Wednesday, November 30, 2011

Mapping the City of Tien: A palimpsest of culture and process

Today's topic: the city of Tien. Tien is the capital city in the Kingdom of Zhan - a whirling nest of high court intrigue, magic, assassins, and the occasional undead. You can read about it in the amazing Kelly McCullough's new book, which I blogged about mapping yesterday, too.

I want to point out my process for making the city map. My goal was less about topography and more about neighborhoods. Where is the Stumbles? How close is it to the Royal Docks? Where is the Ismere library in relationship to the Royal Palace and the River Zien? How do the canals provide transportation and sewer service?

And, summarily, how would all of this have accreted over the centuries as new places sprung up, old ones decayed or gentrified, and more and more people tried to use the space?

While I'm not a geographer, I do spend a fair amount of time thinking about how people interact with the landscape. Starting from a scanned sketch from Kelly, I knew where the major features were. In this case, I had to do less geologic creation, and more urban planning. I did know that there were four major hills - kind of like the seven hills of Rome. So my first thought was to figure out how those hills got there - this would give me geologic constraints on the locations of various streets and neighborhoods. Plus, I would illustrate the general topography and keep the detail for specific places and buildings named in the book. Since we had a river that flowed into the harbor, my first thought was to have the four hills as remnant high stream terraces, with the majority of the city built around the (heavily modified) floodplain or low terraces. But there were some plot devices used in the book that needed good bedrock cliffs. So I adjusted my terrace idea to be remnant bedrock highs, surrounded by the lower floodplain. Plus a remnant terrace on which to place the Royal Palace and a few other neighborhoods - these breaks in the flat-lying landscape often create neighborhoods in real cities (especially ones along rivers).

Here was my first pass at organizing the city landscape. I ended up symbolizing the hilly areas differently, but it gave me the layout of the major features.

Now came filling in the neighborhoods and implying that most of the city was a dense maze of city blocks - it's a lot easier to erase away the streets to define the general pattern. I didn't intend to draw every single building - that way would lead to madness...

With much of the street layout defined, I started to place a few important buildings and work out how I was going to show the reader where the hills were located. It's tricky. Many maps use hachure lines to display topographic information. But this didn't mesh with the way I had drawn some of the other features, so I played around with some possibilities. Besides - some of these hills were really steep bedrock cliffs, while others were just rounded and steeper than the surrounding plain.

This was too "smeared" and I also didn't think it would reproduce well as a halftone bitmapped image.

This was better - plus, I could show the ruggedness of the slopes.

So here's the city with the four major hills and the streets. I adjusted the canals so they would at least seem to have the potential to act as both a sewer and transportation system.

Tossing in some text, a few important buildings and a rough scale, here's the finished map.

Keep in mind that this map was being printed only 3" wide, so I gave prime location to the names, rather than specific features. A few tweaks to the final halftone so the grays would reproduce well and it went with it's sibling world map to the publisher. And now it's in print. That makes me happy. So go buy the book already!

Tuesday, November 29, 2011

Making a Map

Guess what? Today is the release date for Broken Blade, a new fantasy series written by my good pal Kelly McCullough. Having read the beta versions, I can say that if you enjoy fantasy novels and film noir, you'll enjoy these books.

Beyond reading the beta copy, I drew the maps used in the book. It's partly an homage to the maps in Tolkein's Hobbit and LOTR, but it's also done from the perspective of 1) A geologist who understands some aspects of how the geography of a region might evolve as a result of some underlying physical process and 2) a traveler or map-maker living in this fictional world, trying to convey what it's like to "be there."

I started with a fairly simple sketch map that Kelly drew up as he was outlining the story. From this, I drew a pencil & pen sketch of how I thought it should look. I scanned this map into the computer so I could adjust things in Photoshop - it's much easier to add text, move mountains (literally), and prep the map for publication as a digital image. Several years ago, I drew a map for a friend, and I had done everything in layers of tracing paper so I could adjust rivers, forests, etc. I much prefer the digital method.

Here's a scan of part of my pen/pencil sketch. I also worked on a map of the principal city, which took Kelly's original sketch and went straight into the computer.

Before going any further with line work, I wanted to make sure that I would draw mountains, hills, and rivers that behaved in a reasonable manner. In the real world, the geography is a function of climate, underlying bedrock, and elevation. I didn't have time to draw up a geologic map, but I had both likely climatic and geologic characteristics in my head when I sketched out a rough elevation map.

The rough elevation map: white=high elevation. This gave me a way to keep things organized - where the mountains should be, where rivers and lakes should be (so I wouldn't draw rivers that had to flow uphill)

Here's a detail that shows how I combined representations of mountains (in a semi-oblique view) with rivers.

And the finished geography portion of the map. I tailored the geomorphology to have some areas with fairly young, active topography, with areas of older, more mature topography.

Then there was the need to provide place names so that people reading the story could check the map to see where they were. I tried to keep large areas of negative space so that I could place text without having to contort it too much. But this is where digital map-making really helped - I could just select and drag an entire mountain or stretch of river and drag it out of the way to accommodate text. Or I could curve text, tighten the kerning or otherwise keep the text legible (although at published size, about 3" wide, nearsighted readers may have some difficulty).

And the finished project, complete with labels. And in print, it looks even cooler (since there's an awesome story that unfolds around it).

So go get a copy!

Ben - here you go:

Sunday, November 27, 2011

Holiday Decorations

I put up some holiday decorations today. Although I may have gotten things turned around a little bit.

Thursday, November 24, 2011

Toy for Bloggers?

Got a blogger in your life? Want to get them something new and fancy? Are you a blogger? Looking to see if the shiny iPad 2 does everything you need?

I don't have one, but my mom ended up getting one, so I spent some time yesterday checking out how easy it would be to use it as a Thurs-Demo tool. I did two tests. The first was pulling a full-size HD movie off my Canon 7D and processing it with the iPad. The second was a video shot with the iPad's video camera. Both of these were done with iMovie and were remarkably quick to make. The slowest part is the USB link between iPad and camera.

I would venture to say that the video quality off the iPad isn't bad. In places with lots of light, it's pretty clear and sharp. But in lower-light locations (indoors with curtains drawn), it's a bit grainy. And the resolution of the video is sufficient, but not so high resolution as to track individual drops of water or grains of sand...

I thought some of you might be interested - I know the most interesting thing about the iPad2 for me is the enhanced video capability. It's not something that would replace the high-end video capability I have with my Canon 7D and computer, but it would shorten the time required for some of the video work and it does create possibilities where none existed before.

Sunday, November 20, 2011

Dune Week

Looks like folks are talking about sand dunes and eolian transport on the geoblogs this week.

Here's some video I shot of blowing sand - you can see at least two distinct modes of movement - large grains are either tumbling individually, or avalanching down the slip face. Smaller grains, however, are picked up by the wind and bouncing (saltating) as they are transported.

Thursday, November 17, 2011

Hey Nature, Don Draper called - he wants his male privilege back

Wow, Nature's editors really served up a turd of a fiction article this time.

From what I've been able to tell, it's some kind of "story" about how women are from venus and men are the only ones who can observe the real world. I'm not going to dissect the piece. There are plenty of people that have done so with more wit and honesty than I could hope to achieve. Suffice to say, I found the "observations" by the so-called protagonist offensive. I feel very sorry for his wife (I assume he's married to one - or was), because she is apparently cursed for all time to be unaware of the concrete gender roles that surround us all. Then again, I buy my own clothes. I cook dinner. I also do science. Apparently the person in the story can't do any of these things - only make biased observations and purchase Jethro Tull albums.

It makes me sad. Not only because it really calls in to question the awareness of the editors at Nature. By association, does this article make any of the quality work published in Nature less good? I don't think so - but it does diminish the appeal of one of the most widely read and prestigious journals.

Which is sad in that it takes away from some really cool fiction published in the same venue. If you want to read something that sounds like an ad copy out of "Mad Men," go read Womenspace (whatever the hell that means).

If you want to read some good fiction in the Futures section of Nature magazine, go check out my pal Steph's story with a much more appealing title, "Here be Monsters."

Sunday, November 13, 2011

Thurs-Demo: The One with (Specific) Gravity

This week's demo has been a little late in coming - but I've got a few moments to get this up. Video is still processing though...

The plastic media that comes with the Emriver stream table is made of ground-up plastic. The stream model's physical behavior is largely determined by the relative difference between the density of flowing water and the sediment (there's also the viscosity of water, but that's another set of posts).

The above graph shows my student's results from soil mechanics lab last week. Students' results (red points) are a bit more varied than mine (blue). Aside from one errant point, student results lie along, or to the left of my own results - this suggests to me that it's a measurement error, rather than very different material. The leftward distribution points to less water than expected, rather than more. This could be the result of letting too much water dribble down the side and not into the measuring container, or waiting for all the water to stop dripping out of the spout. Or that the coarser fraction doesn't displace water as easily as a more graded mixture. Still, for 10-15 minutes worth of lab work, not a bad set of data.

This graph shows the results from a more extended set of measurements. The lab had students using a small (~100ml) overflow beaker - small errors like missed drops end up having a very large effect. So I tried using a much larger overflow beaker. My results were very consistent (basically a SG of about 1.50 ±0.01). But these values are a bit lighter than what Steve Gough (head of the LRRD) had for their color-coded material at 1.7. It's possible that my method allows for too much material to cling to the top of the beaker. Or the air bubbles trapped next to the surface of the plastic result in lighter-than-actual measurements.

So why graph the data this way? I can measure the plastic media's mass very accurately. And the amount of water displaced is proportional to the specific gravity of the material. So by making a bunch of measurements of two values, I can define a third as a linear function of the other two. It also saves some time on the calculation side of things.

Monday, November 07, 2011

Writing Challenge, Part the first

Anne Jefferson issued a challenge last week. She has some writing that needs to be done and to keep things motivated, she asked fellow geobloggers to join in and share their progress - and it seems that 41 folks joined in. The logo comes from Anne's fellow Allochthonian, Chris Rowan. I have two papers I'd like to finish this month, so I figure this will be a good kick in the pants.

What did I get done this week? Well, about the only thing I got done was some organization - I had a paper rejected (with the encouragement to resubmit) last month and I think the biggest thing to improve it will be to split it into two papers. Especially because the data I presented at GSA this last month ties into the part of the paper that deals with the fluvial chronology of the Upper Mississippi Valley. I've got most of the pieces for each paper, but many of them are out of place, or hanging out somewhere else. So I spent some time trying to figure out what needs to be where.

Aside from that, I taught classes, had my birthday, and then had to go to a wedding (where I got to see my new niece - she's very cute). So last week was a slow start. Not to worry - I have most of the figures in a near-final form already, over 5 pages of comments from the reviewers, and several pages worth of my own notes all ready dealt with.

This week, I would like to have all the pieces for the chronology paper in place (they don't need to be very pretty right now). Once I know how much I have to say for the methods, results, etc. I will be able to get a handle on how much detail and time I'm going to need to finish up the chronology paper. The alluvial sedimentology paper is going to take some time - because I'll have to abandon my ego and go through the reviewer's comments in detail.

Thursday, November 03, 2011

Thurs-Demo: The one with Terraces

Part of my research deals with the history of rivers. Well, a few rivers in particular, but they are an example of how the landforms associated with rivers and streams can tell us about past changes to the river system. Terraces are one of my favorite. Terraces reflect periods of transition for the river system. Periods when something happened - whether it be tectonics, climate, or changes in the base level (lowest point) terraces mark a change from a stream that is relatively "stable" to a stream that is able to erode down into its floodplain.

Callan, over at Mountain Beltway, had a post about terraces last year. The picture below shows some of the work I'm doing along the Red Cedar River - a tributary of the Chippewa River - which itself is a tributary of the Mississippi River.

Depending on how picky I feel like being, I count over six terrace levels - possibly as many as ten. One of the questions I'd really like to answer is "how did these terraces form?" Did they form as a result of changes in sediment supply? Cutting off sediment supply (or increasing water discharge) allows the stream to pick up sediment along the floodplain and erode downwards. Or base level drop? A drop in the main stream would lower the mouth of the tributary. This would increase the slope of the stream locally. Increased stream flow would increase erosion. I've sketched out the two most likely scenarios for the Red Cedar below (I'm ruling out tectonics for now, but isostatic readjustment as a result of glacial retreat may play a role).

It's important to note that these terraces may not be synchronous - depending on the rate of erosion, one part of the terrace may form much later than another. Also, the direction that the terrace develops is different. With sediment supply, the erosion starts upstream and progresses downstream. By contrast, a drop in base level occurs at the mouth first and erosion progresses upstream.

This is rather an abstract concept. It's hard to intuitively understand these processes. That's where the Emriver model comes in. By manipulating the system, it becomes easier to see what's going on. But how well does the Emriver replicate these terrace forming processes? Pretty good, actually. Here's a video where I managed to alter sediment supply (by limiting the sediment mobilized upstream) and dropping the standpipe to simulate a fall in base level. Pay close attention to the direction that the incision propagates.