Introduction to the European Soil Data Base
(distribution version v2.0)
The
European Soil Data Base (distribution version
v2.0) consists of a number of databases:
·
the Soil Geographical Data Base of Eurasia at Scale 1:1,000,000
(SGDBE), which is a digitized Eurasian soil map and related attributes (version
4 beta) ;
- the PedoTransfer Rules
Data Base (PTRDB), version 2.0, which holds a number of pedotransfer rules
which can be applied to the SGDBE ; the results
of the application of the pedotransfer rules to the SGDBE are delivered as a table with new attributes related to the
Europasian soil map;
- the Soil Profile
Analytical Data Base of Europe (SPADBE), version 2.1.0.0, delivered as
tables ;
- the Database of
Hydraulic Properties of European Soils (HYPRES), version 1.0, delivered as
a set of Word documents.
In
this introduction, an overview will be given of these components.
Soil Geographical Data Base of Eurasia
at Scale 1:1,000,000 (SGDBE), version 4 beta
The Soil Geographical Database of Eurasia at Scale
1:1,000,000 is part of he European Soil Informatin System (EUSIS). It is the
resulting product of a collaborative project involving all the European Union
and neighbouring countries. It is a simplified representation of the diversity
and spatial variability of the soil coverage. The methodology used to
differentiate and name the main soil types is based on the terminology of the
F.A.O. legend for the Soil Map of the World at Scale 1:5,000,000. This
terminology has been refined and adapted to take account of the specificities
of the landscapes in Eurasia. It is itself founded on the distinction of the
main pedogenetic processes leading to soil differentiation: brunification,
lessivage, podzolisation, hydromorphy, etc.
The database
contains a list of Soil Typological Units (STU). Besides the soil names
they represent, these units are described by variables (attributes) specifying
the nature and properties of the soils: for example the texture, the water
regime, the stoniness, etc. The geographical representation was chosen at a
scale corresponding to the 1:1,000,000. At this scale, it is not feasible to
delineate the STUs. Therefore they are grouped into Soil Mapping Units (SMU)
to form soil associations and to illustrate the functioning of pedological
systems within the landscapes. Each SMU corresponds to a part of the mapped
territory and as such is represented by one or more polygons in a geometrical
dataset.
Harmonisation of the soil data from the member
countries is based on a dictionary giving the definition for each
occurrence of the variables. Considering the scale, the precision of the variables
is weak. Furthermore these variables
were estimated over large areas by expert judgement rather than measured on local soil samples. This expertise
results from synthesis and generalisation tasks of national or regional maps
published at more detailed scales, for example 1:50,000 or 1:25,000 scales.
Delineation of the Soil Mapping Units is also the result of expertise and
experience. Heterogeneity can be considerable in Eurasian regions. The spatial
variability of soils is very important and is difficult to express at global
levels of precision. Quality indices of the information (purity and confidence
level) are included with the data in order to guide usage.
As a result, the SGDBE
consists of both a geometrical dataset and a semantic dataset (set of attribute
files) which links attribute values to the polygons of the geometrical dataset.
How map polygons, SMU’s and STU’s are
linked together is illustrated in the figure below :
In
the STU table, each STU has a number of attributes: an overview of these
attributes is given below. It is important to know that values for an attribute
A are chosen among a set of defined classes for that attribute.
|
Attribute Name |
Confidence Level ? |
Short description |
|
AGLIM1 |
|
Code of the most important
limitation to agricultural use of the STU. |
|
AGLIM2 |
|
Code of a secondary
limitation to agricultural use of the STU. |
|
CFL |
|
Code for a global
confidence level of the STU description. |
|
FAO85-FULL |
yes |
Full soil code of the STU
from the 1974 (modified CEC 1985) FAO-UNESCO Soil Legend. |
|
FAO85-LEV1 |
yes |
Soil major group code of
the STU from the 1974 (modified CEC 1985) FAO-UNESCO Soil Legend. |
|
FAO85-LEV2 |
yes |
Second level soil code of
the STU from the 1974 (modified CEC 1985) FAO-UNESCO Soil Legend. |
|
FAO85-LEV3 |
yes |
Third level soil code of
the STU from the 1974 (modified CEC 1985) FAO-UNESCO Soil Legend. |
|
FAO90-FULL |
yes |
Full soil code of the STU
from the 1990 FAO-UNESCO Soil Legend. |
|
FAO90-LEV1 |
yes |
Soil major group code of
the STU from the 1990 FAO-UNESCO Soil Legend. |
|
FAO90-LEV2 |
yes |
Second level soil code of
the STU from the 1990 FAO-UNESCO Soil Legend. |
|
IL |
|
Code for the presence of an
impermeable layer within the soil profile of the STU. |
|
PAR-MAT-DOM |
yes |
Code for dominant parent
material of the STU. |
|
PAR-MAT-DOM1 |
yes |
Major group code for the
dominant parent material of the STU. |
|
PAR-MAT-DOM2 |
yes |
Second level code for the
dominant parent material of the STU. |
|
PAR-MAT-DOM3 |
yes |
Third level code for the
dominant parent material of the STU. |
|
PAR-MAT-SEC |
yes |
Code for secondary parent
material of the STU. |
|
PAR-MAT-SEC1 |
yes |
Major group code for the
secondary parent material of the STU. |
|
PAR-MAT-SEC2 |
yes |
Second level code for the
secondary parent material of the STU. |
|
PAR-MAT-SEC3 |
yes |
Third level code for the secondary
parent material of the STU. |
|
ROO |
|
Depth class of an obstacle
to roots within the STU. |
|
SLOPE-DOM |
|
Dominant slope class of the
STU. |
|
SLOPE-SEC |
|
Secondary slope class of
the STU. |
|
TEXT-DEP-CHG |
|
Depth class to a textural
change of the dominant and/or secondary surface texture of the STU. |
|
TEXT-SRF-DOM |
|
Dominant surface textural
class of the STU. |
|
TEXT-SRF-SEC |
|
Secondary surface textural
class of the STU. |
|
TEXT-SUB-DOM |
|
Dominant sub-surface
textural class of the STU. |
|
TEXT-SUB-SEC |
|
Secondary sub-surface
textural class of the STU. |
|
USE-DOM |
|
Code for dominant land use
of the STU. |
|
USE-SEC |
|
Code for secondary land use
of the STU. |
|
WM1 |
|
Code for normal presence
and purpose of an existing water management system in agricultural land on
more than 50% of the STU. |
|
WM2 |
|
Code for the type of an
existing water management system. |
|
WR |
|
Dominant annual average
soil water regime class of the soil profile of the STU. |
|
WRB-ADJ1 |
yes |
First soil adjective code
of the STU from the World Reference Base (WRB) for Soil Resources. |
|
WRB-ADJ2 |
yes |
Second soil adjective code
of the STU from the World Reference Base (WRB) for Soil Resources. |
|
WRB-FULL |
yes |
Full soil code of the STU
from the World Reference Base (WRB) for Soil Resources. |
|
WRB-LEV1 |
yes |
Soil reference group code
of the STU from the World Reference Base (WRB) for Soil Resources. |
|
WRB-SPE1 |
yes |
Specifier of the first soil
adjective of the STU from the World Reference Base (WRB) for Soil Resources. |
|
WRB-SPE2 |
yes |
Specifier of the second
soil adjective of the STU from the World Reference Base (WRB) for Soil
Resources. |
|
ZMAX |
|
Maximum elevation above sea
level of the STU (in metres). |
|
ZMIN |
|
Minimum elevation above sea
level of the STU (in metres). |
For
the values of some attributes, it is indicated what is the confidence in the value.
The confidence value is qualitatively expressed as high, moderate, low or very
low. The confidence values for an
attribute with name A are reported in an additional column with name A.CL. Also
a confidence level for each STU record as a whole is provided under the
attribute with name CFL.
In
the above table “yes” in column “Confidence Level ?” indicates that for this
attribute a confidence level is available.
The Pedotransfer Rules Database (PTRDB), version 2.0
Pedotransfer
rules define how to infer values for an output attribute based on a set of values from a number
of input attributes. Within the Soil Database, the input
attributes are selected among the attributes in the STU table from the SGDBE.
The whole set of pedotransfer rules constitute the PedoTransfer Rules Database
The
following list contains the new attributes for which rules have been defined.
Attribute Name |
Short description |
TEXT
|
Dominant surface textural
class (completed from dominant STU). |
|
AGLIM1NNI |
Dominant limitation to agricultural
use (without no information). |
|
AGLIM2NNI |
Secondary limitation to
agricultural use (without no information). |
|
USE |
Regrouped land use class. |
|
ALT |
ELEVATION |
|
MAT1HEV |
Dominant parent material
code as translated from MAT1 by Hartwich & al. |
|
PAR-MAT-DOM |
Code for dominant parent
material of the STU (inferred). |
|
PAR-MAT-SEC |
Code for secondary parent
material of the STU (inferred). |
|
OC_TOP |
Topsoil organic carbon
content. |
|
PEAT |
Peat. |
|
PMH |
Parent material
hydro-geological type. |
|
DGH |
Depth to a gleyed horizon. |
|
DIMP |
Depth to an impermeable
layer. |
|
HG |
Hydro-geological class. |
|
ALT_MIN |
100 m class minimum
altitudes. |
|
ALT_MAX |
100 m class maximum
altitudes. |
|
ATC |
Accumulated temperature
class. |
|
DIFF |
Soil profile
differentiation. |
|
MIN |
Profile mineralogy. |
|
MIN_TOP |
Topsoil mineralogy. |
|
MIN_SUB |
Subsoil mineralogy. |
|
CEC_TOP |
Topsoil cation exchange
capacity. |
|
CEC_SUB |
Subsoil cation exchange
capacity. |
|
BS_TOP |
Base saturation of the
topsoil. |
|
BS_SUB |
Base saturation of the
subsoil. |
|
DR |
Depth to rock. |
|
VS |
Volume of stones. |
|
TD |
Rule inferred subsoil
texture. |
|
STR_TOP |
Topsoil structure. |
|
STR_SUB |
Subsoil structure. |
|
PD_TOP |
Topsoil packing density. |
|
PD_SUB |
Subsoil packing density. |
|
AWC_TOP |
Topsoil available water
capacity. |
|
EAWC_TOP |
Topsoil easily available
water capacity. |
|
AWC_SUB |
Subsoil available water
capacity. |
|
EAWC_SUB |
Subsoil easily available
water capacity. |
|
TEXT-CRUST |
Textural factor of soil
crusting. |
|
PHYS-CHIM |
Physi-chemical factor of
soil crusting & erodibility. |
|
CRUSTING |
Soil crusting class. |
|
TEXT-EROD |
Textural factor of soil
erodibility. |
|
ERODIBILITY |
Soil erodibility class. |
The Soil Profile Analytical Database of Europe (SPADBE)
The
idea of incorporating profile data into the Soil Database was to extend the
SGDBE data with quantitative data (whereas SGDBE attribute values are
qualitative (e.g high, low, medium) and taken from a discrete set of predefined
values). Such quantitative data should
allow better modeling. Two types of profile data are provided: estimated
profiles and measured profiles.
Measured
profile data come from geo-located profiles taken in the field, analyzed
according to own (non-harmonized) procedures in order to fill in a specific
measured-profile form, according to specific
instructions ; ideally these measured profiles should correspond to an STU from
the SGDBE.
Estimated
profile data come from profiles that should be representative for a specific
STU and have been estimated by experts in order to fill in a specific
estimated-profile form, according to specific instructions. The
values that had to be reported in this form were subject to a kind of
harmonization.
The
database includes the following analytical results for the different soil
horizons :
· Texture
(& particle size grades) · Electric
conductivity
· Organic
matter content (C, N) · CEC
and exchangeable bases
· Structure · Soil
water retention
· Total
nitrogen content · Bulk
density
· pH · Root
depth
· ESP or
SAR · Groundwater
level
· Calcium
carbonate content · Parent
material
· Calcium
sulphate content
The
result of the profile data collection and compilation are :
- A set of spreadsheet
documents that hold the measured profile data (Proforma I). Since the
gathered data were quite heterogeneous, hardly any attempt has been made
to harmonize the data which are delivered as received.
- A table that holds the
estimated profiles (Proforma II). An attempt has been made by the data
provider or the data compiler to link each profile to an existing STU;
however some profiles could not be linked. Note that estimated profiles
are not geo-located.
Database of Hydraulic Properties of European Soils (HYPRES), version 1.0
A major obstacle to the wider application of water
simulation models is the lack of easily accessible and representative soil
hydraulic properties. To overcome this apparent lack of data, a project was
initiated to bring together the available hydraulic data on soils, residing
within different institutions in Europe, into one central database. This
information has been used to derive a set of pedotransfer functions that can
provide a satisfactory alternative to costly and time-consuming direct
measurements.
A total of 20 institutions from 12 European countries
collaborated in establishing the database of HYdraulic PRoperties
of European Soils (HYPRES). As a consequence, it was necessary to
standardise both the particle size and the hydraulic data. Standardization of
hydraulic data was achieved by fitting the Mualem-van Genuchten model
parameters to the individual q(h)
and K(h) hydraulic properties stored in HYPRES.
The HYPRES database contains information on a total of
5521 soil horizons. Each soil horizon was allocated to one of 11 possible soil
textural/pedological classes derived from the 6 FAO texture classes (5 mineral
and 1 organic) and the two pedological classes (topsoil and subsoil) recognised
within the 1:1,000,000 scale Soil Geographical Data Base of Europe. Then, both
class and continuous pedotransfer functions were developed. The class
pedotransfer functions were used in combination with the 1:1,000,000 scale Soil
Database of Europe to determine the spatial distribution of soil water
availability.