modelling

Oracles and Science: The Trouble with Predictions
“Mortagne-reeds and elms refracted in the ball” by Mo is licensed under CC BY 2.0 We all want to know the future, but what is… Read More

2 November 2016
Soil mapping, classification, and pedologic modeling: History and future directions
Soil mapping, classification, and pedologic modelling have been important drivers in the advancement of our understanding of soil. Advancement in one of these highly interrelated areas tend to lead to corresponding advances in the others. Traditionally, soil maps have been desirable for purposes of land valuation, agronomic planning, and even in military operations. The expansion of the use of soil knowledge to address issues beyond agronomic production, such as land use planning, environmental concerns, energy security, water security, and human health, to name a few, requires new ways to communicate what we know about the soils we map as well as bringing forth research questions that were not widely considered in earlier soils studies. Read More

10 March 2016
Comparison of spatial association approaches for landscape mapping of soil organic carbon stocks
A comparison of direct and indirect approaches for mapping SOC stocks from rule-based, multiple linear regression models applied at the landscape scale via spatial association. The final products for both strategies are high-resolution maps of SOC stocks (kg m‾²), covering an area of 122 km², with accompanying maps of estimated error. Although the indirect approach fit the spatial variation better and had a lower mean estimated error for the topsoil stock, the mean estimated error for the total SOC stock (topsoil + subsoil) was lower for the direct approach. The optimal approach would depend upon the intended use of the map. Read More

4 May 2015
CLORPT: Spatial Association in Soil Geography
Eugene W. Hilgard(Online Archive of California) From as early as 500 BCE, humans have recognized that some things vary together in space. This is essentially… Read More

24 April 2015
Error Propagation Toolbox
New estimated errors are calculated for each raster cell based on the combination of the two input rasters. Quantifying uncertainty can be a very useful… Read More

28 January 2015
Impact of multi-scale predictor selection for modeling soil properties
Results suggest that models with limited predictor pools can substitute other predictors to compensate for unavailable variables. However, a better performing model was always found by considering predictor variables at multiple scales. Although the scale effect of the modifiable area unit problem is generally well known, this study suggests digital soil mapping efforts would be enhanced by the greater consideration of predictor variables at multiple analysis scales. Read More

19 January 2015
Fundamentals of Spatial Prediction
In the process of creating a map, geographers often have to engage in the activity of spatial prediction. Although there are many tools we use… Read More

16 November 2014
Multi-scale Parameter Selection for Predicting Soil Organic Carbon (2014 Digital Soil Mapping Workshop)
Multiscale-parameter-selection-2014-DSM-wkspDownload… Read More

29 April 2014
Potential benefits of wetland filters for tile drainage systems
Nitrate concentration and stream discharge data from USGS National Stream Quality Accounting Network monitoring stations in the upper Mississippi River (UMR) and Ohio River basins were used to calculate stream nitrate loading and annual flow-weighted average (FWA) nitrate concentrations. The model accounts for 90% of the variation among stations in long term FWA nitrate concentrations and was used to estimate FWA nitrate concentrations for a 100 ha grid across the UMR and Ohio River basins. To estimate potential nitrate removal by wetlands across the same grid area, mass balance simulations were used to estimate percent nitrate reduction for hypothetical wetland sites distributed across the UMR and Ohio River basins. Modeling results suggest that a 30% reduction in nitrate load from the UMR and Ohio River basins could be achieved using 210,000-450,000 ha of wetlands targeted on the highest nitrate contributing areas. Read More

9 March 2006