My First Project in Illustrator

[su_liam]

Had some success with my rivers. Yay! In the image below the green lines are from my raster river layer, the blue lines are the rivers I've named and digitized into a shapefile. Again, I have a lot of naming ahead of me .

I noticed that a lot of my favorite rivers lie right under the subtropical high-pressure zone. The Everflow has its mouth at about 30*, that's pretty marginal to the high-pressure belt and most of its headwaters are in more temperate regions. This area works for me.

The big fan in the northwest corner of the northwest continent is close enough to the equator to benefit from moisture from the ITCZ. Some of its more southerly tributaries may have more seasonal monsoonal moisture patterns. It is largely downwind of high mountains from the prevailing equatorial easterlies. I figure it has wildly varying discharge, with limited flow in the winter and floods in the summer.

The Bloodhammer River which more or less defines the somewhat fluid southeastern extent of the Orclands, could well be pretty much intermittent. It's not like we expect orcs to live in paradisical places.

The Longwater basin in the west is my problem child. Most of the area drained by this river system is pretty firmly embedded in the subtropical desert belt. Doesn't seem well suited to halfling shires. It might be best to move my hobbits to a spot between Colonia Bellcap and Pennyfarthing Island. I'm a bit irritated, though, 'cause that's a pretty attractive drainage system and it's just about the perfect location for a nasty little desert. The Applewater and the Longwater could well be fed from mountain glaciers.

Deserts are a problem for this continent. I want some, and I've had to handwave away some of the best desert locations for the sake of my good rivers. I might skip some of the left bank tribs to the Everflow and let the area between the Everflow and the Bloodhammer go to desert. Most of the eastern shore of the Middle Sea should probably be desert.

I think I need to drop back into Photoshop or Wilbur to composite in my climates next.

[Ascension]

Between Applewater and South Sea you have a basin that could be a desert of approx 500 miles wide. Not a big one by any means but the mountains around it aren't all that huge and it could be in a rain shadow. Or maybe around Squidward. My two cents.

[su_liam]

I measured that basin between the South Sea and the Applewater River. Came out to about 135,000 sq. mi. That's about twice the size of the Mojave. Not a bad idea. I'm thinkin' the isthmus itself will be a lot like the Eastern US. Warm summer rains a lot of mesoscale convective storms, maybe tornadoes. The coast wouldn't get as many hurricanes with such a broad expanse of land-bound sea between it and the equator.

Looking at my elevation histogram again, this place is a good deal more rugged than the Earth taken as a whole. I had a method in Wilbur to bring the histogram more in line with real world values, but I didn't document it. If I can recreate my steps, I'll try to put up a tutorial. After all, the best reason to create tutorials is as a reminder to yourself of how the heck you did something!

[Ascension]

I completely agree with that last statement, if I don't write it down I'll lose it and since it's written down why not post it up, right? I also would like to read that tut if you ever do it.

[su_liam]

If I ever figger out how to do select by value on a floating-point raster in ArcGIS, I'll be very happy.

I loaded up the ETOPO1 grid and got a histogram for comparison to see how reasonably my elevations looked. ETOPO includes bathymetry, though, and my elevations are clipped at sealevel(I knew my bathymetry was whack, and didn't want to deal with it). So I wanted to select just the areas above sealevel on the ETOPO for a more reasonable comparison. No dice as yet.

I'm also trying to get ETOPO into Wilbur, 'cause it looks like Wilbur has better selection tools. Even if I could get that off the ground, I don't know how well Wilbur would handle a 21601x10801-pixel raster. Unless Mr. Slayton put a lot of work into optimizing the program for speed, it will likely be balky...

Eyeballing the Earth elevation histogram on wikipedia, it looks like the 90th to 95th percentiles are close enough to 1000 meters. On my continent, slightly smaller than North America, 90th percentile is about 1600 meters and 95th is about 2500. I'm not sure how reasonable that is.

[su_liam]

Well I've been engaged in a long, largely useless digression into playing with the Earth. I don't have a lot of time till I go back to scholarly pursuits so I need to get back to Al Burphaban. I read a post on a Traveller forum about a future where global warming had rendered the Earth essentially uninhabitable except near the poles. This made me curious about what Antarctica would look like without 3km or so of ice. A quick bit of play with an exported tiff of the ETOPO bedrock map led to the following image. The edges of the dark areas are at current sea level, with all that ice melted actual coastlines would be higher. Isostatic rebound would complicate things further...

Just a treat for my loyal readers(reader?).

Also my attempt at getting a slopemap in ArcGIS failed ugly. Pretty much everything but ocean surface came out close to 90º. I think it's because my data is in geographic reference. To get slope, the dumb algorithm compares n units of elevation change(possibly several meters), to the cell size of m units(in this case degrees). That means my slopes are off by factors approaching 100,000 near the equator. Yech!

Anyway, back to work!

[Ascension]

I'm sure there are other readers, almost none of us have the software that you have and the technical knowledge you talk about goes over our heads so we can't really make any decent comments without sound like noobish idiots I don't care if I sound like a noobish idiot (because I'm cool like that) so I'll keep on talkin at ya and helpin if and where I can Plus it helps me learn the technical side of things even if I never put that much thought into what I do on my own...the smarter my gut gets the better my whims will be.

[su_liam]

Sorry, I've been off for the last couple of days. Still can't look at the screen long before my stomach starts roiling. Great plan to lose all those eggnog pounds! I lost five pounds overnight!

At the start I intended this just to be another one of my pointless experiments, this time in using Illustrator. I just kind of fell into using the ArcGIS, although it solved a few problems. Having the map scaled and georeferenced gave it an odd sense of reality. To be honest it wound up a bit bigger than it needed to be. I'm enjoying the hell out of using some toys that just won't be available to me for much longer!

If anybody feels like a noobish idiot it's me! I look at some of the stuff I made when I started here and I cringe. I've been worldbuilding for a long time, but terrain-building is new. Cartography is really new, and my maps still lack a certain touch of good taste.

I haven't quit on this I'm just still having a little trouble doing detailed work.
Later

[su_liam]

No real mapping work done in the last week(travel an' all that), just thought I'd mention that I am now the proud owner of a new Garmin Nüvi GPS. At last, the geography nerd will have some idea where he is on the face of the Earth!

[su_liam]

Created a version of my original HF with bathymetry omitted. Some things work better this way, but some things like erosion become problematical. Everything deposits on the flat, zero-level sea surface. Second experiment with simpliflied bathymetry(gradual dropoff to somewhat significant depths). Doesn't look too bad and does make erosion work better. Tried to make hypsometry more realistic with limited success. Played with erosion and hydrology in another app. Nice effect, but it should look even better with some climate going on.

The image is my current stage on this little side-experiment. I haven't tried importing this to ArcGIS yet as it's really early days.

My question is, do the terrain features look better before or after? Comments greatly appreciated.