Dear Redha,

I m completely agree with Yash Sir.

We do 2D areal simulation modeling when we do not have the adequate data
(T,S,head etc) of some layers under consideration. As in 2D areal simulations,
effects of partial penetration of pumping is usually ignored (well is considered
to be fully penetrating the aquifer) because the effects of partial pumping are
limited to a radius equal to 1.5 (KX/KY)1/2 times the saturated thickness of the
aquifer.
2D modeling is perfectly valid under data scarced condition. No doubt about
that.

With Best Regards
Vivek Gupta
Mtech (Water Resources)
IIT Kharagpur



Yashpal Saharawat <yash_saharawat@...> wrote:
Dear Redha

You can do pumping test under in 2D modelling in axis-symmetrical mode when you
really do not know much about aquifer parameters and hydraulic gradient and
specially in confined aquifer (as Vivek's case) it can be useful. I appreciate
yours suggestions.

thanks with regards

Yashpal Singh Saharawat (Ph.D. DAAD)
Scientist
International Rice Research Institute-India office
1st Floor NASC Complex DPS Marg Pusa
New Delhi-110012 India
+ 91 11 25843802/25842802 (O)
+ 91 9311007818 (M)




----- Original Message ----
From: "rbeddek@..." <rbeddek@...>
To: visual-modflow@...
Sent: Wednesday, November 1, 2006 3:55:43 AM
Subject: Re: [visual-modflow] Pumping Well Schedule...

Dear Vivek,

I would like this opportunity to put this forward to anyone in the group:
How valid is simulating pumping in a 2D groundwater model ?, as a 2D set
up will miss the radial dimension which is proper to a pumping bore set
up.

I 'll appreciate your thoughts on that.

Cheers,
Redha


Please find embeded answers
>
>
> ----- Original Message ----
> From: vivek gupta <jazzvivek_2002@...>
> To: visual-modflow@...
> Sent: Sunday, October 29, 2006 9:43:35 AM
> Subject: Re: [visual-modflow] Pumping Well Schedule...
>
> Dear Yash..
>
> Thank you for ur intelligent reply. Sir, some more things i wanted to
> ask u, As i m a beginner in Modeling, so i m seeking some more help frm
> u...
>
> 1) Does MODFLOW account for the pumping hrs or it only accounts for the
> pumping days, because of the fact that pumping schedule in MODFLOW
> should be throughout the stress period.
>
> For your test you will be taking only one unit it may be days or hours
> whichever suits to your problem. But for one cycle of analysis it will be
> a single unit.
>
> 2) I want to calibrate the model for 2 years transient period, I have
> weekly groundwater data, can u suggest me how should i divide this 2 yrs
> in to stress period and time steps for getting good results.
>
> You can take stress period in hours/days and give it as a zero value for
> one stress period. Actually the unit will depend on your objective what
> you want to get.
>
> 3) Actually Sir I m doing 2D modeling, and i have the case of a
> confined aquifer, i.e. top layer confined, confined aquifer and again
> layer. and i want to model the saturated thickness as my model layer,
> but the problem is that a river which i have to use as a Cauchy boundary
> condition, is partially penetrating upto only upper confined layer (
> river bed elevation is above the saturate thickness of aquifer), so how
> can i use this river as a cauchy boundary without (perhaps)any hydraulic
> connection between them.
>
> If you have confined layer then river or anything outside is not going to
> matter and to have effect of river it should be unconfined and you can
> take total amount of water in yours layer as fixed i.e. if water coming
> from river by seepage it goes out from the other side of layer by
> gradient.
> .
>
> 4) The properties( T & S) and the boundary conditions that i will be
> assigning, will that be only for the saturated thickness(model layer) or
> i have to assign those for the top layer too.
>
> If you have confined layer then then need not to assign for upper layers.
> but its betetr to assign as while writing paper you will need these
>
> Thanks again for ur fast response, I m again lookin forward for ur fast
> reply, it will help me assist in my project.
>
> With Best Regards
> Vivek Gupta
>
>
> Yashpal Saharawat <yash_saharawat@...> wrote:
> Dear Vivek
>
> You can give pumping rate as 0 pumping rate during the non-pumping period
> and you should use actual well screen thickness.
>
> cheers...
> yash
>
>
> ----- Original Message ----
> From: vivek gupta <jazzvivek_2002@...>
> To: visual-modflow@...
> Sent: Friday, October 27, 2006 11:39:46 AM
> Subject: [visual-modflow] Pumping Well Schedule...
>
> Hi all...
>
> I m doing 2D transient GW modeling using Visual MODFLOW. I m facing some
> problem while entering pumping schedule. The problem is that MODFLOW
> allows a continuous pumping schedule, but in my study area pumping is
> intermittent, like in rainy season 15 days in a month will be used for
> pumping, rest 15 days sustain with rain, i explain my prob with an
> example..( I have the case of constant pumping rate in one particular well
> site)
>
> suppose i have following pumping schedule for one of the well...
> jan- daily, 10h , -16 lps
> feb- daily, 10h, -16 lps
> mar- daily, 10h , -16 lps
> apr- daily, 10h, -16 lps
> may, daily, 10h , -16 lps
> june, 15 days, 6h, -16 lps
> july, 10 days, 6h, -16 lps
> AUG, daily, 6 h, -16 lps
> .
> . and so on.
>
> Now while entering in MODFLOW i can't take account of those 15 days of
> june and july in which no pumping had been done, because MODFLOW allows
> continuous pumping schedule and the pumping schedule has to be through-out
> the full transient period, thats y i could'nt follow the continous pumping
> schedule too.
>
> so the only way out is...suppose if i have 2 yrs transient stress period
> with a constant pumping rate, the pumping schedule will be..
> start day stop day pumping rate(LPS)
> o 720 -16
>
> I want to check my above mentioned conclusion..suggestions are heartly
> welcomed.
>
> ALSO another question is that in 2D modeling shud the pumping wells'
> screen thickness be entered with full saturated thickness or shud i use
> the actual well screen thickness if i have the data of screen locations.
>
> With best Regards
> Vivek Gupta
> IIT kharagpur