# Estimation of Groundwater Recharge in the Lobo Catchment (Central-Western Region of Côte d’Ivoire)

^{1}

^{2}

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Study Area

^{2}. The mean rainfall over the period 1971–2016 was about 1200 mm, and the average temperature was 25 °C. This figure also shows all the observation points and gauging stations in the Lobo catchment area. The observation points have made it possible to collect piezometric data over three years (2018–2020), while the gauging stations have made it possible to obtain hydrological data over two years (2019–2020).

^{2}, with an annual growth rate of 3.72%. Within this zone, the drinking water supply for large agglomerations is ensured by the collection of surface water, whereas in rural areas, drinking water comes mainly from boreholes.

#### 2.1. Stream Runoff

^{3}/s, with a maximum of 39 m

^{3}/s recorded in September 2019, and from 5 to 7 m

^{3}/s with a maximum of 25 m

^{3}/s recorded in October 2020. These flows are generally higher at the Sikaboutou station upstream of the Lobo reservoir than at the Nibéhibé station at the outlet of the Lobo catchment and downstream of the Lobo reservoir.

#### 2.2. Geological and Hydrogeological Overview of the Study Area

#### 2.3. Groundwater Recharge Processes

## 3. Materials and Methods

#### 3.1. Data

#### 3.2. Methods

#### 3.2.1. Hydrograph Analysis

#### Recession Curve Displacement

^{3}), Q

_{1}is the groundwater discharge at the critical time (Tc) (m

^{3}/day), and Q

_{2}is the groundwater discharge at Tc (m

^{3}/day).

_{c}, representing the time at which the recession becomes linear, can be determined from Equation (2). A detailed procedure for this process is given by [22]:

_{I}is the recession rate in days per logarithmic cycle and can be estimated manually [9,23]. In this study, the United States Geologic Survey RORA software was used to apply this method.

#### Graphical Separation (Constant Slope Method)

#### Automated Web GIS-Based Hydrograph Analysis Tool (WHAT)

- ✔
- Single parameter digital filter [26]

_{0}= 0), and the base-flow is equal to the streamflow (B

_{0}= Q

_{0},). Thus, for each step, the runoff is calculated from Equation (3):

_{p}is the streamflow at time step p, R

_{p}is the direct runoff at time step p, and α is the base-flow filter parameter. The following assumptions are made: if R

_{p}< 0, then R

_{p}= 0, or if R

_{p}> Q

_{p}, then R

_{p}= Q

_{p}. Finally, the base-flow is calculated from Equation (4):

_{p}is the base-flow at time step p.

- ✔
- Two-parameter digital filters or Eckhardt method [27]

_{0}= 0), and the base-flow is equal to the streamflow (

**B**

_{0}= Q

_{0}). Then, at each step, the runoff is calculated using Equation (5):

_{max}is the maximum value of the long-term ratio of base-flow to total streamflow. This ratio is equal to 0.25 for perennial streams with hard rock aquifers, 0.50 for ephemeral streams with porous aquifers, and 0.80 for perennial streams with porous aquifers. For our study, the ratio of 0.25 for perennial streams was used.

- ✔
- Local minimum method

- Use the methods of graphical separation, local minimum, and one- and two-parameter numerical filters to calculate the monthly base-flow.
- Calculate the average monthly base-flow over a long period.
- Sort and accumulate the long-term average monthly base-flow to obtain the cumulative long-term average monthly base-flow.
- Select the most stable (nearly linear) segment to obtain the slope of the stable base-flow.
- Using linear interpolation over the remaining months, the annual average base-flow is finally obtained.

_{p}) can be calculated by the following equation using the base-flow and the stable base-flow, with (Q

_{b}) the base-flow and (Q) the total stream runoff, as in Equation (6).

#### 3.2.2. WTF Method

_{y}= specific yield; ∆H = change in water table elevation (water level rise), and ∆t = the time period.

#### Specific Yield

#### Determination of ΔH: Water Level Rise

_{1}, h

_{x}, and h

_{2}are the initial water levels of the river (in m) at distance x (in m) and distance L from the river, and y

_{1}, y

_{x}, and y

_{2}are the water levels at the time of the flood (in m) at distance x and distance L from the river (Figure 8).

_{2}being equal to h

_{2}, Equation (8) becomes Equation (9).

#### 3.2.3. Empirical Formulas

_{i}is the groundwater recharge estimated by WTF, and F

_{i}is the recharge calculated by the modified empirical formula. The lower the MAP, the more accurate the result.

#### 3.2.4. Estimation of Annual Recharge

_{a}is annual recharge, ${\mathrm{Q}}_{\mathrm{off}}^{\mathrm{gw}}$ is groundwater flow out of the catchment, ${\mathrm{Q}}_{\mathrm{on}}^{\mathrm{gw}}$ is groundwater flow into the catchment,${\mathrm{Q}}^{\mathrm{bf}}$ is base-flow, ${\mathrm{ET}}^{\mathrm{gw}}$ is evapotranspiration from the groundwater table, and $\Delta {\mathrm{S}}^{\mathrm{gw}}$ is change in groundwater storage.

_{a}is annual recharge,$\Delta {\mathrm{S}}^{\mathrm{gw}}$ is change in groundwater storage or direct recharge estimated by the WTF method, and ${\mathrm{Q}}^{\mathrm{bf}}$ is base-flow estimated by WHAT.

## 4. Results and Discussion

#### 4.1. Recession Curve Displacement

^{2}), the distribution of rainfall may not be uniform over the area. This uneven rainfall distribution could make the recession curve displacement method unsuitable for our area.

^{2}), the distribution of precipitation is not uniform, thereby making this method unsuitable. This difference between the recharge obtained at these two stations could also be explained by the presence of the Lobo reservoir downstream from the Sikaboutou station and upstream from the Nibéhibé station as well. Indeed, this reservoir retains a large quantity of water and reduces the downstream flows, which could explain the low values obtained at the Nibéhibé station. These values of recharge obtained by the displacement recession curve method are subject to the assumption inherent in this method. This assumption states that the recharge occurs instantaneously and uniformly, directly after a rainstorm [22], which is not the case, especially for large watershed areas. Therefore, this method is unsuitable for estimating recharge in large areas.

#### 4.2. Base-Flow Analyses

#### 4.3. Direct Recharge Estimated by the WTF Method

_{y}, obtained by conducting pumping tests in 134 drillings, was 4.8%.

#### 4.4. Empirical Formulas

#### 4.5. Annual Recharge in the Lobo Catchment

## 5. Conclusions

## Author Contributions

## Funding

## Institutional Review Board Statement

## Informed Consent Statement

## Data Availability Statement

## Acknowledgments

## Conflicts of Interest

## References

- Koffi, B.; Sanchez, M.; Kouassi, K.L.; Kouadio, Z.A.; Kouassi, K.H.; Yao, A.B. Evaluation of the Impacts of Climate Change and Land-Use Dynamics on Water Resources: The Case of the Lobo River Watershed: Central-Western Côte d’Ivoire. In EGU General Assembly Conference Abstracts; EGU General Assembly 2021 Author(s) 2021, EGU21: Gather Online; EGU: France, 2021; pp. 21–506. Available online: https://www.researchgate.net/publication/351225184 (accessed on 15 November 2021).
- Silveira, L.; Usunoff, E.J. Groundwater; EOLSS Publications Co. Lid.: Oxford, UK, 2009; p. 3. Available online: https://books.google.de/booksid=1UqNCwAAQBAJ (accessed on 20 February 2009).
- Alley, W.M.R.; Thomas, E.; Franke, O.L. Sustainability of Ground-Water Resources; Denver, C.O., Ed.; USA Geological Survey Branch of Information Services [Distributor], USA Dept. of the Interior USA Geological Survey, USA GPO: Washington, DC, USA, 1999.
- Margat, J. The Over Exploitation of Aquifers. Selected Paper on Aquifer Over Exploitation from the 23rd International Congress of the IAH. In Puerto de la Cruz, Tenerife; Simmers, I., Villarroya, F., Rebollo, L.F., Eds.; Verlag H. Heise: Hannover, Germany, 1992; pp. 366–371. [Google Scholar]
- Lerner, D.N.; Issar, A.; Simmers, I. Groundwater Recharge. A Guide to Understanding and Estimating Natural Recharge. Verlag Heinz Heise, Hannover, West Germany International Contributions to Hydrogeology. IAH Publ.
**1990**, 8, 345. [Google Scholar] - De, V.; Jacobus, J.; Simmers, I. Groundwater Recharge: An Overview of Processes and Challenges. Hydrogeol. J.
**2002**, 1, 5–17. [Google Scholar] - Healy, R.W.; Cook, P.G. Using Groundwater Levels to Estimate Recharge. Hydrogeol. J.
**2002**, 1, 91–109. [Google Scholar] [CrossRef] - Healy, R.W.; Scanlon, B.R. Estimating Groundwater Recharge; Cambridge University Press: Cambridge, UK; New York, NY, USA, 2010. [Google Scholar]
- Hussein, J.; Broder, J.M. Estimating Groundwater Recharge in the Semiarid Al-Khazir. Water
**2014**, 6, 2467–2481. [Google Scholar] - Hung, V.V.; Broder, J.M. Estimating Groundwater Recharge for Hanoi, Vietnam. Sci. Total Environ.
**2019**, 651, 1047–1057. [Google Scholar] [CrossRef] - Lim, K.J.; Engel, B.A.; Tang, Z.; Choi, J.; Kim, K.; Muthukrishnan, S.; Tripathy, D. Automated Web GIS-Based Hydrograph Analysis Tool, WHAT. JAWRA J. Am. Water Resour. Assoc.
**2005**, 41, 1407–1416. [Google Scholar] [CrossRef] - Manna, F.; Cherry, J.A.; McWhorter, D.B.; Parker, B.L. Groundwater Recharge Assessment in an Upland Sandstone Aquifer of Southern California. J. Hydrol.
**2016**, 541, 787–799. [Google Scholar] [CrossRef][Green Version] - Adeleke, O.O.; Makinde, V.; Eruola, O.A.; Dada, O.F.; Ojo, A.O.; Aluko, T.J. Estimation of Groundwater Recharge in Odeda Local Government Area, Ogun State, Nigeria Using Empirical Formulae. Challenges
**2015**, 2, 271–281. [Google Scholar] [CrossRef][Green Version] - Varade, S.R.; Patel, J.N. Development of Empirical Formula for Recharge Estimation for Basaltic Areas. J. Hydraul. Eng.
**2017**, 68–73. [Google Scholar] [CrossRef] - Ali, M.; Mubarak, S.; Islam, A.; Biswas, P. Comparative Evaluation of Various Empirical Methods for Estimating Groundwater Recharge. Arch. Curr. Res. Int.
**2017**, 11, 1–10. [Google Scholar] [CrossRef] - INS. Recensement Général De La Population Et De l’Habitation (RGPH) 1998. Données Sociodémographiques Et Économiques Des Localités, Résultats Définitifs Par Localités, Région Des Lagunes; INS: Montrouge and Metz, France, 2014; p. 26. [Google Scholar]
- Tagini, B. Esquisse Structurale De La Côte d’Ivoire. Essai De Géotectonique Régionale. Ph.D. Thesis, Université De Lausanne (Suisse), Lausanne, Switzerland, 1971. [Google Scholar]
- Lachassagne, P.; Dewandel, B.; Wyns, R. Review: Hydrogeology of Weathered Crystalline/Hard-Rock Aquifers—Guidelines for the Operational Survey and Management of Their Groundwater Resources. Hydrogeol. J.
**2021**, 29, 1–34. [Google Scholar] [CrossRef] - Yao, A.B. Evaluation Des Potentialités En Eau Du Bassin Versant De La Lobo En Vue D’une Gestion Rationnelle (Centre-Ouest De La Côte d’Ivoire). Ph.D. Thesis, Université Nangui Abrogoua, Abidjan, Côte d’Ivoire, 2015. [Google Scholar]
- Ali, R.S.E.; Chibane, B.; Boucefiène, A. Sensitive Analysis of Ground Recharge Estimation Model, for Semiarid Areas. Appl. Water Sci.
**2018**, 193, 1–10. [Google Scholar] - Rutledge, A.T. Program User Guide for RORA; USA Geological Survey: Reston, VA, USA, 2007.
- Rorabaugh, M.I. Estimating Changes in Bank Storage and Ground-Water Contribution to Streamflow. Int. Assoc. Sci. Hydro. Publ.
**1964**, 63, 432–441. [Google Scholar] - Bevans, H.E. Estimating Stream–Aquifer Interactions in Coal Areas of Eastern Kansas by Using Streamflow Records. In Selected Papers in the Hydrologic Sciences; Subitzky, S., Ed.; Geological Survey Water-Supply Paper; U.S. Government Printing Office: Atlanta, GA, USA, 1986; Volume 2290, pp. 51–64. [Google Scholar]
- McCuen, R.H. Hydrologic Analysis and Design, 3rd ed Pearson/Prentice-Hall, Upper Saddle River New Jersey. J. Am. Water Resour. Assoc.
**2005**, 40, 838. [Google Scholar] - Blavoux, B. Étude Du Cycle De L’eau Au Moyen De L’oxygène 18 Et Du Tritium: Possibilités Et Limites De La Méthode Des Isotopes Du Milieu En Hydrologie De La Zone Tempérée. Ph.D. Thesis, Université Pierre et Marie Curie, Paris, France, 1978. [Google Scholar]
- Nathan, R.J.; McMahon, T.A. Evaluation of Automated Techniques for Base Flow and Recession Analyses. Water Resour. Res.
**1990**, 7, 1465–1473. [Google Scholar] [CrossRef] - Eckhardt, K. How to Construct Recursive Digital Filters for Baseflow Separation. Hydrol. Process.
**2005**, 2, 507–515. [Google Scholar] [CrossRef] - Sloto, R.A.; Crouse, M.Y. HYSEP: A Computer Program for Streamflow Hydrograph Separation and Analysis. Water Resour. Invest. Rep.
**1996**, 96–4040. [Google Scholar] - Rutledge, A.T. Computer Programs for Describing the Recession of Ground-Water Discharge and for Estimating Mean Ground-Water Recharge and Discharge from Streamflow Records-Update; US Department of the Interior, US Geological Survey: Washington, DC, USA, 1998; pp. 98–4148.
- Zektser, I.S. Principles of Regional Assessment and Mapping of Natural Groundwater Resources. Environ. Geol.
**2002**, 3, 270–274. [Google Scholar] [CrossRef] - Chen, W.P.; Lee, C.H. Estimating Ground-Water Recharge from Streamflow Records. Environ. Geol.
**2003**, 3, 257–265. [Google Scholar] [CrossRef] - Delin, G. Comparison of Local- to Regional-Scale Estimates of Ground-Water Recharge in Minnesota, USA. Hydrol. J.
**2007**, 334, 231–249. [Google Scholar] [CrossRef][Green Version] - Phan, N.C.; Ton, S.K. Hydraulic Groundwater; Vietnam Education Publishing House: Hanoi, Vietnam, 1981. [Google Scholar]
- Chaturvedi, R.S. A Note on the Investigation of Groundwater Resources in Western Districts of Uttar Pradesh. Annu. Rep.
**1973**, 86–122. [Google Scholar] - Baweja, B.K.; Karanth, K.R. Groundwater Recharge Estimations in India; Central Groundwater Board: New Delhi, India, 1980.
- Krishna, R. Hydrometeorological Aspects of Estimating Groundwater Potential. Seminar on Groundwater Potential in Hard Rock Areas, Bangalore. Geol. Soc. India
**1970**, 1, 18–99. [Google Scholar] - Maxey, G.B.; Eakin, T.E. Ground Water in Groundwater in White River Valley, White Pine, Nye, and Lincoln Counties, Nevada. Nevada Department of Conservation and Natural Resources. Water Resour.
**1949**, 8, 1–64. [Google Scholar] - Kirchner, J.; Van, T.G.J.; Lukas, E. Exploitation Potential of Karoo Aquifers. Research Report. Ph.D. Thesis, University of the Orange Free State, Bloemfontein, South Africa, 1991. [Google Scholar]
- Bredenkamp, D.B. Manual on Quantitative Estimation of Groundwater Recharge and Aquifer Storativity: Based on Practical Hydro-Logical Methods; Water Research Commission: Pretoria, South Africa, 1995. [Google Scholar]
- Makridakis, S. Accuracy Measures. Theoretical and Practical Concerns. Int. J. Forecast.
**1993**, 4, 527–529. [Google Scholar] [CrossRef] - Schicht, R.; Walton, W. Hydrologic Budgets for Three Small Watersheds in Illinois; Illinois State Water Survey: Champaign, IL, USA, 1961. [Google Scholar]
- Abiye, T.A.; Tshipala, D.; Leketa, K.; Villholth, K.G.; Ebrahim, G.Y.; Magombeyi, M.; Butler, M. Hydrogeological Characterization of Crystalline Aquifer in the Hout River Catchment, Limpopo Province, South Africa. Groundw. Sust. Develop.
**2020**, 11, 100–406. [Google Scholar] [CrossRef] - Kamenan, Y.M. Elaboration d’un Modèle De Protection Des Eaux Souterraines En Zone De Socle: Cas Des Aquifères Du Bassin Versant De La Lobo à Nibéhibé (Centre-Ouest De La Côte d’Ivoire). Ph.D. Thesis, Université Jean Lorougnon Guédé, Daloa, Côte d’Ivoire, 2021. [Google Scholar]

**Figure 2.**Variation in the average monthly flows at Sikaboutou and Nibéhibé gauging stations between 2019 and 2020.

**Figure 3.**Geological formations of the Lobo catchment modified from [19].

**Figure 4.**Description of the groundwater recharge mechanism in a catchment, modified from [6].

**Figure 7.**Linear separation method for hydrograph components [25].

**Figure 8.**Impact of surface water rise on groundwater, modified from [33].

**Table 1.**Variations in piezometric level in 2019 and 2020 in the boreholes selected for the direct recharge study.

Drillings | Water Level Fluctuation (m) | ||
---|---|---|---|

2018 | 2019 | 2020 | |

Tiahouo | 0.78 | 1.2 | 0.2 |

Bazra-Nattis | 1.3 | 1.1 | 0.5 |

Teneforo | 0.5 | 1.2 | 0.7 |

Sokoura | 0.2 | 0.1 | 0.4 |

Dananon | 0.3 | 0.6 | 0.5 |

Vaafla | 0.8 | 1.4 | 0.3 |

Seitifla | 1.2 | 2.8 | 0.8 |

Diafla | 0.2 | 0.2 | 0.3 |

Pelezi | 0.4 | 1.1 | 0.6 |

Zoukouboue | 2.5 | 3 | 0.3 |

Monoko-Zohi | 0.6 | 0.4 | 0.3 |

Bohinou | 0.2 | 1.6 | 0.3 |

Yacouba | 0.1 | 0.7 | −0.9 |

Banoufla (Bediala) | 0.3 | 0.8 | 0.6 |

Gnamienkro2 | 0.3 | 0.7 | 0.2 |

Bonoufla (vavoua) | 1 | 0.9 | 0.6 |

Ketro-Bassam | 2.3 | 1.9 | 2.1 |

Broukro | 1.8 | 2.1 | 3.2 |

Zouzoukro | 1.2 | 0.9 | 2.2 |

Gbena | 1.4 | 0.9 | 1.9 |

Dediafla2 | 2.4 | 1.4 | 3.5 |

Vrouo1 | 0.4 | 1.3 | 0.8 |

Bouhitafla | 0.8 | 1.2 | −1 |

**Table 2.**Overview of the empirical equations for estimating groundwater recharge. Modified from [10]. R represents recharge (mm), P represents annual precipitation (mm), and MAP represents mean annual precipitation.

Modified Formula | Equation No. | |
---|---|---|

Chaturvedi [34] | R = 3(P − 15)^{0.4} | (11) |

Irrigation Research Institute, Roorkee [35] | R = 2(P − 14)^{0.5} | (12) |

Sehgal [36] | 1.8(P − 0.6)^{0.5} | (13) |

Krishna Rao [37] | 0.37(P − 600) | (14) |

Maxey-Eakin [38] | 0.22 × P | (15) |

Kirchner [39] | 0.26(MAP − 200) | (16) |

Bredenkamp [40] | 0.29(MAP − 360) | (17) |

Gauging Stations | |||
---|---|---|---|

Sikaboutou | Nibéhibé | ||

2019 | 2020 | 2019 | |

Methods | |||

Graphical method (mm) | 24.6 | 18.7 | 7.6 |

Local minimum method (mm) | 62.4 | 25.8 | 13.2 |

Single parameter filter (mm) | 56.5 | 21.9 | 13.8 |

Eckhardt method (mm) | 26.9 | 27 | 8.7 |

Mean base-flow (mm) | 42.6 | 23.4 | 10.8 |

**Table 4.**Spearman correlation coefficients between base-flow analysis results for both gauging stations.

Methods | Graphical Method | Local Minimum Method | Single-Parameter Filter | Eckhardt Method |
---|---|---|---|---|

Sikaboutou station | ||||

Graphical method | 1 | |||

Local minimum method | 0.97 | 1 | ||

Single-parameter filter | 0.98 | 0.99 | 1 | |

Eckhardt method | 0.96 | 0.97 | 0.98 | 1 |

Nibéhibé station | ||||

Graphical method | 1 | |||

Local minimum method | 0.99 | 1 | ||

Single-parameter filter | 0.94 | 0.99 | 1 | |

Eckhardt method | 0.98 | 0.99 | 0.99 | 1 |

Drillings | Direct Recharge (mm) | ||
---|---|---|---|

2018 | 2019 | 2020 | |

Tiahouo | 37.9 | 58.3 | 12.4 |

Bazra-Nattis | 65 | 55 | 25.3 |

Teneforo | 23.9 | 57.4 | 36 |

Sokoura | 12.4 | 6.2 | 21 |

Dananon | 14.1 | 28.2 | 23.4 |

Vaafla | 38.3 | 67 | 15.3 |

Seitifla | 58 | 135 | 40 |

Diafla | 10 | 10 | 14 |

Pelezi | 19.3 | 53 | 27.2 |

Zoukouboue | 119.5 | 143.4 | 15.3 |

Monoko-Zohi | 25.5 | 17 | 15 |

Bohinou | 9.5 | 76 | 13 |

Yacouba | 4.8 | 33.5 | 0 |

Banoufla (Bediala) | 14 | 37.3 | 28.2 |

Gnamienkro2 | 14.7 | 34.4 | 11 |

Bonoufla (vavoua) | 45.6 | 41 | 31 |

Ketro-Bassam | 111.7 | 92.3 | 100.4 |

Broukro | 87.7 | 102.3 | 155 |

Zouzoukro | 55 | 41 | 106.1 |

Gbena | 65.5 | 42.1 | 93 |

Dediafla2 | 117.3 | 68.4 | 167 |

Vrouo1 | 18.5 | 60 | 36 |

Bouhitafla | 38.9 | 58.4 | 0 |

Mean groundwater recharge | 44 | 57.3 | 43 |

Maximum | 119.5 | 143.4 | 167 |

Minimum | 4.8 | 6.2 | 0 |

75% Quartile | 65 | 68 | 38 |

25% Quartile | 14.1 | 36 | 14.3 |

**Table 6.**Empirical formulas modified according to [10].

Original Authors | Recharge 2019 | Recharge 2020 | MAP (%) 2019 | MAP (%) 2020 |
---|---|---|---|---|

Chaturvedi | 51.5 | 41.8 | 9.9 | 26.8 |

Irrigation Research Institute, Roorkee | 69.9 | 53.9 | 22.3 | 5.64 |

Sehgal | 63.2 | 49 | 10.70 | 14.3 |

Krishna Rao | 235.7 | 52.4 | 312.7 | 8.3 |

Maxey-Eakin | 272.1 | 163.1 | 376 | 185.4 |

Kirchner | 0 | 0 | 100 | 100 |

Bredenkamp | 0 | 0 | 100 | 100 |

Original Authors | Modified Formulas | Recharge 2019 | Recharge 2020 | MAP (%) 2019 | MAP (%) 2020 |
---|---|---|---|---|---|

Chaturvedi | 1.21 (P − 15)^{0.4} | 61.6 | 50.2 | 7.8 | 17.5 |

Irrigation Research Institute, Roorkee | 1.8 (P − 14)^{0.5} | 62.9 | 48.5 | 10.1 | 13.5 |

Sehgal | 1.7 (P − 0.6)^{0.5} | 59.7 | 46.2 | 4.5 | 8.2 |

Krishna Rao | 0.055 (P − 55) | 65 | 37.7 | 13.7 | 11.6 |

Maxey-Eakin | 0.051 × P | 63.1 | 37.8 | 10.3 | 11.5 |

Kirchner | 0.69 (MAP − 10) | 64.2 | 35.7 | 12.3 | 16.3 |

Bredenkamp | 0.73 (MAP − 10) | 67.9 | 37.8 | 18.8 | 11.5 |

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

## Share and Cite

**MDPI and ACS Style**

Jean Olivier, K.K.; Brou, D.; Jules, M.o.M.; Georges, E.S.; Frédéric, P.; Didier, G. Estimation of Groundwater Recharge in the Lobo Catchment (Central-Western Region of Côte d’Ivoire). *Hydrology* **2022**, *9*, 23.
https://doi.org/10.3390/hydrology9020023

**AMA Style**

Jean Olivier KK, Brou D, Jules MoM, Georges ES, Frédéric P, Didier G. Estimation of Groundwater Recharge in the Lobo Catchment (Central-Western Region of Côte d’Ivoire). *Hydrology*. 2022; 9(2):23.
https://doi.org/10.3390/hydrology9020023

**Chicago/Turabian Style**

Jean Olivier, Kouadio Kouamé, Dibi Brou, Mangoua oi Mangoua Jules, Eblin Sampah Georges, Paran Frédéric, and Graillot Didier. 2022. "Estimation of Groundwater Recharge in the Lobo Catchment (Central-Western Region of Côte d’Ivoire)" *Hydrology* 9, no. 2: 23.
https://doi.org/10.3390/hydrology9020023