Annual Progress Report
CLEO 2011
Project
3.3 Linking scales and fluxes for national soil and water simulations
Project leader
Berit Arheimer
SMHI, 60176 Norrköping, Sweden
e-mail: berit.arheimer@smhi.se
General Objective:
The primary aim of small-scale/large-scale integration is to trace the magnitudes of flux
and pathways of the selected elements from the air to waters and coastal areas, through
soils and surface waters. Developing these links, we will be able to estimate how changes
in climate, deposition and land-use interfere with both biogeochemical and hydrological
cycles on the small scale, and the large-scale riverine transport of substances in the future.
Short description of activities 2011:
The dynamic water quality model, HYPE, was set up for all of Sweden (∼450 000 km2),
divided into 38000 sub-basins with an average area of about 10 km2. Readily available
national databases were used for physiographic data, emissions and agricultural practices,
fixed values for representative years were used. Daily precipitation and temperature were
used as the dynamic forcing of the model for the period 1960-2011. Results for the period
1990-2011 are available for free down-loading at http://vattenweb.smhi.se/
The model has been evaluated for water discharge and nitrogen and phosphorus
concentrations based on data from several hundred monitoring sites, of which
approximately 90% had not been used in calibration on a daily scale (Strömqvist et al.,
2012). Results were evaluated using the Nash-Sutcliffe efficiency (NSE), correlation and
relative errors: 92% of the spatial variation was explained for specific water discharge, and
88% and 59% for total nitrogen and total phosphorus concentrations, respectively. Day-today variations were modelled with satisfactory results for water discharge and the seasonal
variation of nitrogen concentrations was also generally well captured. In 20 large,
unregulated rivers the median NSE for water discharge was 0.84, and the corresponding
number for 76 partly-regulated river basins was 0.52 (Fig. 1). In small basins, the NSE was
typically above 0.6. Furthermore, internal model variables such as snow depths,
groundwater and lake level fluctuations were evaluated (Fig. 2) for a number of
independent sites with good correlations to observations (Arheimer et al., 2011), which
further increases the crediability of the national model concept. The achievements using
the S-HYPE model relative to previous similar experiments were ascribed to the step-wise
calibration process using representative gauged basins and the use of a modelling concept,
whereby coefficients are linked to physiographic variables rather than to specific sites.
Deliverables 2011
D3.3.1 Method for lake typology to be used in the national up-scaling with S-HYPE, i.e.
extrapolation of model results to lakes without monitoring. Month: 30, status: on-going
D3.3.2 Routines for linkage between SOIL-N, COUP, MAGIC and HYPE (including
hydrological variables delivered to MAGIC and concentrations delivered to HYPE).
Month: 30, status: on-going
Additional staff involved in project:
Johan Strömqvist, Göran Lindström, Charlotta Pers, Joel Dahné
Co-operation outside CLEO:
Water authorities in the Swedish WFD work
SMHI water management programme
SMED water consortium (Swedish Environmental Emission Data)
Reports and publications:
Arheimer, B., Dahné, J., Lindström, G. Marklund, L. and Strömqvist, J. 2011. Multivariable evaluation of an integrated model system covering Sweden (S-HYPE). IAHS Publ.
345:145-150.
Strömqvist, J., Arheimer, B., Dahné, J., Donnelly, C. and Lindström, G. 2012. Water and
nutrient predictions in ungauged basins – Set-up and evaluation of a model at the national
scale. Hydrological Sciences Journal 57(2):229-247.
Oral presentations:
IUGG General Assembly in Melbourne, 28 June - 7 July 2011
Oral presentation at the IAHS session H01: Conceptual and modelling studies of integrated
groundwater, surface water, and ecological systems
Arheimer, B.: Multi-variable evaluation of an integrated model system covering Sweden
(S-HYPE)
Appendix:
Mean RE (%)
15
<200 km2
Small:
Intermediate: 200-2000 km2
>2000 km2
Large:
Large (20)
Large (76)
5
Regulated (148)
Unregulated (168)
Small (71)
Mean RE=0
Intermediate (77)
Intermediate (61)
-5
-15
Small (11)
-25
0.5
0.6
0.7
Median NSE
0.8
0.9
Figure 1. Typical agreement (median NSE and mean relative error RE, number of monitoring
stations in brackets) between simulated and observed daily discharge, for different spatial scales,
and for unregulated versus regulated basins all over Sweden. (from: Strömqvist et al., 2012)
1000
100
Discharge
(m3/s)
100
10
1000
Tot-N
(mg/L)
10
100
1
10
0.1
1
Tot-P
(µg/L)
1
0.1
0.01
0.001
0.0010.01 0.1
Frequency
0.5
1
0.3
Snow depth
Correlations
0.4
0.1
10 1001000
0.3
0.2
1
10
100
1
0.6
Groundwater level
Correlations
0.2
0.4
0.1
0.2
0
0
10
100
1000
Lake water level
Correlations
0.1
0
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
0
0.2
0.4
0.6
0.8
1
Figure. 2 Comparison of modelled and observed values for several variables in the national
S-HYPE model. Above: Spatial evaluations of average levels of discharge, Tot-N and Tot-P
(simulated values on y-axes and observed values on x-axes). Below: Histograms of
correlations (daily values) for snow depth, groundwater depth below land surface, and lake
water-level fluctuation. (from: Arheimer et al., 2011)