Landscape Architecture-Liberating Digital by 张世豪

Liberating Digital Design Research Seminar

RMIT University Landscape Architecture Seminar Leader: Dr Ata Tara Semester 02- 2020

Improving water supply system in a coastal landscape: A digital approach to implement suitibility analysis

BARWON Prepared by : Shihao Zhang S3802032

OCT 2020

Improve water supply for future development

CLIMATE CHANGE

Content

Impact on the Barwon region in the context of current global climate change.

WATER The extreme weather caused persistent drought and reduced rainfall, which threatened rainwater storage.

RESIDENTS Due to population growth, surrounding residents have increased their desire for water supply.

RMIT University Landscape Architecture Design Research Seminar - Liberating Digital Seminar Leader: Dr Ata Tara Semester 02 - 2020

Background Introduction The relfection of climate change HydrologyHistorical and cultural significance Issues and study area

Composition Water and people density Basins and water structure Hydrology Landuse

Relationship Lithology Water resource Vegetation, Salinity Euclidean distance from cities

Generation Reclassfication of salinity and groundwater Reclassfication of cities and vegetation Reclassfication of streams and lithology Suitability analysis (Weighted overlay) GIS generated design strata Dams height analysis

Conclusion

BACKGROUND BARWON CONTEXT Our climate is getting hotter and drier. Australia’s climate has warmed just over 1 °C since 1910 and rainfall over southeastern Australia has been particularly low in recent decades.

Introduction

Hotter weather and less rainfall directly impacts our water supplies. For example, West Barwon Reservoir in the Otways, one of our biggest catchments, has seen a 32% reduction in annual inflows since 1997. This equates to a quarter of the Greater Geelong region’s annual water use.

site

The impact of extreme weather on surface water in VIC

Mallee

Wimmera Southern Mallee Loddon Campaspo

Oven Murray

Goulburn

Central Highlands Gippsland

Greater Melbourne Great South Coast

BARWON AREA

City name

The Barwon Area is postcard perfect featuring pristine beaches, ancient rainforests, worldclass golf courses and wineries, small coastal towns and rural hamlets – and Victoria’s largest regional city, Geelong. 4

Barwon

[

Flooding area Disappearing water Elevator Value 0 15 30

Figure 1- Barwon area

120

150

Miles 180

High : 2045 Low : -68

Sea Level Rise in Barwon

The reflection of climate change on Barwon The temperature has risen by 1.4-1.6° from 1950 The annual precipitation has dropped by 100-200mm in 70 years Sea level today is approximately 225 mm higher than in 1880 The number of ‘extreme’ fire danger days will generally increase by between 5%-40%

The reflection of climate change

- TEMPERTURE - RAINFALL - SEA LEVEL RISE - BUSHFIRE

Climate change affects the amount of rainfall in the region and the increasing temperature. Rainfall in Victoria has declined in most seasons over recent decades and Victoria’s temperature increased by over 1°C between 1910 and 2018. Due to the combined effect of these two reasons, Geelong’s water storages had dropped to just 14% in 2007, which makes residents pay more attention to water supply. (Barwon Water, 2020)

Legend Township

slr00cm_2009 slr20cm_2040 slr47cm_2070 slr82cm_2100

3.25

6.5

19.5

Miles 26

At Geelong by the 2050s, sea level is expected to rise by a median value of 24 cm (4 mm/yr) compared to the 1990s(Barwon Climate Projections, 2019). The rising sea level not only affects the activities of residents, but is also related to surface water storage facilities and groundwater. Fire History in Barwon

Figure 2- Annual Rainfall(Victoria Waterwatch, 2020)

↑ 1.4-1.6℃ ↓ 100-200mm

Miles 40

Boundry

2003

Township

2004

gray_Erase

2005

Fire History

2006

SEASON

2007

1990

2008

1991

2009

1992

2010

1993

2011

1994

2012

1995

2013

1996

2014

1997

2015

1998

2016

1999

2017

2000

2018

2001

2019

2002

2020

Figure 3- Temperature and rainfall change in the Barwon region since 1950

Mapping Question: Why is it important to improve water supply? CONCLUSION: Because climate change is the main factor in the reduction of rainfall, temperature, fire risk and sea level rise, their combined effect causes a water supply crisis in the future.

Fire weather has become more dangerous in southern Australia since the mid-1900s. In addition, fire seasons have become longer and commenced earlier over this time. Adequate water supply plays a vital role for the forest community.

Historical and cultural significance

1866 Mapping Question: From 1866 to 2005, especially under the influence of urban expansion and the development of productive industries, how did the main functions of land use change? Could these changes cause changes in water supply demand? DATA SOURCES: Landuse_histrory_1837_2005 & Watercourse - Vic Data

1911

1988

CONCLUSION: After more than a century of evolution, the indigenous peoples of this area have gradually migrated and merged, but the main production activities are still timber production and agricultural grazing. Moreover, with the combination of rapid population growth, reduced rainfall and the large demand for water reserves in production activities there are hidden dangers in the local ecological water supply system.

Important components of agriculture

The Barwon catchment has a particular spiritual and cultural significance for the Eastern Maar and Wadawurrung Traditional Owners. Traditional Owners have cultural, spiritual and economic connections to the land, water and other resources through their associations and relationships with Country. Connection to land, waters and resources on Country is important for Traditional Owners’ health and wellbeing.

Australia’s largest milk production area Contributing about $1 billion annually to the regional economy

8 These production activities are sensitive to reduced water supply and higher temperatures(Climate-ready Victoria, 2015).

2005

Legend

YEARS

Main River And Water Structure in Barwon

Main River

Extent 100Years ARI

Stony Creek Reservoirs

Historic Height Of Flooding

Issues and study area

Built Up Area

Wurdee Boluc Reservoir

West Barwon Reservoir

Extreme weather and Water supply

Mapping Question: What is the distribution of the main rivers in the Barwon area and its relationship with surrounding towns? DATA SOURCES: vmlite_hy_watercourse & dtm20m - Vic Data CONCLUSION: The Barwon catchment has some of the state’s most flow-stressed waterways. Significant population growth and a changing climate are expected to place increasing pressures on the health of the catchment’s waterways and its natural landscapes.

Legend

Miles 40

° Mapping Question: What is the distribution of the main rivers in the Barwon area and its relationship with surrounding towns? DATA SOURCES: vmlite_hy_watercourse, townships, 100 Years ARI, Historical height of flooding, dtm20m - Vic Data CONCLUSION: In the water-rich Barwon area, there is a possibility of seasonal flooding due to the unbalanced distribution of water storage facilities. In addition, because the overall temperature in Victoria is on the rise, the short-term water shortage in summer directly affects the lives of surrounding residents and animal husbandry activities. Therefore, the abundance of water resources, the distance from the river, and the area that may be covered by floods are necessary factors for potential water storage facilities.

Legend Main River Built Up Area Extent_100Years_ARI Historic_Height 1 2 3 4 5 DTM High: 1005.53 Low: -29.3143

DensityWater of surface water distribution Density in Barwon

Composition BARWON

Water and People Density

Composition

Through a detailed analysis of the site, the following diagram is a summary of the current site. Analyzing the content of the existing site and finding out the shortcomings is the key to discovering the conflicts between the surrounding residents and the environment. Legend

Seasonal water shortages and flooding coexist with the Barwon area. In addition, most densely populated areas are close to the river bank, which provides convenient conditions in the development design.

Boundry

River

0.63 - 0.79

WATER STRUCTURE

0.79 - 0.94 0.94 - 1.10

0 - 0.15

1.10 - 1.26

0.15 - 0.31

1.26 - 1.42

0.31 - 0.47

People density Density inin Barwon People Barwon

Stream order and density Relationship with residents Reseroir

Existing hydrology

Catchment

Water supply zone

Dam/Levee Stony Creek Reservoirs

Drought time Sea level rise

Extreme Weather

Flooding

IMPROVE WATER SUPPLY

Fully loaded

Insufficient

Water storage

Quantity

Wurdee Boluc Reservoir

Find the right place

Distribution People increasing demand

Land use

West Barwon Reservoir

Legend

Lithology

WATER STORAGE

Main River

Soil type

NAME BARWON RIVER BIRREGURRA CREEK

Evaluation criteria

Slope

Map2.mmap - 2020/8/23 - MSI1

Elevation high 0

Water flow

0.47 - 0.63

WATER DENSITY Miles 40

Township

Accumulation Stream order

Miles 40

BOUNDARY CREEK DEANS MARSH CREEK

EAST BRANCH SAINT PATRICKS RIVER <VALUE> LEIGH RIVER

0 - 27

MOORABOOL RIVER

27 - 55

NATIVE HUT CREEK

55 - 82

SUTHERLAND CREEK

82 - 110

WARRAMBINE CREEK

110 - 137

WAURN PONDS CREEK

137 - 165

WEST BRANCH SAINT PATRICKS RIVER

165 - 192

People Density

192 - 220 220 - 247

Mapping Question: The distribution of the density of water and people in the site. DATA SOURCES: vmlite_hy_watercourse, water area and township - Vic Data CONCLUSION: The center of the entire site is the place with the highest water density is at a certain distance from the crowd, part of which is at a certain distance from the built-up area, which creates the possibility for the establishment of large-scale water storage facilities.

Water Structure And Levees

Basins in Barwon

Water Structure And Levees

Barwom Catchment SHELFORD TOWNSHIP LEVEES

LARA TOWNSHIP LEVEES

Basins and Water Structure

Composition

BARWON HEADS TOWNSHIP LEVEES

Miles 40

The increase in extreme weather events poses a challenge to infrastructure In the near future (2030), year to year changes in rainfall will dominate trends caused by greenhouse gases. By the middle of the century, and under high emissions, winter and spring rainfall reductions will become evident against natural variability. Conditions outside these projections are also possible, from either natural variability (such as extended drought) or climate changes that are outside the range we currently estimate.(Climate-ready Victoria, 2015)

LARA TOWNSHIP LEVEES

Mapping Question: Are the existing water conservancy facilities adequate and geographically reasonable?

Legend

BARWON HEADS TOWNSHIP LEVEES

DATA SOURCES: hy_water_struct_line, levee, township and dtm20m Vic Data

Barwon Area Township

CONCLUSION: Existing levees and water conservancy facilities are concentrated at the junction of plateau mountains and plains. In the central area, the flat terrain and hard geological areas lack water storage facilities.

Water struct line levee HillShade Value

5 14 10

Miles 40

High : 254 Low : 0

Mapping Question: Analyze the basin and the direction of water flow to explore the area where natural water flow converges DATA SOURCES: DTM & Basins- Vic Data CONCLUSION: The northern part of the Barwon area is the lower basin, which helps people understand the general location of the catchment area. The central part of the site is dominated by plain terrain, while the southwestern part is surrounded by mountains, forming a valley-like terrain.The currents converge in the middle area from south to north. Main River

THE INTERACTION OF GROUNDWATER AND SURFACE WATER STREAM

The Interaction Of Groundwater And Surface Water

LANDUSE

Stony Creek Reservoirs

Composition

Barwom Catchment

Wurdee Boluc Reservoir

Hydrology

LAND FORM soil type

West Barwon Reservoir

Legend

GROUNDWATER

Barwon Area Barwon Catchment Township

Water Storage

Groundwater

Mapping Question: 3D model of streams, land form and ground water to understand how the relate to each other. CONCLUSION: The stream on the site gradually increased from the south to the middle and the land use has also changed from nature reserves and irrigated timber production to grazing and dryland agriculture. In addition, the terrain changes from a mountainous plateau to a sedimentary plain and the groundwater content decreased from south to north.

0-5m

Mapping Question: The relationship between groundwater and surface water in Barwon. DATA SOURCES: WATERTABLE_DEPTH, gw_sw_interaction and WATER_ STORAGE - Vic Data CONCLUSION: This mapping shows the interaction between groundwater and surface water. Facilities can be set up at these junctions for further development to protect groundwater resources and store surface water. 0

5-10m 10-20m 20-50m >50m GW and SW Interaction

Miles 40

Composition Landuse

Legend Barwon Soil Type GMUT3DESC Alluvial plains Basaltic residuals Cliff top; stranded Coastal plains with ridges and dunefields Dissected plains Eruption points and volcanic plains Eruption points: maars, scoria cones and lava shields Hills and low hills

Hills, valley slopes and plains on non- granitic Palaeozoic rocks Hills, valley slopes and plains on plutonic Palaeozoic rocks Lagoonal Plains and plains with low rises Plains with poorly developed drainage and shallow regolith Plains with well developed drainage and deep regolith Plateau Plateaux and broad ridges Plateaux and broad ridges Barrabool Hills, Athlone Forrest, Barramunga, Poowong, Fish Creek

Plains, Terraces

Sea level Steep slopes with basal cliffs; with shore platform Plains, Hill Stony rises Subaerial dominant processes; without shore Hill,platform Plateau Terraces and floodplains Terraces and floodplains, and coastal plains Plateau, Forrest Terraces, floodplains and lakes, swamps Tidal Valleys, alluvial terraces and floodplains waterbody wetlands

Elevation and waterways in Barwon

Mapping Question: What are the characteristics of the landscape topography in this area? Does it reflect the soil conditions and its potential impact on water resources? DATA SOURCES: Landscape Classification and dtm20m - Vic Data CONCLUSION 1: Through the observation of the land type of the site, the southwest area is composed of a plateau surrounded by forests, which provides a topographical difference for the catchment area.

CONCLUSION 2: Comparing with the mapping of land types, lithology intuitively shows that most of the southern Barwon is sedimentary and aeolian soil types. This property enhances the water permeability. In contrast, the northern part is composed of large areas of basalt. The terrain of the entire research area gradually changed from the southern plateau to the northern plain. The space between the canyons is conducive to the convergence of water and guide its direction.

Barwon Water Area Watercourse Elevator VALUE 1 - 7 7 - 17 17 - 26

26 - 35

Kilometers 40

35 - 44 44 - 53

Mapping Question: The relationship between stream trends and soil types? What is the interaction between different rock layer types and water flow? DATA SOURCES: Landscape Classification, stream, dtm20m - Vic Data

Lithology

Relationships

CONCLUSION : Stream is highly correlated with lithology. The alluvial plain and sedimentary rock layers formed by the action of water flow are fully reflected in the Barwon area, so these factors are considered as one of the suitability standards for resilient regions.

5 10

Miles 40

Contours River Sedimentary Aeolian Basalt

CONCLUSION : The main stream spreads along the boundary of the basalt rock layer (hard rock layer) to the sedimentary rock plain, which indicates that the hardness of the land may affect the direction of water flow.

Mapping Question: What is the relationship between surface water and groundwater? Are areas with high salinity conducive to agricultural activities and construction of water conservancy facilities? DATA SOURCES: Stream, groundwater, salinity and dtm20m - Vic Data

Water resource

Relationships

CONCLUSION : It can be roughly seen from the figure that the groundwater is more abundant in areas with dense water flow, but if people want to find the most suitable area, they must also consider the salinity of the water because the water salinity is high, it is not conducive to water reprocessing. These factors work together to the final result.

5 10

Miles 40

Mapping Question: What is the relationship between plants and groundwater? Can the salinity of the land and water affect the coverage of the land by plants? DATA SOURCES: Landscape Classification, stream, flora, salinity, dtm20m - Vic Data

Vegetation & Salinity

Relationships

CONCLUSION : Plant rhizomes can help solidify groundwater resources and become a buffer between human and nature, which improves the resilient space of water. Salinity affects the growth of plants and the reuse of water resources to a certain extent, so both must be strictly considered.

Stream Vegetation Density High

Low Watertable Salinity A1 A2 B C D E F

CONCLUSION : The salinity of the land has an inverse relationship with the density of vegetation.

Mapping Question: Whether the slope will affect the flow of the floods affecting people’s lives? DATA SOURCES: Floodway, township, streams and dtm20m - Vic Data

Euclidean distance from cities

Relationships

CONCLUSION : The relationship between the flood and the city must be considered in the final result, and the extent of the flood is proved to be highly correlated with the water flow, so the optimal area should be kept at a reasonable distance from the water flow.

0 3.25 6.5

19.5

Miles 26

Stream Floodway Township Slope Low High

CONCLUSION : The central plains with gentle slopes are prone to flood areas.

Generation Salinity and Groundwater

Salinity

F E D C B A2 A1

Groundwater

Ecological Suitability Value

0 1 2 3 4 5 6 7 8 9 10

0-Least

0-600TDS (mg/L) 601-1200 1201-3100 3101-5400 5401-7100 10-Most

Grazing Cereal cropping Dryland agriculyure

7101-10000 >10001

Mapping Question: Is the salinity of groundwater evenly distributed in coastal areas? Which areas have less salt in groundwater? DATA SOURCES: Landscape Classification and Salinity - Vic Data

CONCLUSION : Grazing and agriculture production that are main activities in Barwon are mainly distributed in the middle buffer zone of two belt-shaped areas with high groundwater salinity., and situate within the Riverine Plains which has well drained soils. The central and northern regions of the barwon catchment area has high salinity and is not suitable for agricultural production.

0-5m 5-10m 10-20m 20-50m >50m

Ecological Suitability Value

0 1 2 3 4 5 6 7 8 9 10

0-Least

Contours 10-Most

Mapping Question: What is the relationship between groundwater resources and water storage facilities? DATA SOURCES: Groundwater - Vic Data CONCLUSION : Due to the role of mountains in the north and south of the site, the rock layers protect the groundwater from loss and infiltration. These areas can be combined with lithology to create favorable conditions for future development.

Generation Vegetation and Cities 30

Vegetation Density

1 2 3 4 5 6 7 8 9 10

Ecological Suitability Value

0 1 2 3 4 5 6 7 8 9 10

0-Least

Miles 40

Vegetation

Value

6 1

10 Main river

10-Most

Towns Distance

Ecological Suitability Value

1 2 3 4 5 10 9 6 7 8

0 1 2 3 4 5 6 7 8 9 10

0-Least

Township Levee

10-Most

Mapping Question: What is the density and coverage of vegetation in this area?

Mapping Question: How far is the distance from the town with intensive human activities to the installation of water storage facilities

DATA SOURCES: Landscape Classification, Watercourse and Flora - Vic Data

DATA SOURCES: Township - Vic Data

CONCLUSION : The most suitable area should have high vegetation cover. The main rivers from north to south in the whole area are well covered by vegetation, which means it is more suitable for dams.

CONCLUSION : There should be a reasonable distance between human activities and water supply facilities. However, with the continuous expansion of the urban area, including the replacement of large-scale vegetation areas with productive land, the quality of water sources close to built-up areas or human settlements is easily affected by the surrounding environment. Therefore, in order to protect the cleanliness and safety of water sources, it should be located between nature and cities.

Generation

Stream and Lithology

Stream Distance

1 2 3 10 9 8 7 6 4 5

Watercourse

Ecological Suitability Value

0 1 2 3 4 5 6 7 8 9 10

Miles 40

0-Least

Reclass_stream Value

Lithology

5 6

Sedimentary Alluvium

Aeolian & Marl

Fluvial Aeolion

10-Most

Mapping Question: How far away from the streams is most suitable for building facilities of water supply? Where is this kind of area located within the study area? DATA SOURCES: Stream and watercourse - Vic Data

CONCLUSION : Barwon has rich river and stream systems. There should be forest land between the river and the land as a buffer, which can resist water flow during the flood season and use the root system of plants to slow down surface water leakage. So the proper distance from the river channel is important. Selecting an area 100-200m away from the river bank can form an effective resilient landscape.

Lagoonal Fluvial Volcanics Basalt Granite Waterbady

Ecological Suitability Value

0 1 2 3 4 5 6 7 8 9 10

0-Least

Miles 40

Reclass_lithology

Value

6 1

10-Most

Mapping Question: What is the relationship between lithology and site water resources? DATA SOURCES: Landscape Classification and dtm20m - Vic Data CONCLUSION : The most suitable area is the rough surface and denser rock layers, which is conducive to the establishment of reservoirs and collecte more water. This should a criterion of locating reservoir.

Lithology 15%

CITIES 15%

STREAM 25%

Location Suitability

VEGETATION 25%

GROUNDWATER SALINITY 10% 10%

Fitered out

Classification Suitability

Generation

High

Suitability Analysis

Middle

Low

Mapping Question: How will those elements influence suitibility value? How many proportion of each elements? CONCLUSION : The stream and vegetations are the core elements of the project. They constitute the basic conditions of the dam and resilient wetland, so they each occupy 25% of the overall weight. The nature of the surface rock layer affects the infiltration of the water storage area, which is an important factor (15%) to determine whether the area is suitable for construction. In addition, the town should maintain a reasonable distance from the proposed dam and fully consider the previous factors. Groundwater content and salinity together affect the final result. The selected area should be located in an area with relatively sufficient water content and low salinity to reduce the difficulty of drawing water and the impact on the surrounding environment.

The most suitable area

GIS Generated Design Strata

Generation

Landuse (Grazing&Dryland Area)

Suitable Area

Stream

Groundwater

Landuse Grazing Dryland agriculture Suitability Low

Groundwater High: 333.186

High

Low: 0.0999756

Original river bed height section(m)

DAM5

DAM1 6M

#3M DAM4 5M # DAM3 # 5M

# #DAM2 5M

Generation

(Data from Barwon Water)

Legend

Suitable Area

Dam height analysis

Mapping Question: How does the dam and wetland work? DATA SOURCES: Landscape Classification, stream and dtm20m - Vic Data

DAM

CONCLUSION : Through the overall analysis of barwon, we find the most suitable areas for building a resilient ecology, and then plan to build a series of dams to alleviate the water shortage in the dry season and serve traditional agricultural activities. When extreme rainfall increases during the flood season, dams and wetlands can be used as buffers between human and nature.

Miles 40

Barwon Catchment

Sources: Esri, USGS, NOAA

The planned multilevel dams and resilient wetlands are expected to provide 1.5 times the water resources compared with the original water storage capacity.

Conclusion

Location of reservoir

Conclusion Summary Grazing and dryland agriculture remains a strong identity to Barwon which is contributed by the geomorphology of the place. The change in Ground provided fertile sediment soils to the area which is suitable for agriculture. Moreover, adequate groundwater aquifer also supported agricultural land use. However, the increase in temperature and the decrease in rainfall caused by climate change make water resources scarce during the dry season, which exposes the crisis of future water supply. The rising sea level also has an impact on the original groundwater salinity that is difficult to change.

Consider the existing topography, hydrology, vegetation, and population density by analyzing the water supply resources and future development challenges of the Barwon area. Using GIS to evaluate altitude, water flow, green coverage, distance from towns and salinity, etc. to weight and calculate the most suitable storage area for resilence, and to reduce the impact on the surrounding environment by controlling reasonable dam height. In addition, the multi-level distribution of dams not only alleviates the impact of extreme weather on residents, but also contributes to local traditional dryland agriculture and grazing activities.

REFERENCE

Australian Government 2015, Recent rainfall, drought and southern Australia’s long-term rainfall decline, viewed 18 August 2020, <http://www.bom.gov.au/climate/updates/articles/a010-southern-rainfall-decline.shtml>. Barwon Water 2019, Annual Water Outlook, Barwon Water, Geelong Victoria. Barwon Water 2020, Water and Waste, Barwon Water, viewed 19 July 2020, <https://www.barwonwater.vic.gov.au/>. King, A & Green, J 2020, ‘RESILIENT DESIGN’, The American Society of Landscape Architects, viewed 11 August 2020, <https://www.asla.org/resilientdesign.aspx>. State Government of Victoria 2020, Data VIC, Victorian Government open date, data file, Australian Government, State Government of Victoria, viewed 17 July 2020, <https://www.data.vic.gov.au/>. South West Climate Change Portal 2020, Projections for South West Victoria, viewed 16 August 2020, <http://www.swclimatechange.com.au/cb_pages/projections.php>. The State of Victoria 2019, Barwon Climate Projections 2019, Department of Environment, Land, Water & Planning, Melbourne Australia. The State of Victoria 2015, How climate change will affect the Barwon South West region and how you can be climate-ready, The State of Victoria Department of Environment, Land, Water & Planning, Victoria. Visualising Victoria’s Groundwater 2020, Depth To Watertable (Victoria), Victorian Government open date, data file, Australian Government, Department of Environment, Land, Water & Planning, viewed 17 July 2020, <https://www.vvg.org.au/data_catalogue.php>. Waterwatch Victoria 2020, Waterwatch map portal, Waterwatch Victoria, viewed 25 July 2020, <http://www.vic.waterwatch.org.au/water_watch_map#>.

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