150 likes | 156 Views
This workshop focuses on the importance of uncertainty assessments in integrated water management. It discusses different needs at different stages of the modeling process and presents the HarmoniRiB methodology for uncertainty assessment. It also showcases examples from the PRB case study. The workshop is held in Ghent on 4-5 October 2004.
E N D
PRB Workshop, Ghent, 4-5 October 2004Harmonised Techniques and Representative River Basin Data for Assessment and Use of Uncertainty Information in Integrated Water Management (HarmoniRiB)Jens Christian Refsgaard Geological Survey of Denmark and Greenland (GEUS) • The problem • why do we need uncertainty assessments ? • different needs at different steps in the modelling process (links to HarmoniQuA) • Uncertainty assessment methodologies - HarmoniRiB • Links to WFD implementation • Example of elements in PRB case study PRB Workshop, Ghent, 4-5 October 2004
Problem statement #1Uncertainty should affect the selection of appropriate modelling tool • “We do not need complex hydrological models which we do not understand and where the output is known to be uncertain” • “Instead we want simple models that are reliable” Statement from water manager responsible for implementation of Water Framework Directive (Harmoni-CA conference, Brussels February 2004) Uncertainty assessments of model predictions both for simple and complex models essential for bridging the perception gap between scientists and practitioners PRB Workshop, Ghent, 4-5 October 2004
Consultant # 1 Consultant # 2 Problem statement #2Uncertainty should affect water management decisions Copenhagen County project on identification of suitable methods for assessing groundwater vulnerability (2000)Assessments from five consultants on areas vulnerable to nitrate pollution from diffuse sources Consultant # 3 Consultant # 4 Consultant # 5 Vulnerable areas Very vulnerable Vulnerable Less vulnerable Well protected
Ignorance: unaware of imperfect knowledge State of knowledge about ‘reality’ (uncertainty concepts) ‘Unbounded uncertainty’ (not all outcomes known) Certainty (outcome known) ‘Bounded uncertainty’ (all possible outcomes known) No outcomes, “Do not know” Some outcomes and probabilities Some outcomes, No probabilities Some probabilities known (rare) No probabilities known All probabilities known QuantitativeQualitative ScenariosCannot formalise
Where and how does uncertainty come into the modelling process Harmonising Quality Assurance in model based catchment and river basin management (HarmoniQuA) • HarmoniQuA - another CATCHMOD project dealing with quality assurance in the modelling process • Modelling protocol with five main steps • Uncertainty is handled differently at different steps in the modelling process
Problem framing, identification of uncertainty sources, water manager and stakeholder perceptions and priorities Modeller reconsiders accuracy requirements Dialogue between modeller and water manager/stakeholders (Comprehensive) uncertainty analyses
Project objectives • To establish a practical methodology and a set of tools for assessing and describing uncertainty originating from data and models • To provide a conceptual model for data management and data base software that can handle uncertain data • To establish well documented datasets (including uncertainty estimates) for eight river basins and make these data available for future research projects (’virtual laboratory’) • To test the developed methodologies through a number of case studies focusing on integration of uncertainty and socio-economic aspects • To disseminate the results among researchers and end users across Europe PRB Workshop, Ghent, 4-5 October 2004
HarmoniRiB- River basin network PRB Workshop, Ghent, 4-5 October 2004
Data being collected from river basins • All data necessary to conduct research projects of relevance for implementation of the EU Water Framework Directive • Time series • meteorological data • rivers (quantity, quality and ecology) • lakes (quantity, quality and ecology) • groundwater (quantity, quality and ecology) • transitional and coastal waters (quantity, quality and ecology) • Spatial data (GIS themes) • land use • pressures • socio-economic data (water users) • system characteristics PRB Workshop, Ghent, 4-5 October 2004
y Time x Temporal data Spatial data Data uncertainty “Guidelines for assessing data uncertainty” • First draft version, September 2004 • Final version, available on www.harmonirib.com, February 2005 PRB Workshop, Ghent, 4-5 October 2004
Uncertainty tools • Data uncertainty • Uncertainty propagation through models PRB Workshop, Ghent, 4-5 October 2004
Links to WFD implementation • Mainly contribution to “Programme of measures” • Database software for handling WFD type data, including information on data uncertainty • Datasets from eight river basins - for use in future research projects on WFD related issues • Methodologies and tools on uncertainty assessments tested on case studies • example from Odense PRB PRB Workshop, Ghent, 4-5 October 2004
Measure Area - ha (percent of agricultural area) Reduced Leaching Tonnes Nitrogen Reduced loading Odense Fjord Tonnes N Cost + Cost eff. 1000 Dkr Dkr./kg N removed 20% reduction on national N-fertilizer quota 508 254 10.160 40 Wetlands in River-valleys 4000 (5,7%) 400 400 11.600 29 New forests on cultivated areas 5000 (7,1%) 214 112 14.000 125 Catch-crops: Increased use on areas with manure 5000 (7,1%) 185 93 1.302 14 10% higher utilisation of N in all manure 148 74 2.960 40 17% reduced livestock production (10000 LU pigs) 108 54 16.200 300 Reduction in cultivated area (urbanisation) 1470 (2%) 57 29 - Organic farming - increased area 2500 (3,6%) 50 25 7.175 287 Catch-crops: Optimised use of existing catch-crops 3200 (4,6%) 38 19 0 0 Total reduction and total costs Cost efficiency – average 1600 1060 63.000 59 Dkr/kgN Odense Fjord loading today (flow normalized): 2000 Fyns Amt “WFD-scenario” Scenario on agricultural measures in the catchment of Odense Fjord to meet environmental objectives Source: Danish Ministry for Food, Agriculture and Fisheries and Danish Forest and Nature Agency December 2003
Effects of… + = Effect Uncertain data Difficult decision: 2 or 3? 2 Uncertain models 3 Uncertain effects PoM 1 Costs + = Costs of alternative programmes of measures Uncertain data Uncertain models Uncertain costs Uncertanties on effects and uncertainties of costs PRB Workshop, Ghent, 4-5 October 2004
More information www.HarmoniRiB.com www.HarmoniQuA.org JCR@GEUS.DK PRB Workshop, Ghent, 4-5 October 2004