Of the several different geographical regions in Oaxaca, the mountain ranges specifically are covered by lush forests of a diverse range of plant species. The high density of vegetative ground cover make this region a perfect example of a transport limited landscape. In this area, the rate of transport of weathered material limits the rate of erosion, as opposed to in a non-vegetative weathering limited landscape, where the rate of rock decay limits the rate of erosion.
 |
| The town of Tlahuitoltepec was built on the steep slopes of a transport limited landscape. |
 |
| Liquefaction occurs when extensive saturation increases the water filled spaces between particles, decreasing friction that normally holds sediment together. |
 |
| This photo of the Tlahuitoltepec mudflow exhibits thixotropic material flowing downslope due to gravity. |
 |
| With its swift speeds, the Tlahuitoltepec mudflow was capable of carrying cars in its flow. |
Mudflows can be incredibly devastating to communities that lie in their path. While mudflows generally carry mostly clay and silt particles and not much rock content, they are still extremely dangerous and can travel at speeds ranging from 10-30 miles per hour. With their viscous properties and high velocity, mudflows are capable of swallowing entire villages. The mudflow of Tlahuitoltepec burried 80% of the town and killed 32 people.
 |
| Citizens, police, and military worked day and night to rescue victims trapped by this geographical disaster. |
References:
Bricker, K. (2010, September 29). Corruption and deforestation caused oaxaca's mudslide disaster. Retrieved from http://upsidedownworld.org/main/mexico-archives-79/2712-corruption-and-deforestation-caused-oaxacas-mudslide-disaster
CBN News. (2010, October 01). Mexico mudslide death toll raised to 32. Retrieved from http://www.cbn.com/cbnnews/world/2010/October/Mexico-Mudslide-Death-Toll-Raised-to-32-/
Hey Melissa and Andrew. This blog post is a great look at a transport limited landscape, and how severe alteration of that landscape can lead to natural disasters like the terrible mudflow that destroyed much of Tlahuitoltepec. It is extremely unfortunate that corruption in the public works of the town lead to deforrestation which ultimately caused the mudflow. Are mudflows and other mass wasting events common in this area of Oaxaca? The town seemed very unprepared for a mudflow of this proportion which leads me to think that they must not be victims of mudflows like this often.
ReplyDeleteI enjoyed your blog post, and the included sources were also great and provided deeper information on the subject.
-Jacob Hirschman
I dream of going to Oaxaca one day so I was immediately drawn to your blog. I had no idea that that part of Mexico had such devastating mud slides. I liked how just explaining its structure you used a real even that happened recently that paints a clearer picture of what actually happens. The details and images depicting how the water fills the spaces in the particles causing liquidation was great. I also didn't know that it had a transport limited landscape instead of a limited one. Hopefully the people in the city will be better prepared next time if another disaster were to happen. Hopefully it won't. Overall, I enjoyed the blog. I learned new facts I didn't know, good job.
ReplyDelete-Alba Valerdi