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SOIL PROTECTION Catalunya - the Balearic Islands / Principality of Andorra

 
 

soil protection (general information)

 

Vienna Soil Declaration

 

soil functions

sustainability criteria

degradation and control processes

soil protection criteria

soil quality indicators

soil maps

what is soil information used fort?

the purpose of soil maps

soil series and correlation

characteristics of a soils map

management and interpretation of soil information on a digital interface

Soil Series and Soil Types catalogue of Catalonia

presentation

criteria

soil Types (> 2010)

soil Series (1993 - 2009)

DEGRADATION AND CONTROL PROCESSES

Degradation process:


Tunnel erosion, piping and suffusion.


Description:


Erosion takes place at the sub-surface level. The circulation of excess water through animal burrows, cracks, poorly compacted embankments or old root holes, in a soil which has loose subsurface matter, produces subsurface erosion with serious consequences. Water entering the soil leads to the suspension of the loose matter and the mud subsequently formed may move. If the tunnel has an exit hole, the water flow will progressively increase the size of the tunnel, which may cause the overlying ground to collapse.

Importance: occasional.



                                             Click on the image
Ampliar foto
Tunnel erosion or piping: entrance hole
(R. M. Poch)



Soil functions affected:


Biomass production (reduction of crop yields and the need for greater inputs), environmental functions (filtration), hydrological function, reduction of carbon sequestration, functions for preventing offsite effects (sediment supply during floods, silting up of dams), function of supporting built infrastructure and constructions.



Diagnostic criteria:

Presence of water entrance holes and exit holes in talus near the entrance. They initially tend to be quite inconspicuous and only become apparent when the land suddenly collapses.





   Click on the image
Ampliar foto
Tunnel erosion or piping: exit hole and collapse. Les Garrigues (J. Porta)






   Click on the image
Ampliar foto
Tunnel erosion or piping: entrance and exit holes
(R. M. Poch)


Prevention and control:


Each case must be studied individually because it is difficult to generalize about the most effective corrective measures (mechanical, chemical and biological) and they are rarely effective.

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