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Optimum land cover products for use in a Glossina-morsitans habitat model of Kenya.

DeVisser MH, Messina JP - Int J Health Geogr (2009)

Bottom Line: Efforts to control the disease were hampered by a lack of information and costs associated with the identification of infested areas.For single date applications, Africover was determined to be the best land use land cover (LULC) product for tsetse modeling.The method can be used to differentiate between various LULC products and be applied to any such research when there is a known relationship between a species and land cover.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Geography and Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI, USA. devisse6@msu.edu

ABSTRACT

Background: Tsetse flies are the primary vector for African trypanosomiasis, a disease that affects both humans and livestock across the continent of Africa. In 1973 tsetse flies were estimated to inhabit 22% of Kenya; by 1996 that number had risen to roughly 34%. Efforts to control the disease were hampered by a lack of information and costs associated with the identification of infested areas. Given changing spatial and demographic factors, a model that can predict suitable tsetse fly habitat based on land cover and climate change is critical to efforts aimed at controlling the disease. In this paper we present a generalizable method, using a modified Mapcurves goodness of fit test, to evaluate the existing publicly available land cover products to determine which products perform the best at identifying suitable tsetse fly land cover.

Results: For single date applications, Africover was determined to be the best land use land cover (LULC) product for tsetse modeling. However, for changing habitats, whether climatically or anthropogenically forced, the IGBP DISCover and MODIS type 1 products where determined to be most practical.

Conclusion: The method can be used to differentiate between various LULC products and be applied to any such research when there is a known relationship between a species and land cover.

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Related in: MedlinePlus

Map A is a 1 km resolution annual precipitation data set from WorldClim for the year 2000 [57]. The WorldClim precipitation data set was classified to create Map B, a binary precipitation suitability map.
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Figure 4: Map A is a 1 km resolution annual precipitation data set from WorldClim for the year 2000 [57]. The WorldClim precipitation data set was classified to create Map B, a binary precipitation suitability map.

Mentions: Tsetse flies are also limited by environmental variables such as temperature, humidity, and soil moisture. No in situ country wide humidity or soil moisture data are available, so following Leak [55], we used 500 mm as a proxy for the minimum level of precipitation for tsetse survival and the 1 km resolution annual precipitation data set from WorldClim for the year 2000 [57] (Figure 4). Moristans prefer temperatures in the mid 20ºC range [58]; however, tsetse flies will take advantage of micro habitats created by woody vegetation in order to survive temperatures above 32ºC [59]. Thus, maximum temperature was not considered a major limiting variable as long as the proper moisture regimes and land cover were present. Tsetse fly pupa do require a minimum temperature of roughly 16ºC for survival [58]; as in previous research (e.g. Leak [55]), this study used a maximum elevation of 2200 m as a surrogate for minimum temperature. The resulting binary suitability maps based on land cover, elevation, and precipitation suitability were then combined to create an overall suitability map for each of the fifteen LULC data sets (Figure 5).


Optimum land cover products for use in a Glossina-morsitans habitat model of Kenya.

DeVisser MH, Messina JP - Int J Health Geogr (2009)

Map A is a 1 km resolution annual precipitation data set from WorldClim for the year 2000 [57]. The WorldClim precipitation data set was classified to create Map B, a binary precipitation suitability map.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2710327&req=5

Figure 4: Map A is a 1 km resolution annual precipitation data set from WorldClim for the year 2000 [57]. The WorldClim precipitation data set was classified to create Map B, a binary precipitation suitability map.
Mentions: Tsetse flies are also limited by environmental variables such as temperature, humidity, and soil moisture. No in situ country wide humidity or soil moisture data are available, so following Leak [55], we used 500 mm as a proxy for the minimum level of precipitation for tsetse survival and the 1 km resolution annual precipitation data set from WorldClim for the year 2000 [57] (Figure 4). Moristans prefer temperatures in the mid 20ºC range [58]; however, tsetse flies will take advantage of micro habitats created by woody vegetation in order to survive temperatures above 32ºC [59]. Thus, maximum temperature was not considered a major limiting variable as long as the proper moisture regimes and land cover were present. Tsetse fly pupa do require a minimum temperature of roughly 16ºC for survival [58]; as in previous research (e.g. Leak [55]), this study used a maximum elevation of 2200 m as a surrogate for minimum temperature. The resulting binary suitability maps based on land cover, elevation, and precipitation suitability were then combined to create an overall suitability map for each of the fifteen LULC data sets (Figure 5).

Bottom Line: Efforts to control the disease were hampered by a lack of information and costs associated with the identification of infested areas.For single date applications, Africover was determined to be the best land use land cover (LULC) product for tsetse modeling.The method can be used to differentiate between various LULC products and be applied to any such research when there is a known relationship between a species and land cover.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Geography and Center for Global Change and Earth Observations, Michigan State University, East Lansing, MI, USA. devisse6@msu.edu

ABSTRACT

Background: Tsetse flies are the primary vector for African trypanosomiasis, a disease that affects both humans and livestock across the continent of Africa. In 1973 tsetse flies were estimated to inhabit 22% of Kenya; by 1996 that number had risen to roughly 34%. Efforts to control the disease were hampered by a lack of information and costs associated with the identification of infested areas. Given changing spatial and demographic factors, a model that can predict suitable tsetse fly habitat based on land cover and climate change is critical to efforts aimed at controlling the disease. In this paper we present a generalizable method, using a modified Mapcurves goodness of fit test, to evaluate the existing publicly available land cover products to determine which products perform the best at identifying suitable tsetse fly land cover.

Results: For single date applications, Africover was determined to be the best land use land cover (LULC) product for tsetse modeling. However, for changing habitats, whether climatically or anthropogenically forced, the IGBP DISCover and MODIS type 1 products where determined to be most practical.

Conclusion: The method can be used to differentiate between various LULC products and be applied to any such research when there is a known relationship between a species and land cover.

Show MeSH
Related in: MedlinePlus