[ai-geostats] problem of spatial continuity of groundwater head
problem of spatial continuity of groundwater head
A few days ago I had a discussion about spatial continuity of hydraulic heads and the following question: Is it allowed to use a krging technique for this variable?
First Opinion: there are different processes which influence the groundwater heads, e.g.:
- gravity (hydraulic gradient)
- grounwater recharge
- anthropogenic influence (pumping/injection)
So there is a global trend which is overlayed from different additional trends like groundwater recharge and anthropogenic influence (pumping/injection) and you can´t seperate these processes. These are the reasons that you get problems with the ergodicity and it is not possible to use kriging techniques, because you haven´t a spatial continuity which is based on one process.
Second Opinion: There is a basic process for the groundwater heads (the movement based on the Darcy law and that´s it) . There exist a global trend (but you can handle it with Universal kriging) and the differences depend on the other processes maybe give you another trend by large scale problems (and then you have problems with the ergodicity and have to use moving window statistics to divide you working area). So you have a spatial continuity which is not necesseraly influenced by problems with ergodicity and you can use kriging techniques. Maybe the anthropogenic influence could be a process which disturb the spatial continuity.
I know it´s quite a hydrogeology problem but anyway I would like to hear your opinion or experiences on that topic.
Looking forward to the answers,
Dipl. Kai Zoßeder
Bayerisches Geologisches Landesamt
Tel.: 089-9214 2655