QUANTIFICATION ON THE CALCULATION PROCEDURE FOR A NEW LANDSCAPE INDEX PLANT COMMUNITY CLUSTER FOR RIPARIAN VEGETATION MANAGEMENT

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1 HydroEco April, Vienna, Austria QUANTIFICATION ON THE CALCULATION PROCEDURE FOR A NEW LANDSCAPE INDEX PLANT COMMUNITY CLUSTER FOR RIPARIAN VEGETATION MANAGEMENT Public Works Research Institute (PWRI) River Restoration Research Team Naoki Tagashira, Denda Msatoshi and Yuichi kayaba

2 HydroEco Background Expansion of woody vegetation on the river channel in Japan Yoneshiro river 11km~13km from the mouth of the river Increasing of the cost to get rid of trees for flood control Decreasing of the biodiversity on the grassland and river beach Strategic and effective riparian vegetation management Plant of river beach origin Annual herb

3 HydroEco Spatial index for vegetation management Plant Community Too complex to predict their dynamics with hydrodynamic model s scale Representative of biological character of inhabiting area Fine scale Conservation Landscape Easy to recognize for everyone No enough for biological information Broad scale Flood control How much scale is appropriate? Landscape scale Plant community scale

4 Hydrodynamic model-2d HydroEco Proposed new spatial index (pre-study) Plant Community Cluster (PCC) Intermediate scale between plant community and landscape Spatial index which was integrated the plant communities (PC) by the physical environments (PE) of inhabiting area Method of PCC calculation GIS layer Cluster analysis PC* HMWL DBWL SS PE** National river census data Ordinary discharge Maximum annual discharge Plant community cluster PE**: Physical environment HMWL : Height over the mean water level DBWL : Distance from the boundary b/w water and land SS : Shear stress on the riverbed SS Water level of maximum annual discharge PC*: Plant community HMWL DBWL Water level of ordinary discharge

5 Dissimilarity distance HydroEco Technical problem of cluster analysis for PCC Which level of integration is appropriate? Level of integration Number of PCC A B C D E F G H Plant community Dendrogram of cluster analysis

6 HydroEco Objective Quantification on the calculation procedure for PCC (Plant Community Cluster) Comparison of PCC between the rivers whose climate and regime of discharge are different

7 HydroEco Study site Yoneshiro river(10~23km) I=1/4,300 ~ 1/1,800 Annual rainfall: 1,659mm, Annual snowfall: 539cm Cyclical snowmelt flooding Yoneshiro river Woody vegetation of willow Chikuma river Chikuma river(171~186km) I=1/1,060 Annual rainfall: 935mm, Annual snowfall: 164cm Stable discharge regime Cultivated land Grassland

8 PE 2 PE 2 PE 2 HydroEco Approach to qualification PE-map: Distribution range (25 th - 75 th percentile) of PCC DOA: Differential of outer area b/w each level and first level OPA: Overlapped area b/w each PCC area DOA OPA Integration level Number of the grids (max.100) First level Intermediate level Last level DOA PE 1 PE 1 DOA OPA Physical environment map (PE-map) PE 1

9 PE 2 HydroEco Calculation flow of DOA & OPA 1. Discretize PE-map to 100*100 grids 2. Calculate DOA & OPA by each combination of PE 3. Sum of DOA & OPA of all combination cases 4. Execute step2~3 on all integration level 100 Outer area of first integration level 100 Combination of PE case HMWL DBWL SS PE 1 PE-map

10 HydroEco Results

11 HydroEco DOA vs OPA Grassland Woodland Yoneshiro River Chikuma River Optimum integration level

12 Woodland Grassland HydroEco List of PCC WW1 WW2 WHF WRF GGS GWS GR GBS GS1 GS3 Result of cluster analysis (Chikuma river) ID GGS GWS GR GS1 GS2 GS3 GBS WW1 WW2 WRF WHF List of PCC by cluster analysis Name of PCC Scientific name of major plant Gravel and sand bar Phragmites japonica Water-side grassland Persicaria lapathifolia Reed Phragmites australis, Miscanthus sacchariflorus Stable range grassland (I) Artemisia indica var.maximowiczii Lespedeza cuneata Stable range grassland (II) Solidago altissima, Miscanthus sinensis Stable range grassland (III) Miscanthus sacchariflorus (with shrub) Bank-side grassland Imperata cylindrica var.koenigii Willow (I) Salix subfragilis, Salix gilgiana, Salix jessoensis Willow (II) Salix serissaefolia Riparian forest Juglans ailanthifolia, Robinia pseudoacacia Hillside forest Amorpha fruticosa, Morus australis Y:Yoneshiro river, C:Chikuma river Y C

13 HMWL HMWL HydroEco Plant community vs PCC Plant community is too complex for the physical environments of 2D hydrodynamic model. PCC has stronger relationship with physical environments than plant community. Plant community PCC SS Grassland in the Chikuma river SS

14 Woodland Grassland HydroEco Comparison of PCC Yoneshiro River Chikuma River GS1 GGS GS2 GWS GBS GR GS3 GR GWS GGS GS1 GS2 GBS Chikuma river has stable dischage regime. WRF WHF WRF WHF WW1 WW2 WW1 Yoneshiro river has snowmelt flooding.

15 HydroEco Abstract plant succession with PCC (For vegetation dynamic model) PCC can abstract complex plant succession. Plant succession of Chikuma river

16 HydroEco Conclusions and future work Quantitative calculation method of PCC has been developed by two opposite index (i.e. DOA and OPA). PE-maps (inhabitating range of PCC) have reflected each river channel characteristics. PCC has stronger relationship of physical environment. PCC can abstract plant succession. Developing the vegetation dynamic model with PCC PCC has higher relativeness with physical environment which is calculated by hydrodynamic model. PCC can simplify complex plant succession. Enhancing the current vegetation management method PCC is summarized the biological information through the plant community.

17 HydroEco Thank you for your attention!

18 HydroEco PCC scale PCC scale Plant community scale Landscape scale