Skip to main content Accessibility help
×
Home

Redistributing Agricultural Data by a Dasymetric Mapping Methodology

  • Maria de Belém Costa Freitas Martins (a1), António Manuel de Sousa Xavier (a1) and Rui Manuel de Sousa Fragoso (a2)

Abstract

This paper examines the adaptation of dasymetric mapping methodologies to agricultural data, including their testing and transposition, in order to recover the underlying statistical surface (i.e., an approximation of the real distribution of data). A methodology based on the ideas of Gallego and Peedell (2001) and on the binary method is proposed. It has several steps: (i) the exclusion of target zones for which no observations exist (binary method), (ii) the application of an iterative process to define the most precise densities for data distribution, and (iii) the stratification/definition of sub-units with homogenous characteristics if the results of the previous step are not satisfactory, and the subsequent application of step two.

The methodology was applied in the Alentejo region of Portugal, using data from the 1999 Agricultural Census. Several counties are used as source zones. The aim was to generate a distribution of agro-forestry occupations as close as possible to reality. Two lines of analysis were followed: (i) application of the methodology simultaneously to all counties (definition of regional densities), and (ii) application of the methodology separately to the different subareas with similar characteristics (definition of sub-regional densities). For an easy application of the methodology, a computer tool was created, which allowed the easy optimization, validation, and exportation of the data into a Geographic Information System (GIS).

The results were validated using several error indicators at the county level, as well as in a sample of parishes. We show that the second variant of the methodology yielded more precise results, and is superior for the types of data available. This method yielded maps in which the distribution of the most relevant agro-forestry occupations is closest to reality.

Copyright

References

Hide All
Bielecka, E. 2005. “Dasymetric Population Density Map of Poland.” Proceedings of the 22nd International Cartographic Conference (in Coruña, Spain).
Direcção Regional de Agricultura e Pescas do Alentejo (DRAPAI). 2007. “Programa de Desenvolvimento Rural-Alentejo” (Rural Development Program—Alentejo). DRAPAI, Évora, Portugal.
Carvalho, M., and Godinho, Μ. 2004. “A Nova Reforma da Política Agrícola Comum e Suas Consequências num Sistema Agrícola Mediterrâneo de Portugal” (The New Common Agricultural Policy Reform and Its Consequences on a Mediterranean Agricultural System in Portugal). Available at http://www.sober.org.br/palestra/2/1099.pdf (accessed January 15, 2009).
Eicher, C., and Brewer, C. 2001. “Dasymetric Mapping and Areal Interpolation: Implementation and Evaluation.” Cartography and Geographic Information Science 28(2): 125138.
Fragoso, R., Martins, M., and Lucas, R. 2008. “A Minimum Crossed Entropy Model to Generate Information to the Disaggregated Level.” In Proceedings of the 4th IASME/WSEAS International Conference on Energy, Environment, and Sustainable Development. WSEAS Press, Faro, Portugal.
Gallego, F.J., and Peedell, S. 2001. “Using CORINE Land Cover to Map Population Density: Towards Agri-Environmental Indicators.” Topic Report No. 6/2001, European Environment Agency, Copenhagen.
Howitt, R., and Reynaud, A. 2002. “Spatial Disaggregation of Production Data by Maximum Entropy.” Paper presented at the Tenth Congress of the European Association of Agricultural Economists, Saragoça, Spain, August 28-31.
Instituto Nacional de Estatística (INE). 1989. “Recenseamento Geral da Agricultura de 1989.INE, Lisbon, Portugal.
Instituto Nacional de Estatística (INE). 2001. “Recenseamento Geral da Agricultura de 1999.INE, Lisbon, Portugal.
Instituto Nacional de Estatística (INE). 2002. “Recenseamento Geral da População—Censos 2001.INE, Lisbon, Portugal.
Instituto Nacional de Estatística (INE). Various years. “Estatísticas Agrícolas.” INE, Lisbon, Portugal.
Instituto Nacional de Estatística (INE). Various years. “Anuários Estatísticos da Região do Alentejo.” INE, Lisbon, Portugal.
Instituto Nacional de Estatística (INE). Various years. “Inquérito à estrutura das explorações agrícolas.” INE, Lisbon, Portugal.
Langford, M., Maguire, D.J., and Unwin, D.J. 1991. “The Areal Interpolation Problem: Estimating Population Using Remote Sensing in a GIS Framework.” In Handling Geographic Information. Essex, UK: Longman Scientific and Technical.
Langford, M., and Unwin, D. 1994. “Generating and Mapping Population Density Surface Within a Geographical Information System.” Cartographic Journal 31: 2126.
Martins, M.B., Fragoso, R., and Xavier, A. 2010. “Recovery of Incomplete Agricultural Land Uses and Livestock Numbers by Entropy.” Paper presented at the annual meetings of the European Association of Agricultural Economists in Berlin, Germany (April 15-16).
McClean, C.J. 2007. “The Spatial Disaggregation of GB and European Agricultural Land Use Statistics.” Paper presented at the GISRUK (GIS Research UK) meetings in Maynooth, Ireland (April 11-13). Available at http://ncg.nuim.ie/gisruk/materials/proceedings/PDF/7B4.pdf (accessed February 20, 2011).
Mennis, J. 2002. “Using Geographic Information Systems to Create and Analyze Statistical Surface of Population and Risk for Environmental Justice Analysis.” Social Science Quarterly 83(1): 281297.
Mennis, J. 2003. “Generating Surface Models of Population Using Dasymetric Mapping.” The Professional Geographer 55(1): 3142.
Mennis, J., and Hultgren, T. 2006. “Intelligent Dasymetric Mapping and Its Application to Areal Interpolation.” Cartography and Geographic Information Science 33(3): 179194.
Mrozinski, R., and Cromley, R. 1999. “Singly—and Doubly—Constrained Methods of Areal Interpolation for Vector-Based GIS.” Transactions in GIS 3: 285301.
Néry, F., Monterroso, P., Santos, A., and Matos, J. 2007. “Interpolação Zonal de Estatísticas Socio-económicas.” Paper presented at the Conferência Internacional de Cartografía e Geodésia, Lidel, Lisbon (April 19-20). Available at www.igeo.pt/instituto/cegig/got/3_Docs/papers_Main_PT.html (accessed January 15, 2009).
Openshaw, S. 1984. “The Modifiable Areal Unit Problem.” Concepts and Techniques in Modern Geography 28: 3841.
Painho, M., and Caetano, M. 2006. Cartografia de Ocupação do Solo de Portugal Continental 1985-2000 Corine Land Cover 2000. Amadoram Agência Portuguesa do Ambiente.
Tobler, W.R. 1979. “Smooth Pycnophylactic Interpolation for Geographical Regions.” Journal of the American Statistical Association 74 (367): 519530.
Wright, J.K. 1936. “A Method of Mapping Densities of Population with Cape Cod as an Example.” Geographical Review 26(1): 103110.

Keywords

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed