Dear Group Member,

With reference to my earlier queries (did not get any response at that time), a
recent response from Mr. Alessandro Casasso is placed below.

Regards
Kumar
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C. P. KUMAR
Scientist 'E1'
National Institute of Hydrology
Jal Vigyan Bhawan
Roorkee - 247667 (Uttarakhand)
INDIA

Web Page : http://www.angelfire.com/nh/cpkumar/
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Re: Modelling of seawater intrusion
Monday, September 22, 2008 3:52 PM
From: "alessandro.casasso" <alessandro.casasso@...>
To: "C. P. Kumar" <cpkumar@...>

Have you found any answer to you questions? I'm working at a MS thesis about
Feflow modelling of a shallow aquifer in Venice. I will not try to model salt
pans - too difficult even to think where they are.

About rainfall and evapotranspiration: I've got rainfall and temperature data. I
calculated ET with Blaney-Criddle formula, but I found that results are
overestimated. I tried to reduce risults by comparing modeling results with real
results (in the area I'm studying, I can get results from 11 piezometers..) and
I found that BC formula results can be divided by 3. I found that ET estimation
is one of the most difficult parts of shallow aquifers modeling...

I've got no idea about brackish water in rivers. In my model, I assigned the
tidal oscillations (1st type boundary conditions) also to a channel of Venice
lagoon that encloses my modeling domain.

I developed a relation between TDS and conductivity (I've got specifical
conductivity measures), but I did a very rude approximation. As I'm modeling a
peninsula, I thought that seawater contains most NaCl , so conductivity
(microSiemens per cm) is dominated by NaCl concentration. Conductivity is linked
to NaCl concentration in this way: - every ion has an equivalent conductivity,
that is the specifical conductivity for a concentration of 1 equivalent/liter
(for NaCl, 1 equivalent = 1 mole); - this equivalent conductivity is also linked
to concentration by Onsager formula; - specifical conductivity = equiv conduct x
concentration [mole/liter]

I visited your site some time ago, I found it very interesting. Sorry for my
English, I have to improve it. About my tip on TDS-conductivity: as we say in
Italy "here I tell it, and here I deny it" :-) I'm only a MS student and I got
these advice reading a laboratory chemistry manual...

See you soon on this forum,
Alessandro Casasso

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Date: Sun, 20 May 2007 20:03:41 -0700 (PDT)
From: "C. P. Kumar" <cpkumar@...>
Subject: Modelling of seawater intrusion
To: hydforum@yahoogroups.com, hydrologymodel@...,
gwmodel@yahoogroups.com, gwrm@..., rhydrology@yahoogroups.com,
feflow@..., seawat@..., coastal@googlegroups.com

Dear Group Member,

I am grateful to the following members/experts for their interesting/useful
observations/comments/suggestions on my report "Modelling of a Coastal Aquifer
using FEFLOW" (available at ftp://ftp.wasy.de/FEFLOW/Goa.pdf ).

(1) Reinhard Zapata (Waterloo Hydrogeologic, Canada)
(2) Krishnaiah C. (India)
(3) S.V.N.Rao (Roorkee, India)
(4) V.V.S. Gurunadha Rao (Hyderabad, India)
(5) Michael Jorgensen (Australia)

I am prompted to seek further suggestions for the following issues in modelling
the seawater intrusion in coastal aquifers.

(a) How to model the effect of salt pans on groundwater in coastal areas?

(b) How to incorporate the evaporation from open water surfaces (e.g. to define
time-variant boundary condition in case of rivers) and evaporation from shallow
groundwater table?

(c) How to model the effect of brackish water in rivers (due to tidal backwater
effect from sea) on groundwater in coastal areas?

(d) How to develop correlation between resistivity values and TDS and between
resistivity values and hydraulic conductivity.

(e) Suitability of Kriging, Akima and Inverse Distance Weighting techniques for
interpolation/regionalization of different parameters/variables.

Any suggestions for the above will be helpful for extension of this (or similar)
study in future.

There is a small errata in the report - title of figure 7 may be read as
"Measured Values of Hydraulic Conductivity (*10E-4 m/s)" - the multiplier was
missing.

Regards
Kumar
==================================================
C. P. KUMAR
Scientist 'E1'
National Institute of Hydrology
Jal Vigyan Bhawan
Roorkee - 247667 (Uttarakhand)
INDIA

Web Page : http://www.angelfire.com/nh/cpkumar/
==================================================