Kickoff meeting

1
Kickoff meeting Twinning on development of
modelling capacity to support water quality
monitoring in Latvia Overview of available water
quality models
Photo Lake Övre hammardammen, Fredrik Ejhed
2
Overview water quality models - selection

• Eutrophication and acidification are well known
  problems
• Water flow and pathways models are numerous
• Nutrients N and P have been extensively
  investigated and models tested
• EUROHARP project provides model test results
• Water quality models are often chains of
  submodels
• Priority substances WFD annex X often unknown
  transport pathways and fate

3
Euroharp project Towards european harmonised
procedures for quantification of nutrient losses
from diffuse sourceswww.euroharp.org

• All 9 models applied in 3 country catchments
• By lottery applied in 3 additional country
  catchments
• Susve in Lithuania modelled with MONERIS, REALTA,
  SA and NOPOLU
• Nationally used models for international report
  obligations

4
Processes of water qualityTransport and
retention and source apportionment
point source contributions
denitrification processes
biota cycling, sedimentation
source apportionment
hydrology and flow pathways
leakage of nutrients from landuse
5
Simple balance model within EUROHARP

• SA Source apportionment follows the procedure
  by HARP-NUT guidelines
• Agricultural load is determined only by
  subtraction of other sources (including retention
  and background load) from monitored and
  unmonitored river load on the sea.
• The empirical retention models for lakes require
  only the hydraulic loading, water temperature, N
  and P loading and an estimate of the P pool in
  lakes.

6
Hydrology and flow pathways

• Hydrological descriptions are very important for
  pollution load calculations
• Only 4 EH models include hydrological module
  ANIMO, SWAT, HBV (TRK), EveNFlow
• Topography, landuse and soil type divide each
  basin into hydrological response units HRU
  (ANIMO, SWAT) or subbasins (HBV) or response
  groups (EveNFlow)
• Daily climate data are drive data
• Major differences in snow routines, surface
  runoff descriptions and how water balance is
  calculated
• SCS (Soil Concervation Service) model
• calculates using flow transport factors dependent
  on landuse and soil type. Snow routine and
  monitored baseflow can be added. Daily data.

7
Hydrology example results
Top graph shows model flow results vs monitored
data. Low graph shows model transport total N
results vs monitored data. TRK (HBV hydrology)
model
8
Diffuse sources models- agricultural
contributions

• Empirical models
• For example regression analysis of most important
  factors for N and P transport
• Ex. EH models REALTA and NOPOLU.
• Limited possibilities to scenario calculations
• Process based models with a high resolution are
  mainly developed to evaluate the effects of
  agricultural management practices or detailed
  (sub-)catchment management.
• Ex. EH models SWAT, NL-CAT (ANIMO), TRK(SOILNDB)
• Input data heavy
• Expert user

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Ex. Animo fertilization level, soil management
to nutrient leakage
10
Ex SOILNDB calculates standard N leaching rates
from combinations of soils,crops, normal yield,
normal climate per region
11
Retention models

• Retention recycling within the freshwater
  ecosystem
• Biota exchange, sediment exchange, atmospheric
  exchange and lake compartments exchange etc.
• EUROHARP-RETNUT
• Retention capacity derived empirically

12
Application for scenario analysis

• Only few of EUROHARP models were considered
  suitable for scenario analysis (predicting
  effects of measures)
• MONERIS, NL-CAT(ANIMO), SWAT, TRK (SOILNDB)
• But MONERIS cannot be used for water measures

13
Watshman PC tool Data management, pollution
flow, source distribution and action/investment
scenarios
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- Data management and presentation options as
selecting, editing, simple calculations and usual
GIS functions. ArcHydro connections under
development.- Nutrient transport options with
chains of models as diffuse leakage, lake
retention model etc.- Scenario management
options as changes in crop, landuse, sewage
treatment etc.
15
Results for Lithuania Susve river catchment

• MONERIS performed well
• difficulties in DIN peak year
• Susve 34 N retention and 66 P retention
• REALTA only calculates risc
• NOPOLU no results yet

16
Proposal to approach in Latvian application

• WFD demands
• Typology
• Reference conditions
• Characterisation
• Pressures
• Measures
• Get a quick overview using simple balance
  calculations if data are available
• Identify problem issues, ex. eutrophication
  acidification, other pollutants, hydrological
  issues resolution etc.
• Identify important processes, ex. snow routines,
  flooding, sediment transport, wetland and lake
  processes etc. to apply the right models.
• Use combinations of well known models tested from
  similar areas.