Date post: | 28-Dec-2015 |
Category: |
Documents |
Upload: | diana-mcdaniel |
View: | 215 times |
Download: | 1 times |
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
Processes of water qualityTransport and retention and source apportionment
leakage of nutrients from landuse
hydrology and flow pathways
denitrification processes
biota cycling, sedimentation
source apportionment
point sourcecontributions
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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.
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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.
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
Ex. Animo –fertilization level, soil management to nutrient leakage
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
Ex SOILNDB –calculates standard N leaching rates from combinations of soils,crops, normal yield, normal climate per region
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
Watshman PC tool
Data management, pollution flow, source distribution and action/investment scenarios
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
- 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.
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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
0
200
400
600
800
1000
1200
1400
1600
1996 1997 1998 1999 2000 2001
DIN load (t/a)
DIN load calc. DIN load obs.
0
200
400
600
800
1000
1200
1400
1600
1800
2000
1996 1997 1998 1999 2000 2001
TN load (t/a)
TN load calc. TN load obs.
Twinning water quality modelling in LatviaHelene Ejhed, 2006-09-05
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.