Coastal Monitoring System Design by Jiaoyang He

COASTAL MONITORING SYSTEM LANDSCAPE TECHNOLOGY 2

JIAOYANG HE UNSW | BUILT ENVIRONMENT LANDSCAPE ARCHITECTURE

ABSTRACT The movement of sediments is closely related to climate change, and a range of social environmental problems can be solved by detecting, designing and changing the way and direction of movement of sediments. This will not only benefit the marine ecosystem, but also solve a series of problems caused by climate change and the rapid increase of urban population. This paper will introduce the relevant landscape technology application to the site through the analysis of the Brisbane water estuary and urban coastal areas, combined with responsive technology, to alleviate the existing flooding, pollution and sediment movement problems.

CONTENT 1. Site Specific Investigations 1.1 Site Context 1.2 Wind Analysis 1.3 Hydraulic Processes 1.3.1 Sediment Movement 1.3.2 Flooding 1.3.3 Water Quality Processes 1.4 Objectives

2. Technology Precedent Study 2.1 Responsive Landscape: Synthetic Mudscape

3. Responsive Landscape Technoloogy Application 3.1 Actuated Spillway Gate 3.2 Ultrasonic Sensor 3.3 Real-time Sensor

4. Conclusion

1. Site Specific Investigations 1.1 Site Context

1.2 Wind Analysis

The study area is selected at Booker Bay and Ettalong Beach encompasses the entire estuary and its catchment with linkages to Broken Bay, which is part of the Woy Woy Peninsula on the Central Coast of NSW, 60km north from Sydney. It is located mostly on the west bank of Brisbane Water and is the entrance of Broken Bay. Therefore, it has important marine and estuary academic research value. In Brisbane water scale, the study area starts form rip bridge and end at the estuary of Brisbane Water where is close to the Broken Bay. Based on the data collected by Gosford Narara Research station, the Southeast winds is the prevailing wind annually in the study area and have an impact on the tidal direction and sediment movement.

1.3 Hydraulic Processes 1.3.1 Sediment Movement

Maximum Surface Tidal

>1m/s 0.5-1m/s <0.5m/s

Breaking Waves Sediment Movement Direction Sandbar formation

Tidal Behaviour Tides are affected by moon, sun and their gravitational attractions. There is a pumped-up phenomenon of sea water levels in the estuary near Ettalong Beach when spring tides comes. This is a common estuarine characteristic in coastal area. Because of the semi-diurnal tidal process in Broken Bay, it is obvious that two high and two low tides happen every day. Flushing times wSince the flushing of Brisbane water estuary is a complex process, it is closely related to the specific characteristics and geographical conditions of each region, according to the report from Gosford City Council and Department of Environment & Climate Change, Ettalongâ&#x20AC;&#x2122;s flushing time: from The Rip The rinse time to Ettalong ranges from 2 to 3 days. Moreover, Significant differences between flushing times in the middle of the channel.

Sediment comparision between 2015 and 2019

Wave events Wave events can affect ecological processes. Under the conditions of estuarine ecology, more frequent wave events will cause serious life and property threats to communities and residents around the coast, and cause damage to coastal biodiversity and ecosystems. Because residents live close to the coast in Booker bay and the Ettalong beach area, unstable waves caused by extreme weather may pose a threat to community stability. Therefore, human intervention and ecological landscape design may have the potential to play an important role in the community structure and biodiversity of the estuarine ecology. Sediment movement Lawson and Treloar (1996) studied the coastal transport characteristics of Ettalong Beach. The highest tidal speed occurs near the high and low tides, not near the average water level. Thus, in the vicinity of high water, there is an upstream flowing tide that, when combined with higher waves at high water levels (local wave formation and expansion propagation are not restricted to water like shoals), causes sand transport along the upper reaches of the beach. Because of the low waves, Ettalong Beach has a small height impact on Booker Bay at low tide; Moreover, the wave rate on the beach does not rise to the height of the beach when it is at high tide, so it does not effectively remove the sand. Beach area. This concept of transport to the northern coastline is consistent with this conceptual model proposed by Public Works (1977).

1.3.2 Flooding

Max. Depth (m) Coastal Fooding 0.4 Areal Flooding 0.01-0.2 Areal Flooding 0.2-0.4 Areal Flooding 0.4-0.8

Modelled Flood Depth for 2yr ARI (50%AEP) with Future Development

Max. Depth (m) Coastal Fooding 0.4 Areal Flooding 0.01-0.2 Areal Flooding 0.2-0.4 Areal Flooding 0.4-0.8

Modelled Flood Depth for 50yr ARI (20%AEP) with Future Development

Max. Depth (m) Coastal Fooding 0.9 Areal Flooding 0.01-0.2 Areal Flooding 0.2-0.4 Areal Flooding 0.4-0.8

Modelled Flood Depth for 100yr ARI (10%AEP) with Future Development According to the flooding model at three different times, the study area is greatly affected by the flood. There are two main types of floods in this area, namely areal flooding occurs in urban areas and coastal flooding occurs along the Brisbane water. According to the flooded area on the flooding model, most of the residents and public facilities of Booker Bay and Ettalong beach are affected by floods, with coastal communities being more affected by coastal flooding. In the next 50 years, the highest altitude of coastal flooding will reach 0.4m, which means that most of the coastal communities will be submerged. And the risk of flooding by waves may be a sudden event. Therefore, relevant marine motion detection systems and ecological mitigation measures need to be introduced in the study area.

Normalised Cu Concentration(ug/g) 10

Normalised Pb Concentration(ug/g) 20

100 0

-20

-40

-60

-80

Depth(cm) -100 -120 -140

-120 -140

-160

100

150

200

Depth(cm) -100

-120 Cu-C1 Cu-C2 Cu-C3

-80

Depth(cm) -100

-120

Normalised Zn Concentration(ug/g)

-120

Pb-C1 Pb-C2 Pb-C3

Zn-C1 Zn-C2 Zn-C3

-120 -140

-160

N C2

Normalised Cu Concentration(ug/g)

Normalised Pb Concentration(ug/g)

Normalised Zn Concentration(ug/g)

250

1.3.3 Water Quality Processes The study of water quality is also a dynamic process. It can be seen from the diagram and charts that the distribution of heavy metals in the sediments of the estuary has increased rapidly from the estuary of Booker Bay to the Gosford area. Booker Bay, as a connection between Gosford and Broken Bay, plays important roles in controlling the water quality. This is because Heavy metal is dynamic in the water system and they can be finally flowed into ocean which will affect the whole marine system. Heavy metals are mainly composed of Cu, Pb and Zn. From the heavy metal research report of this area, the concentration of heavy metals in this sea area has risen rapidly. Although it has not yet shown a serious threat to marine life, control measures need to be considered as soon as possible. The water quality in this study area is based on sediment and seawater nutrition, and the pollution of the seawater system will pose a huge threat to both ecosystems and residents. On the one hand, marine organisms will die or even become extinct due to excessive pollutants such as heavy metals. On the other hand, the residents living in the coastal area cannot live without water, and the water with excessive metal content will affect the health of residents. Therefore, monitoring and control of water quality and sediments in the marine system is very important.

1.4 Objectives

1. Analyse the ecological and biological processes of the estuary, including hydrodynamic issues, tidal behavior and direction, sediment distribution and movement, and communication with Broken Bay and the internal Gosford waters. 2. Improve the health of the estuary, including the distribution and concentration of pollutants, the types of pollutants and ecological solutions. 3. Introduce a coastal detection system to monitor the relevant ecosystems of the estuary, such as the composition and distribution of habitats, the health status of the ecosystem, the movement process of the sediments and the direction of movement. 4. Combine responsive landscape design, establish sensing devices across the water surface, and design devices that manage and control the direction of sediment movement to improve marine ecology and economic development in coastal areas.

2 Technology Precedent Study 2.1 Responsive Landscape: Synthetic Mudscape

Synthetic Mudscape master plan from Responsive Landscape (Cantrell and Holzman, 2015)

As the frequency and intensity of storms increase, the environment is facing increasingly serious challenges such as subsidence, ocean pollution, and seawater intrusion. In these complex marine areas, effective marine system testing is an effective means of mitigating risks. It supports the information and ocean structures that people need through non-structural design projects and flexible implementation systems, considers environmental fluctuations in an efficient manner. When designing coastal wetland areas, we will consider building a solid structure such as a flooding wall to prevent flooding, physically slowing down the momentum of the storm and preventing the hurricane from pulling up more water. However, the effectiveness of this method will decrease with environmental factors changes over time. In this responsive landscape, the designer builds a framework with a grid of elements through spatial nodes and measures it in a changing environment. This will be a flexible mitigation strategy that promotes habitability while monitoring and targeted improvements in the marine environment. The following is the site design of this monitoring system. At the first site, excavated materials and cuttings remain in the nearby waters, deepening the transport corridors and expanding the oil fields to maintain land growth in the physical repository. The second site is the expansion of the Mississippi River levee system, which transfers sediments from the river basin and screened landfill materials to deposit them to accelerate the natural land-building process.

These two large-scale marine projects are processes that assess changes and activities, reconstruction and design of marine systems by monitoring and documenting changes and developments in marine ecosystems. Nature and ecosystems change over time, so landscape design can also be a dynamic process. This inspection system will effectively monitor ocean data and upload real-time data, which will have a positive effect on Booker bay and Brisbane Water facingfloods, pollution and sediment movements problems.

Synthetic Mudscape SIte Stratefy from Responsive Landscape (Cantrell and Holzman, 2015)

Synthetic Mudscape Site Strategy from Responsive Landscape (Cantrell and Holzman, 2015)

3. Responsive Landscape Technoloogy Application 3.1 Actuated Spillway Gate

Actuated Spillway Gate

Spillway Gate Location Actuated spillway gates are placed at the narrow channel between Woy Woy and Booker Bay. This is because here is the junction of Brisbane water and the internal city connection. The water quality and the sediment movement on both sides show obvious differences. Spillway gate can not only change the direction of the water flow and the movement state of the sediment to form a new terrain, but control the heavy metal pollutants in the internal waters and prevent it from coming to the outer waters to ensure the marine ecology.

Different conditions of spillway gate

By opening or closing the gate, it can interact and begin to envolve working with the speed of water.This technology could help people to speed water up or slowing it down to test its behavior and modify the movement direction of the sediment and water. Therefore, the new landform will be built to benefit marine system and social economy.

3.2 Ultrasonic Sensor

Ultrasonic Sensor

Ultrasonic Sensors Location Ultrasonic sensors basically measure the distance from the equipment to the sediment underwater, and cut a section of sediment in real time, then the cross section underwater can be then showed in monitoring system. The process of this technology is to use photogrammetry to build a real model of the water surfaces and detect the sediment movement and the biological state of the sea floor. In the state of real-time monitoring of the marine system, the observer can record the movement and communication of multiple systems on the seabed in real time. This method can effectively monitor the movement state of seabed sediments and predict natural disasters such as coastal flooding and take effective measures.

Ultrasonic Sensors Utilize echolocation in order to extraxt sediment spot elevations and supply data for sectional studies

Conductivity data is utilized to track sediment saturation and draw correlations between sediment dormation and water retention

Section data helps make informed decisions about sediment formation in order to simulate predictable scenarios

Capacitive Sensors Utilize conductivity in order to detect water movement, sediment saturation and the conductive field of the sand table

3.3 Real-time Sensor

Sensor

Real-time Sensors Location

Real-time sensors are distributed in Brisbane Water to monitor the status of different points in the water system. It monitors the sediment status and land building process at each point. The choice of sensor position is based on the movement direction of the sediment in different positions. Because of the complexity of hydraulic processes in the Booker Bay area, sensor is placed in the position where the direction or condition of movement changes. By measuring the angle of the sediment, the researcher can get the basic real-time sediment motion map.

Real-time sensors

Coastalwide Reference Monitoring System

Flora

Fauna

Salinity

Bathymetry

Salinity dynamic change

Net change in underwater elevation

4. Conclusion Monitoring and designing Brisbane water through responsive landscape technology is a long-term marine project that benefits nature, economy and society. Based on research findings of flooding in Booker Bay, large-scale sediment movement and marine pollution, the project has given long-term mitigation options. This is a way of using technology to interact with the world and adopt them in landscape architecture.

Reference Cantrell, B.E. and Holzman, J., 2015. Responsive landscapes: strategies for responsive technologies in landscape architecture. Routledge. Cardno Lawson Treloar, 2007b. Brisbane Water Estuary Processes Study. Hydraulic Processes, Appendix C. Report Prepared for Gosford City Council and Department of Environment and Climate Change. Cardno Lawson Treloar, 2007. Brisbane Water Estuary Processes Study. Estuarine Morphology and Siltation. Appendix D. Report Prepared for Gosford City Council and Department of Department of Environment and Climate Change. Cardno Lawson Treloar, 2008. Brisbane Water Estuary Processes Study. Report Prepared for Gosford City Council and Department of Environment and Climate Change. Public Works, NSW, 1977. Ettalong Beach Erosion Study and Management Programme. Public Works, NSW, 1992. Photogrammetric Analysis: Report prepared by Coast and Rivers Branch