Sunday, January 27, 2013

Land Use/Cover Change in Central Tibet

There is current research being conducted in central Tibet to compare approximate amounts of cultivated land in 1830 to 1990.  In order to find these data, researches must use the tax decree that instigated the use of the kang.  A kang refers to an approximate weight of barley seed sown by an estate.  Only by calculating seed weight is it possible to determine an area of cultivated land.  Rather than determining precise rates of change, since the information is often ambiguous or inaccurate and the tax decrees have been inconsistent, the researchers will test several general hypotheses relating to general regional patterns of land use and coverage.  Obviously, not all cultivated land was controlled by estates or taxed but most of it probably was.

Unfortunately, there is much unknown data because Tibet remained fairly independent and did not keep records of this variety back in 1830. The distribution of land grants was also mapped for which approximate sizes are known.  The resulting grid cells were located to within 2-10 km of accuracy.

 By studying the changes historically in agrarian land use patterns, we can examine a traditional theme of cultural geography. In this manner, we are able to see how the people and the culture changed as well as the land. 

Some traditional central Tibetan districts are not included in the Iron Tiger land decree that established the kang.  Also, the Sakya monastery and its landholdings are excluded.  There are a few other areas excluded due to certain historical events.

Below is the map of central Tibet divided into groups by kang distribution.

Researchers are also able to find potential cultivatable land area because the kang only refers to the amount of seed sown in a given area.  The actual land size depends on other factors such as soil fertility and local climate conditions.  Using more recent county-level data we can figure out county boundaries within which kang tax records from 1830 most likely apply.  On average, Tibet's cultivated land increased by 59% over the 160 year period. 

This data exemplifies how environmental and economic history are often intertwined and can be used to effectively answer many questions about a certain region.


Source: The Geographical Journal, Vol. 167, No. 4 (Dec., 2001), pp. 342-357Published by: Wiley-Blackwell on behalf of The Royal Geographical Society (with the Institute of BritishGeographers)

3 comments:

  1. The correlation between economic and environmental histories is fascinating, and this is a neat used of GIS to illustrate it. This certainly depicts the fascinating spread of ownership of the land in 1830, between the nobles, monks, and government officials. I wonder how that compares to land ownership today, if it is still largely held by these three groups, or if there is individual or familial ownership of some farmland now. If not, or even if so, that may say quite a bit about the income levels and general lifestyle of the different regions in Tibet today. It would be interesting to analyze how each area was affected by its owner type. Would the monk's land be more socially "just" today, as one would assume from a religious owner? The nobles' land? The government's? The history of a region certainly does factor into contemporary culture and I wonder if it would do so in this case in the ways one would expect.

    ReplyDelete
  2. What I like about this article is the use of "kang" as a way to measure change over time as it stays relatively consistant. It makes the research so much less confusing and convoluted. I'm also curious about the dispersion of land ownership today and how it compares. Also, could there possibly be a distinct change in land ownership after China incorporated Tibet?

    ReplyDelete
  3. The subject matter of this article is really fascinating. I agree with Jen's comment that "kang" is a unique way to measure the changes in Tibet over time. This approach takes a relatively complicated subject and makes it easier to understand via the combination of visual and statistical data. I also enjoyed the idea that environmental and economic history are often closely tied together. It would be interesting to apply that concept to other countries/time periods throughout history.

    ReplyDelete