Monday, 21 January 2008

"Houston - we have no problem!"

I turned over my desk calendar this morning and had a sense of deja vu (a mixed metaphor given that the calendar is German!). .... However, the question is... "where and when did we see these along Mark's route?"

Returning to Mark's current wherabouts, the GPS tracker this morning showed yesterday's route as follows.... Given that there is a six hour time difference between Texas and GMT, Mark apparently pitched his tent late last night after a day when his cycle computer turned 16000 miles somewhere in the vicinity of Houston. It's amazing to think that there are just 2000 miles to go! (If you want to get a fix on how far that is, it is approximately the distance Mark cycled between Paris and Istanbul ... and he seemed to do that in no time at all!)

Having mentioned Houston, although it was not strictly speaking along Mark's route yesterday, I took a wee 'detour' to look for NASA's Johnson Space Centre and here it is. This is Mission Control and astronaut training centre, Houston which, judging from the number of parked cars, must house thousands of employees......

More directly on Mark's route yesterday was the Sam Houston National Forest surrounding the northern portion of Lake Conroe. I have to say that until the last couple of days forestry was certainly not something I would have associated with south east Texas. Yet, it would seem that the 'Piney Woods' are a recognised ecoregion in southeastern USA. The moderate to high rainfall supports a sort of coniferous rainforest dominated by several species of pine including the 'indicator species' Loblolly Pine . The Sam Houston National Forest is managed under the multiple purpose concept. Under this concept, the uses of the forest, such as recreation, fish and wildlife, timber, grazing, soil and water, and minerals, are planned to maintain a balance among the benefits, yet provide for public needs. Mark's route yesterday morning took him through an area of Piney Wood forest which he noted as 'beautiful' in the Artemis web diary and certainly the route through the trees and across the causeway at the north end of Lake Conroe must have seemed such a contrast to the high plains of west Texas where he was just a few days ago. Lake Conroe, the result of damming the San Jacinto river back in 1973, helps supply water to the city of Houston but it is also managed for recreation..... and real estate at its southern edge if the image on the right found on Flickr is anything to go by...

About 30 miles east of Lake Conroe, while traversing more Piney Woods, Mark crossed the valley of the Trinity River which exhibits some of the best examples of ox bow lakes in the making which I have ever seen.....




This image 'reads' just like a textbook - deposition on the inside of the meander and erosion on the outside, causing the meanders to become more sinuous over time until one day the river takes a short cut just as it has done below.....


.....leaving the old meander to silt up and separate from the river's course forming an ox-bow lake.


From a little higher the valley of the Trinity River stands out in the landscape in a way so different from the rivers crossing deserts which we have seen on many occasions along Mark's route...
Instead of cultivated land being beside the river where it can benefit from irrigation water, here the cutivated land is on the higher interfluve areas avoiding the wet and poorly drained valley floor. The map shows the Trinity to be another of those Texan rivers with very narrow drainage basins and many dams in its upper course designed to regulate flow.
And finally... the answer to the question at the beginning of today's posting is a beach near Dunedin in New Zealand as described in this posting on 18th December.

4 comments:

GeoBlogs said...

They're the Moeraki boulders...
I have a good pic via my friend Simon here:
http://photos1.blogger.com/blogger/3676/197/1600/IMG_0897.jpg

WENDEE HOLTCAMP said...

The excess sand deposited in the river meanders is actually not natural but caused by excess siltation from sand mining! Check out www.sanjacinto.cc - I've been trying to raise awareness of this for some time! I also wrote an article for TX Parks & Wildlife magazine about it: http://www.tpwmagazine.com/archive/2006/dec/ed_3/

Interesting blog though - I stumbled on it after googling for some images!

WENDEE HOLTCAMP said...

I just tried to leave a comment and I don't know if it went through - but the excess sand in the river meanders is not natural but exacerbated by sand mining - check out the article I wrote above for TX Parks & Wildlife mag (http://www.tpwmagazine.com/archive/2006/dec/ed_3/ )and www.sanjacinto.cc. Sorry if you get this twice... you can just post one! :)

WENDEE HOLTCAMP said...
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