Spatial variability

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Spatial variability occurs when a quantity that is measured at different spatial locations exhibits values that differ across the locations. Spatial variability can be assessed using spatial descriptive statistics such as the range. Let us suppose, that the Rev' z(x) is perfectly known at any point x within the field under study. Then the uncertainty about z(x) is reduced to zero, whereas its spatial variability still exists. Uncertainty is closely related to the amount of spatial variability, but it is also strongly dependent upon sampling.4

Geostatistical analyses have been strictly performed to study the spatial variability of pesticide sorption5-7 and degradation8 in the field. Webster and Oliver9 provided a description of geostatistical techniques. Describing uncertainty using geostatistics is not an activity exempt from uncertainty itself as variogram uncertainty may be large10 and spatial interpolation may be undertaken using different techniques.11

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  1. Isaaks, E.H., Srivastava R.M.: Applied Geostatistics. 1989
  2. Fortin, Marie-Josee, Dale, Mark.: Spatial Analysis A Guide for Ecologists. 2005. Cambridge University Press, 365 pp.
  3. Kristensen, Terje, Ohlson, Mikael, Bolstad, Paul, Nagy, Zoltan: Spatial variability of organic layer thickness and carbon stocks in mature boreal forest stands. Environmental Monitoring and Assessment 187(8), 1-19. DOI: 10.1007/s10661-015-4741-x
  4. DELHOMME, J.P.: Spatial Variability and Uncertainty in Groundwater Flow Parameters: A Geostatistical Approach
  5. Cambardella CA, Moorman TB, Novak JM, Parkin TB, Karlen DN, Turco RF, Konopka AE. Field-scale variability of soil properties in Central Iowa soils. Soil Sci Soc Am J 1994;58:1501 –1511.
  6. Novak JM, Moorman TB, Cambardella CA. Atrazine sorption at the field scale in relation to soils and landscape position. J Environ Qual 1997;26:1271 –1277.
  7. Jacques D, Mouvet C, Mohanty B, Vereecken H, Feyen J. Spatial variability of atrazine sorption parameters and other soil properties in a podzoluvisol. J Contam Hydrol 1999;36:31 –52
  8. Price OR, Walker A, Wood M, Oliver MA. Using geostatistics to evaluate spatial variation in pesticideysoil interactions. In: Walker A., (Ed.), Pesticide behaviour in soils and water, BCPC Symposium Proceedings No. 78, Farnham, UK, 2001, pp. 233–238.
  9. Webster R, Oliver MA. Geostatistics for environmental scientistsJohn Wiley and Sons Ltd, 2001. p. 286
  10. Jansen MJW. Prediction error through modelling concepts and uncertainty from basic data. Nutr Cycl Agroecosys 1998;50:247 –253.
  11. Dubus, I. G.; Brown, C. D.; Beulke, S. Sources of uncertainty in pesticide fate modelling. Sci. Total Environ. 2003, 317, 53−72.

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