gwrm : Message: Impact of Climate Change on Groundwater Recharge

Message #92 of 96 |

From cpkumar@... Wed Apr 08 17:34:21 2009
Return-Path: <cpkumar@...>
Received: (qmail 9436 invoked from network); 9 Apr 2009 00:34:19 -0000
Received: from unknown (98.137.34.45)
by m3.grp.sp2.yahoo.com with QMQP; 9 Apr 2009 00:34:19 -0000
Received: from unknown (HELO n44a.bullet.mail.sp1.yahoo.com) (66.163.168.138)
by mta2.grp.sp2.yahoo.com with SMTP; 9 Apr 2009 00:34:19 -0000
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoogroups.co.in; s=foxtrot; t=1239237255; bh=TtZ9JK8u99tp/Vij8U3VbixPrpQaG5MnXaOX0ejfX6c=; h=Received:Received:X-Sender:X-Apparently-To:X-Received:X-Received:X-Received:X-Received:X-Received:Date:To:Message-ID:User-Agent:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Mailer:X-Yahoo-Newman-Property:X-Originating-IP:X-eGroups-Msg-Info:X-Yahoo-Post-IP:From:Subject:X-Yahoo-Group-Post:X-Yahoo-Profile:Sender:X-eGroups-Approved-By:X-eGroups-Auth; b=r1czaUsJzi44KpWQY+L7u5A5D6ObHH6QwRwCoRZhNZ5LY6rAXiuu948rFpNIAB/1991MvD9kPbfX+emG8mAPxj5pQGFplwiqIF5g4mJdjyykyAqQTr0aoMR7L1b8vPWV
Received: from [69.147.65.151] by n44.bullet.mail.sp1.yahoo.com with NNFMP; 09 Apr 2009 00:34:15 -0000
Received: from [98.137.34.33] by t5.bullet.mail.sp1.yahoo.com with NNFMP; 09 Apr 2009 00:34:15 -0000
X-Sender: cpkumar@...
X-Apparently-To: gwrm@...
X-Received: (qmail 76695 invoked from network); 9 Apr 2009 00:29:02 -0000
X-Received: from unknown (98.137.34.44)
by m1.grp.re1.yahoo.com with QMQP; 9 Apr 2009 00:29:02 -0000
X-Received: from unknown (HELO n35b.bullet.mail.sp1.yahoo.com) (66.163.168.149)
by mta1.grp.sp2.yahoo.com with SMTP; 9 Apr 2009 00:29:02 -0000
X-Received: from [69.147.65.147] by n35.bullet.mail.sp1.yahoo.com with NNFMP; 09 Apr 2009 00:28:49 -0000
X-Received: from [98.137.34.184] by t10.bullet.mail.sp1.yahoo.com with NNFMP; 09 Apr 2009 00:28:49 -0000
Date: Thu, 09 Apr 2009 00:28:48 -0000
To: gwrm@...
Message-ID: <grjfg0+shnh@eGroups.com>
User-Agent: eGroups-EW/0.82
MIME-Version: 1.0
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: quoted-printable
X-Mailer: Yahoo Groups Message Poster
X-Yahoo-Newman-Property: groups-system
X-Originating-IP: 66.163.168.149
X-eGroups-Msg-Info: 1:6:0:0:0
X-Yahoo-Post-IP: 117.201.80.37
From: "C. P. Kumar" <cpkumar@...>
Subject: Impact of Climate Change on Groundwater Recharge
X-Yahoo-Group-Post: member; u=11962743; y=5BBaKFaPjuyATQeKtkT2wNSI72zK31FGgQ57iv3Wd6SdRA
X-Yahoo-Profile: cpkumar
X-eGroups-Approved-By: cpkumar <cpkumar@...> via web; 09 Apr 2009 00:34:15 -0000

Dear Friend,

While climate change affects surface water resources directly through chang=
es in the major long-term climate variables such as air temperature, precip=
itation, and evapotranspiration, the relationship between the changing clim=
ate variables and groundwater is more complicated and poorly understood. Th=
e greater variability in rainfall could mean more frequent and prolonged pe=
riods of high or low groundwater levels, and saline intrusion in coastal aq=
uifers due to sea level rise.=20

Groundwater resources are related to climate change through the direct inte=
raction with surface water resources, such as lakes and rivers, and indirec=
tly through the recharge process. The direct effect of climate change on gr=
oundwater resources depends upon the change in the volume and distribution =
of groundwater recharge. Therefore, quantifying the impact of climate chang=
e on groundwater resources requires not only reliable forecasting of change=
s in the major climatic variables, but also accurate estimation of groundwa=
ter recharge. Quantification of the groundwater recharge will help in takin=
g appropriate adaptation strategies due to the impact of climate change.=20

There have been many studies relating the effect of climate changes on surf=
ace water bodies. However, very little research exists on the potential eff=
ects of climate change on groundwater. The scientific understanding of an =
aquifer's response to climate change has been studied in several locations =
within the past decade. These studies link atmospheric models to unsaturate=
d soil models (such as Visual HELP), which were further linked into a groun=
dwater model (Modflow). The groundwater models used were calibrated to curr=
ent groundwater conditions and stressed under different predicted climate c=
hange scenarios. The HELP-MODFLOW approach proceeds in the following manner=
-

1. Synthetic generation of daily values of precipitation, mean temperature,=
and solar radiation (using a weather generator) for projected climate chan=
ge.

2. Estimation of groundwater recharge based on available precipitation and =
temperature records and anticipated changes to these parameters (using Visu=
al HELP).

3. Quantification of the spatially distributed recharge rates using the cli=
mate data and spatial soil survey data.

4. Simulation of groundwater flow using each recharge data set and evaluati=
on of the changes in groundwater flow and levels through time.

Regarding the above approach, I would like to know the views of learned mem=
bers on the following aspects -

(a) Which is the most appropriate method to downscale GCM outputs for a bas=
in?=20

(a) If there are any flaws associated with HELP-MODFLOW methodology (descri=
bed above) mostly used by various researchers during last few years?

(b) If the runoff generation process (rainfall-runoff modelling) needs to b=
e essentially incorporated in the study?

(c) Whether instead of HELP, distributed unsaturated modelling (Richards eq=
uation) should be done for climatic impact studies? What are the relative a=
dvantages of using HELP (e.g. simplistic approach and ease of use) and disa=
dvantages of distributed modelling (e.g. extensive data requirement and lar=
ge computation resources) and vice versa?=20

(d) Whether any comprehensive overland-unsaturated-saturated model such as =
MIKE-SHE can be used for studying the impact of climate change on groundwat=
er recharge? And relative advantages and disadvantages?

I look forward for the comments on above.

Regards
Kumar
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
C. P. KUMAR
Scientist 'E1'
National Institute of Hydrology
Jal Vigyan Bhawan
Roorkee - 247667 (Uttarakhand)
INDIA

Web Page : http://www.angelfire.com/nh/cpkumar/
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

Thu Apr 9, 2009 12:28 am

Show Message Option

"C. P. Kumar" <cpkumar@...>

cpkumar

Offline

Send Email

Yahoo! Groups Tips

Did you know...

Messages