The challenges of collating legacy data for digital mapping of Nigerian soils

Mapping soils in two watersheds using legacy data and extrapolation for similar surrounding areas

Ciência e Agrotecnologia ◽

10.1590/1413-70542016405011416 ◽

2016 ◽

Vol 40 (5) ◽

pp. 534-546 ◽

Cited By ~ 13

Author(s):

Marcelo Henrique Procópio Pelegrino ◽

Sérgio Henrique Godinho Silva ◽

Michele Duarte de Menezes ◽

Elidiane da Silva ◽

Phillip Ray Owens ◽

...

Keyword(s):

Decision Trees ◽

Soil Maps ◽

Kappa Index ◽

Digital Mapping ◽

Legacy Data ◽

Mapping Techniques ◽

Surrounding Areas ◽

Cart Algorithm ◽

Source Of Information ◽

Extract Information

ABSTRACT Existing soil maps (legacy data) associated with digital mapping techniques are alternatives to obtain information at lower costs, however, tests are required to do it more efficiently. This study had as objectives to compare different methods to extract information from detailed scale soil maps using decision trees for mapping soil classes at two watersheds in Minas Gerais, validate these maps in the field and use the best method to extrapolate information to larger areas, also validating these maps of larger areas. Detailed soil maps of Vista Bela creek (VBW) and Marcela creek (MCW) watersheds were used as source of information. Seven methods to extract information from maps were compared: the whole polygon, eliminating 20 and 40 m from the polygon boundaries, and with buffers around the sampled points with radii of 25 m, 50 m, 75 m, and 100 m. The Classification and Regression Trees (CART) algorithm was employed to create decision trees and enable creation of soil maps. Accuracy was assessed through overall accuracy and kappa index. The best method was used to extrapolate information to larger areas and maps were validated. The best methods for VCW and MCW were, respectively, eliminating 20 m from polygon edges and buffer of 25 m of radii from points. Maps for larger areas were obtained using these methods. Removing uncertainty areas from legacy soil maps contribute to better modeling and prediction of soil classes. Information generated in this work allowed for validated extrapolation of soil maps for regions surrounding the watersheds.

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Digital mapping of selected WRB units based on vast and diverse legacy data

GlobalSoilMap ◽

10.1201/b16500-58 ◽

2014 ◽

pp. 313-317 ◽

Cited By ~ 1

Author(s):

I Waltner ◽

E Michéli ◽

M Fuchs ◽

V Láng ◽

L Pásztor ◽

...

Keyword(s):

Digital Mapping ◽

Legacy Data

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Legacy data-based national-scale digital mapping of key soil properties in India

Geoderma ◽

10.1016/j.geoderma.2020.114684 ◽

2021 ◽

Vol 381 ◽

pp. 114684 ◽

Cited By ~ 2

Author(s):

Nagarjuna N. Reddy ◽

Poulamee Chakraborty ◽

Sourav Roy ◽

Kanika Singh ◽

Budiman Minasny ◽

...

Keyword(s):

Soil Properties ◽

National Scale ◽

Digital Mapping ◽

Legacy Data

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‘Imagined San Francisco’: Unpacking Urban Regime Theory through Interactive Cartography

International Journal of Humanities and Arts Computing ◽

10.3366/ijhac.2017.0182 ◽

2017 ◽

Vol 11 (1) ◽

pp. 126-143

Author(s):

Ocean Howell

Keyword(s):

San Francisco ◽

Political Power ◽

Regime Theory ◽

Commercial Development ◽

Urban Regime Theory ◽

Digital Mapping ◽

Urban Regime ◽

Historical Processes ◽

The City ◽

Interactive Cartography

American urban historians have begun to understand that digital mapping provides a potentially powerful tool to describe political power. There are now important projects that map change in the American city along a number of dimensions, including zoning, suburbanization, commercial development, transportation infrastructure, and especially segregation. Most projects use their visual sources to illustrate the material consequences of the policies of powerful agencies and dominant planning ‘regimes.’ As useful as these projects are, they often inadvertently imbue their visualizations with an aura of inevitability, and thereby present political power as a kind of static substance–possess this and you can remake the city to serve your interests. A new project called ‘Imagined San Francisco’ is motivated by a desire to expand upon this approach, treating visual material not only to illustrate outcomes, but also to interrogate historical processes, and using maps, plans, drawings, and photographs not only to show what did happen, but also what might have happened. By enabling users to layer a series of historical urban plans–with a special emphasis on unrealized plans–‘Imagined San Francisco’ presents the city not only as a series of material changes, but also as a contingent process and a battleground for political power.

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