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Agricultural Census ► Variables Available Disturbance – Land Use Variables Grain Crops Row Crops & Vegetables Farm Size
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► There were two sampling frames for the agricultural census in 1969 and 1974 One for all farms and one just for those farms deemed to be commercial in nature (selling produce of $2500 or more) A’s and C’s in the tables denote which universe applies. The green shading indicates the years for which data will have to be collected (outside of Konza and SGS).
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► The naming conventions of the Great Plains project made use of underscores and a standard variable name length. An underscore _A at the end of a variable name indicates that the variable is measured in acres An underscore _Q tells you that the variable represents a count. An underscore _V at the end of the variable name to denote an amount in dollars.
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► List of variables for the study sites focuses on land use information. The total proportion of land in agriculture can best be tracked by a combination of improved land in farms (the best approximation of total cropland in the late nineteenth century) combinations of cropland and pasture in the early twentieth century then total cropland (CRP_XX_A) beginning in 1945.
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► Thinking about outcomes of interest and the drivers in the dataset that help explain spatial patterns Why does farmland shift to western edge of Konza? ► Adding data from supplementary datasets Weather data from VEMAP modeling of instrumental weather records fitted to county boundaries STATSGO soils data fitted to county boundaries with levels of sand, silt, clay and depth of A layer.
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VEMAP ► Modeled from instrumental record, summarized to county boundaries ► www.cgd.ucar.edu/vemap
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STATSGO ► Sand, silt, clay, depth of A-layer ► www.ncgc.nrcs.usda.gov/branch/ssb/produc ts/statsgo/index.html
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► Nesting lower level, individual level, repeated measures data in the county-level data, like the wildlife data from TNC ► Using the county-level data longitudinally. Treating counties as time-varying individual level units, nested in contextual predictors that reflect time-invariant, between unit, differences
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► What questions of interest should we pursue with the sample data sets? ► What outcome would you like to model? Let’s explore the data series How complete is the information to attack our question?
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