Seepage meters directly measure the direction and rate of flow between groundwater and a surface water body like a lake or stream. The basic design encloses the sediment-water interface with a cylinder open at the bottom, and the change in water volume collected over time indicates flow direction and rate. Historical tracers like carbon-14 and chlorine-36 from past events are used to determine groundwater movement rates. Spring hydrographs resemble surface stream hydrographs, especially for unconfined or karst aquifers, showing seasonal discharge changes influenced by precipitation and infiltration.

1. "Instruments for measuring the flow
of water between groundwater and a
surface water body such as a lake,
wetland, estuary, or stream."
Seepage Meter

2. The basic concept of a seepage meter is to enclose and isolate an area of the
sediment–surface water interface with a cylinder that is open at its base
and vented at the top to a plastic collection bag (Figure 1).
The change in the volume of water in the collection bag over a measured
time interval is used to determine the direction and rate of flow between
surface water and groundwater.
Mechanism

3. A gain in water volume in the collection bag indicates that flow is occurring
from groundwater to surface water
A loss in water volume indicates that flow is occurring from surface water to
groundwater.
Mechanism

4. flow measurements can be made without measurements of the
hydraulic conductivity of the sediment.
can be constructed inexpensively from readily available
materials and can be custom-built for specific applications.
When flow measurements from seepage meters are combined with
hydraulic head measurements from mini-piezometers, the
hydraulic conductivity of the bottom sediment can be calculated.
Advantages of seepage meter

5. "A chemical entity (ion, radical) for which high
concentrations resulted from some historical
event. It has long time to move and is used to
determine the rate of movement or to estimate
the recharge rate (e.g. change of farming
practice or factory pollution)."
Historical
Tracers

6. • Groundwater contains a larger or smaller amount of inorganic and organic
substances, mainly in solution but also in colloidal or even suspended form.
• Suspended matter is not a usual feature of groundwater, because such particles are
effectively filtered out due to the generally slow rate of movement through the
interstices in aquifers. It may be, however, a noticeable component in fast-flow
systems such as those typically developed in karstic terrain.
• Ions dissolved for a considerable length of time may be utilized to estimate recharge
rate since the mixture.
Principle

7. Types of tracers
The most important historical tracers for isotope
hydrological studies are those that are commonly used are
bomb tracers:
1. 3 H
2. 14C
3. 36Cl
4. 137Cs
For these the peak injection occurred in 1963/1964
(Fig.2.1).

8. "The spring discharge hydrograph is the final
result of various processes that govern the
transformation of precipitation and other
water inputs in the spring's drainage area into
the single output at the spring."
Spring
Hydrograph

9.  In many cases, the discharge hydrograph of a spring closely resembles hydrographs
of surface streams, particularly if the aquifer is unconfined and reacts relatively
quickly to water input.
 Springs draining karst and intensely fractured aquifers are typical examples—their
discharge can increase several times after heavy rains.
 At the opposite spectrum are deep ascending springs isolated from a direct influence
of surficial processes, such as infiltration of precipitation and showing only slight,
delayed seasonal changes in discharge characteristics.
Characteristics

10. • The complexity of the water budget determination depends on many natural and anthropogenic
factors present in the general area of interest, such as climate, hydrography and hydrology,
geologic and geomorphologic characteristics, hydrogeologic characteristics of the surface soil and
subsurface porous media, land cover and land use, presence and operations of artificial surface
water reservoirs, surface water and groundwater withdrawals for consumptive use and irrigation,
and wastewater management.
• The shape of a discharge hydrograph depends on the size and shape of the drainage area, as well
as the precipitation intensity.
Factors

11. Possible springwater budget components influencing yield(Qs)

12. • Analysis of spring hydrographs always includes:
• determination of the general statistical parameters of the time series, such as average,
minimum, and maximum flows for the period of record
• Standard deviation of the flows
• Coefficient of variation
• Flow duration curves
• Frequency of characteristic flows at the minimum
Analysis

13. Cost Complexity Applicability Customizable?
Seepage meter low simple
lake, wetland,
estuary or
stream
yes, can be
tailored for
specific needs
Historical tracers high sophisticated
water rich in
specific tracer
no
Spring hydrograph medium moderate
limited to karst
aquifers
no
Brief comparison

14. https://www.researchgate.net/publication/49825345_Estimation_of_Groundwater_Residence_Ti
me_Using_the_Cl-36_Bomb_Pulse
https://edis.ifas.ufl.edu/publication/AE465
https://link.springer.com/article/10.1007/s13201-018-0695-9
http://www.groundwateruk.org/Using-Man-Made-Gases-as-Groundwater-Tracers.aspx
https://www.tandfonline.com/doi/pdf/10.1080/02626669009492419
https://www.researchgate.net/publication/279947917_Spring_discharge_hydrograph
References

15. Thanks!