The radial collector well is on perennial river on a alluvial terrain. The river is a braided one. The water channels on the stream bed are separated by sand stretches.
The information provided by you is inadequate to arrive at the answer.
Well,
thats depend on the values of the hydraulic coefficients of the sediments(water bearing horizons) and the design of the radial well.
regards
it depends on lot of parameter but i thinks you can find your answer in WHO code.
The amount of water a radial well can yield depends on various factors like, hydraulic properties of the aquifer; width & length of the river contributing to the water yield; thickness of the saturated media; length & diameter of the radial arms; depth at which the radial arms are embeded; diameter & depth of the collector well; etc.
You may try to refer the following article published in the ASCE journal:
Rajagopalan.S.P and Narasimha Prasad.N.B, 1989, Subsurface Water in River Beds as Source for Rural Water Supply Schemes, Journal of Water Resources Planning And Management, American Society of Civil Engineers, New York, Vol.115, No.2.
Thanks to all of you for your interest on the question.
I felt to clarify a little on the issue. Whether the radial collecector well in question draws (1) only ground water, draws (2) only surface water or (3) both. Being on the perennial river bed induced recharge from the stream to the radials is very much there. Whether the amount of induced flow to the radials is part of surface water or ground water. If it is a mixture of both surface and ground water how can that be quantified.
Well,
Both,
Chloride concentration is used to calculate the fractionation ratio because it is least affected by chemical reactions (Langmuir, 1997).
R% = {[Cl m ] - [Cl r ]} / {[Cl g ] - [Cl m ]} × 100,
Cl m: chloride concentration of mixed water (collector); suppose, 230 ppm
Cl r: Chloride concentration of river; suppose, 152 ppm
Cl g : Concentration of chloride in groundwater; suppose, 1330 ppm
R % = (230 ppm -152 ppm) / (1330 ppm -230 ppm)} x 100 = 7.1%.
This means that 7.1% of the chloride concentration in the mixed water is derived from the river water before mixing and 92.9% from the groundwater.
Here, you can quantify on the bases of each percentile.
Sincerely
In my opinion, as the river is perennial, water collected through the radials is nothing but the surface water which is infiltrated through the river bed material, without too much of residence time. If that is the case, there can be no differentiation between surface water or groundwater. However, if one wants to try, then the method mentioned by Dr. Bayan can be followed or tracer method using isotopes can be tried.
Thanks to Dr. Bayan and Dr. Prasad for your suggestions. Dr Bayan's suggestions refer to a situation after the construction of the radial collector well. I meant if we can ascertain before construction. I would sincerely solicit your views.
Well,
Before the construction, in this case, the mixing method should be tested by drilling a water well to the expected depth. Experimental and pumping test , further hydrochemical and / or isotope analyzes are carried out, and the final decision is made to build it according to the desired target.
Regards
In any given scenario along the river course, there will be surface flow and sub-surface flow (below the river bed within the river bed material - aquifer). The water in the aquifer below the river is a mixture of surface water/river water and groundwater discharging into the river system from the banks. However, the scenario gets diluted once a well is constructed and artificially river water is induced into the aquifer through creating any type of drawdown or gradient. With this the dominance of river water over groundwater takes place, and with time it may be significantly river water.