Historic overview Egmond: Kick off Plymouth: CSI table Utrecht: Introduction frame of reference Santander: Recasting CSIs into the frame of reference

DefinedNot defined Defined Not defined Strategic objective Operational objective  Indicators  Parameters -Monitoring -Measurement -Modelling  System knowledge Reference state Current state 3. Intervention procedure 1. Quantitative state concept 4. Evaluation procedure 2. Benchmarking procedure Momentary coastline Intertidal Coastline X Beach width Exceedance curves IBCSI

Overview Dutch presentations Arno (RIKZ): Introduction Aart (UU): Scientific results and CSIs –highwater line and beachwidth –storm Egmond Stefan (WL): Scientific results and CSIs –multiyear evolution of nourished beach (beach width) –video derived observations of longshore currents Troels (UCo): Scientific results Arno (RIKZ): Recasting scientific results into the frame of reference

DefinedNot defined Defined Not defined Strategic objective Operational objective  Indicators  Parameters -Monitoring -Measurement -Modelling  System knowledge Reference state Current state 3. Intervention procedure 1. Quantitative state concept 4. Evaluation procedure 2. Benchmarking procedure Momentary coastline Intertidal Coastline X Beach width Exceedance curves IBCSI

Example: Dynamic Preservation Strategic objective: “Sustainable preservation of functions and values in the coastal zone” Structural erosion no longer acceptable Operational objective: “Maintain the coastline at its 1990 position”

1. Quantitative State Concept

2. Benchmarking procedure

3. Intervention procedure

“Sustainable preservation of functions and values” “Maintaining the coastline at its 1990 position”  System knowledge  State indicators -JARKUS BCL TCL 3. Nourishment 1. Momentary CoastLine (MCL) 4. Evaluation procedure 2. Benchmarking procedure OK? Not OK? Frame of reference: Dynamic Preservation

Video Survey Array y = -130 m Array y = m Video-based quantification of the MCL (Subtidal Beach Mapper, Aarninkhof 2003)

Working with the Intertidal coastline Strategic objective: –sustainable preservation of functions and values Operational objective: –maintain the coastline at its 1990 position QSC: –location of the coastline based on the intertidal beach volume - MICL Benchmarking procedure: –Reference: 10 year regression of MICLs to find the 1990 coastline - BICL –Test: 10 year regression of MICLs to find the year T coastline - TICL Intervention procedure: –IF the TICL exceeds the BICL THEN nourish Evaluation procedure: –Coastline will be maintained at its 1990 position –Maybe the existing procedure is represented but ARGUS data not effectively used NAP-5m NAP+3m (Dunefoot) MCLMICL

Time (months) MCL & MICL (m) Egmond MCL (surv.) and MICL (vid.) – Raw data Time (months) MCL & MICL (m) MICL (video) MCL (survey) Egmond MCL (surv.) and MICL (vid.) – Normalized data

Working with the high water line Strategic objective: –guarantuee sustainable safety of beach property Operational objective: –build no property seaward of the line with a 5% exceedance probability QSC: –probability curves of the high water line Benchmarking procedure: –Reference: location of the 5% exceedance line –Test: exceedance percentage of desired location Intervention procedure: –IF percentage of desired location is too high THEN relocate Evaluation procedure: –No property built at locations with exceedance probabilities higher than 5% –Long term developments unknown (system timescale & policy timescale)

Location of the exceedence curves of the high-tide levels GMT 2001

Working with beach width Strategic objective: –guarantuee sustainable recreation on the beach Operational objective: –maintain a minimal beach width for bathing people QSC: –width of inter tidal and supra tidal beach (waterlines) Benchmarking procedure: –Reference: minimal beach width (to be defined by the end user - municipalities) –Test: actual beach width as measured by ARGUS Intervention procedure: –IF actual beachwidth smaller than reference beach width THEN nourish Evaluation procedure: –Beach width maintained constant throughout the season –Nourishments during wintertime could be inefficient

Width of the inter-tidal & supra-tidal beach d c b a beach width (m) beach width (m) beach width (m) tidal range (m) Time: Y = -250m Y = -500m Y = -750m Inter-tidal beach Mean width = 80 m

beach width (m) beach width (m) beach width (m) tidal range (m) Time: Y = -250m Y = -500m Y = -750m Supra-tidal beach Mean width = m d c b a

This presentation was brought to you by: Arno de Kruif Stefan Aarninkhof Aart Kroon Troels Aagaard Susanne Quartel Mark van Koningsveld Discussion