Well,

The dynamic case implies that the reserve cannot be designed in one time step, due to budget constraints, and that habitats can be lost before they are reserved, due for example to climate change, flowing springs or human development.

Returning to your question, the dynamic reserve represents the volume of water in the aquifer that comes out of the reservoir in springs, usually including the water that is located above the level of the spring discharge point.

Sincerely

Hello! Let's begin with your initial questions...

Definitions:

1) Dynamic reserve is associated with the groundwater storage capacity of an phreatic aquifer giving rise to a natural spring (In Spanish: El manantial). It is represents the aquifer's annual recharge via precipitation in cubic meters (m3/yr).

2) Drenajes manantiales y fuentes actually refers to two types of natural Springs - Springs and Artesian wells. Los manantiales or Springs are formed when groundwater within a local perched aquifer is forced to move laterally high above the main zone of saturation in an unconfined aquifer due to the presence of an aquitard, aquiclude or aquifuge. Los fuentes de aqua or Artesian wells are formed when a groundwater aquifer is "sandwiched" between two tilted aquicludes, producing an inclined confined aquifer system. Because groundwater is under pressure in this particular system, when the upper aquiclude (or cap rock) is pierced, water will flow out of the system naturally.without having to be pumped to the surface.

3) Aquifers and their hydraulic conductivities are controlled by the porosity and permeability of a rock or rock material present within the groundwater system. If an aquifer has "infiltration" but "no percolation or seepage", most likely the rock or rock material involved has either poor porosity, or poor permeability; thus resulting in low to very low hydraulic conductivity within said system.

Perhaps the following publications might be of some interest to you:

Groundwater Essentials

(Australian Goernment - National Water Commission, 2012)

http://www.groundwater.com.au/media/W1siZiIsIjIwMTIvMTAvMTYvMjBfNThfNTZfNTdfR3JvdW5kd2F0ZXJfZXNzZW50aWFscy5wZGYiXV0/Groundwater_essentials.pdf

The estimation of groundwater recharge from spring hydrographs

(KORMAZ, 1990)

Article The estimation of groundwater recharge from spring hydrographs

CLASIFICACIÓN HIDROGEOLÓGICA DE LAS FORMACIONES ROCOSAS

(Luis F. REBOLLO, Universidad de Alcalá - 1987)

https://portal.uah.es/portal/page/portal/GP_EPD/PG-MA-ASIG/PG-ASIG-67044/TAB42351/T3-Clasificaci%F3n%20hidrogeol%F3gica.pdf

Dear C. Mei-Ling Hamilton ,

Thanks a lot for your answer. Having read your answer, I am confused with this statement.

It is said that a main water source of aquifer is rain infiltration which is about 14 hm3 and dynamic reserve of aquifer is about 6 hm3.

It is confusing as you said dynamic reserve is aquifer recharge after precipitation.

Hello again! Yes, I can see how my initial response is confusing. Let me attempt to clear things up.

First, to visualize what is being described, refer to "Fig. 1 - 'Schematic depiction of an aquifer'" on page 210 in the article entitled "The estimation of groundwater recharge from spring hydrographs" by KORMAZ, 1990. Please note from the figure that Dynamic reserve is V, Static reserve is V subscript s, and the Discharge level of the aquifer is shown as a dashed line (- - -).

Second, please refer to the excellent definition of Dynamic reserve given by Bayan HUSSIEN.

As you previously stated, your source of confusion stemmed from the following sentence: "...the main water source of an aquifer is rain infiltration which is about 14 cubic hectometers and the dynamic reserve of the aquifer is 6 cubic hectometers".

The total recharge (or input) of water within the groundwater system of the depicted phreatic aquifer is rainfall (precipitation) at a volume of 14 hm3. However, only a portion of this stored input volume will subsequently discharge from the aquifer as a natural spring. This stored groundwater fraction is stated to be the dynamic reserve of the aquifer, and is reported as 6 hm3.

Referring back to "Fig. 1 - The Schematic depiction of an aquifer" (KORMAZ, 1990); the dynamic reserve represents the volume of groundwater located between the surface of the water table and the discharge level of the aquifer that actively discharges to form a spring. The static reserve represents the volume of groundwater located below the discharge level of the aquifer that is not discharge, but rather remains within zone of saturation where it is permanently stored.

Therefore, dynamic reserve is a fraction of the total volume of infiltrated precipitation stored within the groundwater system of a phreatic aquifer, that actively discharges as a natural spring.

Also...

The relationship between groundwater discharge and dynamic reserve is found on page 211, with mathematical formula (2) from KORMAZ, 1990, as follows:

Q = αV

or

V = 86 400 Q/α

where Q = Groundwater Discharge (cubic meters per second),

α = Discharge Coefficient (per day)

V = Storage Capacity or Dynamic Reserve (cubic meters)

Dear C. Mei-Ling Hamilton,

Let's say, I have a formulation to estimate aquifer's volume: 5·10e-7x^2 + 0,7861x+1092.

x is the height of the hydraulic head and I have data "Medida Validada (m)" and "Nivel Validada (m)".

Which one should I embed as x "Medida Validada (m)" or "Nivel Validada (m)" ?

:Hello! From the looks of your hypothetic question, two equations comes to mind; the Potentiometric or Hydraulic Head Equation (h) and DARCY's Law (Q).

Potentiometric or Hydraulic Head Equation:

h = Z + p/γ + v2/2g

where h = Hydraulic head

  Z = Elevation of a point measured above a chosen datum

[Measurement from sea level to the bottom of the Well screen].

  p/γ = Pressure head

[Measurement from the bottom of the Well screen to the surface

of the water].

  v2/2g = Velocity head

(Negligible for Groundwater)

which can also be written as

h = Z + ψ

where h = Hydraulic head

Z = Elevation energy

  ψ = Pressure energy

Therefore, look very closely as the description of your Hydraulic head data (x). The head measurement between sea level and bottom of the well screen is Z, whereas the head measurement between the bottom of the Well screen and the Well water surface is p/γ or ψ.

I believe that "Medida Validada" should correspond to Z, and "Nivel Validada" should correspond to p/γ or ψ.

Note:

Upon calculating the total Hydraulic head (h) from two (2) separate wells, you can then proceed to calculate Q (Aquifer volume) using DARCY's Law:

Q = KA[(Δh)/Δl)

or

 Q = KA[(h1 - h2)/d]

Well Water Reports and Hydrogeology

(NELSON, 2003)

https://www.oregon.gov/oha/PH/HEALTHYENVIRONMENTS/DRINKINGWATER/SOURCEWATER/Documents/gw/wellreport.pdf

Potential Energy and Hydraulic Head

(ARTHUR et al.: Pennsylvania State University)

https://www.e-education.psu.edu/earth111/node/931

Correction: Q is the "Volumetric Flow or Discharge Rate of an Aquifer", not "Aquifer Volume"!

Review: Hydraulic head measurements - new technologies, classic pitfalls

(POST and von ASMUTH, 2013)

https://www.researchgate.net/profile/Jos_Asmuth/publication/257471742_Review_Hydraulic_head_measurements-New_technologies_classic_pitfalls/links/553b66180cf29b5ee4b6819b/Review-Hydraulic-head-measurements-New-technologies-classic-pitfalls.pdf?_sg%5B0%5D=0U7Pc6PYjoOud8ihTcDfOOrgy_2rWiudQKG6YYbRVc_71mwa-SG84fLyycBIYFyGksZs66hADqXsJgt9NaO0KQ.K93exX2njpD94Fq6kTdUhmqgQitRG9C79EaEisPa2WvEmQW9znXZbLdKsJwcHZJLNlTGADpspzNcoXMtwhoWnw&_sg%5B1%5D=JhAzXDJnNWICy1uVASO41ufQQXAk_naBtBN7PDUDjo8thgIm21UXIcOl7l4_O1bJ8XyaFcN0p5a56G5tyHDk86TMrksZj_lMFCiuhsfDV92H.K93exX2njpD94Fq6kTdUhmqgQitRG9C79EaEisPa2WvEmQW9znXZbLdKsJwcHZJLNlTGADpspzNcoXMtwhoWnw&_iepl=