Project Details

http://en.wikipedia.org/wiki/File:Thailand_Buriram_locator_map.svg

The thesis of my project is as follows: My project will use Google Earth, a geographic information system (GIS), to generate spatial estimates of how much shrimp aquaculture activity is occurring in Thailand’s Trang province. By coupling that estimate with point measurements of harmful nutrients that shrimp farmers add to local ecosystems, I will estimate a nutrient budget for shrimp aquaculture in the region.


Some things have changed since this thesis was approved by the committee that provides research grants. I chose to use a different software, ArcGIS 10, but used satellite imagery nonetheless.

 WHAT is a GIS?!

--A GIS, or geographic information system, is essentially any analytical tool storing geographical and attribute data. Examples of commonly used GISes include Google Maps and Google Earth. These systems integrate not only spatial or geographical data (the maps themselves), but also qualitative and quantitative data about spatial or geographical features (the names of restaurants, photographs of certain locations, etc.). GIS is a powerful analytical tool because it allows for the manipulation of datasets to reveal the mechanisms that function within a complicated system.

WHAT is going on in the Trang Province?

--The Trang province in southern Thailand experience a huge economic boom in the 90s and early 2000s as a result of the rise in global demand for tiger prawns, a species of large shrimp. Because the Trang province possesses many naturally brackish estuaries, the area was ideal for the development of outdoor shrimp ponds. Unfortunately, the places where shrimp ponds are constructed and maintained often coincides with mangrove forests, which are biodiversity hotspots and highly endangered ecosystems worldwide. Mangrove forests are directly destroyed in the construction of shrimp ponds. Furthermore, delicate balances of nutrient inflows can be upset due to runoff from the shrimp ponds, which are rich in nitrogen and phosphorous. Nitrogen and phosphorous are two nutrients that typically limit plant growth, but when extra nitrogen and/or phosphorous are added to limited ecosystems, the results can be catastrophic with regard to alterations in the food chain and oxygen dynamics. These are the scientific explanations of shrimp aquaculture in the Trang province. I will offer a consideration of how the political economy of shrimp farming relates to the degradation of mangrove forests in a later post.

WHAT is a nutrient budget?

--The term 'nutrient budget' refers to the equilibrium of nitrogen and phosphorous in limited ecosystems. Studies of nutrient budgets can demonstrate that ecosystems are either experiencing deprivation of concentration of key nutrients. Although nutrient budgets do not necessarily explain dynamics of runoff and actual distribution of nutrients throughout ecosystems, they can be useful tools to prove that some nutrients are being concentrated in one place at the expense of another.

HOW does the project work?

--ArcGIS 10 is an amazing software program that allows for the importation of satellite imagery. By zooming in to a scale of 1:5000, I was able to identify structures as shrimp ponds because of their distinctive shapes, clustering patterns, and the presence of white aeration tubes. Using the 'create features' tool in ArcGIS 10, I drew lines around each individual ponds using what I deemed 'obvious vertices.' By drawing these polygons around each pond on top of the satellite imagery, I connected each pond to a real, geographic set of coordinates. In total there were almost 3,000 ponds in the region. In order to estimate nutrient budgets, I will take water quality samples at 25 randomly selected ponds within a 5 kilometer radius of three coastal towns in the Trang province. By averaging the results of those tests and multiplying them by the volume of the ponds, I will create a numerical estimate of how much nitrogen and phosphorous is entering the ecosystem as a whole. I will also be taking a separate measurement called density. Pond density, measured in ponds per kilometer traveled, will help establish and estimate of how accurate my data is. Accuracy is important for this study because if there are not ACTUALLY ponds where I created polygons, or if there are more ponds than I created polygons, the nutrient budget could be off by some margin. Hopefully, my data sets will be greater than 90% accurate.



IN OTHER NEWS, I arrived in Thailand yesterday. My dad picked me up at the airport in Bangkok, and we drove 4 hours to Buri Ram, a rural province in eastern Thailand. The town itself is unlike anything I have ever seen, and social dynamics are even more foreign, but I am loving every second of it. The food is GREAT, spicy, and cheap, and people are so friendly that I sometimes find myself distrustful of their motives. But that's probably just a result of my New York City cynicism because they have thus farm always just been trying to help! Stay tuned!