Population, Land Use, and Environment Research Directions (2005) / Chapter Skim
Currently Skimming:
6 Population Change and Landscape Dynamics: The Nang Rong, Thailand, Studies--Stephen J. Walsh, Ronald R. Rindfuss, Pramote Prasartkul, Barbara Entwisle, and Aphichat Chamratrithirong
6 Population Change and Landscape Dynamics: The Nang Rong, Thailand, Studies--Stephen J. Walsh, Ronald R. Rindfuss, Pramote Prasartkul, Barbara Entwisle, and Aphichat Chamratrithirong
Pages 135-162
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 135... ...
data became available only in the early 1970s. Initial research with Landsat data focused on broad mapping issues that only suggested pattern-process relationships, including the human dimensions of land use and land cover and subsequent changes in landscape patterns.
|
From page 136... ...
In this chapter, we describe the portion of our ongoing work in Nang Rong, Thailand, relevant to the human dimensions of global environmental change, with an emphasis on mapping and modeling patterns and dynamics of land use and land cover by linking people, place, and environment in fundamental ways to address research questions that extend across the social, natural, and spatial sciences and that require integration of data, methods, and perspectives. QUESTIONS IN CONTEXT What are the reciprocal relations between population change and landscape dynamics?
|
From page 137... ...
Plate 4 shows the district in 1972-1973 and 1997. Changes in the composition and spatial patterns of land use and land cover, principally caused by deforestation of the uplands and the cultivation of cassava or sugar cane or both, are most obvious, but more subtle changes in the lowlands, caused by pond development, loss of isolated trees and small clusters of trees, and the expansion of Nang Rong town, the central market and administrative town (shown in light blue)
|
From page 138... ...
. This is a period of peak labor demand in Nang Rong.
|
From page 139... ...
For instance, circular migration patterns of young adults working in Bangkok, the eastern seaboard, and other urban places are related to the efficacy of monsoonal rains for the cultivation of lowland paddy rice in Nang Rong district and the selected mode of rice cultivation, broadcast or transplant, which have very different labor requirements. Feedbacks between the monsoon, characterized by floods, droughts, delayed rains, or normal to near-normal rainfall conditions, have implications for people and the environment.
|
From page 140... ...
We choose the life course perspective because, although central in our work, it is relatively new in research on land use and land cover change. The complexity perspective is also relatively new, both to our research and to the field more generally.
|
From page 141... ...
. In Nang Rong, young people generally finish their schooling at age 12; few go beyond a primary education.2 Then, they work: cultivating rice and other crops in their home village; as temporary laborers in agriculture and construction in the district and other nearby places; and as factory, service, and construction workers in major urban destinations, such as Bangkok.
|
From page 142... ...
Cohort size is a key element of historical context that needs to be recognized when drawing general conclusions, not only from the Nang Rong study but most studies currently under way in different parts of the world. Complexity and Hierarchy Perspectives The goal of complexity is to understand how simple, fundamental processes can be combined to produce complex holistic systems (Gell-Mann, 1994)
|
From page 143... ...
It is multithematic, representing social, biophysical, and geographical domains. The design and collection of the relevant data and their integration into a wide-ranging and flexible, spatially explicit GIS database is one of the accomplishments of the Nang Rong projects.
|
From page 144... ...
. The 2000-2001 data collection included a community survey in all villages in Nang Rong; a household survey; a complete census in the 51 study villages; and the collection of locational data for dwelling units and agricultural plots, linked to the household survey, as well as a migrant follow-up that tracked migrants from 22 villages to the four urban destinations and to rural villages in Nang Rong district.
|
From page 145... ...
data have been acquired for selected high interest dates approximated to social survey periods. Also, Ikonos data3 are being used to assess settlement patterns of Nang Rong district migrants who have sought off-farm employment in Bangkok.
|
From page 146... ...
Using a derived aerial photo image mosaic for 1954, 1967-1968, and 1994, the road network captured from the 1984 Thai military map has been expanded to examine how changes in geographic accessibility through a dynamic road network may contribute to land use and land cover dynamics throughout the Nang Rong district. The district outline was also captured from the 1984 base map, as well as district villages and regional market towns.
|
From page 147... ...
Again, in the life course framework, the transition to adulthood is a time when numerous transitions are occurring in both the work and family spheres. In the 1970s and 1980s, land was ambiguously titled in much of Nang Rong, which allowed young people to clear a land parcel, farm it, and claim it as their own.
|
From page 148... ...
This is true for all three time intervals, although the strength of the association varied, suggesting some temporal scale dependency. Distance to Nang Rong town, the central market town in the district, was also significantly correlated with the percentage of land cover change for all three time intervals, but, interestingly, the correlation was positive for seasonal and decadal change but negative for annual change.
|
From page 149... ...
Cellular automata are used in our research to simulate land use and land cover dynamics. Cellular automata models are composed of a regular grid of cells each in a finite state that are iteratively updated in discrete time steps.
|
From page 150... ...
Complexity theory concepts of critical thresholds, feedback mechanisms, and hierarchy relationships are infused into the cellular automata models for generating simulations to match observed states or for future periods by allowing the model to iterate within the expected bounds of the defined rules. For example, we have developed transition or growth rules to model rice, forest, and upland field crops (cassava and sugar cane)
|
From page 151... ...
The entire grid is then updated, and the model moves to the next iteration. Cellular automata models allow us to spatially simulate patterns of land use and land cover, examine likely future land use and land cover scenarios, and examine how social and demographic factors at the household or community levels, as well as exogenous shocks, have altered trajectories of land use and land cover change, resulting in possible shifts in the composition and spatial structure of the landscape, which has implications for human behavior.
|
From page 152... ...
A challenge we have faced is the validation of classifications of land use and land cover based on these images. The general idea is to find individuals who have lived and farmed in Nang Rong for at least 20 years, preferably longer.
|
From page 153... ...
Long Distance Collaboration Since the mid-1980s, researchers at the Institute for Population and Social Research, Mahidol University, Bangkok, and at the Carolina Population Center, University of North Carolina, Chapel Hill, have been collaborating on the ever-evolving Nang Rong studies. Bangkok and Chapel Hill are separated by 12 time zones.
|
From page 154... ...
Its focus on a single district, a significant proportion of the villages in that district, and all of the people and households in those villages created opportunities for blending diverse data and analytic techniques to address interesting questions about population change and landscape dynamics. However, the specifics of the starting
|
From page 155... ...
Our goal is a comprehensive account of social, economic, demographic, and environmental change in Nang Rong district. Our approach is cumulative, with research questions and data intimately connected.
|
From page 156... ...
Borrowing from spatial analysis, we have developed approaches for characterizing the spatial organization of "functional" village territories by generating activity spaces, "radiance" diagrams that show the vector connections between the village centroids and the center of land parcel being used by village household, and triangulated irregular networks for characterizing village territories using facets whose nodes are land parcels in use by village households. Building on our classifications of nearly 35 Landsat TM images, we are developing land cover trajectories or "pixel histories" so that we can examine space-time patterns of land cover change (Crews-Meyer, 2001, 2002)
|
From page 157... ...
Cellular automata models are being used to simulate the environment (using the satellite time series for model calibration and validation) through patterns of land use and land cover change (set by initial conditions, transition or growth rules, and neighborhood relationships)
|
From page 158... ...
We use perspectives fundamental to the social, natural, and spatial sciences and also those that offer new theoretical insights and possible links to evolving analytical methods. Our questions are about human behavior, primarily migration and demographic characteristics at the household level, and the concommittal changes in the composition and spatial structure of the land.
|
From page 159... ...
And finally, and perhaps most importantly, we would like to acknowledge the cooperation of the people of Nang Rong. Our requests for information have been many, and Nang Rong residents have cooperated completely, and for that we are in their debt.
|
From page 160... ...
Rindfuss, and S.J. Walsh no Village Settlement, Deforestation, and the Expansion of Agriculture in a Frontier date-a Region: Nang Rong, Thailand.
|
From page 161... ...
Konrad, C.E. 2000 Summary Report: Nang Rong Precipitation Climatology.
|
From page 162... ...
Welsh, and K.A. Crews-Meyer 2001 A multiscale analysis of land use and land cover and NDVI variation in Nang Rong District, Northeast Thailand.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.