LARHYSS Journal

10

Authors: KAHOUL M., TOUHAMI M.

Chemical pollution of water becomes today a public health concern. Indeed, many water-borne diseases are due to the presence of natural or synthetic chemicals, and for this, the use of water or for food hygiene requires excellent physico-chemical and microbiological quality. To contribute to quality control of water intended for consumption in the city of Annaba (Algeria), our study focused on the evaluation of the physico-chemical quality of water in this region which has very significant water resources both surface and underground. The analyzes were performed according to standard methods on several samples at three sites in the city and involved temperature (T°), pH, electrical conductivity (EC), total hardness(TH), nitrate (NO3), calcium (Ca) and chloride (Cl-). By comparing the obtained results to algerian and international standards, it appears that most of the physicochemical parameters are normal and thus the quality of controlled water is relatively well.

11

Authors: SAADI S., KHATTACH D., EL KHARMOUZ M.

The urban waste produced by Oujda city, mixed with solid waste of industrial and hospital origin, was disposed since 1990 until 2005 on an open-air landfill situated approximately 7 km southeast of the city center. The groundwater circulates deeply (25-30 m) in grounds post-Miocene on an impermeable substratum formed by the marls of Miocene. The ground is calcimagnesic not very deep, with a more or less important layer of silts and clays. To evaluate the impact of the leachate resulting from this landfill on groundwater quality, samples of leachate and groundwater were taken during the year 2005 (five samples of leachate inside the landfill) (three groundwater samples were taken from three wells located near the landfill) and two profiles of recognition by electric imaging were realized according to the device pole–pole two dimensional (2D) inside the landfill. The analyses of the sample leachate revealed strong content of Chemical oxygen demand (COD max = 30760 mg/l), biodegradable organic matter (DBO5 max = 653.3 mg/l) and of mineral matter (conductivity: max = 63.73 mS/cm). The analysis of groundwater revealed that NO3- presents an average concentration higher than 50 mg/l (Standard suggested by WHO). The concentration of chloride exceeds 1450mg/l (Standard suggested by WHO is 600 mg/l for fresh waters). Concerning heavy metals, the concentrations of Iron, Zn and Ni largely exceed the French values standards fixed for groundwater, while the Cd contents are lower than this standard. The results of the geo-¬¬¬electric prospecting showed that the very low electric resistivities (5 ohm.m), were observed in the inside and in the direct approval of the landfill site. These results highlight zones electrically very conductive, they indicate the progress of the pollution plume in the under ground. The central part of the landfill site is the place under which the contamination affected depths of 20m. These data plead in favour of a strong mineralization of waters circulating in the trainings approached the site, whose potential source is bound to a contamination by leachate very mineralized and charged in organic matter.

12

Authors: HANNACHI A., GHARZOULI R. , DJELLOULI TABET Y.

Water is a limiting factor in the development of agriculture; scarcity is understood in terms of water stress and irregularity of the resource, two factors likely to increase with climate change. Face the challenge of ensuring the coverage of water needs for agriculture in Algeria , an active political mobilization of water resources has been implemented , as well as new management tools is the reuse of wastewater in agriculture . In Algeria, the presence of specific discharge standards for wastewater reuse in agriculture (Executive Decree n ° 93-160 of 10 July 1993 and Executive Decree No. 06-141 of 19 April 2006) and the presence of regulations fixing the modality wastewater reuse and the list of crops and their conditions of irrigation by treated wastewater (Executive Decree No. 07-149 of 20 May 2007 and the ministerial decree of 2 January 2012) is a promotion of projects reuse of treated wastewater. Leaders, public and private, have to make decisions on wastewater reuse in agriculture. They are faced with the need to exploit increasing amounts to meet ever greater demands. Integrated management of treated wastewater in Algeria, now institutionally recognized as a model of public- private partnership is the best approach to development and an effective and sustainable management of treated wastewater in the face of increasing water demands.

13

Authors: LAKEHAL M., ACHOUR B.

Normal depth plays a significant role in the design of open channels and in the analysis of the non-uniform flow as well. Currently, there is no analytical method for calculation of the normal depth in open channels, including the egg profile. Current methods are either iterative or approximate. They also consider, unreasonably, Chezy’s coefficient or Manning’s roughness coefficient as a given data of the problem, despite the fact that these coefficients depend on the normal depth sought. In this study, a new analytical method is presented for calculating the normal depth in an egg shaped conduit. The method takes into account, in particular, the effect of the absolute roughness which is a readily measurable parameter in practice. In a first step, the method is applied to a referential rough model in order to establish the relationships that govern its hydraulic characteristics. In a second step, these equations are used to easily deduce the required normal depth by introducing a non-dimensional correction factor. A practical example is considered to better explain the advocated method and to appreciate its simplicity and efficiency.

14

Authors: LARAKEB M., YOUCEF L., ACHOUR S.

The aim of this study is to test the efficiency of adsorption of zinc by use of goethite and an Algerian bentonite (bentonite of Maghnia). Adsorption tests are conducted in synthetic solutions of distilled water. The results showed that fixation of zinc (5 mg/l) on both adsorbents (1 g/l) is fast. Using the goethite, a removal percentage of 18 ℅ zinc was obtained after an equilibrium time of 30 minutes. After 20 minutes of stirring, the zinc removal by Maghnia bentonite was maximal with efficiency equal to 98,24 ℅. Removal efficiency of Zinc is improved with the increase of the dose of the adsorbent (0,1 to 8 g/l). Removal efficiencies decrease with the increase of the initial content of zinc (2 to 20 mg/l) and are interesting at basic pH. The adsorption tests showed that the Maghnia bentonite was more efficient than goethite, whatever the studied reaction parameter.

20

Authors: ACHOUR S., CHABBI F.

Drinking water is disinfected to inactivate waterborne pathogens. The most common form of disinfection is chlorination, although ozone and UV light are also used in some plants of the world. Disinfection equipment depends on the type of disinfectant used. In developing countries, the water disinfection problem is large and complex. There are a number of appropriate methods but chlorine continues to be one of the most popular options. In Algeria, it is the only method of disinfection used. Chlorine is a very effective disinfectant, it is relatively easy to handle, the capital costs of chlorine installation are low, simple to dose, measure and control and it has a relatively good residual effect. Chlorination efficiency depends on chlorine residual, contact time, type of chemical used, location in the treatment process, and on characteristics of the water being treated. The chlorine demand involves the reaction of chlorine with compounds in water, reducing the amount of chlorine available to kill microorganisms. Chlorination of humic substances in drinking water is known to produce mutagenic and carcinogenic compounds such as trihalomethanes. Because of their chemical quality, Algerian waters could lead to complex and competitive reactions during chlorination step. The widespread detection of chloroform and other organohalogenated compounds contamination in the water reservoirs appear to be largely a consequence of the use of chlorination for the disinfection of drinking water. Those documented as probable human carcinogens and mutagens have been detected in large amounts and have been considered as the major component of DBPs. Taking into account above drawn conclusions, greater efforts are needed to evaluate and set priorities for drinking water disinfection in Algeria. The challenge is to maintain the level of microbial protection while minimizing the exposure of the consumers to DBPs. If disinfection by chlorination is maintained, the best way to reduce THM generation is to reduce the concentration of precursors through various water treatment techniques prior to chlorination.

22

Authors: GOURINE B.

The present paper deals with the use of neural networks in the displacement and deformation fields modelling and analysis. The Generalized Regression Neural Network (GRNN) has proved its efficiency and reliability than the classical methods in the approximation of the displacement function. Based on the strain tensors, the deformation of GPS network is evaluated and represented according to a regular grid. In order to analyse this deformation, the concepts of deformability and deformation reliability are introduced, where the Monte Carlo method is employed to compute the significance degrees of the resulting tensors. At each stage of deformation field process, the GRNN neural network is used to perform an optimum interpolation of displacement field. The application concerns the GPS auscultation network of the Liquefied Natural Gas (LNG) underground tank of GL4/Z industrial complex (Arzew, Algeria). Composed of 119 points surrounding the LNG tank, the GPS network was observed between 2000 and 2006. The data concern the horizontal and vertical displacements of the network points according to local geodetic coordinates (E, N, U). The results show the performance of the adopted neural networks method in the generating and analysis of displacement and deformation fields. The most deformations measured are significant and at the deformability level. They support the physical interpretation by the presence of a rocky area at the WS side (landward) of the LNG tank which leads to compression and swelling, and the role of sea which acts as a warmer of freezing front causing important dilatations at the NE side (seaward).

9

Authors: SEGHIR K.

As in all areas of the North, including the Maghreb Africa, the region of the Great Basin Mellegue has experienced over the last twenty years a very intense and persistent drought. This drought is characterized by a significant lack of rainfall has had a very negative impact on the flow regimes wadis and springs and the aquifer recharge. This hydro rainfall deficit has affected all socio -economic activities in the region especially in its agricultural development. More over, this phenomenon has an ecological impact and degrading treatment, in general, the environment and promoting particular, water pollution and decline of the natural environment. Given the gravity of this situation, comes at a time when, the demand for water for different uses has increased significantly, it is important to develop a policy that would enhance and protect our water resources. In order to locate the areas vulnerable to pollution and origin of water sampling and piezometric measurements campaigns were conducted during periods of High and Low water years 2005, 2006. The contamination index calculated enabled us to develop vulnerability maps on which identified three areas increasing degree of contamination.

11

Authors: REMINI B., ACHOUR B., KECHAD R.

The oases of Timimoun are irrigated by ancestral techniques called Foggara. The Foggara system is based on a gallery of slightly sloping conveying the groundwater to the surface. The Foggara is a collective proprety belongs to several owners, the water is subject to a sharing between subscribers, and each receives a share of water in relation to its contribution. The work carried out missions in the years 2007, 2008 and 2010 revealed to the population of Timimoun that the imput of modern water capture (such as pumps and wells) have caused the disappearance of traditional methods of watershed with the including the disappearance of certain occupations such as the Kial el Ma. Currently there is only about 10 Kial el Ma in the Timimoun region.

12

Authors: CHAMEKH K., BAALI F., YAHIAOUI A., DJABRI L.

The area of Chéria is located at Algerian, with 45 kilometers in the South-west of the town of Tébessa. The area catchment to study extends on a surface from 720 km2, shelters more than 74300 inhabitants and characterized by a semi-arid climate. The area is formed primarily by limestones of Maestrichtien and Eocene which are fissured karstic and which constitute the aquiferous potential of the area. This study tries to confirm the relations between morphology and the fracturing in limestones and to confront them with the flows of the tablecloths of the latter.

13

Authors: HADDAD H., GHOUALEM H.

Water is vital element for humans. It is necessary to have quality and sufficient quantity thus ensuring a healthy and safe long term. The environmental protection is to safeguard water resources against all types of pollution. In this work, special attention is given to water resources. The objective of our work is to quantify the water resources of some sites Watershed Coastal Algiers which includes nine sub-basins. Hydrochemical study was conducted to better understand the quality of some resources in the basin. The analysis focused on a number of physico-chemical parameters such as water temperature, hydrogen potential, electrical conductivity, total hardness, Cl- , SO42-, NO3 - ,HCO3- Ca2+, Mg2+ K+ and Na+. This study has allowed us to highlight a number of parameters that come into play in determining the quality of the water and found that the content of these elements, however, remains low and does not, for the most part, risk of major pollution of the watershed Coastal Algiers.

15

Authors: ZEGAOULA W., KHELLAF N.

The environmental assessment of effluents generated by the manufacturing industry of mineral fertilizers, Fertial (Annaba) is the main objective of this study. Liquid effluents containing organic and inorganic pollutants are released in the marine littoral without proper treatment. Additionally, this plant contributes to the atmospheric pollution of the city by discharging gas highly charged with ammonia and particles. Hence, estimation and continuous monitoring of degree of pollution caused by this industry are important according to the national and international law on the protection of environment. This would allow establishing a monitoring tool and decision support for ensuring effective and sustainable management of industrial effluents of Fertial.

17

Authors: HAMIMED A., BENSLIMANE M., KHALDI A., NEHAL L., ZAAGANE M.

The quantification of evapotranspiration from irrigated areas is important for agriculture water management, especially in arid and semiarid regions where water deficiency is becoming a major constraint in economic welfare and sustainable development. Conventional methods that use point measurements to estimate evapotranspiration are representative only of local areas and cannot be extended to large areas because of heterogeneity of landscape. Remote sensing based energy balance models are presently most suited for estimating evapotranspiration monitoring water stress at both field and regional scales. In this study, we aim to develop a methodology based on the triangle concept, allowing access to evapotranspiration through the classical equation of Priestley and Taylor (1972) where the proportional coefficient α in this equation is ranged using a linear interpolation between surface temperature and Normalized Difference Vegetation Index (NDVI) values. Preliminary results, using remotely sensed data sets from Landsat ETM+ over the Habra Plains in west Algeria, are in good agreement with ground measurements. The proposed approach appears to be more reliable and easily applicable for operational estimation of evapotranspiration over large areas.

18

Authors: SORO G.E., ANOUMAN D. G.L., GOULA BI T.A., SROHOROU B., SAVANE I.

The northwest of Cote d'Ivoire, as most tropical regions has alternating wet and dry periods. In a context climate more and more disrupted by human activities, it is essential to analyze the dry spells at various time scales in order to propose to the people of mitigation and adaptation measures in the field of water management. In this perspective, three stations with longer rainfall series were analyzed. The analysis used the values of the standardized precipitation index calculated for time scales of 5 years, 35 years and 70 years. The results indicate that the most remarkable for their drought intensity, duration and frequency occurred during the period 1970-1999 and regardless of the time scale considered. These dry spells have reached their peaks in 1983 and 1987 with extremely severe droughts type. The stations of Tengrela and Boundiali located north of the study area are most affected by drought. In addition, it analyzes showed that the time scale long-term seems more appropriate to describe with more details the dry spells.

10

Authors: ABDOULAYE DEMBA N’DIAYE, MOHAMED OULD SID’ AHMED OULD KANKOU

The study assessed the microbiological and physicochemical parameters of wastewater collected between October 2011 and September 2012 from the effluent of the WWTP in vegetable farming area of Sebkha in Nouakchott. The results of physicochemical analysis presented in this work have shown those the values of pH varied from 7.3 to 8. The EC values of experimental samples varied from 1050 to 1650 μS/cm. The turbidity values of experimental samples varied from 26.5 to 51.2 NTU. Effluents from the WWTP are characterized by a maximum iron and manganese content respectively of 412 µg/L and 22 µg/L and a minimum of 210 µg/L and 4 µg/L. Effluents from the WWTP are characterized by a maximum ammonia and orthophosphates content respectively of 120 mg/L and 60 mg/L and a minimum of 10 mg/L and 13.8 mg/L. The values of COD recorded at the WWTP effluent ranged from 25 mg/L and 75 mg/L. The microbiological results show that the microbial load of fecal coliforms and fecal streptococci is very important. The levels of fecal coliforms and fecal streptococci ranged respectively between 3.103 to 8.103 CFU/100 mL and from 5.103 to 9.103 CFU/100 mL. The microbiological analysis revealed high concentrations of faecal coliforms and faecal streptococci, values exceeding the microbiological standards of the WHO. The application of Principal Component Analysis indicates that two groups of wastewater: a group of wastewater turbid characterized by a mineral salt, some metals and organic and inorganic matter expressed by COD and a group of wastewater consists of very high levels of fecal loads, ammonium and phosphates.

12

Authors: YOUCEF L., OUAKOUAK A., BOULANOUAR D., ACHOUR S.

The aim of this study is to test the efficiency of removal of phosphate in natural waters by adsorption on powdered activated carbon (PAC). The treated solutions are synthetic phosphate solutions in distilled water and ground waters in the region of Biskra. Phosphate adsorption tests have shown that the retention of phosphate on the PAC is a reversible phenomenon. The equilibrium time is less in mineralized water (30 seconds) then in distilled water (3 hours). Removal rate are improved with the increase of the dose of the adsorbent (0,1 to 4 g/l). Adsorption of phosphate follows the two models of Langmuir and Freundlich. The process is influenced by the pH of treatment. In synthetic solutions of distilled water, removal rate decrease with the increase of the initial phosphate content (1 to 20 mg/l) in contrast in synthetic solutions of mineralized water the opposite occurs. This is a result of unlike the removal mechanisms of phosphate in the two media of different mineralization.

13

Authors: ZOUGGAGHE F., MOUNI L., TAFER M.

The objectif of this study is to draw a map of quality or health of the river system watershed of Soummam by using standard global biological index (IBGN) of AFNOR (1992) and identify the most degraded sections of the watershed. The assessment of the biological quality is based on the general principle according to which each type of natural environment has its own characteristics community of organisms. Any degradation of the natural organisms indicates that some disturbance has occurred. Benthic invertebrate community were sampled on three areas of watershed of Soummam, in a total of 34 stations were sampled between 20m and 1100m of altitude between 2004 and 2010. The environmental quality is good in 5.9% of the stations where the index IBGN values displays 13 and 14, which meant that is not far from the fair quality, since these values are located just to the boundary between good and fair quality. A fair biological quality in 26.5% of stations, a bad quality in 52.9% of stations and finally, a very poor quality in 14.7% of the stations.

14

Authors: DIALLO A.D., IBNO NAMR K., N’DIAYE A.D., GARMES H., KANKOU M., WANE O.

In order to better understand and manage the quality of surface water, is often undertaking long and tedious analysis campaigns. These usually generate enough data whose interpretation is not always easy. Application of Principal Component Analysis (PCA) for such a task could be beneficial . It is in the context of such an application as 26 physico-chemical parameters: The potential hydrogen (pH) , electrical conductivity (EC), total dissolved solids (TDS), temperature (T°), turbidity (Turb) Total Hardness (TH), bicarbonate (HCO3-), sulfate (SO42-), nitrate (NO3-), nitrite (NO2-), chloride (Cl-), orthophosphate (PO43-), sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), oxidizability permanganate (MO) , aluminum (Al) , ammonium (NH4+), silica (SiO2), zinc (Zn), lead (Pb), copper (Cu), manganese (Mn), iron (Fe) and fluorine (F-), derived from the analysis of water samples collected during the months of June, July, August and September 2012, of eight (8) locations at the right bank of the Senegal River. This study shows that it is possible, with a view to creating a management tool to simplify the model initially constructed from 26 variables to bring it to the extent of one variable whose turbidity relatively simple and less expensive. This reduction is even more interesting that the variable is to consider measurement is simple. In view of the creation of management tools, this tool looks like a good alternative. In the area of quality control the turbidimetry prove essential analytical tools in the treatment of water like the pH-metry, the conductimetry and the colorimetry.

18

Authors: NANFACK N.A. CARINE, FONTEH F. ANYANGWE, VINCENT K. PAYNE, KATTE BRIDGET, FOGOH J. MUAFOR

This paper looks at the quality of non-conventional waters and their effects on the health of consumers in seven (07) quarters deprived of conventional water network in Mbouda, West Cameroon. Sociological techniques were used to obtain data on water sources, existing types of waterborne diseases in households, the nature of hygiene and sanitation of the water points and the treatment provided to these drinks water before consumption. The number of cases of various waterborne diseases recorded in hospitals in the town from January 2012 to February 2013 was also verified. Water samples were collected from 4 wells, 4 springs and 2 boreholes in December 2012 and March 2013 for analyzes using the techniques of counting bacteria on liquid and solid medium. Results of this study shows that water from non-conventional sources are contains high levels of pathogenic microorganisms, such as fecal streptococci, Salmonella, fecal coliforms and Proteus sp. The consumption of these waters exposes consumers to serious health risks, thus requiring appropriate treatment before consumption.

20

Authors: N’GUESSAN KOUAMÉ A., KOUASSI AMANI M., GNABOA R., TRAORÉ K.S, HOUENOU P.V.

This study focuses on the analysis of hydrological phenomena causing pollution landscaped lakes of Yamoussoukro city (Center of Ivory Coast). The methodology takes into account the analysis of climate variability (Pettitt test and graphical representation), water balance (Coutagne method, of Thornthwaite method and Tixeront-Berkaloff method) and comparative analysis using from potential evapotranspiration and real evapotranspiration on a monthly time. The results of this study were used to characterize the main manifestations of climate variability (1975-2009) observed for more than three decades in the region of Yamoussoukro. It appears from the study of the conditions of prolonged rainfall deficits have been identified before 1992. The post-1992 is characterized by a resumption of rainfall without reaching the heights of rainfall before 1970. Climate variability is manifested by a monotonic increase of air temperature. The water balance shows that the region receives an average of 1137 mm of rain annually and real evapotranspiration (ETR) is 853 mm, or about 74.98 % of the height of precipitated water. The infiltrated water slide is in the order of 70 mm or 6.15% of the height of precipitated water. The amount of runoff is in the order of 215 mm, or 18.87% of the height of precipitated water. The change observed on the cumulative heights rainfall was accompanied by a change in the duration of the rainy season. A trend towards shorter rainy seasons is demonstrated in the region of Yamoussoukro.

23

Authors: ALALI A., BENMOHAMMADI A., BOUDAD L., AQID N.

The descriptive study of dune facies plain Tafilalet enlightened us on the likely sand sheets, the axis of advance of the sands, and any remobilisassions. Only a more detailed analysis will shed light on the behavior of particles during transport, according to their size or nature of their origin, their specific areas of migration, deposition and remobilization. This characterization of the sand through his elementary particle, will be by laboratory analyzed by granulometric by sieving, morphoscopic by observing the insoluble fraction and mineral by separating the soluble fraction and heavy mineral Identification

10

Authors: ADJIM M., BENSAOULA F.

Mapping the vulnerability of ground waters in regions of high anthropogenic actions is a crucial step in any realisation in order to ensure rational management of water resources as well as a harmonious urban and socio-economical development. The present work aims at the determination of vulnerable areas of one of the most important aquifer in the north western region of the “wilaya” (department) of Tlemcen. Indeed, this important aquifer of Maghnia which encroaches on the Moroccan territory is increasingly used by farm operators. It is formed by alluvial and clayey sand formations of Plio-Quaternary. Water pumping in this region is realised by means of classical wells (the most widely used method) as well as by drillings. Unlike wells, the drillings can capture all the water, which may results in an intensive exploitation of the aquifer. In this paper, we used the DRASTIC method to obtain the mapping of the intrinsic vulnerability of this aquifer. The results clearly indicate two vulnerable areas. This map constitutes an important basis for the integrated groundwater management studies and the long-term planning of protective measures. Keywords: Map of vulnerability, pollution, groundwater protection, Drastic, aquifer of Maghnia.

13

Authors: MORRI M., DAGHARI H.

In Tunisia, saline soils occupy an area of 1,5 million hectares, roughly 25% of the total area of arable land in the country. The irrigated area of Kalâat EL Andalous, is a part of this environment and already characterized by low yields. The present work aims to quantify the dose of salt leaching and verification of its effectiveness to predict the risk of salinity on the soil and on plants. The measured of leaching dose is about 1100 m3/ha, close to the theoretical value determined by the formula of Rhoades. A quantity of salts made by the irrigation water is about 15 t / ha, the amount of leached salt is about 9 t / ha. The amounts of salt accumulated in the root zone during the irrigation season is 6 t / ha. Keywords: Salinity, irrigated area, Kalâat El Andalous, leaching dose, drainage.

14

Authors: DOUBI M., DERMAJ A., AIT HADOU B., CHEBABE D., ERRAMLI H., HAJJAJI N., ABDELLAH SRHIRI A.

The study concerns the analysis of physico-chemical parameters (temperature, pH, E.C, NO3, Cl, PO43-, HCO3, SO4, Ca, Mg) of water of Moulouya river and its tributary "Chog Wadi Al Ard" in order to establish a diagnosis of pollution degree of the river waters in study area. Thus, water samples were carried out at six stations in two different seasons in order to establish a comparison between a dry period and during floods. The analytical results obtained during the study period, show that water stations present calcium bicarbonate and magnesium character. The parameters studied during like the temperature, hydrogen potential, conductivity, alkalis, alkaline, sulphate, chloride show that in general the obtained values a good quality. Results of nitrate and orthophosphate analyses give very low values in accord with few “fertilizer and pesticide agricultural treatment”. Keywords: physico-chimical quality, Low flow, Flood, Moulouya river, Oued Chog al ard.

18

Authors: KOUASSI A.M., KOUAME K.F., SALEY M.B., BIEMI J.

The objective of this study is to evaluate the impacts of climate change on groundwater resources of crystalline and crystallophyllian basement aquifers. This study was applied to the particular case of N'zi-Bandama watershed in Ivory Coast. This catchment lies between longitudes 3°49' and 5°22' West and latitude 6°00’ and 9°26' North and covers an area of 35,500 Km2. It belongs to three climatic regimes that are from North to South, the tropical transition regime, the humid tropical regime and sub-equatorial regime. The main geological formations of the basin are granites, migmatites and granodiorites. There are two types of aquifers that are the regolith aquifers and fissured aquifers. The methodological approach is based on the evaluation of recession coefficients, of the dry period and the water volume mobilized by the aquifers. All these parameters were estimated from the law of Maillet. The recession coefficients estimated average between 3.14.10-2j-1 and 3.56.10-2 j-1 either side 1968, whether an average increase of 15.26% and highlight a drain much faster aquifers supplying base flow after 1968. Shortening of 1 to 9 days with an average of 5 days of drying time after 1968 was highlighted. The water volume mobilized by the average aquifer fluctuates between 0.84 and 0.42 Km3 before and after 1968 whether an average decrease of -49.3%. These results show a decrease in the water volume mobilized by aquifers after 1968 and suggest a considerable decline of groundwater resources under the influence of climate change. Keywords: Climate change; Water resources; Maillet law; N’zi-Bandama; Ivory Coast. INTRODUCTION