International: Use of phase-sensitive radar to monitor discharge and recharge of Moroccan aquifers
Lead Research Organisation:
British Antarctic Survey
Department Name: Science Programmes
Abstract
The motivation for the proposed study is the difficulty in managing water abstraction in the absence of good information about the degree of charge of aquifers, the growing consensus that groundwater recharge will diminish in arid and semiarid areas in sub-Saharan and western Africa, and the ever-increasing pressure on aquifers from increased abstraction.
The aim of the proposed work is to determine the feasibility of using a NERC-developed instrument (ApRES) to aid the management of water resources in arid and semi-arid regions by allowing water-table depths to be monitored without recourse to boreholes. The challenge has both technical and societal aspects.
The Autonomous phase-sensitive Radio Echo Sounder (ApRES) was jointly developed by the British Antarctic Survey and University College London to monitor the changing thickness of the floating portion of the Antarctic Ice Sheet. Lightweight, robust and relatively inexpensive, ApRES was designed to be deployed on an ice sheet for a year or more, withstanding the harsh conditions of the Antarctic winter.
The problem of detecting the changing depth of the base of an ice sheet is essentially the same as that of detecting the depth of the water table in an otherwise dry environment. ApRES can therefore potentially be used as relatively inexpensive (compared with boreholes) method for monitoring the depth of the water table, providing a tool to assist in the management of water abstraction.
Our choice of country for this study is Morocco. Morocco boasts a useful range of soil types, climatic conditions, and water table depths. Its many boreholes provide the necessary ground truth by offering an independent measure of the depth of the water table.
A short pilot study was undertaken in Morocco in March 2017, funded through a NERC ODA Innovation pump-prime grant, and locally facilitated by the partners on the present proposal. The results were promising. Several sites were visited, with varying water table depths, primarily to find a suitable location for a multi-hour deployment. The instrument was able to detect the water table at most of the sites and was able to monitor its changing depth over a 6-hour (overnight) trial.
The promising results from the pilot now prompts the next step - a comprehensive study in Morocco, alongside our Moroccan partners, to determine more precisely the envelope of capability of the instrument, and to reduce impediments to its use in monitoring groundwater depth: ease of use, robustness, cost. In the proposed study visits to different field sites in Morocco will allow the utility of ApRES to be assessed for a range of soil types, soil moisture contents, water table depths, local conditions (urban/rural) and seasons (wet/dry). The instrument and antennas will be scrutinised to see where costs can be reduced and what hardening will be needed to deal with the non-polar conditions. Finally, the data-processing steps will be rationalised such that a non-expert could carry them out.
The societal aspect of the challenge, how to ensure uptake of any new technique, will be addressed in two ways. An independently resourced, but parallel study that we have instigated (to be delivered by Development i-Teams in October and November 2017) will investigate how having the ability to monitor the discharge and recharge of aquifers in real time can be used to improve the sustainability of groundwater exploitation in water-scarce regions. Second, our project partners in Morocco will prepare an implementation pathways document to define how the technology could be rolled out in Morocco. Should the project that we are proposing here confirm the technical feasibility of using ApRES for ground water monitoring in arid regions, the outcomes of the i-Teams study and the implementation pathways report will put us in a strong position to take the project forward to the next level of application, both within Morocco and beyond.
The aim of the proposed work is to determine the feasibility of using a NERC-developed instrument (ApRES) to aid the management of water resources in arid and semi-arid regions by allowing water-table depths to be monitored without recourse to boreholes. The challenge has both technical and societal aspects.
The Autonomous phase-sensitive Radio Echo Sounder (ApRES) was jointly developed by the British Antarctic Survey and University College London to monitor the changing thickness of the floating portion of the Antarctic Ice Sheet. Lightweight, robust and relatively inexpensive, ApRES was designed to be deployed on an ice sheet for a year or more, withstanding the harsh conditions of the Antarctic winter.
The problem of detecting the changing depth of the base of an ice sheet is essentially the same as that of detecting the depth of the water table in an otherwise dry environment. ApRES can therefore potentially be used as relatively inexpensive (compared with boreholes) method for monitoring the depth of the water table, providing a tool to assist in the management of water abstraction.
Our choice of country for this study is Morocco. Morocco boasts a useful range of soil types, climatic conditions, and water table depths. Its many boreholes provide the necessary ground truth by offering an independent measure of the depth of the water table.
A short pilot study was undertaken in Morocco in March 2017, funded through a NERC ODA Innovation pump-prime grant, and locally facilitated by the partners on the present proposal. The results were promising. Several sites were visited, with varying water table depths, primarily to find a suitable location for a multi-hour deployment. The instrument was able to detect the water table at most of the sites and was able to monitor its changing depth over a 6-hour (overnight) trial.
The promising results from the pilot now prompts the next step - a comprehensive study in Morocco, alongside our Moroccan partners, to determine more precisely the envelope of capability of the instrument, and to reduce impediments to its use in monitoring groundwater depth: ease of use, robustness, cost. In the proposed study visits to different field sites in Morocco will allow the utility of ApRES to be assessed for a range of soil types, soil moisture contents, water table depths, local conditions (urban/rural) and seasons (wet/dry). The instrument and antennas will be scrutinised to see where costs can be reduced and what hardening will be needed to deal with the non-polar conditions. Finally, the data-processing steps will be rationalised such that a non-expert could carry them out.
The societal aspect of the challenge, how to ensure uptake of any new technique, will be addressed in two ways. An independently resourced, but parallel study that we have instigated (to be delivered by Development i-Teams in October and November 2017) will investigate how having the ability to monitor the discharge and recharge of aquifers in real time can be used to improve the sustainability of groundwater exploitation in water-scarce regions. Second, our project partners in Morocco will prepare an implementation pathways document to define how the technology could be rolled out in Morocco. Should the project that we are proposing here confirm the technical feasibility of using ApRES for ground water monitoring in arid regions, the outcomes of the i-Teams study and the implementation pathways report will put us in a strong position to take the project forward to the next level of application, both within Morocco and beyond.
Planned Impact
Who might benefit from this project?
The ultimate beneficiaries of the project are water users such as communities, farmers and industries suffering as a result of groundwater management that is hindered by not knowing the day-to-day state of the groundwater levels. One of the principal technical difficulties faced by water basin managers, whether they are government agencies or farm cooperatives, is that groundwater is a resource that is essentially invisible, and that the negative effects of over-abstraction often become obvious only when wells run dry. The water users will benefit when implementation of our ApRES groundwater monitoring will lead to water management decisions that will protect the long-term sustainability of this precious resource. Maintaining this resource will also benefit wildlife and ecosystems, which in turn will have economic benefits through e.g. encouraging tourism industry. The beneficiaries will in the first instance be located in Morocco, where our field work will take place and where we would expect adoption to occur first. We will also put mechanism in place that pave the way for adaptation/adoption of the technology in other (semi)arid DAC-listed countries, targeting first African countries with Climate Innovation Centres (Kenya, Ethiopia, Ghana, South Africa), who are linked to our Project Partner Morocco Climate Innovation Centre.
The more direct beneficiaries will be water basin managers in Morocco, as a result of the engagement catalysed by our Moroccan Project Partners.
How might they benefit from this project?
The project is proving and refining a technique for groundwater level monitoring, where none exists today, short of by drilling boreholes. The project is also a study of how to implement the technique, both in Morocco and beyond. It will not in itself create a network of monitoring stations, but it will point out how technical and societal impediments to such a network can be addressed. The project will hence pave the way, both in terms of technology development, and implementation plan for the technology once proven, for water managers to gain visibility of the previously hidden status of groundwater levels. This will aid evidence-based decision making to protect groundwater resources from over-exploitation and achieve long-term sustainability.
The ultimate beneficiaries of the project are water users such as communities, farmers and industries suffering as a result of groundwater management that is hindered by not knowing the day-to-day state of the groundwater levels. One of the principal technical difficulties faced by water basin managers, whether they are government agencies or farm cooperatives, is that groundwater is a resource that is essentially invisible, and that the negative effects of over-abstraction often become obvious only when wells run dry. The water users will benefit when implementation of our ApRES groundwater monitoring will lead to water management decisions that will protect the long-term sustainability of this precious resource. Maintaining this resource will also benefit wildlife and ecosystems, which in turn will have economic benefits through e.g. encouraging tourism industry. The beneficiaries will in the first instance be located in Morocco, where our field work will take place and where we would expect adoption to occur first. We will also put mechanism in place that pave the way for adaptation/adoption of the technology in other (semi)arid DAC-listed countries, targeting first African countries with Climate Innovation Centres (Kenya, Ethiopia, Ghana, South Africa), who are linked to our Project Partner Morocco Climate Innovation Centre.
The more direct beneficiaries will be water basin managers in Morocco, as a result of the engagement catalysed by our Moroccan Project Partners.
How might they benefit from this project?
The project is proving and refining a technique for groundwater level monitoring, where none exists today, short of by drilling boreholes. The project is also a study of how to implement the technique, both in Morocco and beyond. It will not in itself create a network of monitoring stations, but it will point out how technical and societal impediments to such a network can be addressed. The project will hence pave the way, both in terms of technology development, and implementation plan for the technology once proven, for water managers to gain visibility of the previously hidden status of groundwater levels. This will aid evidence-based decision making to protect groundwater resources from over-exploitation and achieve long-term sustainability.
| Description | In the Moroccan context, ground-based, phase sensitive radar is capable of determining and monitoring the depth of the water table. The alternative approaches are time-consuming and bulky. The only other approach to monitoring the depth of the water table, which is to use a borehole, is expensive and, by definition, non-portable. In addition, the instruments used to measure the depth within the borehole are prone to failure. There have been two workshops held at BAS which Moroccan partners attended. The first of these helped forge links between Moroccan Water basins Agencies (or one in particular) and the UK hydrogeological community. The second enabled the joint authorship of a report that outlined a roadmap that illustrated how the technology could be developed to make an impact in DAC countries in Africa. |
| Exploitation Route | We are continuing discussions with our Moroccan partners. They are keen to focus more on the prospecting aspects of the instruments, and would like to have more fieldwork done demonstrate to the water basin agencies the potency of the technique. We extended the project, in collaboration with University of Cambridge colleagues, by visiting Kruger National Park in South Africa to undertake additional fieldwork in a different hydrogeological context. It is likely that we will undertake further studies there. Additional extension have been made, again with University of Cambridge colleagues (this time in the Archeology Department), and it involved some fieldwork in India to study aspects of the hydrology and how they might have related to the historical development of the Two Rains region in the north west of the country. An additional follow-up of the research has been to obtain some Cambridge Africa funding to carry out fieldwork in Ethiopia. |
| Sectors | Agriculture, Food and Drink,Environment |
| Description | The impacts at this stage are admittedly subtle. A key Water Basins Agency in Morocco is now fully aware of the potential of the instrument both to monitor and prospect for groundwater. The instrument would clearly need further development before it could be widely used, but the principle has been proved. Thus the findings have primarily been used to raise awareness with the relevant authority, and to define the development that would be needed to move forward. |
| First Year Of Impact | 2019 |
| Sector | Agriculture, Food and Drink |
| Impact Types | Economic |
| Description | Collaboration with Hassan 1st University of Settat |
| Organisation | Hassan-I University |
| Country | Morocco |
| Sector | Academic/University |
| PI Contribution | We have introduced the hydrogeology department to a new technique for monitoring and detecting groundwater. We have undertaken field activities with our partners to provide data for joint papers. |
| Collaborator Contribution | Our partners have provided us with local information about every needed to undertake successful fieldwork in Morocco, from accommodation to a local knowledge of the hydrogeology of the region. |
| Impact | A draft paper on the technique of using ApRES to monitor and detect groundwater in the Moroccan context. |
| Start Year | 2018 |