What is specific coefficient?
Definition. A factor that measures the absorbance of light per unit of path length (of the spectrophotometer cuvette, usually expressed in centimeter) and per unit of mass concentration (usually expressed in grams/liter)
What is aquifer transmissivity?
Transmissivity describes the ability of the aquifer to transmit groundwater throughout its entire saturated thickness (Figure 7). Transmissivity is measured as the rate at which groundwater can flow through an aquifer section of unit width under a unit hydraulic gradient.
How do I calculate specific yield?
The method involves the determination of the volume of dewatered material in the cone of depression during the course of a pumping test. The specific yield is then determined by comparing the volume of dewatered material with the total volume of discharged water.
Why is Storativity dimensionless?
15.1. Storativity (S) is a dimensionless measure of the volume of water that will be discharged from an aquifer per unit area of the aquifer and per unit reduction in hydraulic head. This will be equal to the effective porosity, minus the fractional volume of water retained under gravity drainage by capillary forces.
What is the advantage of a confined aquifer?
When such zones are penetrated by wells, the water rises above the point at which it was first found because a confined aquifer is under pressure exceeding that of atmospheric pressure. Confining beds vary in permeability and, hence, in their ability to confine artesian aquifers.
How do you calculate water yield?
Depth (mm) Total water yield = surface runoff + groundwater flow + tile flow − transmission loss. The hydrological process for each year was quantified for the study area to determine the contribution of water balance to the overall annual average.
What controls specific yield?
Specific yield depends on the distribution of pores, their shape, and grain size (Table 1). The larger the surface area of the rocks or sediment particles per unit volume (“specific. surface area”), the more water adheres to these surfaces. This decreases the specific yield.
Is specific yield dimensionless?
2 Aquifer storativity and specific yield. Storativity (S) is a dimensionless measure of the volume of water that will be discharged from an aquifer per unit area of the aquifer and per unit reduction in hydraulic head.
How is storativity related to the storage of water?
Storativity is also known by the terms coefficient of storage and storage coefficient. Pumping a well in a confined aquifer releases water from aquifer storage by two mechanisms: compression of the aquifer and expansion of water. where S is storativity [dimensionless], Ss is specific storage [L-1] and b is aquifer (or aquitard) thickness [L].
How are specific storage properties determined in hydrogeology?
Specific storage. In the field of hydrogeology, storage properties are physical properties that characterize the capacity of an aquifer to release groundwater. These properties are Storativity (S), specific storage (Ss) and specific yield (Sy) . They are often determined using some combination of field tests (e.g.,…
What is the storativity of a confined aquifer?
Aquifer storativity (also called storage coefficient) of a confined aquifer is defined as S=S s b, where S is storativity (dimensionless), S s is specific storage (L -1) and b is thickness (L) of the aquifer ( 66 ). A confined aquifer is an aquifer that is confined between two aquitards ( 66 ).
Is the storativity of water a dimensionless measure?
Storativity (S) is a dimensionless measure of the volume of water that will be discharged from an aquifer per unit area of the aquifer and per unit reduction in hydraulic head. For a confined aquifer, storativity results only from the rock and fluid compressibilities and is typically very small (~10−4 –10 −5 ).