Estimating karst groundwater recharge from soil moisture observations – a new method tested at the Swabian Alb, southwest Germany
<p>Understanding groundwater recharge processes is important for sustainable water resource management. Experimental approaches to study recharge in karst areas often focus on analysing the aquifer response using a disintegration of its outlet signals, but only a few approaches directly invest...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2023-01-01
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| Series: | Hydrology and Earth System Sciences |
| Online Access: | https://hess.copernicus.org/articles/27/385/2023/hess-27-385-2023.pdf |
| _version_ | 1797948097452572672 |
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| author | R. Berthelin T. Olarinoye M. Rinderer M. Mudarra D. Demand M. Scheller A. Hartmann A. Hartmann |
| author_facet | R. Berthelin T. Olarinoye M. Rinderer M. Mudarra D. Demand M. Scheller A. Hartmann A. Hartmann |
| author_sort | R. Berthelin |
| collection | DOAJ |
| description | <p>Understanding groundwater recharge processes is important for sustainable water resource management. Experimental approaches to study recharge in
karst areas often focus on analysing the aquifer response using a disintegration of its outlet signals, but only a few approaches directly investigate the
recharge processes that occur at the surface of the system. Soil moisture measurements have a high potential to investigate water infiltration to
deeper soil depth or epikarst with an easy and not too intrusive installation. They can yield long-term measurements with high temporal
resolution. Using these advantages, we developed and tested a method to estimate recharge based on soil moisture measurements. The method consists
of the extraction of linked events in rainfall, soil moisture, and discharge time series, as well as a subsequent fitting of the parameters of a simple
drainage model to calculate karst recharge from soil moisture metrics of individual events. The fitted parameters could be interpreted in physically
meaningful terms and were related to the properties of the karstic system. The model was tested and validated in a karst catchment located in
southwest Germany with hourly precipitation, soil moisture, and discharge data of 8 years duration. The soil moisture measurements were
distributed among grassland (<span class="inline-formula"><i>n</i></span> <span class="inline-formula">=</span> 8) and woodland areas (<span class="inline-formula"><i>n</i></span> <span class="inline-formula">=</span> 7) at 20 <span class="inline-formula">cm</span> depth. A threshold of about 35 % (<span class="inline-formula">±</span> 8 %) of
volumetric water content was necessary to initiate effective infiltration. Soil moisture averaged during the wetting period of each event was the
best metric for the prediction of recharge. The model performed reasonably well, estimating recharge during single rainfall events. It was also
capable of simulating 88 % of the average annual recharge volume despite considerable differences in the performance between years. The
event-based approach is potentially applicable to other karstic systems where soil moisture and precipitation measurements are available to predict
karst groundwater recharge.</p> |
| first_indexed | 2024-04-10T21:38:04Z |
| format | Article |
| id | doaj.art-6aad3f295bf14b13b47f1bb2d692f8bb |
| institution | Directory Open Access Journal |
| issn | 1027-5606 1607-7938 |
| language | English |
| last_indexed | 2024-04-10T21:38:04Z |
| publishDate | 2023-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Hydrology and Earth System Sciences |
| spelling | doaj.art-6aad3f295bf14b13b47f1bb2d692f8bb2023-01-19T07:53:13ZengCopernicus PublicationsHydrology and Earth System Sciences1027-56061607-79382023-01-012738540010.5194/hess-27-385-2023Estimating karst groundwater recharge from soil moisture observations – a new method tested at the Swabian Alb, southwest GermanyR. Berthelin0T. Olarinoye1M. Rinderer2M. Mudarra3D. Demand4M. Scheller5A. Hartmann6A. Hartmann7Chair of Hydrological Modeling and Water Resources, Freiburg University, Freiburg 79098, GermanyChair of Hydrological Modeling and Water Resources, Freiburg University, Freiburg 79098, GermanyChair of Hydrological Modeling and Water Resources, Freiburg University, Freiburg 79098, GermanyDepartment of Geology and Center of Hydrogeology of the University of Málaga, Faculty of Science, 29071, Málaga, SpainChair of Hydrology, Freiburg University, Freiburg, 79098 GermanyChair of Hydrological Modeling and Water Resources, Freiburg University, Freiburg 79098, GermanyChair of Hydrological Modeling and Water Resources, Freiburg University, Freiburg 79098, GermanyInstitute of Groundwater Management, Technical University of Dresden, 01069 Dresden, Germany<p>Understanding groundwater recharge processes is important for sustainable water resource management. Experimental approaches to study recharge in karst areas often focus on analysing the aquifer response using a disintegration of its outlet signals, but only a few approaches directly investigate the recharge processes that occur at the surface of the system. Soil moisture measurements have a high potential to investigate water infiltration to deeper soil depth or epikarst with an easy and not too intrusive installation. They can yield long-term measurements with high temporal resolution. Using these advantages, we developed and tested a method to estimate recharge based on soil moisture measurements. The method consists of the extraction of linked events in rainfall, soil moisture, and discharge time series, as well as a subsequent fitting of the parameters of a simple drainage model to calculate karst recharge from soil moisture metrics of individual events. The fitted parameters could be interpreted in physically meaningful terms and were related to the properties of the karstic system. The model was tested and validated in a karst catchment located in southwest Germany with hourly precipitation, soil moisture, and discharge data of 8 years duration. The soil moisture measurements were distributed among grassland (<span class="inline-formula"><i>n</i></span> <span class="inline-formula">=</span> 8) and woodland areas (<span class="inline-formula"><i>n</i></span> <span class="inline-formula">=</span> 7) at 20 <span class="inline-formula">cm</span> depth. A threshold of about 35 % (<span class="inline-formula">±</span> 8 %) of volumetric water content was necessary to initiate effective infiltration. Soil moisture averaged during the wetting period of each event was the best metric for the prediction of recharge. The model performed reasonably well, estimating recharge during single rainfall events. It was also capable of simulating 88 % of the average annual recharge volume despite considerable differences in the performance between years. The event-based approach is potentially applicable to other karstic systems where soil moisture and precipitation measurements are available to predict karst groundwater recharge.</p>https://hess.copernicus.org/articles/27/385/2023/hess-27-385-2023.pdf |
| spellingShingle | R. Berthelin T. Olarinoye M. Rinderer M. Mudarra D. Demand M. Scheller A. Hartmann A. Hartmann Estimating karst groundwater recharge from soil moisture observations – a new method tested at the Swabian Alb, southwest Germany Hydrology and Earth System Sciences |
| title | Estimating karst groundwater recharge from soil moisture observations – a new method tested at the Swabian Alb, southwest Germany |
| title_full | Estimating karst groundwater recharge from soil moisture observations – a new method tested at the Swabian Alb, southwest Germany |
| title_fullStr | Estimating karst groundwater recharge from soil moisture observations – a new method tested at the Swabian Alb, southwest Germany |
| title_full_unstemmed | Estimating karst groundwater recharge from soil moisture observations – a new method tested at the Swabian Alb, southwest Germany |
| title_short | Estimating karst groundwater recharge from soil moisture observations – a new method tested at the Swabian Alb, southwest Germany |
| title_sort | estimating karst groundwater recharge from soil moisture observations a new method tested at the swabian alb southwest germany |
| url | https://hess.copernicus.org/articles/27/385/2023/hess-27-385-2023.pdf |
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