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[ai-geostats] Kriging along streams

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  • oscar garcia
    Dear list members, I want to perform kriging of water quality indicators measured in stations along a river course, so Can you help me with references about
    Message 1 of 5 , Feb 24, 2005
      Dear list members,

      I want to perform kriging of water quality indicators
      measured in stations along a river course, so Can you
      help me with references about kriging along streams in
      a river basin?? is there software to perform this kind
      of analysis???

      Thanks in advance for your help,

      Oscar Javier García-Cabrejo
      Master in Hydrosystems, Civil Engineering Department
      Pontificia Universidad Javeriana
      Bogota, Colombia
      South America

      _________________________________________________________
      Do You Yahoo!?
      La mejor conexión a internet y 25MB extra a tu correo por $100 al mes. http://net.yahoo.com.mx
    • Noemi Barabas
      Dear Oscar, It sounds like you need kriging in a single dimension. If so, I think what you need to do is a kind of coordinate transformation, for example
      Message 2 of 5 , Feb 24, 2005
        Dear Oscar,

        It sounds like you need kriging in a single dimension. If so, I think what
        you need to do is a kind of coordinate transformation, for example using
        river mile as your distance vector. You would also need to pay attention to
        the dates of the samples. Variation in time might obscure spatial trends
        along the river's course if you just have a few sampling events at different
        times for the stations.

        If you have data in space as well as time, there are several methods for
        space-time interpolation. Constructing correlograms for data vs time on
        paired stations could give you an idea of what constitutes a data pair for
        kriging purposes in terms of the time lag between them. Methods will differ
        depending on whether it is the time or space dimension that is more densely
        sampled.

        References on techniques include the following:

        For straightening rivers (which might be more involved than you need):

        Barabas, N., Goovaerts, P. and P. Adriaens. 2001. Geostatistical assessment
        and validation of uncertainty for three-dimensional dioxin data from
        sediments in an estuarine river. Environmental Science & Technology, 35(16):
        3294-3301.

        For space-time data:

        Pebesma and de Kwaadsteniet (1997) Mapping spatial and temporal variation of
        groundwater quality in the Netherlands. In GeoENVI - Geostatistics for
        Environmental Applications, eds., Soares et al, pp. 139-151. Kluwer
        Academic Publishers, Netherlands.

        Kyriakidis and Journel (1999) Geostatistical space-time models: A review.
        Mathematical Geology (not sure which volume etc.)

        Heuvelink et al (1996) Spatio-temporal kriging of soil water content. In
        Geostatistics Wollongong '96, eds Baafi and Schofield. pp. 1020-1030.
        Kluwer Academic Publishers,Netherlands.


        Noémi



        -----Original Message-----
        From: oscar garcia [mailto:osgarcia@...]
        Sent: Thursday, February 24, 2005 11:56 AM
        To: ai-geostats@...
        Subject: [ai-geostats] Kriging along streams


        Dear list members,

        I want to perform kriging of water quality indicators
        measured in stations along a river course, so Can you
        help me with references about kriging along streams in
        a river basin?? is there software to perform this kind
        of analysis???

        Thanks in advance for your help,

        Oscar Javier García-Cabrejo
        Master in Hydrosystems, Civil Engineering Department
        Pontificia Universidad Javeriana
        Bogota, Colombia
        South America

        _________________________________________________________
        Do You Yahoo!?
        La mejor conexión a internet y 25MB extra a tu correo por $100 al mes.
        http://net.yahoo.com.mx
      • Edzer J. Pebesma
        Noemi, the idea of transforming to a one-dimensional situation, distance along river, was the first one I got. Then, I rejected it because it will not work for
        Message 3 of 5 , Feb 24, 2005
          Noemi, the idea of transforming to a one-dimensional situation,
          distance along river, was the first one I got. Then, I rejected
          it because it will not work for river networks; it will for a
          single sections without joints though. Space-time modelling may
          be complicated by the fact that there will be a strong
          correlation with future observations downstream, but not with
          observations upstream because water flows down; this may call
          for another translation of space-time using flow speed to get
          to a space-time coordinate system where the usual models make
          sense.
          --
          Edzer

          Noemi Barabas wrote:
          > Dear Oscar,
          >
          > It sounds like you need kriging in a single dimension. If so, I think what
          > you need to do is a kind of coordinate transformation, for example using
          > river mile as your distance vector. You would also need to pay attention to
          > the dates of the samples. Variation in time might obscure spatial trends
          > along the river's course if you just have a few sampling events at different
          > times for the stations.
          >
          > If you have data in space as well as time, there are several methods for
          > space-time interpolation. Constructing correlograms for data vs time on
          > paired stations could give you an idea of what constitutes a data pair for
          > kriging purposes in terms of the time lag between them. Methods will differ
          > depending on whether it is the time or space dimension that is more densely
          > sampled.
          >
          > References on techniques include the following:
          >
          > For straightening rivers (which might be more involved than you need):
          >
          > Barabas, N., Goovaerts, P. and P. Adriaens. 2001. Geostatistical assessment
          > and validation of uncertainty for three-dimensional dioxin data from
          > sediments in an estuarine river. Environmental Science & Technology, 35(16):
          > 3294-3301.
          >
          > For space-time data:
          >
          > Pebesma and de Kwaadsteniet (1997) Mapping spatial and temporal variation of
          > groundwater quality in the Netherlands. In GeoENVI - Geostatistics for
          > Environmental Applications, eds., Soares et al, pp. 139-151. Kluwer
          > Academic Publishers, Netherlands.
          >
          > Kyriakidis and Journel (1999) Geostatistical space-time models: A review.
          > Mathematical Geology (not sure which volume etc.)
          >
          > Heuvelink et al (1996) Spatio-temporal kriging of soil water content. In
          > Geostatistics Wollongong '96, eds Baafi and Schofield. pp. 1020-1030.
          > Kluwer Academic Publishers,Netherlands.
          >
          >
          > Noémi
          >
          >
          >
          > -----Original Message-----
          > From: oscar garcia [mailto:osgarcia@...]
          > Sent: Thursday, February 24, 2005 11:56 AM
          > To: ai-geostats@...
          > Subject: [ai-geostats] Kriging along streams
          >
          >
          > Dear list members,
          >
          > I want to perform kriging of water quality indicators
          > measured in stations along a river course, so Can you
          > help me with references about kriging along streams in
          > a river basin?? is there software to perform this kind
          > of analysis???
          >
          > Thanks in advance for your help,
          >
          > Oscar Javier García-Cabrejo
          > Master in Hydrosystems, Civil Engineering Department
          > Pontificia Universidad Javeriana
          > Bogota, Colombia
          > South America
          >
          > _________________________________________________________
          > Do You Yahoo!?
          > La mejor conexión a internet y 25MB extra a tu correo por $100 al mes.
          > http://net.yahoo.com.mx
          >
          >
          >
          >
          > ------------------------------------------------------------------------
          >
          > * By using the ai-geostats mailing list you agree to follow its rules
          > ( see http://www.ai-geostats.org/help_ai-geostats.htm )
          >
          > * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to sympa@...
          >
          > Signoff ai-geostats

          --
          Edzer
        • Donald E. Myers
          Additional space-time references * 2003, De Iaco, S, Myers, D.E., and Posa, D., The Linear Coregionalization Model and the Product-Sum Space-Time Variogram.
          Message 4 of 5 , Feb 24, 2005
            Additional space-time references

            Also see   Cressie-Huang   in JASA  and Gneiting  in JASA

            Donald E. Myers

            Noemi Barabas wrote:
            Dear Oscar,
            
            It sounds like you need kriging in a single dimension.  If so, I think what
            you need to do is a kind of coordinate transformation, for example using
            river mile as your distance vector.  You would also need to pay attention to
            the dates of the samples.  Variation in time might obscure spatial trends
            along the river's course if you just have a few sampling events at different
            times for the stations.  
            
            If you have data in space as well as time, there are several methods for
            space-time interpolation.  Constructing correlograms for data vs time on
            paired stations could give you an idea of what constitutes a data pair for
            kriging purposes in terms of the time lag between them.  Methods will differ
            depending on whether it is the time or space dimension that is more densely
            sampled.
            
            References on techniques include the following:
            
            For straightening rivers (which might be more involved than you need):
            
            Barabas, N., Goovaerts, P. and P. Adriaens. 2001. Geostatistical assessment
            and validation of uncertainty for three-dimensional dioxin data from
            sediments in an estuarine river. Environmental Science & Technology, 35(16):
            3294-3301. 
            
            For space-time data:
            
            Pebesma and de Kwaadsteniet (1997) Mapping spatial and temporal variation of
            groundwater quality in the Netherlands.  In GeoENVI - Geostatistics for
            Environmental Applications, eds., Soares et al, pp. 139-151.  Kluwer
            Academic Publishers, Netherlands.
            
            Kyriakidis and Journel (1999) Geostatistical space-time models: A review.
            Mathematical Geology (not sure which volume etc.)
            
            Heuvelink et al (1996) Spatio-temporal kriging of soil water content. In
            Geostatistics Wollongong '96, eds Baafi and Schofield. pp. 1020-1030.
            Kluwer Academic Publishers,Netherlands.
            
            
            Noémi
            
            
            
            -----Original Message-----
            From: oscar garcia [mailto:osgarcia@...]
            Sent: Thursday, February 24, 2005 11:56 AM
            To: ai-geostats@...
            Subject: [ai-geostats] Kriging along streams
            
            
            Dear list members,
            
            I want to perform kriging of water quality indicators
            measured in stations along a river course, so Can you
            help me with references about kriging along streams in
            a river basin?? is there software to perform this kind
            of analysis??? 
            
            Thanks in advance for your help,
            
            Oscar Javier García-Cabrejo
            Master in Hydrosystems, Civil Engineering Department
            Pontificia Universidad Javeriana 
            Bogota, Colombia
            South America
            
            _________________________________________________________
            Do You Yahoo!?
            La mejor conexión a internet y 25MB extra a tu correo por $100 al mes.
            http://net.yahoo.com.mx
            
            
              

            * By using the ai-geostats mailing list you agree to follow its rules ( see http://www.ai-geostats.org/help_ai-geostats.htm ) * To unsubscribe to ai-geostats, send the following in the subject or in the body (plain text format) of an email message to sympa@... Signoff ai-geostats
          • Noemi Barabas
            Edzer, You are right about river networks. I do think that the uni-directionality of flow is not necessarily a problem in terms of what can inform what.
            Message 5 of 5 , Feb 24, 2005
              Edzer,

              You are right about river networks.

              I do think that the uni-directionality of flow is not necessarily a problem
              in terms of what can inform what. Statistically, a downstream station can
              inform an upstream station because what is downstream is there because of
              what happened upstream, and the same for past and future. While there may
              not be a *physical* link from future to past, there will still be a
              *statistical* link from future to past as long as there was a statistical
              link from past to future. [That is the idea in inverse modeling for example
              (which are a combination of physical and statistical modeling)].

              Intuitively, kriging backwards might have to be done according to a
              different model than forward, but, I am open to surprises. It is worth a
              try, anyway.


              Noémi



              -----Original Message-----
              From: Edzer J. Pebesma [mailto:e.pebesma@...]
              Sent: Thursday, February 24, 2005 5:19 PM
              To: Noemi Barabas
              Cc: oscar garcia; ai-geostats@...
              Subject: Re: [ai-geostats] Kriging along streams


              Noemi, the idea of transforming to a one-dimensional situation,
              distance along river, was the first one I got. Then, I rejected
              it because it will not work for river networks; it will for a
              single sections without joints though. Space-time modelling may
              be complicated by the fact that there will be a strong
              correlation with future observations downstream, but not with
              observations upstream because water flows down; this may call
              for another translation of space-time using flow speed to get
              to a space-time coordinate system where the usual models make
              sense.
              --
              Edzer

              Noemi Barabas wrote:
              > Dear Oscar,
              >
              > It sounds like you need kriging in a single dimension. If so, I think
              what
              > you need to do is a kind of coordinate transformation, for example using
              > river mile as your distance vector. You would also need to pay attention
              to
              > the dates of the samples. Variation in time might obscure spatial trends
              > along the river's course if you just have a few sampling events at
              different
              > times for the stations.
              >
              > If you have data in space as well as time, there are several methods for
              > space-time interpolation. Constructing correlograms for data vs time on
              > paired stations could give you an idea of what constitutes a data pair for
              > kriging purposes in terms of the time lag between them. Methods will
              differ
              > depending on whether it is the time or space dimension that is more
              densely
              > sampled.
              >
              > References on techniques include the following:
              >
              > For straightening rivers (which might be more involved than you need):
              >
              > Barabas, N., Goovaerts, P. and P. Adriaens. 2001. Geostatistical
              assessment
              > and validation of uncertainty for three-dimensional dioxin data from
              > sediments in an estuarine river. Environmental Science & Technology,
              35(16):
              > 3294-3301.
              >
              > For space-time data:
              >
              > Pebesma and de Kwaadsteniet (1997) Mapping spatial and temporal variation
              of
              > groundwater quality in the Netherlands. In GeoENVI - Geostatistics for
              > Environmental Applications, eds., Soares et al, pp. 139-151. Kluwer
              > Academic Publishers, Netherlands.
              >
              > Kyriakidis and Journel (1999) Geostatistical space-time models: A review.
              > Mathematical Geology (not sure which volume etc.)
              >
              > Heuvelink et al (1996) Spatio-temporal kriging of soil water content. In
              > Geostatistics Wollongong '96, eds Baafi and Schofield. pp. 1020-1030.
              > Kluwer Academic Publishers,Netherlands.
              >
              >
              > Noémi
              >
              >
              >
              > -----Original Message-----
              > From: oscar garcia [mailto:osgarcia@...]
              > Sent: Thursday, February 24, 2005 11:56 AM
              > To: ai-geostats@...
              > Subject: [ai-geostats] Kriging along streams
              >
              >
              > Dear list members,
              >
              > I want to perform kriging of water quality indicators
              > measured in stations along a river course, so Can you
              > help me with references about kriging along streams in
              > a river basin?? is there software to perform this kind
              > of analysis???
              >
              > Thanks in advance for your help,
              >
              > Oscar Javier García-Cabrejo
              > Master in Hydrosystems, Civil Engineering Department
              > Pontificia Universidad Javeriana
              > Bogota, Colombia
              > South America
              >
              > _________________________________________________________
              > Do You Yahoo!?
              > La mejor conexión a internet y 25MB extra a tu correo por $100 al mes.
              > http://net.yahoo.com.mx
              >
              >
              >
              >
              > ------------------------------------------------------------------------
              >
              > * By using the ai-geostats mailing list you agree to follow its rules
              > ( see http://www.ai-geostats.org/help_ai-geostats.htm )
              >
              > * To unsubscribe to ai-geostats, send the following in the subject or in
              the body (plain text format) of an email message to sympa@...
              >
              > Signoff ai-geostats

              --
              Edzer
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