The Baseflow Detective looking to uncover the secrets of Tanzania’s rivers

Interview with Hezron Philipo, GroFutures by Sean Furey, Skat Foundation

Hezron Philipo has a BSc in Geology (University of Dar es Salaam, Tanzania), MSc in Water Resources and Environmental Management (University of Twente at  ITC, The Netherlands) and is currently doing his PhD research at Sokoine University of Agriculture in Tanzania as part of the UPGro GroFutures project.

I caught up with him at 41st WEDC Conference in Nakuru, Kenya, where he explained the research that he is doing and what new insights him and his colleagues are uncovering.

Continue reading The Baseflow Detective looking to uncover the secrets of Tanzania’s rivers

New paper helps unravel the mysteries of groundwater recharge in Benin

A new paper entitled: Relationships between rainfall and groundwater recharge in seasonally humid Benin: a comparative analysis of long-term hydrographs in sedimentary and crystalline aquifers has been published by the GroFutures team in collaboration with the GRIBA project (Groundwater Resources In Basement rocks of Africa), Belgian NGO – PROTOS, and Via Water in the Netherlands.

Key Points:

  • Groundwater Recharge – the set of processes that govern how rainwater seeps through soils and rocks to replenish aquifers – is not well understood across much of Africa. It is important to understand because it is central to determine the sustainable use of groundwater resources;
  • The authors analyse three rare sets of long-term (19-25 years) groundwater-level observations from three different, but common, geological settings in Benin;
  • The year-to-year changes in groundwater storage correlate well with rainfall patterns, but there were big differences the relate to the type of geology:
    • In the shallow, sand aquifer as much as 40% of the rainfall becomes groundwater
    • In the deeper sandstone and weathered crystalline rocks, a much lower proportion of rainfall becomes groundwater recharge (13% and 4% respectively)
  • Recharge was found to occur on a seasonal basis; however on a daily basis the groundwater fluctuations are best explained with a threshold of 5-15 mm per day – meaning that only more intense rainfall events lead to recharge.
  • These results are consistent with the growing body of evidence that, in Sub-Saharan Africa, intensification of rainfall associated with climate change may increase groundwater recharge.
  • Because the groundwater recharge is so strongly influenced by geology, it is essential for water resource planning that good geological maps are available and used, and that investment is made into long-term groundwater monitoring of strategic aquifers.

 

New paper: No evidence found of large scale groundwater depletion in major African aquifers

A new paper has been published by the GroFutures team as part of a Special Issue “Remote Sensing of Groundwater from River Basin to Global Scales”

Key Points : –

  • GRACE (Gravity Recovery and Climate Experiment) satellite can be used to estimate changes in water storage on time resolution of 1 month and a spatial resolution of about 450 x 450 km.
  • GRACE can be used to estimate groundwater storage changes where it is the dominant water mass. It is therefore useful in many areas of Sub-Saharan Africa where there are relatively few direct groundwater level measurements.
  • The paper focuses on the major sedimentary aquifers basins, where the majority of Africa’s groundwater resources are to be found. Away from these basins, groundwater storage is 1-2 orders of magnitude less.
  • There is no evidence of continuous long-term declining trends of Total Water Storage (mostly groundwater) in any of the major sedimentary aquifers, which indicates that none are stressed by current abstraction rateshowever it is important to stress that local scale depletion may be occurring but is beyond the resolution of GRACE to detect.

There are also some interesting findings in regard to the combination of GRACE and Land Surface Modelling and how well (or not) they represent groundwater recharge processes in the different basins.

Read the full paper here:

Bonsor, H.C.; Shamsudduha, M.; Marchant, B.P.; MacDonald, A.M.; Taylor, R.G. Seasonal and Decadal Groundwater Changes in African Sedimentary Aquifers Estimated Using GRACE Products and LSMs. Remote Sens. 201810, 904. http://www.mdpi.com/2072-4292/10/6/904

photo: Well for cattle, Songho, Mali, Credit: Emeline Hassenforder. Well for cattle and domestic use. , Songho, Mali.

 

Vote for Roads for Water!

Following an UPGro Catalyst Grant, over the last three years much work has gone into making use of roads for water management. Roads have in many areas an enormous impact on hydrology. Now often negative with roads causing erosion and sedimentation, or creating floods and water logging, this can be turned around to making roads instruments for water harvesting.

Under the RoadsforWater initiative see also www.roadsforwater.org  this approach is introduced in ten countries already contributing to improved water security for more than 2 Million people – hoping to get much higher still. With a global investment in roads amounting to more than 1 Trillion dollar, ‘adding’ water management to road development and maintenance can have an enormous impact.

 We now have very good news and a request to make:

RoadsforWater is among the 11 finalists of the 2017 – Resilience Award! We invite you to vote for this powerful initiative before Monday (15th Jan) Midnight (US Eastern Standard Time)? 

Here is the link: https://goo.gl/R8wbsW – (it is number five on the list).

Thank you for supporting this RWSN-UPGro fostered collaboration. Please also take some time to visit www.roadsforwater.org to find about more about this really interesting and successful initiative.

African aquifers can protect against climate change

Floods and droughts, feasts and famines: the challenge of living with an African climate has always been its variability, from the lush rainforests of the Congo to the extreme dry of the Sahara and Namib deserts. In north western Europe, drizzle and rain is generally spread quite evenly across the year, as anyone who has gone camping in British summer will tell you. But when annual rainfall happens within just a few months or weeks of the year then it is a massive challenge for farmers, towns and industry to access enough water through long dry seasons and to protect themselves and their land from flooding and mudslides when the rains come.

New research[1] suggests that Africa’s aquifers could be the key to managing water better. Professor Richard Taylor at UCL explains: “What we found is that groundwater in tropical regions – and Sub-Saharan Africa in particular – is primarily replenished from intense rainfall events – heavy downpours. This means that aquifers are an essential way of storing the heavy rain from the rainy season for use during the dry season, and for keeping rivers flowing.”

Continue reading African aquifers can protect against climate change

10 things to know about groundwater: #2

Hidden Treasure: 10 reasons to know more about groundwater / 2 priorities to take seriously – briefing note

GROUNDWATER is the water stored in the pores and other openings in rocks below ground. It is a precious resource which must be safeguarded for the benefit of mankind.

recharge

2. However, from a water resource point of view, what matters is how much natural replenishment, or recharge, takes place

Recharge rates vary from a few to hundreds of millimetres per year. In dry regions recharge ranges from zero to a few mm per year.

In humid regions recharge rates represent a higher proportion of rainfall.

Find out more:

What you can do:

Join the conversation through the RWSN Sustainable Groundwater Development community: https://dgroups.org/RWSN/groundwater_rwsn

Tropical groundwater resources resilient to climate change

Tropical groundwater may prove to be a climate-resilient source of freshwater in the tropics as intense rainfall favours the replenishment of these resources, according to a new study published in Environmental Research Letters.

Continue reading Tropical groundwater resources resilient to climate change

How to… design roads for water harvesting and groundwater recharge

Road construction affects the hydrology of an area; causes erosion, flooding, water logging (photo: Meta Meta Research)
Road construction affects the hydrology of an area; causes erosion, flooding, water logging (photo: Meta Meta Research)

Roads can devastate a landscape – scarring it, creating barriers for wildlife and accelerating stormwater so that valuable farmland, habitats and homes get washed away or polluted. What if didn’t have to be that way? What if roads would work with the grain of nature rather than against it?

One of the UPGro teams, lead by Frank van Steenbergen, at Meta Meta Research, has being doing just that. Over the last year, their UPGro Catalyst project has been researching how roads can be used for rainwater harvesting on a landscape scale to recharge aquifers and ponds for later use in the dry seasons.

Working closely with the Mekelle University and the Government of Ethiopia, Frank and his team (including the Institute for Development Studies) has not only been testing the theory but they have been putting into practice. In the region of Tigray, the methods of road design have captured imaginations as well as water and now the government is keen to roll these ideas out further around the country.

The Catalyst project is now complete and a number of resources are now available online:

The principles have also been explained in a recent RWSN-UPGro webinar on groundwater recharge

Roads for Water: Effecting Change in Tigray, Ethiopia

from the WaterChannel:

Question: How can dusty roads provide water?
Answer: By harvesting and storing rainwater when it falls on them. 

A 30 mm rainfall over a 1-kilometre stretch of road can produce up to 100,000 litres of water. This number points to a huge potential. And not one that has not been adequately tapped (around 7 billion USD are spent on road construction in sub-Saharan Africa alone).

Continue reading Roads for Water: Effecting Change in Tigray, Ethiopia

New Paper – Roads for water: the unused potential

Image

A new paper by Diego Garcia-Landarte Puertas, Kifle Woldearegay, Lyla Mehta, Martin Van Beusekom, Marta Agujetas Peréz and Frank Van Steenbergen from the Catalyst Project: Optimising Road Development for Groundwater Recharge and Retention

Download the open access Waterlines paper from Practical Action.

Abstract:

“Roads are generally perceived as infrastructure to deliver transport services, but they are more than that. They are major interventions in the hydrology of areas where they are constructed – concentrating runoff and altering subsurface flows. At present, water-related damage constitutes a major cost factor in road maintenance. Using ongoing research from Ethiopia, this article argues to reverse this and turn water from a foe into a friend and integrate water harvesting with road development.

Continue reading New Paper – Roads for water: the unused potential