Hello.
I want to calculate the CVI along a coast. I have all the data needed. What troubles me is how to calculate the slope near the coast. The easy way is just to create a DEM and then use this to assign a value to a polyline representing the coast with multiple segments.
However if i do this, i take into account only the nearest cell of the slope Raster to the coast..
If i have pixel size of 5 m since i am working with maps of 1:5000 scale i think this is too narrow and not that representive of the whole beach slope..
Maybe it is a better way if i just measure the distance to the contour of 1 or meters and then calculate the slope that will be assigned to the polyline representing the coast?
What do you think?
It depends upon the coastal landform....
beaches, beach barriers = upper limit the maximum elevation of beach (in Greece usually < 3m)
Deltas < 5m
for other landforms (Cliffs, alluvial plains 0 to 4 or 5 m contour???)
SP
The selection can also depend on what kind of hazard are you trying to evaluate and
for which spatial and temporal resolution.
Within the EU project RISCKIT there is a 2 step methodology developed for
regional scale vulnerability and risk assessment.
Have a look at the projects results
http://www.risckit.eu/np4/8/
Regards
e
We are also studying on the CVI for Kuwaiti coast. We are doing the measurement of beach slope for each nautical mile along the coast using NIkon distometer. Since the study is on CVI and the vulnerability is what is expected in future, the slope of the beach from High water line and above is important. We are taking few points below high water line and few above high water line for getting a linear best line fit. After few points above high water line, the land area, in many places becomes almost horizontal. Hence we need to judge, where to stop for considering few points above the high water line. It is a good experience.
In my remember the coastal slope concern the inland behind the dune. Because CVI is sea level rise impact oriented, the slope is supposed to take into account the ability of the sea level to submerge the coastal zone. This is the reaseon why cliffs are considered as "safe" to sea level rise and barrriers, salt marshes, deltas... are potentially "very sensitive risk".
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