Urbanization and climate change and the in-stream animals of the Dandenong catchment(s)

Transcription

1 Urbanization and climate change and the in-stream animals of the Dandenong catchment(s) Chris Walsh, Yung En Chee (University of Melbourne), Rhys Coleman (Melbourne Water), and Nick Bond (Latrobe University) Presentation at Healthy Waterways Strategy workshop for Dandenong catchment Thursday 28 September 2017 Melbourne Waterway Research-Practice Partnership

2 My brief today The nature of rivers and their catchments Drivers of habitat suitability in rivers and streams Predicting distributions of instream animal species The effects of urbanization and climate change (and their interaction) on habitat suitability and distributions Melbourne Waterway Research-Practice Partnership

3 What makes a healthy stream? Sherbrooke Creek, Dandenong Ranges National Park

4 Ferny Ck

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7 20+ years of biological data

8 Environmental Data: carefully selected variables (e.g. ) Mean annual discharge depth Mean annual air temperature Effective imperviousness Weighted forest cover

9 Overview of the Habitat Suitability Modelling Process Biological data Model fitting MODELLING Model selection Model evaluation DATA Environmental predictors understand predict SDM OUTPUTS Applications

10 Habitat Suitability Models (HSMs) 59 macroinvertebrate families 23 fish species Total Platypus & Female-only Platypus Today, a focus on 53 macroinvertebrate families

11 Mean annual discharge depth (mm)

12 Mean annual air temperature ( o C)

13 Connected imperviousness (stormwater drainage impacts)

14 Manipulating predictor variables to simulate scenarios of human actions and climate change. The example of 53 sensitive macroinvertebrate families

15 1. What it once was. Number of sensitive macroinvertebrate families in the absence of human impacts

16 2. What it is today. Number of sensitive macroinvertebrate families in

17 3. (BAU) urban growth Number of sensitive macroinvertebrate families following urban expansion (urban growth area fully developed, assuming businessas-usual stormwater management)

18 3. (BAU) urban growth Number of sensitive macroinvertebrate families following urban expansion (urban growth area fully developed, assuming businessas-usual stormwater management) >8 4 to 8 2 to 3-1 to 1-3 to -2-8 to -4 <-8

19 4. BAU urban growth in a warmer climate Number of sensitive macroinvertebrate families following urban expansion o warmer climate >8 4 to 8 2 to 3-1 to 1-3 to -2-8 to -4 <-8 (urban growth area fully developed, assuming business-asusual stormwater management, no change in forest cover)

20 5. BAU urban growth in a warmer, drier climate Number of sensitive macroinvertebrate families following urban expansion o warmer climate + 25% less river flow at the mouth of the Yarra >8 4 to 8 2 to 3-1 to 1-3 to -2-8 to -4 <-8 (urban growth area fully developed, assuming business-asusual stormwater management, no change in forest cover)

21 Improvement from all streams having a 20m buffer for vegetation >8 4 to 8 2 to 3-1 to 1-3 to -2-8 to -4 <-8

22 Improvement from all properties retaining stormwater onsite >8 4 to 8 2 to 3-1 to 1-3 to -2-8 to -4 <-8

23 Water on a hectare of forest over a year...

24 Replace the forest with a building...

25 Stormwater runoff is a BIG flow problem

26 Keeping stormwater in the catchment... or (over)-irrigation TF