Building a Spatial Framework for the Analysis of Benthic Fauna Along the River Network of Switzerland

Transcription

1 Building a Spatial Framework for the Analysis of Benthic Fauna Along the River Network of Switzerland Lehmann 1 A., S., Stucki 2 P. and Gonseth 3 Y. 1 University of Geneva, 2 private consultancy, 3 CSCF SWAT 2007 / June

2 Photos: Pascal Stucki Swiss river spatial framework Introduction GIS spatial framework SWAT contribution Red lists of rare species Generalized Regression Analysis and Spatial Predictions Conclusions

3 DISTAL Introduction: conceptual model Ecological factors Abiotic factors Geographic factors Biotic factors Geological factors Climate: temperature rainfall Altitude Food Species interactions Reproduction Chemical factors: ph Conductivity Landuse Slope Geo-chemical cycles: carbon, minerals Oxygen Flow SPECIES DISTRIBUTION Morphology Substrate Anthropic factors: Toxics Fertilizers Heavy metals Salts Heat Corrections PROXIMAL Biogeographic factors Geographic barriers Habitat patches From Braukmann 1987

4 Rhein Inn Rhône Ticino Switzerland: km 2, alt. 193m-4634m, 4 main watersheds, pop. 7.5M, 178hab/km 2

5 500m segments Seg 500m 1/ dissolve with Gewiss ID 2/ split every 500m 3/ sample grids Scale and Segmentation and Segmentation

6 Hydrological Atlas On screen digitalisation Scale and Segmentation and Segmentation

7 1000m Watersheds Precipitation sum Scale and Segmentation 1/ script to delineate watersheds 2/ script to sample grid layers

8 Available Predictors 500m segments Altitude Hydrologic atlas Flow type Watersheds (1000m) CaCO3 Sinuousity Population density Slope Naturalness Dam influence Rainfall Air temperature % Slope > 30 Geodatabase %Agriculture %Forest % Glaciers Sewage capacity % Agriculture

9 SWAT SWAT contribution 4854 sub watersheds, 49000HRU, river length

10 Climate in Swizerland Swiss climate

11 Comparing methods on annual flow SUM of PRECIPITATION SWAT Relative scale gages SWAT m 3 /s m 3 /s A proper calibration is under way!

12 ArcGIS geodatabase Geodatabase

13 Red list for MEPT species Molluscs Ephemeropters Plecopters Tricopters New red list status Length of suitable rivers Several hundred species

14 IUCN Red lists criteria: Extent of occurence Land Observations Observations Rivers Zone of occurrence Occurrence length Area of occupancy Occupancy length

15 GRASP 4.Prediction 3.Model CaCO3 Air temperature Rainfall 1.Observations: Y Lehmann et al., Ecol. Mod Predictors: Xs

16 Type of responses Data Presence only: Distribution pseudo 0 > binomiale Distributions Presence absence: Abundance: Richness: binomiale Poisson Poisson Cover : binomiale Biomass : normale

17 Statistical Models Xs New Xs CALIBRATION PREDICTION Ys observed Ys estimated Y Y Y X1 X1 X1 X2 Inference GLM X2 GAM X2 NN Prediction

18 Running GRASP from Splus GUI Choice of Ys and Xs Data exploration Selection methods Interpretation & Predictions

19 GRASP Website R version Splus version

20 GRASP Correlation between predictors

21 Ancylus fluviatilis GRASP

22 Epeorus alpicola GRASP

23 GRASP Statistical validation

24 GRASP Mean contribution on 326 species

25 Next tasks Improve soil database Run SWAT on separate the watersheds to increase resolution Proper calibration, sensitivity analysis Extract water temperature data for every reach Re-run GRASP species models Evaluate species length of occupation Next

26 Conclusions Conclusions SWAT could greatly contribute to the study and modeling of river invertebrates distribution. The combination with true climatic data will allow taking into account river floods and droughts, as well as simulating the impact of future climatic changes. GRASP is an interesting companion to SWAT in order to extrapolate point measurements such as species observations to an entire river network. SWAT+GRASP should allow defining species red lists criteria in terms of length of available river for every species

27 Swiss river spatial framework Thanks Acknowledgements: Dr. F. Cordillot (OFEV), Dr. H. Aschwanden (OFEV), Dr. J. Leathwick (NIWA), Dr. R. Caloz (EPFL), Sophie Rast (Master student), Numerous and indispensible species data providers