Coastlines fascinate

Seems like I am pulled to the coastlines. Seems like I am not alone. People tend to gravitate towards food resources, and where the ocean meets land, and even rivers, food has always been plenty. Trade too. And the boats of course.

I have a house, in the northern parts of Norway where the shoreline is but 200 meters away. From where I live in Trondheim I can see the fjord. The ocean has  always been around.

I am one of those with fond memories of small waves, a grandfather safely steering the boat, and days blessed with sun and fishing. When the weather was less than fair we stayed in or near my grandparents house enjoying our small adventures around the old farm.

Seems also that the places I travel to these days are close to the ocean. Zanzibar is one of these fantastic places where oportunities and challenges arise practically on the shoreline. Mapping those oportunities and challenges is part of what I do. It invoves drones, big databases, partners in many institutions, researchers and more. Sometimes it comes together in a map describing the sensitivities of a coastal area. I like the thought of it, but fear that we more often than not do not have enough knowledge to present detailed enough maps.

In September we took some time off from our QGIS workshop to play around with the EPA drone. Great fun in the tennis court.

Ghana is an other of those places. My stays are usually in Accra, and although the coastline is

never far away it is merely the frame of the ocean and not much more. Inaccessible because of restricted daytime for me, the workshop participant and meetings participant. Workshops outside Accra usually end up being in Sogakope, a 60 minute drive down to Keta. But my meetings usually revolve on issues related to the ocean and its shoreline.

What’s with the coastal areas then? Here are some of the processes I am involved in:

  • Environmental atlases
  • Coastal sensitivity analysis for emergency response
  • Digitalization of drone data in coastal areas (coastline/mangrove/substrate)
  • Methods development of sensitivity assessments (both coastal and terrestrial)

I have attached a video from a recent (September 2017) trip to the Keta Lagoon area in Ghana. On a small strip of land between the Keta Lagoon and the coastline thousands of people live their lifes. The inland areas which are not flooded (remember this is a lagoon) are occasionaly flooded rendering the areas uninhabitable for parts of they year.

In the video you can see the sand traps designed to “harvest”sand so that the thin strip does not erode. You can see this as big dumps of stone perpendicular to the shoreline.

Apart from letting us see some of the areas near the coast the video also shows some highlights form a QGIS training near Sogakope.

Mindværet – nordligst del

Jeg har laget noen ortofoto av de nordligste delene av Mindværet. Mindværet er en skjærgård som ligger rett sør for øya Mindland på helgelandskysten. Øyområdet er godt egna for dagsturer med båt/kajakk. Det fins mange naturlige ankringssteder.

Området  har et rikt fugleliv. Det er dessverre amerikansk mink i området, noe som går sterkt ut over fuglelivet i området.

Ortofotoene er satt sammen av 1.355 enkeltbilder tatt fra en høyde på 120 meter over havet. Bildene er bearbeidet ved hjelp av spesialprogramvare.

Et spesielt vakkert parti med svært gode muligheter for både fortøyning og bading.

Sammenstillingen er laget med utgangspunkt i bilder som er i berøring med landområder. Oppløsningen på kartene er i full størrelse så god at de kan egne seg til utskrift i størrelsesorden 1×1 meter.

Kartene kan lastes ned og kan benyttes vederlagsfritt.

Ortofotoet viser de største øyene i området. Sjøområdene mellom mer ikke tatt med. Filen er om lag 150 Megabyte stor og kan lastes ned. Et trykk på bildet vil ta deg til en nedlastingsside.

 

Ortofotoet/kartet viser de største øyene i området. OpenStreetMap er benyttet som bakgrunnskart. Dermed vises også øyer i omrdet uten ortofoto. Filen er om lag 125 megabyte stor og kan lastes ned. Et trykk på bildet vil ta deg til en nedlastingsside.

 

Brørholmen – ortofoto

Brørholmen ligger et par hundre meter fra Mindtangen på Mindland. Kartet/ortofotoet er satt sammen av 95 separate vertikalbilder tatt med drone. Bildene er tatt fra en høyde på 120 moh. Bildene er tatt om ettermiddagen den 19. juli 2017.

Det er fritt frem å laste ned og å skrive ut kartet til utskrift og lignende.

Mulig det dukker opp flere slike bilder  fra Mindland i løpet av sommeren.

Wilderness 3d: The Canary Islands wilderness

Wilderness on Lanzarote, Canary Islands, Spain.

Wilderness on Lanzarote, Canary Islands, Spain.

Like many other Europeans I have had my share of visits to the Canary Islands (three and counting). The climate is decent from February until November. Some even like it in December and January. Most of us go to the Canary Islands for sunbathing, for long walks, to swim, spend time with friends or just get away from it all.

Few, if any, go to the Canary Islands for the wilderness. In this article I will be looking at your options if you were interested in getting away from people in the Canary Islands. It is not easy, but it is possible. If you are looking for wilderness in the Canary Islands I would suggest going to Lanzarote. Parque National de Timanfaya is the easiest accessible wilderness area.

The above map is based on publicly available vector data from the OpenStreetMap-project covering the Canary Islands. A wilderness analysis based on insufficient data will only represent a map of more or less mapped areas. In this case the basis for the analysis is decent. There will still be many errors.

The analysis has not in any way been sanctioned by Spanish authorities. It will not be used by the authorities and the audience (GIS geeks) of this posting is anyway quite limited.

The criterias used to map the wilderness areas based on OpenStreetMap in the Canary Islands are as follows:

  • Roads: primary, secondary, tertiary, unclassified, motorway, trunk
  • Land use: industrial, reservoir, military, farmland, residential, orchard, commercial, quarry, farmland and salt_pond
  • Railways
  • Waterways: canal

Like it or not – the presented map is what you get.

Wilderness 4: Wilderness degradation analysis

Area with wilderness and encroachment. Visualization of change of wilderness status.

Area with wilderness and encroachment. Visualization of change of wilderness status.

Wilderness degradation happens when new encroachments are made changing the wilderness status of an area. It is a complex issue which does not easily lend it self to a GIS based analysis. I will refer to my posting on wilderness for a peek into the complex world of wilderness philosophy.

It is possible to set up a system like FME to do an analysis of changes in wilderness due to new encroachments. The procedure I made generates a wilderness degradation data set based on wilderness and (new) encroachment data. It is based on procedures used by the Norwegian government in their analysis of wilderness and encroachment. The system should however be easy to accommodate for different preconditions by manipulating the number of wilderness zones and/or their buffer distances.

To visualize the degradation of wilderness it is necessary to make a categorization and furthermore establish a cartography to carry the information to the reader. In my view this can not be done unless the author/mapmaker to some extent takes side in what is good or not good related to wilderness degradation. This will be the focus on a forthcoming posting, but I will touch into the issues here as well.

FME is but one of the potential solutions for producing the results. QGISGeoKettle and even PostGIS could be good alternatives. The GitHub project has room for alternative implementations.

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