BATHIMETRIC EVOLUTION ANALYSIS OF "COMACCHIO WATLAND" BY IRF-K CO-REGIONALIZATION

The "Valli di Comacchio" are a vast Italian wetland which has been declared a protected natural reserve. The behaviour of its bed was measured by means of two heterotopic sampling campaigns conducted 20 years apart. The order of magnitude of the changes in bed features which must be taken into account if one wants to foresee and prevent irreversible upsets in natural balances is of only a few centimeters and, in order to achieve such a degree of precision, a FAI-k co-regionalization study was carried out. The purpose was to estimate, by means of direct FAI-k cokriging, the variations of the bed at the nodes of a grid. The study explains why such a procedure isnecessary if estimation variance is to be calculated coherently through the combination of FAI-k krigings that pertain to different but correlated variables, such as those involved in bed changes; covariances, moreover, have to be used to solve the problems raised by the heterotopic sampling. After the discussion and review of the results, the study discusses the operativeness of the FAI-k cokriging tool.