Author: Bradley Miller

Towards mapping soil carbon landscapes: Issues of sampling scale and transferability

This study examines the spatial patterns and accuracies of predictions made by different spatial modelling methods on sample sets taken at two different scales. These spatial models are then tested on independent validation sets taken at three different scales. Each spatial modelling method produced similar, but unique, maps of soil organic carbon content (SOC%). Kriging approaches excelled at internal spatial prediction with more densely spaced sample points.

History of soil geography in the context of scale

Categories of cartographic scale correspond to the selection of environmental soil predictors used to initially create historical soil maps. Paradigm shifts in soil mapping and classification can be best explained by not only their correlation to historical improvements in scientific understanding, but also by differences in purpose for mapping, and due to advancements in geographic technology. Although the hierarchy of phenomena scales observed in this study is generally known in pedology today, it also represents a new view on the evolution of soil science.

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.

Spatial modeling of organic carbon in degraded peatland soils of northeast Germany

The objective of this study was to evaluate the ability of high-resolution, minimally invasive sensor data to predict spatial variation of soil organic carbon stocks within highly degraded peatland soils in northeast Germany. Soil organic carbon density was related to elevation, electrical conductivity, and peat thickness. Modeling peat thickness based on sensor data needs additional research, but seems to be a valuable set of covariates in digital soil mapping.

What is Colluvium? An Interactive Poster Seeking a Common Definition to Improve International Communication (2015 SSSA Conference)

UPDATE: This poster was a test run for a survey asking the audience for their perspectives on how to differentiate colluvium and alluvium. That has now evolved into an online survey that you can now take. Respondents have told us that taking the survey was fun and thought-provoking. Please add your perspective by completing the … Continue reading What is Colluvium? An Interactive Poster Seeking a Common Definition to Improve International Communication (2015 SSSA Conference)

The use of soil surveys to aid in geologic mapping with an emphasis on the Eastern and Midwestern United States

After soil science became established as a scientific discipline, there has been a continued interplay between geologists and soil scientists, both fields benefiting from advancements made by the other. There is strong agreement between preliminary geology maps created from soil maps and traditional geology maps. Despite the results obtained when using soil maps to create surficial geology maps, there is a need for more quantitative studies to assess the degree of compliment between soil-based maps and traditional geology maps, expansion of the technique into a wider range of geologic and climatic environments, and more research in locations that use classification systems other than Soil Taxonomy.

The Real Benefits of Digital Soil Mapping

Proponents of digital soil mapping sometimes criticize traditional soil mapping for using a discrete data model to describe a continuous surface (field) and lacking a quantified estimation of error. Although most of my research is on digital soil mapping, I like to give due credit to the accomplishments of traditional soil mapping. I understand the need for … Continue reading The Real Benefits of Digital Soil Mapping

Surficial Geology of Iowa

This raster is a highly detailed (delineations made at the 1:15,840 scale) map of geologic materials at the surface, covering the entire state of Iowa. The map is based on the interpretations of the US Soil Survey, which regularly needs to assess the soil parent material in their mapping activities. The raster was generated from … Continue reading Surficial Geology of Iowa

Types of Measurement Error

We always want to avoid error, but it is a fact of life. At the foundation of analysis and modelling, we rely on measurements. Because errors in measurements are inescapable, the important question is how much does the error affect the result? I start the conversation by explaining what measurement error is, including its component parts, and what we can do to minimize its effect.