Urban Soil Classification:Article Review

Lacey Hancotte SWS 4715C–Pedology Course

@UF Spring 2015

Experimental Order 1 soil survey of vacant urban land, Detroit Michigan, USA

Jeffrey L. Howard & William D. Shuster

CATENAVolume 126March 2015

Pages 220–230

Research Objectives:

• assess the mappability of demolition site soils in a typical urban landscape

• test the hypothesis that there is a mappable pattern of anthropogenic soils

“There is a pressing need for soil maps in many urban areas because building demolition has produced large tracts of vacant land. This

open space has attracted considerable interest…however, demolition site soils are

usually in need of revitalization”

Methods & Area of Study:

• Perform an Order 1 soil survey (scale = 1:200)

• Samples were collected using: a Geoprobe, a soil pit, & hand augers

• Artifacts were separated from the bulk coarse fragment by hand, weighed, and classified into types and numbers of each type counted.

Terminology as Defined by the Article:

• Human-altered material (HAM)

• formed in place either by deep mixing, excavation and replacement from a single pedon, or truncation and removal of the surface soil.

• the term “anthrosol” are used informally for soils formed in HAM

• Human-transported material (HTM)

• formed by excavation of material from one pedon and mixing with materials from other pedons, or by moving earth material horizontally onto a pedon from other sources, usually with the aid of hand tools or mechanized equipment

• the term “technosol” is used informally for soils formed in HTM

These soils are roughly equivalent to the corresponding Reference Soil Groups in the World Reference Base

Characteristics of anthropic soils in the sampling grid:Technosol           Anthrosol

Type A   Type B   Type C   Type S  

Depth (cm)

DescriptionDepth(cm)

DescriptionDepth(cm)

DescriptionDepth(cm)

Description

0–102^Au, Black (10YR2/1), light clay

loam; 5 to 10% artifacts0–20

^Au, Black (10YR2/1), light clay loam; b5% artifacts

0–56^Au, Black (10YR2/1), light

clay loam; b5% artifacts0–30

^Au, Black (10YR2/1), sandy clay loam; b5 % artifacts

102–137^Cu, Dark gray (10YR4/1),

heavy clay loam; b5% artifacts20–55

^Cu, Dark gray (10YR4/1), heavy clay loam; b5 %

artifacts56–102

^Cu, mixed mottled gray(10YR5/1) and dark brown

(10YR4/3), heavy clay loam; b5% artifacts

30–44^A, Very dark gray (10YR3/1),

sandy clay loam

137–150C, mottled gray (10YR5/1) and

strong brown (7.5YR5/6), heavy clay loam

55–69Ab, Very dark gray (10YR3/1),

light clay loam102+

C, mottled gray (10YR5/1) and strong brown (7.5YR5/6),

heavy clay loam44–61

^C and mixed ^A and ^C, Dark gray (10YR4/1), sandy

clay loam

    69–112C, mottled gray (10YR5/1) and strong brown (7.5YR5/6), heavy

clay loam    61–76

C, mottled gray (10YR5/1) and dark brown (10YR4/3), sandy

clay loam

            76+2C, mottled gray (10YR5/1)

and strong brown (7.5YR5/6), heavy clay loam

Results & Findings:

Artifacts… Complex Horizonization…

Fig. 3. Map of soil types and other characteristics at the study siteA: Soil map based on 2 m grid spacing;

B: Borings where auger refusals (AR) occurred;

C: Isopach map of ^Au horizon thickness (cm);

D: Isopach map of approximate fill thickness based on maximum depth (cm) of artifacts.

Discussion:• ^A horizons have formed in demolition site soils within ~15 to 20 years under grass vegetation (Howard and

Olszewska, 2011; Howard et al., 2013a)

• Other studies have also shown that topsoils can develop in human-transported material within a few a decades or less

• The standard approach of mapping soils on the basis of landscape position, and morphological characteristics ascertained with a hand auger, is difficult or impossible to apply in most urban areas because:

1) The land usually has been leveled by earthmoving equipment

2) Auger refusals occur 50 to 90% of the time

3) The morphological properties of soils and anthropogenic parent materials are geospatially variable.

• The properties of demolition site soils can be predicted to some extent based on prior land use history, which can possibly be gleaned from Sanborn fire insurance and similar maps, aerial photographs, public records pertaining to building construction, demolition and utilities, and newspaper accounts. However, historic records are often incomplete, inaccurate or unavailable.

• The data suggest that the history of the site studied can be reconstructed from the spatial distribution of artifacts and soil types

• There are mappable patterns of anthropogenic soils in urban settings

Fig. 9. Genetic model showing how construction and demolition processes affect demolition site stratigraphy and anthrosequence development:

A: residential site prior to constructionB: Inverted stratigraphy resulting from excavation for basementC: stratigraphy following demolition and backfilling D, E, and F: map views of A, B and C, respectivelyNS: native soilCF: construction fillDF: demolition fillSx, glaciolacustrine sand cappingDc: clayey diamicton

S = f(C, R, O, P, T, A)

Special thanks too:

Jeffrey Howard & William Shuster for their research and advancements made in the name of Soil Science.

&

Professor WillIe Harris

For providing me with a greater understanding of soil taxonomy, soil mineralogy and soil interpretations.