2. COURSE PLAN
1 week intensive training
Theory– Introduction, basics, procedures
Practical – hands-on practice
Assignments
Half-day– discussion on problems encountered
Case-study
Development of case studies
Practical application on own dataset
Presentation of case-studies,
Final evaluation
3. COURSE AIMS
To equip soil scientists/staff at national
institutions with recent techniques in DSM.
Exposure to recent developments in DSM methods and
tools for developing and updating national and
regional soil information.
Practical orientation to give opportunity to implement
the DSM techniques
Allow simultaneous use of own data to develop
relevant DSM products
Support update of soil information
4. COURSE OUTCOMES
To be able to:
Compile and harmonize legacy data and other
input data for DSM applications
Use various software to implement DSM
Develop accurate digital soil maps for updating
national soil information systems
5. COURSE STRUCTURE
Lectures
Discussions and clarifications
Practical sessions
Demonstrations
Hands-on exercises
Assignments
Follow-up work
Case study
Individual work
Own case study
Plenary discussions
Group discussion
Individual presentations
6. OBJECTIVES FOR DAY 2
To expose participants to the theory and
principles of DSM
To introduce DSM input requirements
To familiarize participants with documentation
steps and DSM methods
7. HOW TO BEGIN DOCUMENTATION IN MS WORD
Documenting steps
Open new word document
Put the requisite headings and explanations
Add images from the computer using: Alt+PrtSc etc.
Save the document
Documenting data information (metadata)
Data type
Data source (author, website, copyright, format)
Data characteristics (number, projection, formula,
etc.)
Date (of creating or access)
Save metadata in the same folder as the data
8. SOME POINTS ABOUT DSM
DSM is a method of producing soil maps. Like other
soil mapping methods, it’s also based on:
A soil-landscape model that relates soil characteristics to
the soil forming factors
Computer applications to implement the soil landscape
model (difference being - heavy dependency )
GIS layers of soil forming factors as input to the model
In addition; Mathematical/statistical models to represent
the soil-landscape model
Defined simply as computer-assisted production of
digital maps of soil
9. MISCONCEPTIONS ABOUT DSM
No need for field sampling (i.e. Remote Sensing is
adequate) ----NOT TRUE
It relies much on adequately sampled soil data as input
Field validation is an integral component of DSM
Geo-referencing and local knowledge are assets in DSM
Computer does all the mapping----NOT TRUE
Computing is a core method/tool in DSM
Computing cannot replace soil profile description
and laboratory analysis – steps in soil mapping
It’s replacing basic soil science----NOT TRUE
Soil science is the foundation
DSM enriches approaches to soil mapping
There are still needs for all soil mapping products
10. HOW DOES DSM WORK
The principles
Soil formation and distribution is influenced by
Climate, organisms, topography, parent materials, time
If spatial distribution of these factors is known then soil
character may be inferred
Soil character may not always show hard boundaries
between differing and contiguous groups
Ordering of soil character in the landscape is not
arbitrary – there is a law obeyed/pattern followed
These principles have been employed for ages in
soil mapping albeit with varied success
They have been combined to lay ground for
development of operating guidelines in DSM
11. DSM THEORY
Spatial distribution of soil forming factors is a function
of magnitude and spatial distribution of soil forming
factors
Theory can be mathematically modelled
There exists a quantifiable/hueristic function f to link
the SCORPAN factors and soil character
If the function is applied at known/sample locations
and quantities, then it can be used to predict the soil
attribute at unknown/un-sampled locations
A
B
C
12. STEPS IN DSM
Three major stages: input data, tools and
methods selection, and soil information system
Legacy soil data
• Soil sampling/survey
• Secondary data
Environmental factors/GIS
database
• Remote sensing images
• DEM
• Land use/cover
• Climate data
• Geology maps
Digital soil assessments
Uncertainties of spatial
prediction
DSM Methods
DSM Tools
GIS layers of soil
Properties and types
Expert/technical support
• Scientists
• Technicians
• Soil information users
• Technical manual
• Standards
Stage I
Input
Stage II
Tools and method selection
Stage III
Soil information system
Spatial database / soil
information system
Soil inference system
14. INPUT 1: DATA
Input data requirements
Existing soil maps
Soil profile data
Lab analytical and field observation soil data
Climate data
Other maps – Altitude, Geology, Land use/cover
Typical sources of input DSM data
Input data Source Level of detail (Resolution)
< 20 m 20 – 200 m > 200 m
Land use/ land cover Multi spectral remote
sensing images
GeoEye, Quickbird,
Ikonos, SPOT
Landsat,
ASTER,
MODIS, AVHRR,
MERIS
Hyper-spectral remote
sensing images
AVIRIS
Radar, radiometry LIDAR ASAR, MWR
Vegetation/land cover GLOBCOVER
Relief DEM National Contour
or Topomaps
ASTER, SRTM GTOPO
Climate Climate (rainfall) data National archives MARS, AVHRR
Parent material Geology maps National archives
Geological surveys Regional studies Gamma –ray
spectrometry
Global geology
map
Soil Soil profile/properties Regional soil
surveys
National, ISRIC, FAO
Soil maps Regional soil maps
15. INPUT 2: DSM METHODS
Spatial interpolation
To make smooth trend over discrete locations
Digital terrain models
To derive relief characteristics
Remote sensing analysis
To extract land use and land cover characteristics
Statistical modelling
To explore and understand data characteristics
To model relationships
To quantify confidence in inputs and outputs
16. DSM TOOLS AND SOFTWARE
Method Tools Software
Spatial interpolation
Geostatistics R
Non-geostatistical method QGIS, ILWIS
Terrain analysis Digital Terrain modelling SAGA, QGIS
Remote sensing analysis
Image correction ILWIS, QGIS
Image Indices ILWIS
Classification ILWIS
Statistical analysis
Multivariate analysis ILWIS, R
Correlation analysis R
Database management
Storage MS Office
Dissemination Google Earth
17. LEGACY DATA
All existing soil information collected to
characterize or map soils
landscape and site descriptions,
soil profile morphological descriptions
laboratory analysis of the main chemical, physical and
biological soil properties
Soil maps
Geophysical/geotechnical surveys
Other maps – climate, geology, land use, contour
and topographic maps
Tacit knowledge - reports, legends, mental
models
18. IMPORTANCE OF LEGACY DATA
Model calibration/validation
Potential in reducing cost of new samples
Core of predictors (soil forming factors)
Enrich interpretation of spatial models
As baseline data for monitoring
Input into SCORPAN modelling
19. PROBLEMS WITH LEGACY DATA
Documentation is usually with gaps
Original authors may not be available
Harmonization issues
Quality (error), language,
Georeferencing (lack/un-clear/diff. projection)
Map units (proportions, classes, impurities)
Classification (names, taxonomy, ref. properties)
Uniformity issues (sampling, depth, units, etc)
21. DATABASE DEVELOPMENT
The core of DSM
Features
It should be user friendly
It should contain adequate information
Amenable to DSM software
Software
MS Office
QGIS
ILWIS
22. OBTAINING DSM DATA
Clarify what is to be done (Map properties/classes)
Specify type of data needed
Identify sources and summarize data availability
Document available data and check for gaps
Obtain the data
Data Type Source
Soil Soil profiles ISRIC (http://www.isric.org/data/isric-wise-global-soil-profile-data-ver-31)
Soil maps UN-FAO (http://www.fao.org/soils-portal/soil-survey/soil-maps-and-
databases/soil-profile-databases/en/)
IIASA
(http://www.iiasa.ac.at/web/home/research/modelsData/HWSD/HWSD.en.html)
Soil legacy reports FAO (http://www.fao.org/soils-portal/soil-survey/soil-maps-and-databases/soil-
legacy-reports/en/)
Laboratory
analytical data
National soil laboratories, research institutes (e.g. NGOs, Universities, etc)
Remote
sensing image
MODIS NDVI (250 m) USDA (http://pekko.geog.umd.edu/usda/apps/)
Land cover (300 m) ESA (http://due.esrin.esa.int/globcover/)
Landsat (30 m) GLCF (http://glcf.umd.edu/data/)
Cover (< 30 m) National aerial photo missions
DEM SRTM (90 m) http://srtm.usgs.gov/ or http://lta.cr.usgs.gov/
ASTER (30 m) http://asterweb.jpl.nasa.gov/gdem.asp or http://lta.cr.usgs.gov/
DEM (<30 m) National contour maps
Geology 1:1 M National geologic maps
> 1:1 M Sub-regional (sub-national) geologic maps
Climate Rainfall National meteorological departments
Create DSM workspace
C:DSM - where we will work
C:DSMInput - where to keep input data
C:DSMOutput - where to keep output data
35. Which soil data is available
Which environmental covariate is
available
Detailed soil map with
Legends and soil data
Soil point data with site
description
Detailed soil map
with legend
No data
All covariates
C, O, R, P
At least 3 covariates
Including R & O
At least 2 covariates
Including R
Only one covariate No data
Increasing level of data inadequacy
Climate (C)
Organism (O)
Relief (R)
Parent (P)
Relief (R)
Organism (O)
Relief (R)
Climate – mean rainfall (map or weather station data)
Organism – Land use/land cover
Relief – Elevation map (DEM)
Parent – Geology map
Soil – georeferenced soil properties, profile, map
37. ASSIGNMENT: BUILDING GEO-DATABASE
FOR DSM APPLICATION-STEP 1
Use your own data/obtain from online data archives
Explore the data
Document the characteristics of the data:
Source and author of data
Data type (profile, analytical, georeferenced, maps, etc.)
Number of samples/cases
Use the table format (use Data, Type, Number, Source, as column
heading)
Save the database & documentation (C:DSMInput)