio Ca2+/HC03- is equal to 2, when the dissolution of Carbonates is in association with atmospheric CO2.
CaCO4 + H20 + C02 ↔ 2HCO3- + Cam2+ (4)
The surface waters of the Babar dam have a molar ratio Ca2+/
HCO3- between 1 and 1.5 in 72% of cases and an Mg2+/HCO3- ratio
are <1 in 100% of cases. This corresponds to the proportion given
by equation (3). So the increase of Ca2+ and Mg2+ in the water
of Babar Dam during the period from January 2013 to March
2016 can be due to the contribution of fertilizers that causes the
dissolution of carbonates.
The linear trend was determined using instantaneous
concentrations and time Table 1. The initial and final average
values for the period considered allowed us to calculate these
variations. It can be seen that for most parameters, the slope
differs significantly from zero with the exception of pH, O2 dis, T
°C, Ca and NO2, where the slope is respectively -1.24, -7.5, +2.69,
+5 and -4.29. All other parameters have a positive slope that
varies between +10 and +108%.
The trend line of the temperature is stable with a very low
slope of 2.96%. This small increase is probably due to climate
change. The slope of the pH trend line is slightly negative (-1.24%).
This reflects the presence of low concentrations of organic matter,
where the increase in CO2 pressure leads to a decrease in pH
according to the formula proposed by Kempe  (5). The salinity
of the water represented by the electrical conductivity, it records
a negative trend of (-17.57%), this is due to the increase of the
volume of water in the dam during the period of sampling.
C02 + H20 ↔ H2C03-↔H+ + HC03- (5)
The carbonate elements have a slope that differs significantly
from zero. They recorded negative trends ranging from -4.29%
for (Ca2+), -18.95% for (HCO3-) and -44.37% for (Mg2+). These
tendencies are related to the equilibrium state of the various
minerals in the water and the increase of the water volume of the
dam. These variations in carbonate parameters contributed to the
decrease in global salinity (CE) by -17.57% and a drop in pH of
-1.24% (Figure 3).
For most salt elements, trend analysis showed a negative
slope ranging from -34.21% for (Cl-), -22.04% for (Na+), -13.10%
for (SO4-2). On the other hand, a positive trend was recorded for
K+ (+41.56%) (Figure 4). These trends are related to the increase
in the water volume of the dam which allows a dilution of the
different chemical elements. On the other hand, the use of potash
fertilizers and the discharge of wastewater from the villages
directly into the main watercourse, lead to the increase of K+.
The salinity of water is represented by the electrical
conductivity and the variation of this parameter makes it possible
to follow the evolution of the global salinity and the chemistry
of the water. In the long term, there was a decrease of -17.54%,
due to the increase in the volume of water in the dam. Salinity
can have two origins, either carbonate or salt. To determine this
origin, we established the ratio Ca2+ + Mg2+ + HCO3-/Na+ + Cl- + SO42- vs CE. The ratio Ca2+ + Mg2+ + HCO3-/Na+ + Cl- + SO42-<1. This reflects the influence of salt minerals on salinity (Figure 5). The increase in the content of the salt elements allows the increase of
the salinity. This resulted in a negative trend in the Ca2+ + Mg2+ +
HCO3-/Na+ + Cl- + SO42- vs CE relationship.
The electrical conductivity of the different samples shows a
good correlation with the elements (Na, Ca, Mg, SO4, Cl) with a
correlation coefficient of (0.34, 0.27, 0.43, 0.68, 0.4). These strong
correlations indicate the direct contribution of these elements in
the salinity of the surface waters of the dam. By tale, potassium
(R = -0.1) and bicarbonates (-0.11) do not seem to influence too
much the salinity of the water. The dissolution of the carbonated
and evaporated minerals is done according to the reactions (6 to 11). .
pH and dissolved oxygen showed a respective negative trend
of -1.24 and -7.5% Table 1. The oxidation of the organic material
according to the reaction 12 or the increase of the CO2 pressure
lead to a decrease in the pH according to the formula 13 proposed
by KEMPE .
CH20 + 02 ↔ CO2 + H2O (12)
C02 + H20 ↔ H2C03 -↔H+ + HC03- (13)
The negative trend of MO (-24.52%) is in line with the trend
of the MES (-42.81%), DCO (-11.08%) and that of the DBO5
(-38.33%). This can be explained by the installation of conditions
of degradation of organic matter by microorganisms. This
degradation was accompanied by a decrease in dissolved oxygen
of (-7.5%) and a decrease in pH (-1.24%).
Data analysis shows a positive trend for NO3
- (35.62%), NO2 - (5). This is mainly due to the development of intensive agricultural
production upstream of the dam and urban discharges  into
the main stream without any prior treatment. Moreover, this
gradual increase in NO3- concentration corresponds to the yield
of nitrification, in the presence of oxygen aerobically according
to the reactions (14) and (15) . This oxidation allowed a
decrease of oxygen of -7.5%.
NH4+ + 3/2O2 + H2O → NO2 + 2H3O+ (14)
NO2 - + ½O2 → NO3- (15)
This positive trend is also related to the use of fertilizers on
these agricultural soils, this has been evidenced throughout the
world by El Achheb , Fischer et al. , Grenz et al. , Travi
et al.  and in Algeria by several authors like Boudoukha et al.
. Indeed the form of nutrient is very toxic for both man and
the aquatic world. This explains why the release of nitrogen in this
form poses a potential risk to the environment .
The phosphorus trend (-80%) does not follow the same
trend as nitrates and nitrites, this situation can be explained
by the immobility of this element on the one hand, and on the
other hand, the elimination of phosphorus by mechanical erosion
processes from adsorption of the latter by soil colloids [33,43]. It
can also concern the regulation of phosphorus concentrations in
Wadi waters by several biogeochemical processes such as apatite
precipitation [(PO4)3 (F, Cl, OH) Ca5]  and consumption by
aquatic plants [45-48].
Looking at the trend line shows a positive trend (+3.41%),
as the inputs represented by precipitation are greater than the
outputs represented by evaporation. The analysis of the evolution
of the volume of water according to the various hydrochemical
parameters shows a very significant linear correlation between
the volume of water and the parameters with a stronger negative
bond (-0.35 to -0.81) for (MES , EC, DBO5, SO4, DCO, Mg), a weak
negative bond (-0.001 to -0.21) for (pH, MO, NO3, Na, Ca, NH4, PO4,
Cl) and for the rest positive bonds were recorded such as HCO3-
(0.129), NO2 (0.22) , K (0.51), O2 (0.06). On this basis, it is noted
that most of the bonds are significant at the threshold of 10%,
except (pH, NO3, Na, O2) which highlights either a phenomenon of
dilution or concentration depending on the case.
The temporal evolution of physicochemical parameters
was monitored during the 39-month period. The results show
that most of the parameters follow negative trends, with the
exception of K (41.56%), NO2 (5%) and NO3 (35.62%). The use of
potash fertilizers and the dumping of village waste directly into
the dam basin without any prior treatment leads to an increase
in K. The increase in NO3 is mainly due to fertilizer input and
ammonium nitrification (-61%), which was accompanied by
a drop in dissolved oxygen levels (-7.5%). The decrease of the
orthophosphate content (-80%) is due to its low mobility on the
one hand, and the elimination of phosphorus on the other hand by
the mechanical erosion processes from adsorption of the latter by
the colloids of the soil.