Back in the Saddle Again

Started the next section of the map 12/29/09 after a rest of a few weeks. This section is south of the big powerline and east of Flat Rock road. I picked the coldest morning of the year to do it which called for fingerless gloves. The camera refused to cooperate, even after I warmed up the batteries in an inside pocket, but I went out again the next day and managed to get a few pictures.

From Chattahoochee Bend

From Chattahoochee Bend

This area is very different. The river is far away - no floodplain here. Instead there are low hills, and cutting across those hills are the bare rock areas that gave Flat Rock Road it's name. I have only barely begun in this section, but already I have learned a few things:

• It's slow going - lots of detail that needs to be mapped - boulders, bare rock, rootstocks.


• the bare rock area has distinct vegetation. Stunted trees, because the rock is right there beneath the surface even if it is not visible; areas of grass and moss where trees cannot grow; complex patterns of green and white forest.


• the flat rock area is almost like a plateau, probably since it is resistant to erosion. It is deceptively flat, tilted down in a northeast direction.


• There are many more bare rock areas than are visible on the photo. Only the larger ones show up, so the photo is of limited use.


• The lidar contours pick out some of the largest boulders, which is very helpful.

This area will take a while. I know that, once I am off the plateau, there are huge boulders out to the east. I've already put more rootstocks in this area than in the entire previous sections, thanks to what must have been a mini-tornado that swirled across the side of one hill.

Construction is on-going on the new road to the visitor center. I am working east of the construction, but I still have to put up with the machine noise. The back-up alarm drives me nuts.

Checking the map

From Chattahoochee Bend

There's a smiling Kevin on the banks of the river holding the new map. He gave me some valuable help by coming out to cast another pair of eyes over the map. We covered a large portion of the northern map visiting most of the problem areas and discussing how best to represent them on the printed page. The many vegetation changes on this part of the map present the biggest challenge for the mapmaker. The weather was great (and dry) and it was fun to walk back over the map and look at places I hadn't seen in months.

I've decided to divide the remainder of the map into two sections instead of one. Flat Rock road will be the dividing line. I'll first work east of the road (where most of the rock features are). There are at least 3 sq. km. there. That should take me into the Spring. Then I will venture east of the road, where all of the park construction is happening. That is the largest section, something around 5 sq. km. With any luck and a lot of hard work I should be done in another year, by Christmas 2010 - but don't hold me to that prediction!

Stats from the north map

The log of my activity is on the Project Time page, but here is a summary:

238 hours and 15 minutes total time, which includes 151 hours of field checking, 45 hours of drafting, and the rest preparing the base map.

A little over 4 sq km mapped. That's almost 60 hours per sq km.

30 trips to the park, at 40 miles per trip, equals 1200 total miles of travel.

I started Feb 28 and ended Nov 15.

Now I will take a break. I will start the southern map (which is bigger) in January.

Week of mapping - Report #2

Hurricane Ida interrupted my week of mapping. Two inches of rain fell in one day.

From Chattahoochee Bend

This put a serious crimp in my field checking. I stayed home the day that it rained. Then went out on the tail-end of the rain the next day only to find it too deep for my boots - and the water was flowing instead of standing still. I took the next day off and went to do trail maintenance on the AT at Hawk Mt. Went out the next day only to discover that the flood crest from Atlanta had just reached the park. You can see the wet areas on the tree trunks where it is falling.

From Chattahoochee Bend

I worked around the edges of the flood as best I could for the next two days. Finally the water went down far enough that I could get back out there, and in one long marathon day I finished the rest of the floodplain.

Here's the river, back within it's banks:

From Chattahoochee Bend

An armadillo that didn't survive the flood:

From Chattahoochee Bend

And an old bus converted into a hunting camp:

From Chattahoochee Bend

Yes, that's a homemade fireplace where the engine should be.

And here is the biggest tree in the northern section of the park - it's probably the biggest tree in the park:

From Chattahoochee Bend

From Chattahoochee Bend

From Chattahoochee Bend

It's on a sandhill just meters from the bank of the river. Too high for Hurricane Ida to reach, but it was flooded in the 500 year flood, and probably many times in the past.

In fact, there was very little real damage from the big flood. Here's a huge raft of trash from Atlanta:

From Chattahoochee Bend

And finally, the early morning fog on the water:

From Chattahoochee Bend

Week of mapping - report #1

I'm taking a week off from my real job to attempt to finish the map north of the big powerline before Christmas. I've mapped three days so far, and been too tired each night to blog about it. Today it is raining, so here's the first report.

From Chattahoochee Bend

Rubber boots are required footwear. I went to Wal-Mart and bought the cheapest ones I could find. Can you believe there is still standing water after the flood? Here's proof:

From Chattahoochee Bend

From Chattahoochee Bend

From Chattahoochee Bend

You can probably tell that I am finally mapping the floodplain. I was waiting for it to dry out. I think it may take a while yet. Why is it still flooded? The floodplain is not flat. Working back at a right angle from the river, there is first a 10-12 foot bank, then a narrow ridge of sand 2-4 feet tall, then a depression 10-15 meters wide, then a sand hill 4-6 feet tall, steep on the river side, very gradually descending on the other side to a much larger depression that extends all the way to the first contour. This large depression is where the standing water collects. There is no path for it to escape to the river, and the ground is saturated after being under 21 feet of water. So it ends up looking more like the Okeefenokee than the Chattahoochee. In several spots ditches have been dug and channels cut through the sandhill by someone attempting to improve the drainage for farming. It hasn't worked and the ditches are all clogged now.

Once the rain stops I will don my rubber boots and head back out. I am about halfway done with the floodplain at this point - at least another 3 days are needed of field checking, and then hours of drafting...

Update from Friends of Chattahoochee Bend

Went along on the Friends of Chat Bend hike this weekend. Showed them a few of the cultural artifacts I had found and some of the terrain down to the tip of the big bend. Laurie also went along, and made a nice photo album.

We also got an update from the board of the friends group. Construction contracts will begin Dec 1st and last for 18 months. These will include the extension of the new park road west, a maintenance shed, visitor center, and campground. Projected opening date to be June of 2011.

If I'm lucky the map will be finished by then!

Nasty Smelly Water

From Chattahoochee Bend

Over a month after the flood and there is still water standing down in the floodplain. I might could deal with the standing water (it's only a few inches deep), but it stinks. Smells like sewage, which is not surprising. Millions of gallons of raw sewage got swept downstream from Atlanta in the flood.

I plan to take a week of vacation from my real job next month and work on the map. Hopefully the water will drain off or soak in before then.

From Summer to Winter

A sudden change in the weather to cool and windy had me wearing a coat and blowing on my hands this morning. I'm still working the forest in the bend of the river, holding off on the flood plain. It's still wet down there, with plenty of standing water.

From Chattahoochee Bend

Here's another photo of the bathtub ring left by the flood. It runs right across the middle of the photo through the cane.

From Chattahoochee Bend

The hardwood forest in the bend of the river is beautiful, with lots of impressive beech trees. This is their preferred habitat, the beech bottoms.

From Chattahoochee Bend

Sometime next month I plan to take a week off from my real job and finish the northern half of the map - I hope.

More Tractor Tires Than Any Orienteering Map?

Or maybe more tractor tires per square kilometer than any orienteering map in the USA.

From Chattahoochee Bend

From Chattahoochee Bend

What happens two weeks after the 500 year flood? The mosquitoes go wild. They're everywhere, they're everywhere! They haven't been a problem since early Spring, but today they were whining around my ears. It was cool enough to wear a coat, so at least I didn't get bit.

Here's another view of the flood bathtub ring, this time over on the west side of the big bend. You can see the mud coated leaves partway up this small tree. There was a lot of water down in here.

From Chattahoochee Bend

You might think there aren't any woods down in the bend of the river, but there's plenty. I spent my time today wandering about in the flat trees. It can be tough to orienteer in deep woods without contour lines. Plenty of ditches and gullies.

Groundbreaking Ceremony

From Chattahoochee Bend

a guest entry by Laurie Searle

The groundbreaking ceremony at Chattahoochee Bend State Park was awesome today. About 100 folks met up at the granite outcrop off of Flat Rock Rd. During the program, gracious thanks was given to the many people who helped make this park a reality. The Friends of Chattahoochee Bend State Park did a great job of coordinating this event, and inviting everyone to participate in the future support of the Park. I can't wait until the park opens, which they say will be in about 18 months.

Here is Laurie's article about the groundbreaking in the Chattahoochee Hills Weekly Reader.

and Sam adds:

There are more pictures in the photo album, including this one of Ronnie Eakins, who made it possible for GAOC to begin making the map of Chattahoochee Bend.

21 feet of water

The great flood of 2009 is over, and I made my first trip to the park after the waters receded. They called this a 500 year flood, and I can believe it. Upstream from the park we received over 18 inches of rain. That water had to go somewhere, so it flooded the Chattahoochee River. The road that I use to access the northern side of the park was flooded and closed in four places. The evidence is easy to see - the muddy water left marks on the trees and vegetation like a dirty bathtub ring.

From Chattahoochee Bend

My totally unscientific survey of the flood in the bend of the River reveals that it was 21 feet above normal level on the east side of the bend and 20 feet on the west side. The high water mark is easy to find. The obvious floodplain was underwater to a depth of maybe 10 feet. I came up with the answer of 21 feet by counting the LIDAR contours on my basemap. The difference between the east side and west side probably has to do with the topography. An area between 300 and 400 meters from the riverbank was flooded. That's a lot of water.

I'm not going down in there to look at it more closely. The news is full of reports that millions of gallons of raw sewage got washed down from Atlanta. I think I will at least wait for the leaves to fall to go back into the floodplain - every leaf is coated with mud. I could see plenty of standing water too.

So I stayed up on the "hills" in the center of the bend. I put "hills" in quotes because they look like hills on the map, but when you are standing there it can be difficult to tell. The contours are very gentle, and cannot really be used for precision navigation. They are covered with a confusing assortment of randomly-shaped fields, pine plantations, green areas, and forest. Not confusing enough to fool an expert orienteer, but I think they will cause some significant head-scratching. There is plenty of this area to keep me occupied until the leaves fall and the flood waters dry out.

From Chattahoochee Bend

Another problem is that now I need to recheck those areas of floodplain that I did before the flood. I haven't done that much, and it was over where the hills make their closest approach to the river. It can't be helped though. At least there have not been significant new blowdowns and resulting rootstocks.

A Rough Day

A rough day in the open fields. The weeds are head high and wet. And you can see the Plant Yates smokestacks from there (a Georgia Power plant). I spent a lot of time standing still, pencil poised over the paper, trying to decide how to represent what I was looking at. There are simply not enough levels of the open field symbol. There is "open", which I reserve for mown fields and lawn. There is "rough open", which I use for everything else. I can modify that by using scattered trees and the two levels of vertical green bars. It gets complicated, and there are a lot of decisions to make. Not much ground was covered. Like I said last week, the bend in the river is going to take a while.

I also ventured down into the floodplain. 300 meters between the last contour and the river. Yikes! This will be very difficult terrain for the orienteer, but at least they will have my map to help them. I have nothing - the photo is of little use unless there is some kind of old field or road. The lidar contours loop back and forth and over and around. It's very wet down there.

So I am thinking of postponing the fields until after the first frost, which won't be until November. Instead I will map the forest around the fields and down into the flood plain. Maybe after the frost the fields will be more pleasant to tromp through.

On the way out I drove south instead of north to see how the new park road is coming along. It looks pretty good. This will be the entrance to the park. No sign that there is much activity inside the park yet. Rumor is that there will be a groundbreaking next month.

And now for something completely diferent

A new page, moving up into the actual bend of the river for which the park is named.

Open fields and pine plantations.

The open fields are extensive and very overgrown. It will be interesting to see how the park manages these fields. From an orienteering standpoint, it would be great if they were cut and burned occasionally. If not, they will grow back into forest, a process that can take decades. We've got plenty of forest. (It's hard to see in that picture, but that's a nice gully that I added to the map).

The pine plantations are planted in rows. Sometimes very thick, sometimes very open, with rows wide enough to drive a truck down. Those were all former fields and pastures, converted at some point to trees. They need thinning and burning too. The thinning that was done further south in the park did not come up this far.

If there are fields and pastures there must be old barns and buildings. If there are old buildings there must be lots and lots and lots of trash. Including glass bottles.

There is a lot of territory in the bend of the river - over two pages of basemap. I'll be up here for quite a while.

The oddest thing I have ever found while mapping

The torso of a manikin. Where's the rest of it?

550 Acres or 2.23 square kilometers

Everything field checked so far has been drafted. That's 2.23 sq km, or a little more than half of the northern half of the map. The southern half of the map is bigger though. I'm averaging about 40 hours/sq km for field checking. If you factor in the drafting and other prep work, it's more like 68 hours/sq km. This is in terrain that is very familiar to me. When I move into the boulders south of the powerline my speed will probably decrease. But next I will move into the bend of the river, which has different terrain but no boulders: fields, pine plantations, and flood plain.

Hopefully I can work in another 80 hours before the end of the year and have the northern map completely field checked. I may take a weeks vacation, a "staycation", and just work on the map in October.

But there is enough to run on now. 550 acres is plenty for an orienteering meet - but that will have to wait for lots of other things to happen first.

Spider Population Explosion

It all begins with just a handful in April. Those have babies and the babies have babies and so forth and so on. How many generations are there in one summer? Who knows, but by the end of August there is a spider web on every branch. Wearing a bill cap is a necessity. Imagine blundering into a web and having the spider dangling before your eyes, or looking down at your shirt to see one crawling up towards your neck. By the end of he day I am covered in webs.

The good news is I finished another page this weekend - eight hours on Saturday and six on Sunday. The area west of the inholding is done, including the beaver swamp. It's about 200 meters long and 150 meters wide. Most of the long, wide flat area is light green and almost featureless. A nice creek meanders through it. The lidar contours are indispensable for mapping that creek. As long as he drop is 2 feet or so, the lidar picks it up. I used to have to do this by pace and bearings.

And what is this thing? More important, how did it get out in the middle of the woods with no roads anywhere around? It's a meter tall and three meters long, made out of that hard black plastic. There's some sort of gate at one end. It looks like a standpipe for a pond. I suppose it could have floated down the mighty Chattahoochee in a flood - it's about 150 meters from the river.

Another milestone - once I get caught up with the drafting, I will have enough map to run on. My plan is to finish the first deliverable for the orienteering club before Christmas. Next area will be north into the Chattahoochee Bend. Much different terrain - open fields, pine plantations, and flood plain.

One Mile an Hour

I set the GPS to record some stats while I field checked on Saturday. Five and a half miles of walking back and forth and up and down for five and a half hours - averaging about a mile an hour. It seems like I should have covered a large area it I walked for five and a half miles, but no - that's not the way that field checking works. Up the bottom of a reentrant, then down a little higher up, then up on the spur, then repeat in the next reentrant. Backtrack when I find a mistake. Wander about in the flat by the river, poking around in the tall cane, then try to sort out an old road that appears out of nowhere. So there is a lot of walking for a small amount of area covered.

I have proof that the river floods the park. Found lots of plastic trash congregating in this section. The river bank is two contours high (six meters), so that's a pretty good flood that can deposit trash that high. I mapped the closest approach of the river to the hills - only thirty meters. That's almost a cliff. South of that spot the hills retreat to a distance of 400 meters - that's a lot of flat land. That's where I started seeing the plastic that had washed down from Atlanta - not sure why it would start to appear there. Probably has something to do with the topography.

The riverside vegetation is thick in his area, which means that I spent quite a bit of time poking around. There is always a rise of land at the bank, followed by a depression and then another rise of land. All very subtle. Getting the contours straight is very important for an orienteering map. The small changes are what will make the map interesting.

Found the first spot where I could actually get down to the water. Usually the bank is so steep and muddy that the only way to get down is to fall. A small gully (which I mapped) gave me the opportunity to get down without getting covered in mud. The view upstream and downstream.

That's the last of the river pictures until I finish the rest of this page. Now I need to work my way south through some logged areas to the big powerline, while skirting the beaver pond. I'm curious to see how extensive the beaver swamp is.

A new page!

I started a new page this weekend - a purely arbitrary milestone, but I take what I can get to keep my spirits up. This is actually the third page of map. Since the base map is at a large scale each page doesn't cover much territory - still it's great to start a new page. That also means I have a lot of drafting to do with the just-retired page.

I finished the ld page in 4.5 hours on Saturday. Last weekend I had found an aluminum tree stand. I have found lots of tree stands, but they are all wooden and in danger of falling at any minute. This one was different, a modern aluminum stand padlocked to a tree. Not sure how long it had been there, since hunting season is long over. Or maybe it's for this fall? Anyway, it's illegal now that the area is a State Park, so I notified my contact with the DNR and he asked me to send him the GPS coordinates. I drifted by there on Saturday and it was gone! How odd. Anyway, the DNR still wants to know where it was so they can check on the area later.

I finally mapped the old house - I'm pretty sure that the cabin in the pines was a sharecrop cabin for this house. It has not survived - it's a total ruin, except for the well house right next to it.

Sunday I started a new area. My first deliverable for the orienteering club is the area north of the big powerline and as far west as the southwest bend in the big powerline. Rather than map up into the bend of the river now I decided to finish the area west of the big inholding. Followed the boundary south for 900 meters to the powerline, then west on the powerline. Found a logging road that I hoped would serve as a western boundary, but it ended up making an S curve through the new area. I predict that I will spend hours walking this road to get access to the area to map it. I am moving farther and farther away from the parking spot.

Found the first beaver dam - the area behind it is 250 meters wide and 900 meters long. I hope it's not all flooded. Also found the largest Beech tree I have ever found while mapping, and I have seen some big trees. It is in a sheltered spot almost on the bank of the river.

The Cabin in the Pines

Made an interesting find today. A small cabin, which I presume used to be a sharecropper cabin. It is extremely well preserved, probably because the tin roof is still intact. It's very well hidden. All it needs are a few floorboards and a new chimney and you could move in. Of course there's no power, but isn't that part of the charm? Here's a better picture of the whole cabin from the other side.

As far as mapping goes, I finished most of the area north of the meadows and as fareast as the corn combine. One more trip and this area should be done - then it's into the open fields in the bend of the river.

Mapping the "Meadows"

It only took about four hours. Most of the variety that I had seen when walking through this area before turned out to be too small to actually map. What's the smallest open area you can put on the map? I added a few very small ones, but most of this area of old logging I was forced to map in different shades of green. Now the map has every color of green, from white woods to light green to the darkest stuff I would not send my worst enemy into.

a dark and gloomy morning

It doesn't take much cloud cover to make it dark and gloomy beneath the leaf canopy of July in Georgia. Very little actual light makes it to he forest floor, and this morning, with rain approaching, it was so dim I had a hard time reading the map.

I covered a lot of area with little actual pencil marks on paper to show for it. I'm starting a new section since I had finished encircling the first area of "meadows". This is still the area west of the small power line. I like to start a new section by using a linear feature ( no matter how obscure) to define it. Not much luck finding anything here. I thought there would at least be an old road running down the spurs but there was nothing. I wandered out to the northeast where one of the old homesteads is located. This is the one with the corn combine and the large barn. I ended up walking the edge of the pine plantation (planted in rows running east and west) out a spur until I could join with a stream I had already mapped. There are several areas of pine plantation that will be on the map. I have mapped areas like this before at Joe Kurz, and will use the directional area symbol for them so that the orientation of the rows of trees will be obvious.

I still need to go back and do the "meadows" - but I will save that for a time when I have enough gumption to tackle it. It will be very important to the map to get the vegetation correct in those areas.

More pictures on the photo page.

Independence Day Mapping

Spent five hours this morning adding more area to the map. I'm still working in the deep forest surrounds the "meadows", saving the actual meadows for later. These hills are the closest to the river of any in the park, several coming right down to the water's edge. Also found the first depression along the river - about 50 meters long. I thought it was a hill on the lidar basemap since there were no tag lines - of course on the orienteering map there will be no doubt what is up and what is down.

Found another quartz pit, where someone (probably Creek Indians) removed all the quarts from an outcropping. One deer skeleton, several small cliffs, and the first of the open fields along the river. These fields are all man-made. Unless the park maintains them by cutting they will gradually revert back to forest. Check the photo page for more new photos.

On the technical side, I have not used the GPS since I started the map. As long as I keep in contact with the basemap so that I always know exactly where I am, it is much quicker to put pencil to paper than to go through the extra added steps of using a GPS.

Power Plant Smokestacks

The new Chattahoochee Bend State Park is on the river between two power plants run by Georgia Power. Plant Yates on the south bank and Plant Wansley on the north bank. Today I got my first glimpse of the stacks at Wansley. It's doubtful that the Yates stacks would be visible from the park.

Four and a half hours in the deep woods. I have just about filled in the area west of the "meadows". Soon I will have to come out of the woods and tackle the much more difficult meadows. The deep woods terrain is very familiar to me - I could probably map it at a walking pace. Very little backtracking is needed and there is almost no change in vegetation. The vegetation changes are what make the meadows difficult for me. I have to decide what symbol to use. I have to treat the edges and boundarys as linear features and get them accurately placed.

Also found an armadillo skeleton today. The outer shell is about the texture of a deflated basketball.

Arrowhead pit?

Found a pit in my mapping today. Quartz rock had been dug out of it. I've seen this before, at Russell State Park on the Savannah River. It's possible that the pit was dug by the Creek Indians while looking for material to construct arrowheads. There's no flint here - quartz was about their only choice for sharp stone tools. Of course all that stopped when the deer trade began and the Creeks could afford to buy rifles.

The county name where the map is located - Coweta, comes from the name of a Creek town on the river, although I believe the actual town wasl located down near Columbus. The Creeks stayed around their towns in the summer and on their hunting grounds on the rivers and "creeks" during the winter.

I mapped five hours today in the heat. It was 93 when I got back to the truck at noon. I start at first light to beat the heat. It's not too bad really. I wear a long sleeve synthetic running shirt that is very light and white. Long sleeves to keep off the skeeters and the deer flies and horseflies. I also wear a bandana around my neck to keep the deer flies off.

Worked on the west of the "meadows" area. I'm just not up to tackling the difficult and detailed meadows in this heat. I worked the deep, dark woods, going up and down the spurs and reentrants, filling in the vegetation boundary on the west side of the meadows. It will be quite a job to get the vegetation cover correct in the meadows - a job for another day. I plan to work around them until I have them completely defined, then come back and fill in the different shades of yellow and green in the meadows.

Drafting has begun

I've always found it a good idea not to let the field checking get too far ahead of the drafting. The more time that passes  the more difficult it is to remember exactly what I drew on a particular day. Is that a boulder or a dead mosquito?

And I shudder to think of anyone else trying to interpret my field notes. The resulting map would not be useful. Orienteers would find trails where there should be roads, dark green where there should be open, boulders where there should be dot knolls.

One thing that I do with vegetation that helps a lot when it comes time to draft is to use the last two digits of the IOF number for the vegetation. I have a list of the numbers for that and other symbols taped to my board. I don't have it in front of me right now, but I think all the vegetation sysmbols begin at 400. So in the field I draw a line around the area and then label the interior with the corresponding number, like 9 or 11. I do the same thing with all the different road and trail symbols, using a solid black line for each and labeling them with a symbol number. I also do this for any other symbol that might be misunderstood or confused later. This reduces the chance of error when I draft.

So now I am up to date on the area north of the big power line along Flat Rock Road. That means about 0.7 sq km has been field checked and drafted.

My Experience

I had someone email me and ask what mapping experience I had, so I sat down in front of Ocad and did some measuring.

I started making maps for the Georgia Orienteering Club back in 1995. Here is a partial list of the maps I have made and their size:

• Cochran Mill - 3.5 sq km


• Sweetwater Creek State Park - 5.8 sq km


• FDR State Park - 13 sq km


• Joe Kurz WMA - 5.8 sq km


• Smithgall Woods State Conservation area - 11.7 sq km

That’s a grand total of 39.8 sq km of map, or 9,835 acres. Chattahoochee Bend will add another 12 sq km to the total when it is finished.

The Mighty Chattahoochee

Two mapping days in a row. 85 degrees today. I start at a litle after seven and quit when it gets too hot.

Printed out more basemap, and started out on the area west of the small powerline. This is a big area, with no obvious handrails to use. My usual tactic is to make a handrail out of something so that I can enclose an area, then radually work away on the interior. I used the northern boundary of the inholding, which has a nice forest road along it. I mapped that out about 700 meters, then mapped a stream north west all the way to the river. The terrain is very pretty here. The stream is in a wide reentrant until the last 100 meters when the hills close in on it and it passes through a two contour deep channel down to the river.

Then I worked my way back up one of the hills and discovered an area that had been logged 20 or 30 years ago. It was only logged along the very top of the hills and spurs. Very odd. This is all hardwood forest, and the loggers did not replant, but let the volunteer trees come back. As a result, there is everything from bare clay to grass, blackberyy canes to muscadines, and trees of every height. Mapping the vegetation changes will be a chore. I predict I will spend a lot of time trying to get this right. My usual tactic is to map the edge as a linear feature first. I tried that and managed to get confused, but by that time the heat was getting to me.

I uploaded plenty more pictures, including a couple of the river. Check them out.

Small Victory

Today I finished the area east of the small powerline over to Flat Rock Road. It's pretty satisfying to actually finish off an area, no matter how small. This section is narrow, no more than 200 meters wide, and I can use the powerline poles as references - after I put them on the map, of course.

Found some pits that someone had dug in this area, as well as the usual root stocks. Also finished the last of the pine forest, which has a narrow strip west of the road.

Worked my way all the way north to where the powerline bends to the east. Here I got totally confused. The photo and the powerline did not agree. I was right at the edge of the photo and I didn't have the next photo north printed out. Gave it up until another time.

At this point I have finished about 0.6 sq km.

By the time I got back to the truck it was 82 degrees. Whoo.

Tickless

The good news today was that I came back from field checking with not a single tick. Last week I picked up 20 or 30 seed ticks. So I went to REI in Atlanta and bought some Sawyer clothing treatment. This has 0.5% permethrin. I followed the directions religiously, spraying my shoes (running shoes), socks (Thorlo hiking socks - seed ticks go through the weave in these like a man throuh a barn door) and my hiking pants from the knees down. I wore my pant cuffs tucked into my socks, so I looked like I did in the Army with my fatiques bloused over my boots.

It worked. I checked my ankles several times during the day and found no ticks. The terrain was the same as last weekend - pine forest with lots of weeds, perfect habitat for ticks. So far, it's a success. I suppose I'll see as the summer progresses.

Finished the area east of Flat Rock Road and north of the power line. Also checked the boundary around the smaller inholding. This is just a few acres along the road with three houses in it.

Found an old homestead. You know you have found one when the privet is so thick you can't move. Long ago the homeowner planted a privet hedge and it escaped. Now it's twenty feet tall and covers everything. Photographed several old buildings, see the photo page.

The northernmost point east of the road is an impressive stand of 20 foot tall cane - also escaped from the old house just outside the boundary. Need a fishing pole?

So now I move on, west of the road and north to the river. Now it will become a chore to walk out and back to the area I am field checking each day - there is no other road access.

A Beautiful Sunny Day

Finally some sunshine so I can get some field checking done. Spent about six hours walking to and fro and back and forth, still in the area along Flat Rock road north of the power line. Got a break about mid-day when the pine forest opened up with visibility of 200 meters at least through the scattered pine trees. That's a beautiful area - reminds me of the longleaf pine forest over at Choccolocco in Alabama. Of course, it will require diligence on the part of the foresters to keep it looking this good - burns at least once every two years would be good. Orienteers love controlled burns. They really clean out the undergrowth and encourage the larger trees.

Found a double decker tree stand, easily the tallest I have every found while mapping. Two photos are on the photo page. I did not climb it - too rickety for me, but I did put it on the map.

And the ticks are out. I probably picked up twenty or thirty - mostly seed ticks about the size of a pinhead, but also four or five dog ticks. I need to find some peremethrin(?) to treat my shoes and socks.

So a good day. The 0.3 sq km between the inholding and the eastern boundary along the road are now mapped. On the next trip I'll work on finishing everything east of Flat Rock road north of the powerline.

First field checking trip

Rain, rain, rain. I hoped to get at least one full day in this weekend, but the rain just keeps coming. I had to wait until Memorial Day to get a half day in between rain showers.

But the map is started now. I began with the area north of the powerline and along Falt Rock Road. There is a 400 meter wide and 800 meter long corridorhere which should be very important when we finally get around to setting orienteering courses here. Although it sounds small, that's still over 0.3 sq. km. I only managed to get 0.1 sq km done before the rain came back.

Field Checking ready to begin

The time has finally arrived. I have a good basemap consisting of LIDAR contours and aerial photos, and I have permission to make the map. Now all that is required is that I spend the time on the ground. This will take at least a year, maybe longer, depending on the level of detail that I encounter.

It's exciting to start a new map, but it's also a little sad. All the secrets of the park will be revealed. Every boulder, every fallen tree, every ditch and gully will be pinpointed (I hope) and drafted on the map. Making an orienteering map is a little like submitting to a full-body search - with photos. There will be no spot left unexamined by the time I am through.

And sometime in the not too distant future, several hundred orienteers will be handed the new map and sent out to see and find for themselves the hidden treasures of the park.

I have also added new photos to the Picasa web album I am keeping. I was out there (in the rain) last Saturday doing an "inventory" of boulder sizes. This is not mapping, but a walkthrough to set some standards. What will be the smallest boulder that I will map? Probably waist-high, unless it is a solitary boulder separated from its cousins. I also found very few rootstocks (fallen trees) and minimal ditches and gullies, but I restricted this inventory to just the area east of the bare rock.

LIDAR contours

The map took a major step forward this week with the acquisition of LIDAR contour data from the Coweta County GIS department. LIDAR is the latest and greatest method of generating contours (and other data) using airborne radar and digital signal processing. This is great news, and should make the finished product much better.

Getting it into a usable form took most of a day. The county supplied two foot contours in a shape file. I had to use qgis, wich is an open source GIS program (free) to translate it from lat/long coordinates to UTM WGS84 in zone 16N. Then I used a demo program to convert from shape to dxf. The dxf file still needed some massaging, which I did with sed in OS X. After all that I was able to import the dxf and have it magicall line up with the geo-referenced aerial photos.

Here's an example.The purple lines are the lidar data. The green lines are the USGS contours from the DRG. The blue lines are contours generated from the USGS DEM. There's a lot of difference.

[caption id="attachment_64" align="alignright" width="425" caption="LIDAR Contour Example"][/caption]

GAOC board approves mapping project

I submitted a proposal to GAOC and they approved it. So now I have permission from the DNR and the blessing of the orienteering club so I am good to go. Can't go out to the park again until after turkey season is over, and by then the leaves will be out. Should be able to work on the open fields and pine plantations in the horseshoe bend this summer, and then move into the woods after the leaves drop in the fall.

Progress Map and Project Time pages

I added two more pages, links are over on the left. A spreadsheet of the time I'm spending on the project, and a map of my field checking progress.

GPS -> DXF -> OCAD

The next piece of the puzzle that I needed to solve was how to et the GPS waypoints into OCAD easily. The scenario is that I mark a waypoint of a boundary marker or a boulder or that old abandoned corn combine while I am out field checking. Then, when I get back in front of the computer I magically transfer that point into OCAD.

OCAD is not a full featured GIS application, at least not version 8. It only acepts DXF files, which are an ancient output format of autocad. Wikipedia has a nice page explaining the format and a link to the official definition. OCAD doesn't need a full fledged file, ust the points section. Here's an example with just two points:

0
SECTION
2
ENTITIES
0
POINT
8
cbwaypoints
10
688166
20
3701504
30
0
0
POINT
8
cbwaypoints
10
688222
20
3701658
30
0
0
ENDSEC
0
EOF

I was able to take the gpsx file from the GPS, and using GPSBabel and a perl program I wrote for my Mac, massage it into the correct format. As long as I name the waypoints in a certain format, I can grep them and convert to a dxf fle.

OCAD imports these in a gray color, marked with a plus sign, with no symbol defined. It's necessary to select them and convert them to the appropriate symbol.

Now it remains to be seen how accurate they are. This is the first time I have attempted to use GPS for making an orienteering map. I guess I will report back in May on the success or failure of this experiment.

DEM -> contours -> OCAD revisited

I have begun construction of the basemap in earnest. All my datasets had to be converted to WGS84, since it turns out that my consumer grade GPS only outputs waypoints in that coordinate system. I will display in other coordinate systems, but not output them.

The gdal utilities to the rescue. gdalwarp will convert any raster dataset to a different coordinate system, so I was able to get all my datasets and aerial photos into WGS84 with no problem.

I them used gdal again to generate three meter contours from the dems. Exporting to dxf presented a problem again, since my free trial period for arcv2cad had expired. Fortunately I found a free utility that would convert from shape files to dxf. DXF Author from Massachusetts GIS, does the job well and is free.

Cleanup with Friends of Chattahoochee Bend

The Friends of Chattahoochee Bend State Park had a cleanup event last Saturday and I showed up to help. There were a couple of dozen people, and we got an update on the park status, then headed out to the park to pick up trash.

Like most rural areas, there has been plenty of illegal dumping going on over the years. We spent a few hours cleaning up several of these dumping sites along the county road that runs through the park and the power line that crosses it.

It was a good start - more work is needed, of course. The bare rock areas are rimmed with trash too.

After the trash pickup I wandered around in the bare rock areas for a couple of hours checking things out. Looks like there will be plenty of detail in some areas and almost no detail in other areas.

We got some good news about the hunting. Looks like they will change to a quota hunt or only a few days. This is how hunting is handled at FDR, Red Top, Lake Russell, Joe Kurz, and Dukes Creek. This means I can map in the winter, which is a much better time because of the increased visibility.

DEM -> contours -> OCAD

Using a USGS digital elevation model (DEM) to generate contours for an orienteering map might be described as "garbage in, garbage out." The USGS DEM is crude at best, at least from the viewpoint of an orienteering map.

But what this technique does offer is the ability to generate contours at a different interval than a USGS quadrangle map. For the Chattahoochee Bend map, I need countours at a 3 meter interval. The USGS quad has 20 foot contours. The object is to take the DEM, run it through some utility programs, and generate contours at a 3 meter interval that I can use a a crude base map.

Every contour must be redrawn during field checking to more accurately match the terrain, but there is an advantage to having contours at the correct interval to start from.

So I got a DEM of the area, for free, from the Georgia GIS Data Clearinghouse. This came in NAD27, which is what I was using with the DOQQ and NAIP photographs, so my OCAD map is already using those coordinates. If I were using some other coordinate wywtem I would have to convert so hat all my data sources are on the same page of the hymnal.

I use the GDAL utilities to do coordinate transformations and to generate the contours. These are command-line programs that are available for almost every operating system. I'm using a mac - not that it matters. The program to generate contours from a DEM is gdal_contour. The command looks like this:

gdal_contour -a contour -i 3 e3384d8.dem whitesburg.shp

The default output is a shape file. Unfortunately, the GDAL utilities don't seem to be able to generate DXF files, which is what OCAD needs. So I had to find a program on the net to do the conversion. I used Arcv2cad, which had a demo version. The dxf file is then imported into OCAD and the contours converted to a symbol. I actually copied the contour symbol and changed the color to gray.

So how does the output look? And how does it compare to the USGS quad contours? Here's an excerpt of the map:

[caption id="attachment_26" align="alignnone" width="341" caption="USGS contours and DEM contours"][/caption]

The USGS contours are in brown, and are at a 20 foot interval. The DEM contours are in gray at a 3 meter interval. So there should be about twice as many DEM contours. Note also that the DEM contours are points connected by straight line segements, and the USGS contours, which are taken from the DRG, are smooth lines.

This excerpt is about 850 meters east to west and 600 meters north to south, so you can see that there is not a lot of elevation chage on this map.

So is this useful? I would like to have both in the field, so that I can contrast and compare. The DEM gives me a clue where the extra contour line should go.

This would not be useful in a map with relief detail that could be obtained with photogrammetry. Photogrammetry would be a vast improvement when there is more relief and there is detail to be discovered. But this is such a "gentle" area that the photogrammetry is not going to reveal much, and comprehensive field checking is needed anyway. It is during the field checking that the detail will be added and the contours smoothed.

NAIP photographs

I am wrestling with the decision of whether to have photogrammetry done or not. It's the traditional way to go. But this map lacks intricate contour detail, so it is debatable that photogrammetry will do any good.

What is needed are recent aerial photographs. I found a new program from the department of Agriculture that is trying to take recent photographs, and I bought two photos that cover most of the park from 2007.

The first example below is a portion of the barerock area. There is a swath of rock features that run across the map. The second is of the northern tip of the horseshoe bend, showing some of the old fields and the new pine plantations. The quality and size of the photo excerpts is reduced, of course.

[caption id="attachment_23" align="alignnone" width="256" caption="Bare rock at Chattahoochee Bend"][/caption]

[caption id="attachment_22" align="alignnone" width="256" caption="Horseshoe Bend"][/caption]

The plan is to load these into Ocad as templates, and print them at 1:7500 with grid lines and other info, then take them out into the field and use them for field checking.

Jan 2009 Update

Spoke with my contact at the DNR this morning to get an update on the park. Last year he had told me to call back in January. Here is what I learned:

- Big surprise - development money has been released, despite the budget problems. They are already widening and paving the road leading into the park. Planning will begin to design the facilities now. It will probably take a few more years.

- They had a lot of problems with the hunting season. He would not give me specifics except to say that the surrounding landowners filed a lot of complaints. Because of this there is a chance this will be the last hunting season, although personally I wouldn't count on it - the hunting lobby is pretty strong.

- Logging will continue a little longer. They are thinning all the pine forests.

I now have permission to go out there and actually make a map, but I cannot go until after Turkey season - May 15th, and I have to call before I go and let him know I will be on the property. This is all because of the complaints they have gotten about the hunting and for liability problems. Not good news, but I have to do what the DNR says.
So I have sent an email to the board of GAOC, informing them of what I have found out and that I now have permission from the DNR to go on the property and make a map. Hopefuly we can squeeze in a meeting this weekend at the A meet and discuss it.