Katarina Holubova & Franz Steiner. Joint efforts for cross-border restoration of the Morava river

Transcription

1 Katarina Holubova & Franz Steiner Joint efforts for cross-border restoration

2 BACKGROUND INFORMATION AUSTRIA LOCALITY THE MORAVA RIVER IS THE DANUBE LEFT SIDE TRIBUTARY IN THE LENGTH OF 70 KM FORMS INTERNATIONALLY BORDER BETWEEN AUSTRIA AND SLOVAKIA SLOVAKIA RIVER CHARACTER LOWLAND RIVER WITH LOW SLOPE, MOBILE SANDY-GRAVEL BED. THE RIVER CREATES WETLAND ECOSYSTEM - UNIQUE IN CENTRAL EUROPE INCLUDING RAMSAR SITES RIVER REGULATION REGULATION FOR NAVIGATION PURPOSES & FLOOD PROTECTION

3 Danube effect degradation of the river bed Dyje tributary MAIN REGULATION MEASURES: - FINALISING OF FLOOD DYKES - CUT OFF MEANDERS, RIVER LENGTH SHORTENING CREATION OF THE UNIFORM CHANNEL HARD BANK REVETMENT IMPACTS OF THE RIVER REGULATION: [m n.m.] , , , , ,5 HPV HPV terén - DEGRADATION OF RIVER BED (up( to 1.5 m) - SURFACE & GROUND WATER LEVELS DECREASE - CHANGES IN FLOW DYNAMICS Q BANK Q SEDIMENATION IN THE FLOODPLAIN, COLMATATION IN CUT-OFF MEANDERS - CHANGES IN THE STRUCTURE OF WATER BIOTA [datum] trend (16) - SUCCESSIVE DEGRADATION OF CUT-OFF MEANDERS OXBOW LAKES

4 PRESENT STATE OF THE RIVER CHANNEL & FLOODPLAIN DISCONNECTION OT THE RIVER AND FLOODPLAIN PROCESSES UNIFORM RIVER CHANNEL LOST NATURAL CHARACTER OF THE MEANDERING RIVER LIMITED FLOW INTERACTION BETWEEN THE OXBOW SYSTEM AND RIVER CHANNEL INTENSIVE FLOODPLAIN SEDIMENT DEPOSITION IN THE MEANDERS, REDUCTION OF FLOODPLAIN CAPACITY SUCCESSIVE DEGRADATION OF THE MEANDER'S ECOSYSTEM

5 OVER 300 YEARS NO IMPACT ANALYSES OF THE RIVER REGULATION ON ENVIRONMENTAL AND RIVER PROCESSES WERE DONE ECOLOGICAL WORSENING OF THE PRESENT STATE HAS LED TO: SEVERAL INDIPENDENT RESTORATION PROJECTS SK - AT THE MAIN AIM: : RESTORATION SOME OF DISAPPEARING NATURAL RIVER FUNCTIONS AND PRESERVATION OF THE OXBOW SYSTEM AGAINST SUCCESSIVE DEGRADATION SOME OF THE GENERAL AIMS: - increasing of hydrological connectivity, - cut-off meanders reconnection/integration integration, preservation & restoration of the original character of meandering river; - reduction of river bed decrease, - increasing habitat diversity of the uniform river channel; - enhacement and restoration of wetland diversity; - restoration of previous floodplain & floodplain protection

6 1994 AT + SK JOINED RAMSAR CONVENTION Formulation of ecological requirements for the Morava river and floodplain (Ramsar sites) MARTHA PROJECT Austrian - project Analyses of engineer.. & ecological status of the river and floodplain (N) MUF PROJECT planning and implementation of restoration measures including abio and bio monitoring (EU LIFE + N) BGM I INTERREG III A Natura 2000, WFD investigations, observations, analyses, first common concept for the Morava restoration strategy (EU + N) GEF Biodiversity Program Global Environment Facility Restoration measures in cut-off meanders implementation measures (World Bank) REMORAVA PROJECT River and environmental processes, abiotic and biotic response to the river regulation (N- SK Government) PHARE PROJECT 1999 Trilateral project- SK part: ImprovementI of implemented restoration measures & basis for restoration strategy (EU) APVV Compilation of investigations and research results, bio & abio monitoring of implemented mesures, first common concept for the Morava restoration strategy (N) Some of the measures were implemented with various effectiveness

7 SLOVAK SIDE CUT-OFF MEANDERS RECONECTION Cut-off meanders were reopened on both sides of the river - to reestablish species richness (4 - on the Slovak side,2-on the Austrian side) erosion (-) sedimentation (+) Meander DVII- km cross section number In this case- restoraion measures have resulted in significant deposition at all localities as they were done without understanding of river processes Highest sedimention rates were observed in cut-off meanders reconnected at both ends RESULTS: LOW EFFECTIVENESS, RAPID SEDIMATATION, OWERALL ABIO & BIO SITATE INTFLOW present state OUTFLOW present state

8 AUSTRIAN SIDE Joint efforts for cross-border restoration LOCAL RESTORATION MEASURES: SYSTEM OF SMALL GROYNES -TO INCREASE HABITAT DIVERSITY IN THE MAIN RIVER CHANNEL MEANDER RECONNECTION LOWER PART (OUT- FLOW): TO IMPROVE WATER REGIME IN OXBOW LAKES LARGE DEFLECTORS ON SK RIVER SIDE TO DIVERT FLOW INTO REOPENED MEANDERS S AND REDUCE SEDIMENT INPUT BANKS PAVEMENT REMOVAL TO INICIATE LATERAL DEVELOPMENT AND INCREASE LATERAL CONNECTIVITY IMPLEMENTED MEASURES mostly local character, lower efficiency highlighted the need of join procedure in preparation of the common restoration startegy

9 PROJECT BGM II-(2006 ( ) 2007) THE FIRST COMMON RESTORATION STRATEGY FOR SLOVAK AUSTRIAN SECTION OF THE MORAVA RIVER PREPARED ACCORDING REQIREMENTS OF WATER FRAMEWORK DIRECTIBE AND EU DIRECTIVES ABOUT WATER AND NATURE PROTECTION BASIC ASSUMPTION: ASSESMENT OF THE RIVER & FLOODPLAIN WITHIN ONE RIVER SYSTEM REGARDLESS OF THE STATE BORDER OUTPUT: BILATERAL PLAN OF RESTORATION MEASURES FOR SLOVAK AUSTRIAN SECTION OF THE MORAVA RIVER

10 MORFOLOGICAL DEVELOPMENT HISTORICAL MAPS STABLE SECTION (km 27 km 33) UNSTABLE SECTION (km 15 km 20) SK ATSECTION INCLUDES: -STABLE SECTIONS (with low morphological dynamics the river channel has low sinousity,, over the many years the lateral activity is limited) -UNSTABLE (high morpholo- gical dynamics high lateral activity creation and extinction of meanders) BACKGROUND FOR THE RESTORATION DESIGNS Morphological clasification and river characterization enable to understand the river behaviour and to avoid proposals of measures that is not typical for given river type

11 BGM II Extensive abiotic and biotic investigation was curried out

12 BGM II Analyses of the river processes using 1D, 2D numerical models

13 BGM II PHYSICAL MODEL WITH MOBILE RIVER BED USED FOR ANALYSES OF VARIOUS SCENRIOS OF MEANDERS RECONNECTION

14 Joint efforts for cross-border restoration BGM II - PLAN OF MEASURES COMPLEX LIST OF RESTORATION MEASURES FOR THE RIVER CHANNEL & FLOODPLAIN (INCLUDING CUTOFF MEANDERS)FOR WHOLE SLOVAK AUSTRIAN RIVER SECTION EVALUATION OF THE MEASURES IMPACT IN RELATION TO REQUIREMENTS INCLUDED IN EU DIRECTIVES ABOUT WATER & NATURE PROTECTION (WFD 2000/60/EC, Natura 2000, Ramsar, Ramsar, Habitat and Bird Directive, Directive, etc.) etc.) FIRST FINANCIAL COSTS ESTIMATION (implementation) implementation)

15 BGM II Joint efforts for cross-border restoration MORAVA RIVER RESTORATION: PLAN OF MEASURES PREPARED ACCORDING REQIREMENTS OF EU DIRECTIVES ABOUT WATER AND NATURE PROTECTION MoRe - THE MAIN PROJECT GOLAS DETAIL PROPOSAL OF RESTORATION MEASURES PREPARED ACCORDING REQUIREMENTS OF EU DIRECTIVES(RSV RSV 2000/60/EC, Natura 2000, Habitat & Birds Directives, Ramsar) FOR THE PILOT SECTION OF THE RIVER (km 69-km 53) WITH THE AIM TO ACHIEVE GES, the concept to SK AT Border Commission BIOTIC AND BIOTIC MONITORINGM - PRIOR IOR-IMPLEMENTATIONIMPLEMENTATION PLANNING DOCUMENTATION FOR ALL PROPOSED AND APROVED RESTORATION MEASURES (pilot section) PREPARATION OF THE PROJECT IMPLEMENTATION

16 PILOT SECTION OF THE MORAVA RIVER km 69 km 53 RESTORATION MEASURES: 1) FLOODPLAIN (including cut-offs offs) 2) CHANNEL, RIVER BANKS & RIVERINE ZONE MEASURES 1 (floodplain( floodplain): - MEANDERS RECONNECTION (hydrological conectivity, controled lateral development) a) full integration b) reconnection on the lower end - IMPROVEMENT OF FLOODPLAIN CAPACITY WITHIN THE PRESENT FLOODPLAIN

17 Pilot section AT SK MEASURES 2 (channel( channel, banks & riverine zone): - REMOVAL OF BANK PAVEMENT - localy - IMPROVEMENT OF WATER REGIME IN MEANDERS RELICTS (lateral( conectivity) - BANK LEVEL DECREASE localy - to enhanced water interaction channel & floodplain) - RIVER CONTINUITY TRIBUTARIES

18 Thank you for your attention DANUBEPARKS International Workshop River Morphology & Restoration Orth,, 26th 27th May 2011