Twinning water quality modelling in Latvia Helene Ejhed, Kickoff meeting Twinning on development of modelling capacity to support water quality monitoring in Latvia Ecosystem model perspectives Photo Lake Övre hammardammen, Fredrik Ejhed

Twinning water quality modelling in Latvia Helene Ejhed, Problems using only 22 agricultural regions in Sweden Problems in a region with large climate gradient. Runoff is overestimated in parts of the region which dilutes thus gives too low concentrations. Total nitrogen concentration vs time in Stensån Sweden. SOILNDB and HBV. The model is used for production of result dependent on the management practices that can be changed by measures. The large shortterm variations is not in focus of the model but it has been validated at field scale.

Twinning water quality modelling in Latvia Helene Ejhed, Swedish monitoring programme adjustments due to WFD  Trend stations monitoring programme consists of stations that –class high or good status from biological parameters –are pristine without any pressures –are sampled yearly both water chemistry and biology  Rotation stations monitoring programme consists of stations that –provide additional areal coverage of information on water chemistry and biology –are sampled in a 6-year rotation  The largest change is increase in monitoring of biology  The large river outlet to the sea monitoring programme continues

Twinning water quality modelling in Latvia Helene Ejhed, Parameter regions for calibration of HBV hydrology HBV 230 stations for calibration 140 stations for validation timesplit validation also Hydrological modelling HBV

Twinning water quality modelling in Latvia Helene Ejhed, Ecosystem models  Combining the complete ecosystem response to pollution  Part of the ecosystem is the water quality models  Combination of atmospheric processes and water processes

Twinning water quality modelling in Latvia Helene Ejhed, Air - water modelling linkage  Wetland  Shallow lakes  WFD demand good ecological status  ICP Critical load = WFD border good-moderate ecological status  Model interface air –water

Twinning water quality modelling in Latvia Helene Ejhed, ICP critical load methods  ICP modelling and mapping –No dynamics needed for ICP exceedence and critical load values steady state. SMB Simple Mass Balance –In water quality model dynamic is essential for e.g. lake processes. –Dynamics can be used to establish steady state. –In case of exceedence dynamic modelling coupled to water quality models is needed to investigate the recovery process.

Twinning water quality modelling in Latvia Helene Ejhed, Nitrogen lake retention from catchment to sea Retention models for lakes – the linkage to air and critical load ?  Small lakes (<1 km 2 ) total circulation  Large lakes have a passive and an active water volume which variate with flow in and out  Retention within the active part (HBV-N) – Inorg. N : denitrification, biota assimilation, algae production and mineralisation. Lake retention = lakeret * cilake * lakearea * tmean5 lakeret = par. calibrated, cilake = concentration of inorg. N in active lake part, tmean5=mean temperature latest 5 days –Denitrification most important. –Takes place in the sediments, thus area and not volume is a parameter.

Twinning water quality modelling in Latvia Helene Ejhed, Retention models for lakes – the linkage to air critical load ?...continued  Lakes with long residence time are more effective in retention of N  Temperature and nutrient status control org.N production –Lakeproduction = lakeorg * cilake2 * vlake * tmean10 lakeorg=calibrated parameter cilake2=concentration of inorganic N in lake vlake=lake volume tmean10=temperatur mean latest 10 days if tmean10>tmean20 then lakeproduction is positive if tmean10<tmean20 then lakeproduction is negative  When the temperature is lower the latest 10 days than latest 20 days, sedimentation and mineralisation exceed the production.

Twinning water quality modelling in Latvia Helene Ejhed, Air and water quality link Runoff from paved surfaces and PM10 particles in air –a local urban problem  EU ARTEMIS project links road emissions model to traffic situations  SIMAIR swedish geographic distribution of traffic emissions  Risc assessment of effects on water bodies

Twinning water quality modelling in Latvia Helene Ejhed, Gross load N from forest landuse kg/ha,y

Twinning water quality modelling in Latvia Helene Ejhed, Whithin WFD Ecosystem expected ecological status  Good ecological quality  Target values ex. Swedish environmental quality targets.  WFD good ecological status ín Sweden –Bottomfauna index –Fish –etc  Critical load index not entirely the same as WFD

Twinning water quality modelling in Latvia Helene Ejhed, Toxic pressure Biota Transport Processes and the use of Models Occurrence and distribution of chemicals in different media

Twinning water quality modelling in Latvia Helene Ejhed, Multimedia fugacity models and screening  Useful tool for predicting environmental fate of chemicals  Point out likely recipient media and transport pathways  Can be used generally or for specific region  Help prioritising chemicals of environmental interest, ”ranking tool”  Quick, cheap, easy Toxic Pressures - Models From IVL presentation in REBECCA

Twinning water quality modelling in Latvia Helene Ejhed, Ref Screening of organic contaminants in Sweden Sternbeck et al 2004 Lake Coastal Sea Screening PBDEs in fish (ng/g lipid) Occurrence

Twinning water quality modelling in Latvia Helene Ejhed, Pollution transport and fate - fugacity models  Calculates transport and fate of the substance from equilibrium qriteria value.  The model evaluates the relative partitioning differences to different media (sediment, biota, water, air)  not applied on national level

Twinning water quality modelling in Latvia Helene Ejhed,

Twinning water quality modelling in Latvia Helene Ejhed,

Twinning water quality modelling in Latvia Helene Ejhed,