Newsgroup sci.geo.hydrology 5153

Directory

Subject: Re: ............... -- From: rtotman@oanet.com (r)
Subject: water quality software -- From: htl@ix.netcom.com(Water Resources Engineer )
Subject: stochastic generation of daily precip -- From: shea@ra.cgd.ucar.edu (Dennis Shea)
Subject: ERS-1/2 data and Interferogram of subglacial volcanic eruption in Iceland and threatening glacial flood. -- From: Christoph Boehm Doktorand FE

Articles

Subject: Re: ...............
From: rtotman@oanet.com (r)
Date: 10 Nov 1996 18:23:42 GMT
In article <328496CE.549F@pianeta.it>, scienza@pianeta.it says:
>
>INTERNET
>
>Some people prefear to go on thinking that the Einstein’s relativity
>theory is right , thinking that  matter cannot reach and substains light
>velocity, because in this case  matter would have an infinitive mass ,
>and it would be necessary to transfer to it an infinitive quantity of
>energy.
>At the same time the physics substain that at elemental material level
>the time does not exist and that in normal conditions it is not possible
>to travel in the time.
>
>As opposite to what mentioned before, the writer, after 20 years of
>research out of the pubblic ufficial circuit of the physical research, 
>can prove that things  are different.
>Some examples of his  theories follows:
>
>-The comception of time and space given by Einstein Relativity  is
>completly inconsistent applied to the case of light velocity of the
>matter , out of light along with the physical and heavy consistance of
>the material invisible particles that translate the time , (towards the
>future or the past).
>In many cases the theories substained by the physics are uncomplete or
>inadeguated to describe the reality, but  because of their lack to give
>an explanation to the real phaenomenouses, they go on thinking  their
>concept as the only truth.
>
>-Some information about: To travel in the time , to travel at light
>velocity , to know the explanation of the forces unification, to know
>the natural formation of the sub-elemental particles of the electricity
>of the magnetism and of the gravity.
>The writers brings explanations and  cases which confutates the
>Einstein’s relativity theory , substaing that the matter can travel at
>light velocity 
>The contrary is possible and it is the right explanation of the world.
>
>End of December 1996 it will be ready a book , entitled "THE
>QUADRIDIMENTIONAL UNIVERSE", where  in about 420 pages with colour
>photos and pictures , the writer explains these theories and many other
>concepts  not already reached by the officials science.
>Shipment: per Airmail.
>Possible markets  :All countries except for  Italy , switzerland ,
>Japan, Cina , URSS  Countries 
>DEPOSITED AND PROTECTED CONTENTS
>
>PLEASE REPLY FOR MORE INFOS :
>
>scienza@pianeta.it
>
This is an inappropriate newsgroup for such a topic. This should appear in
alt.sci.fiction or some similar group.
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Subject: water quality software
From: htl@ix.netcom.com(Water Resources Engineer )
Date: 11 Nov 1996 15:11:05 GMT
I am looking for a canned software package that would substitute for 
developing an Access or Dbase database.  The package must offer 
statistical as well as spatial/temporal analyses for water quality 
data.  Data validation is a essential component of the stats 
package...therefore the program must be capable of dealing with 
changing detection limits, etc...  In addition, want to be able to
store the data and export the data in ASCII format.
Jim Schechtman
htl@ix.netcom.com
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Subject: stochastic generation of daily precip
From: shea@ra.cgd.ucar.edu (Dennis Shea)
Date: 11 Nov 1996 22:35:40 GMT
Hello,
I am trying to model daily precipitation and am 
having a problem [Perhaps, several problems ;>)].
It is certainly not my area of expertise so I 
would be grateful for pointing me in the right direction.
The following outlines the situation:
Given the observed mean precipitation amount on "wet days"
and the variance about this mean, I would like
to stochastically generate a large number of daily 
series. Each series represents a season (eg, winter).
that have (approximately) this mean and variance.
[I also have some other information: the mean unconditional
 probability of precip on a given day within a season,
 prob of dry-to-wet; prob wet-to-wet but I want to ignore
 that for this question.]
My first look was at Richardson's (1981) "weather generator"
[Water Resourc. Res 17:182-190 and  a tech note entitled
 "WGEN: A Model for Generating Daily Weather Variables"
 Dept of Agriculture: August 84, ARS-8]. The latter
 has some fortran code (p72) which I copied [code at end
 of message]. Richardson used the method outlined in Haan (1977).
 The resulting code seems (generally) to generate reasonable 
 mean prc amounts but the variances are MUCH larger then I expected.
Next, I thought  "I'll use use a two-parameter gamma
distribution": something like 
     prc   = scon*gamma2 (alpha, beta) 
  where
     beta  = scale factor to stretch or squeeze the
             gamma density function   
     alpha = shape 
     scon  = scaling constant [perhaps?, scon=beta]
note: ave = alpha*beta;   variance = alpha*bets**2
In my case alpha is always    0 < alpha < 1 with
typical values of 0.25 to 0.6. My test case
is alpha=0.3; scale=270  ==> ave=9 mm   var=900 mm**2
[Because I do not have the actual daily values I used
 the method of moments to determine alpha and beta.
 I know that max likelihood estimates are best but
 I can not calculate them given the data at hand.]
The function "gamma2" would randomly sample from
gamma distribution with shape alpha and produce
a random amount.
I "grabbed" the (fortran) code from ranlib which
is in the netlib public domain archive. It is called
gengam(x,alpha) where "x" is a location parameter.
[I am not sure what the location parameter actually
is so I took a wild (er, I mean, educated) guess!!]
Anyway, the way I am using it does not seem to do the job.
THX for any info!!
===================
Code from WGEN (in f77): 
c -------------------------------------------------------
      real function prc_gam (shape, scale)
c stochasticaaly generate a precip amount from a gamma distribution
c Reference:
c .   WGEN: A Model for Generating Daily Weather Variables
c .   Agricultural Research Service [ARS-8]  August 1984
c .   inparticular see pg 72
c .   Possibly, the book by Haan (1977) Iowa St. Univ Press
c .   actually describes where tr1 and tr2 come from ....
      aa  = 1./shape         ! shape = alpha
      ab  = 1./(1.-shape)
      tr1 = exp(-18.42/aa)   ! ?? 18.42 ?? 
      tr2 = exp(-18.42/ab)   ! possibly delineate regions 
      ntry = 0
   10 ntry = ntry + 1        ! number of iterations
      rn1  = ranf()
      rn2  = ranf()
      if ((rn1-tr1).le.0.) then
          s1 = 0.0
      else
          s1 = rn1**aa
      endif
      if ((rn2-tr2).le.0.) then
          s2 = 0.0
      else
          s2 = rn2**ab
      endif
      if ((s1+s2).gt.1.) go to 10  ! try again
      z = s1/(s1+s2)
      prc_gam = -z*alog(ranf())*scale
      return
      end
+++++++++++++++ next code from ranlib +++++++++++
      REAL FUNCTION gengam(a,r)
C**********************************************************************
C
C     REAL FUNCTION GENGAM( A, R )
C           GENerates random deviates from GAMma distribution
C
C
C                              Function
C
C
C     Generates random deviates from the gamma distribution whose
C     density is
C          (A**R)/Gamma(R) * X**(R-1) * Exp(-A*X)
C
C
C                              Arguments
C
C
C     A --> Location parameter of Gamma distribution
C                              REAL A
C
C     R --> Shape parameter of Gamma distribution
C                              REAL R
      .
      .
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Subject: ERS-1/2 data and Interferogram of subglacial volcanic eruption in Iceland and threatening glacial flood.
From: Christoph Boehm Doktorand FE
Date: Sun, 10 Nov 1996 11:55:32 +0100
VOLCANIC ERUPTION ON ICELAND: ERS-SAR-IMAGES
November 8, 1996
New ERS-1/2 SAR images and interferogram of the recent subglacial
eruption of Loki ridge, a subglacial volcano on Iceland, are now
available on the DFD homepage:=20
http://www.dfd.dlr.de/HOT-TOPICS/volcano/
These images show the newest eruption on Vatnaj=F6kull, Europe's
largest glacier, which started on October 1. and the subglacial
reservoir which is now filled with some km3 of meltwater. This huge
amount of water will cause a catastrophic flood.=20
This page is available both, in English and German language, and
will be updated as soon as new SAR data are processed and analyzed.
-------------------------------------------------------------------
This is a service of the German Remote Sensing Data Center (DFD).
For further information, please contact:
boehm@dfd.dlr.de
mueschen@dfd.dlr.de
roth@dfd.dlr.de
------------------------------------------------------------------
Christoph Boehm
DFD (German Remote Sensing Data Center)
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