Sunday, February 28, 2010

Winter Olympics: Exercise Physiology



For Crossfit perspective on recovery, see. They don't see much in it, but if you follow the model above, recovery interval is all-important.

Another idea in exercise physiology: "specificity" versus transference.


Thursday, February 04, 2010

Environmental Degradation in Haiti

Google maps has high-quality satellite imagery of Haiti, and reading remote-sensing images is a big part of my job as an ecologist so I decided to take a brief fly-over to see what it looks like. What immediately called out to me was the widespread and obvious degradation of the rivers and streams; the images of Haiti are consistent with a highly disturbed landscape. Most unconfined rivers in Haiti appear braided, meandering over large areas of bare ground.

These rivers are rapidly aggrading (depositing sediment), most likely due to excess sediment from erosion in the uplands. Of course, natural disturbances such as hurricanes, forest fires, and perhaps even earthquakes, could cause similar river channel adjustments. Braided channels may be a natural response to naturally high-erosional areas. Here is such a stream in Southern California:

If Haiti had a Californian/Mediterranean climate instead of a Carribean climate, these levels of disturbance could be explained naturally. Instead, these high-disturbance, silt-choked rivers and streams are likely better explained by human overuse and consequent environmental degradation: "Haiti...was largely self-sufficient in grain 40 years ago. In the years since, though, it has lost nearly all its forests and much of its topsoil, forcing the country to import more than half of its grain." Brown, Lester R. "Could food shortages bring down civilization?" Scientific American. May 2009. p. 50




Closeup view of wide, unvegetated floodplain in Haiti:

Of course, Haiti is not the only place with altered erosion visible from space. In fact, the images above are becoming the norm across much of the world. Even richer countries have impacted rivers, but some, such as Costa Rica, also have many rivers that are allowed to remain in their unimpacted, natural state. This is what tropical rivers should look like when they have a natural disturbance regime:

Wednesday, February 03, 2010

Springerville, AZ Riparian Restoration Project

Natural Channel Design, inc, has finished their riparian restoration project and evaluation on a stretch of the Little Colorado River near Springerville, AZ.

The site can be visited on a constructed trail: "The trail provides a public walkway along the Little Colorado River from Hwy 260 to Airport Road in Springerville, with a total distance of approximately 4,300 feet."