Interpolation of Tidal Levels in the Coastal Zone for the Creation of a Hydrographic Datum

As part of the U. K. Hydrographic Office (UKHO)-sponsored Vertical Offshore Reference Frames (VORF) project, a high-resolution model of lowest astronomical tide (LAT) with respect to mean sea level has been developed for U.K.-Irish waters. In offshore areas the model relies on data from satellite altimetry, while in coastal areas data from a 3.5-km-resolution hydrodynamic tide-surge model and tide gauges have been included. To provide for a smooth surface and predict tidal levels in unobserved areas, the data have been merged and interpolated using the thin plate spline method, which has been appropriately tuned by an empirical prediction test whereby observed values at tide gauges were removed from the solution space and surrounding data used to predict its behavior. To allow for the complex coastal morphology, a sea distance function has been implemented within the data weighting, which is shown to significantly enhance the solution. The tuning process allows for independent validation giving a standard error of the resulting surface of 0.2 m for areas with no tidal observation

PLM och erfarenhetsbaserat lärande

Att driva förändringsarbete är, för att uttrycka det milt, ingen enkel sak. Den främsta orsaken är förmodligen att det är svårare att beskriva och hantera system, där människor är en del av systemet. Metoder och strategier, som fungerar bra inom tekniska tillämpningar, går inte att använda rakt av där människors handlingar kan omtolka, förändra och kanske t.o.m. motverka fattade beslut

Forest exploitation in Cameroon (1884-1994): An oxymoron of top-down and bottom-up forest management policy approaches.

Forest exploitation in Cameroon goes back to the pre‐colonial period when early ethnic settlers used the ‘law of status’ system to manage land and forests in the territory. With the arrival of colonial powers, beginning with the Germans in 1884, the law of status system was replaced by top‐down state‐centred management system. This top‐down management system was inherited by post‐colonial authorities and enforced until 1994 when a new forestry law was launched, based on bottom‐up management system. This paper reviews all these three systems. Communities are not benefiting from an actual bottom‐up management system. The author argues that the forests sector in Cameroon needs a new management paradigm