off models developed for a specific study and
count only the more generic models, it must
exceed a thousand. Some existing model overviews cover numerous models. Amongst others
(with the number of models mentioned) are:
IRRISOFT (2014), 114; USGS (2014), 110; EPA
(2014), 211; USACE (HEC, 2014), 18; and REM
(2014), 681” (for details on these references the
reader is referred to Droogers and Bouma 2014).
The conclusion can be that there is an enormous and overwhelming amount of methods and
models available for measuring and simulating
water movement in soils and landscapes. Which
ones are particularly suitable to assess the watersoil-waste nexus? Mannschatz et al. (2016) have
provided a first attempt to present a web-based
comparison tool for analysing models characterizing the water-soil-waste nexus.
1.2 Developments in Soil Science
The various sub-disciplines in soil science (soil
survey/pedology, soil chemistry, -physics and –
biology) have operated rather independently in
the past and still do. Currently, much effort is
spent on obtaining databases with a global
extent, derived from pedological data. Some are
based on existing soil maps, such as the Harmonized World Soil Database (FAO et al. 2012;
Batjes 2016) or S-World (Stoorvogel et al. 2017).
Others are based on digital soil mappings, such
as Soil Grids (Hengl et al. 2014) and the Global
Soil Map (Arrouays et al. 2014). All include a
reference to worldwide soil classification systems
(IUSS-WRB 2015; Soil Survey Staff 2010). The
following functional soil characteristics are distinguished: Depth to rock, plant exploitable
depth, organic carbon, pH, Clay, Silt, Sand,
coarse fragments, ECEC, Bulk density, Bulk
Density of the fine earth, available water
capacity (AWC), Electrical Conductivity (EC).
These data are relevant for the nexus as they
allow direct or indirect assessments of soil
moisture regimes and the capacity of soils to
absorb and filter waste components.
In recent years many new proximal sensing
techniques have been developed that allow rapid
measurement of soil properties in the field. This
implies a major improvement as compared with
cumbersome, costly and time consuming laboratory measurements as made in the past (e.g.,
Viscarra Rossel et al. 2010; Vicarra-Rossel and
Bouma 2016). The link of soil data with functionality was initially focused on empirical land
evaluation, later quantified by simulation of soil–
water-plant processes (Bouma et al. 2011, 2012,
2016a; Stoorvogel et al. 2015). Functionality is
now also emphasized by the Soil Security concept that distinguishes soil condition, -capability,
-capital, -connectivity (links with stakeholders
and policy makers) and -codification (links with
legislation) (Field et al. (2017) with many
examples; Bouma et al. (2017)). One major
activity is to link elementary soil data (often
texture, bulk density and %C) by regression
analysis to parameters needed for simulating
water and nutrient regimes in soils (for example,
hydraulic conductivity and moisture retention)
developing so-called pedotransfer functions
(ptf’s) (e.g., Bouma 1989; van Looy et al. 2017).
These ptf’s provide a major link between soil
science and hydrology.
1.3 Engineering and Waste
Generation
Installations to purify wastewater and treat solid
waste have been built all over the world and can
by now be based on well established and proven
technologies as well as quality indicators. Composting facilities are frequently attached to solid
waste plants, utilizing only decomposable parts
of solid waste. Bouma (2016b) mentioned the
Edmonton Composting Facility in Canada, the
largest in North America, and the Qatar
Domestic Solid Waste Management Centre, the
largest in the Middle East and the large Lahore
Composting Facility. The quality of purified
wastewater is a function of the sources of sewage. Urban inputs, also by industry, may result in
relatively high contents of heavy metals, drug
remnants or hormones that are difficult to
remove. Even though on-site liquid waste disposal in septic tank systems is common in rural
How to Integrate and Balance Water, Soil and Waste …
17
count only the more generic models, it must
exceed a thousand. Some existing model overviews cover numerous models. Amongst others
(with the number of models mentioned) are:
IRRISOFT (2014), 114; USGS (2014), 110; EPA
(2014), 211; USACE (HEC, 2014), 18; and REM
(2014), 681” (for details on these references the
reader is referred to Droogers and Bouma 2014).
The conclusion can be that there is an enormous and overwhelming amount of methods and
models available for measuring and simulating
water movement in soils and landscapes. Which
ones are particularly suitable to assess the watersoil-waste nexus? Mannschatz et al. (2016) have
provided a first attempt to present a web-based
comparison tool for analysing models characterizing the water-soil-waste nexus.
1.2 Developments in Soil Science
The various sub-disciplines in soil science (soil
survey/pedology, soil chemistry, -physics and –
biology) have operated rather independently in
the past and still do. Currently, much effort is
spent on obtaining databases with a global
extent, derived from pedological data. Some are
based on existing soil maps, such as the Harmonized World Soil Database (FAO et al. 2012;
Batjes 2016) or S-World (Stoorvogel et al. 2017).
Others are based on digital soil mappings, such
as Soil Grids (Hengl et al. 2014) and the Global
Soil Map (Arrouays et al. 2014). All include a
reference to worldwide soil classification systems
(IUSS-WRB 2015; Soil Survey Staff 2010). The
following functional soil characteristics are distinguished: Depth to rock, plant exploitable
depth, organic carbon, pH, Clay, Silt, Sand,
coarse fragments, ECEC, Bulk density, Bulk
Density of the fine earth, available water
capacity (AWC), Electrical Conductivity (EC).
These data are relevant for the nexus as they
allow direct or indirect assessments of soil
moisture regimes and the capacity of soils to
absorb and filter waste components.
In recent years many new proximal sensing
techniques have been developed that allow rapid
measurement of soil properties in the field. This
implies a major improvement as compared with
cumbersome, costly and time consuming laboratory measurements as made in the past (e.g.,
Viscarra Rossel et al. 2010; Vicarra-Rossel and
Bouma 2016). The link of soil data with functionality was initially focused on empirical land
evaluation, later quantified by simulation of soil–
water-plant processes (Bouma et al. 2011, 2012,
2016a; Stoorvogel et al. 2015). Functionality is
now also emphasized by the Soil Security concept that distinguishes soil condition, -capability,
-capital, -connectivity (links with stakeholders
and policy makers) and -codification (links with
legislation) (Field et al. (2017) with many
examples; Bouma et al. (2017)). One major
activity is to link elementary soil data (often
texture, bulk density and %C) by regression
analysis to parameters needed for simulating
water and nutrient regimes in soils (for example,
hydraulic conductivity and moisture retention)
developing so-called pedotransfer functions
(ptf’s) (e.g., Bouma 1989; van Looy et al. 2017).
These ptf’s provide a major link between soil
science and hydrology.
1.3 Engineering and Waste
Generation
Installations to purify wastewater and treat solid
waste have been built all over the world and can
by now be based on well established and proven
technologies as well as quality indicators. Composting facilities are frequently attached to solid
waste plants, utilizing only decomposable parts
of solid waste. Bouma (2016b) mentioned the
Edmonton Composting Facility in Canada, the
largest in North America, and the Qatar
Domestic Solid Waste Management Centre, the
largest in the Middle East and the large Lahore
Composting Facility. The quality of purified
wastewater is a function of the sources of sewage. Urban inputs, also by industry, may result in
relatively high contents of heavy metals, drug
remnants or hormones that are difficult to
remove. Even though on-site liquid waste disposal in septic tank systems is common in rural
How to Integrate and Balance Water, Soil and Waste …
17