Coastal Engineer and Research Coordinator. Using twitter to showcase my work. Research in beach erosion | coastal monitoring | morphodynamics of reef islands
Currently involved in a shore protection project where we're use
#reefballs
instead of traditional armour rock to construct a breakwater.
The concept is to use the reefballs to dissipate wave energy and at the same time facilitate growth of
#coral
to improve marine life.
Unfortunate example showcasing the delicate nature of
#CoralReef
islands. The
#island
shape was completely altered due to disposal of dredge waste within the lagoon.
Goes to show that even "simple" actions can lead to drastic changes when it comes to
#CoastalZones
.
What happens when an
#island
is no longer in equilibrium with
#waves
?
If there is no intervention it's simply swept away.
The pattern in which the lost sand is deposited within the lagoon is fascinating to watch.
#Maldives
#beach
#BaaAtoll
One of the biggest
#challenges
for
#research
in
#Maldives
is that though there are numerous studies and projects on our
#environment
, the
#data
is never available.
My co-authors and I have tried to understand why this is. We have summarized our findings into a
#policy
brief on
After more than 35 years, my father
@MatheenMDV
has honourably retired from military service. We are immesurably proud of his career achievements and are excited to be a part of the many projects he has planned for the future.
@MNDF_Official
bids farewell to Brigadier General Abdul Matheen Ahmed as he retires honorably after 35 years of distinguished military service to our nation.
The last time Male' region experienced averaged-daily
#rainfall
above 175 mm was in 1977!
Interestingly that too was outside the
#Monsoon
and also during December.
Shorelines from
#CoastSat
showing the magnitude and orientation of seasonal changes to an uninhabited coral reef island in the
#Maldives
. These changes are caused by an oscillation in wave direction of approx. 70° throughout the year.
With this announcement of a simultaneous positive
#IOD
and
#ElNino
I thought it relevant to share this research which shows that following the 2019 pIOD event unusual
#shoreline
behaviour was observed in the
#Maldives
.
The Bureau of Meteorology has declared that El Niño and a positive Indian Ocean Dipole (IOD) are underway. Warmer and drier conditions have already been forecast for spring and summer for parts of Australia. Details:
Effective early warning systems that reach every person need all stakeholders to unite to save lives. Community resilience is critical. The
#EarlyWarningsForAll
initiative launched in MV today aims to achieve this before end of 2027, and support achieving
#Agenda2030
Has it felt like the
#monsoon
this year has particularly bad?
You are correct. There is currently a consensus among global climate models that we are in a negative Indian Ocean Dipole event. Based on climate projections, expect the weather to get worse over the next two months.
Could the recent wave-induced
#flooding
(Udha) on Dhigurah have been predicted?
#Wave
#forecasts
from
#NOAA
on 9th October (3 days before event) show large
#waves
with long periods coinciding with a spring high
#tide
. The ideal conditions for Udha as suggested by recent research.
New paper out!!
Title: Bathymetric Data Requirements for Operational Coastal Erosion Forecasting Using XBeach ().
In this paper we explore alternative, simpler bathymetries that can be used instead of pre-storm surveyed bathymetry to
#forecast
#erosion
It was a pleasure to publically inaugurate our ongoing "Digital Earth Maldives" project. The DE platform allows easy access to earth observation products across the
#Maldives
. The goal is to provide the much needed data to enable more
#sustainable
#development
and
#policy
A mini dye test which we recently carried out at a project site. The simple dye (in red) helped visualize complex flows and identify the cause of
#erosion
around the jetty of a resort. Tests like this can be a cost-effective method for identifying the cause of coastal issues.
Can
#hyperspectral
images be used to derive accurate
#bathymetry
over these shallow
#reef
flats? We're exploring this on Day 3 of the
#research
project.
This analysis could identify methods to more frequently collect bathymetric data and better understand the
#environment
.
The intention of this post is not to point fingers, but to raise awareness about the need for in-depth coastal studies and
#CoastalModelling
(which I have been advocating for) to be undertaken prior to any action being taken on
#CoralReef
#islands
.
This newly published paper provides the framework for a national-scale
#EarlyWarningSystem
for
#storm
#hazards
along sandy
#coastlines
. The framework has currently been implemented at an operational capacity at two pilot sites in Australia, and is the culmination of several of
The magnitude of the erosion that occurred at Narrabeen in front of the existing shore protection is clear from these before and after pictures taken at the same locations.
#ErosionHotspot
A negative IOD event increases the intensity of the prevalent monsoonal conditions. For the
#Maldives
this means above-average rainfall, stronger winds, and larger waves (more
#erosion
).
Stay safe during your travels over the next few months.
This graph is from an experimental setup used as proof-of-concept for an
#Udha
#EarlyWarning
system. Funds are currently being sought to develop and validate a
#prototype
of this system
🌍🛰️ Exciting news! Our Goidhoo-Atoll Earth Observation Pilot Project was a success! Have a peek behind-the-scenes look at our expedition. Thankful for our partners and all the support for this pilot. Stay tuned for preliminary findings at
@sinc
#geop
#msromv
#sinc2023
🚀
Excited and looking forward to being a part of this panel at
#COP26
.
Join us to talk about topics from coastal resilience to governance and security of water resources.
Why is COP26 significant for future water leaders? Join Nashwan Matheen
@NashwanMatheen
talk climate, commitment, and consequences
@COP26
. Event hosted by UNSW Global Water Institute,
@unswwater
.
4th November | Free virtual event
We hope these findings can be used to improve institutional capacity and data management principles. I see this as an essential step needed for the development of Maldives.
If anyone would like to discuss the findings further please feel free to reach out
#MentorSpotlight
: Meet
@NashwanMatheen
, a Coastal Engineer & Research Scientist, specializes in coastal erosion and early warning systems. His work at
@Msromv
focuses on Earth Observation research for better coastal management and climate adaptation in the Maldives.
Happy that my paper has been selected as the editors choice article.
In this paper we explored the extent to which simpler, more readily available bathymetries can be used as an alternative to pre-storm surveyed bathymetries when carrying out operational erosion forecasts.
Pre-storm surveyed bathy is one of the most difficult datasets to get when forecasting coastal
#erosion
. But do we actually need it? I am tackling this question at
#vICCE
to evaluate whether we can use simpler alternatives.
Time: 6th Oct 2:15pm AEDT
Last week's East Coast Low event resulted in surprisingly minimal overall erosion at Narrabeen. Most of the erosion occurred south of PF4, in front of existing coastal protection and hasn't been captured by changes to these representative profiles.
A nice animation showing the bi-modal
#wind
climate of the
#Maldives
using 20 years of measured wind data. Interestingly the shift in wind direction due to the
#monsoon
happens really abruptly, over just 15-20 days.
"Evaluation of prototype
#erosion
‘hot-spot’ Early Warning System". The title of my talk at Coastal Dynamics this weeks. I will be showing the accuracy of this new prototype EWS at
#Narrabeen
, and identifying the dominant source of error within this erosion
#forecast
framework
#remotesensing
is a very effective method for monitoring coastal change especially at dispersed, hard-to-frequent sites such as the islands in
#Maldives
12 months of beach change at
#CoastSnapManly
. The beach more or less ended the year as it started, but a few storm erosion-recovery cycles in between. Thanks to the community for your snaps - bring on 2023!
#CoastSnap
I will be co-chairing the workshop on satellite-derived
#bathymetry
(SDB) at the
#GEOBluePlanet
Symposium next week.
If this is a topic you are interested in and you are in the region, please come join us. We would love to hear your thoughts.
Based on this it is possible that some
#islands
may experience unusual erosion during the first half of 2024. In such a case, it is important to understand here that reactive coastal measures without necessary studies may cause more harm than good in the long-term.
Thought it would be a good time to review the performance of the previous implementation of
@NOAA
WW3 off the coast of Sydney now that 16-day wave forecasts are available through the new
#GFSv16
.
Keen to compare these to the new forecasts once more data has been generated!
This
#research
#Forum
highlighted major gaps within the research community of
#Maldives
. An interesting gap was the need for further research into communication and dissemination strategy: how best to convey research so that it is understandable and most importantly, actionable
Our Institute for Research and Innovation (IRI) organised a Research Forum today (February 26, 2024), as part of the preparatory phase for shaping the our Research Strategy. The forum's primary objective was to establish a conducive platform for key stakeholders to
Wave forecasts are predicting another storm at the beginning of next week, with waves coming in from a similar direction as the last
#EastCoastLow
. This is quite troubling given the already eroded state of the beach especially at hotspots like
#Narrabeen
and
#Wamberal
.
The magnitude of the erosion that occurred at Narrabeen in front of the existing shore protection is clear from these before and after pictures taken at the same locations.
#ErosionHotspot
I could not afford to make my most recent paper addressing
#coastal
change in
#Maldives
, open access.
So the actual community that it concerns, which would be able to get the greatest benefits from the research outcomes, will likely have the least access to it.
I was considering submitting a paper to Nature Ecology and Evolution, then I saw that the open access fee was 12 THOUSAND dollars! What the actual crap!? I can do a lot of research for 12k. Charging authors 12 grand to publish THEIR OWN work is the craziest nonsense imaginable
Great chance to test out the prototype
#EarlyWarningSystem
we have been developing for the SE coast of Australia.
Going to be presenting a first-pass evaluation of
#erosion
forecasts from this new system at
#CoastalDynamics2021
.
Keeping a very close eye on some possible major beach
#erosion
for this weekend. Wave forecasts showing a prolonged and large southerly storm combined with several spring high tides
With this test we had to carefully determine the concentration and amount of dye used as the resort was operational at the time. Having the water around guest villas red would not have been acceptable at this site.
I will be joining a panel at
@mvoceanhack
's information session to talk about some of the challenges in the
#Maldives
from a
#coastal
perspective.
Come by and have a chat about our
#islands
We are coming back with our second informative — ASK ME ANYTHING (AMA) session about the Maldives Ocean Hackathon. 🌊 Join us this Wednesday to know more about the challenges!
📅 Sept 20, 2023
⏰ 8:30 PM
📍
@VillaCollegeMv
QI Campus
#MVOCEANHACK
@sherymono
@shafeeu
Hi Shery, it must be really good to see your work being used!
As for the current project we are using Goliath reef balls (each of which weighs 2.2 tonnes) and we've done our due diligence to check their suitability for the project environment. So hopefully they stay put :)
The Ministry of Climate Change, Environment and Energy, along with Global Ocean Accounts Partnership co-organized an interactive workshop on ‘Blue Carbon as a Nature-based solution within the Maldives’ focusing on policy and technical considerations.
@KhalylKhaleel
Yes, we obtained a molds from the Reef ball foundation. For this project we are using three different sizes of reef balls, with the largest size being the Goliath reef ball which weighs approximately 2.4 tonnes.
@Thoriqibrahim
@MetMaldives
@MMuizzu
Improving operational hazard forecasting is something I strongly believe is essential to improving livability in the Maldives as extreme scenarios become more common.
Happy to contribute and provide assistance in any way I can.
A valuable
#opportunity
for
#research
#funding
. If you are interested and would like to have a chat about your proposal please don't hesitate to reach out.
Hopeful that this will lead mechanisms that allow collaboration between government and independent researchers/research institutions from the Maldives.
At the Maldives’
#SIDS4
event on Public-Private Partnerships, President Dr.
@Mmuizzu
emphasised the importance of forging strong partnerships between governments and the private sector for economic diversification and climate resilient development.
#MaldivesAtSIDS4
#SmallIslands
@SIRGNGO
I don't have enough data to say with certainty what caused this. But I suspect that it may be associated with changes in wave patterns caused by the formation of a new island just to the north of this island.
What kickstarted this process will need to be researched.
2020 has been a big year of storms for
#Narrabeen
. The site faced 2 of the most energetic
#storm
events over the past 40 years. So how does the beach now compare to the beach at the beginning of the year? (1/4)
@AhmudP
@oxiqamv
@mvoceanhack
@MoEnvmv
You are correct in that I was a mentor at
@mvoceanhack
and I did have conversations about shoreline mapping with participants, and specifically used CoastSat as an example in these discussions. It may be that the discussions resulted in something similar, but the work presented
@HasanHalym
Hu Hasan, I had a look and Vovah appears to be a resort island. As a personal preference I do not show islands that can easily be identified as I know it can sometimes be controversial and politicising.
I would like my tweets to remain educational.
@tweetsfromanim
You are correct that monsoon related oscillation of the beach is natural in the Maldives. Usually though the sand is redistributed along the island. In this case the sand actually falls off the reef flat into the deeper water, causing the island to lose sand over time and shrink.
@nihax
If you have a look at the About link in the collapsible toolbar the methodology is written there. As this is a research product, the method is kept transparent and open for constructive criticism to allow improvement.
@AishathAzfa
It's also worth noting that just looking at the island design shape, it doesn't appear to follow the principles of coastal engineering and so is likely to undergoe erosion.
Unfortunate if this goes forward
Have you ever wondered about
#georeferencing
errors in satellite imagery?
Work by our student Jordan Gois (with
@KDSplinter
) looked at implementing co-registration to reduce this wobble when mapping shorelines with
#CoastSat
on
@CopernicusEU
Sentinel-2 imagery.
1/4🧵
Great presentation which shows how waves can cause elevated water levels on reef islands like in the
#Maldives
. This understanding is necessary to be able to predict wave-induced
#flooding
(locally referred to as
#Udha
in the Maldivian language).
And it's ready! Ryan Lowe's wonderful presentation on wave propagation on reef's surf zones is now on
@YouTube
and you can watch it when you can (but don't forget, it is really worth it!) So glad I watched it live!
#Coast2Coast
#zoominar
Wondered how islands in the Maldives formed? This paper (freely for the next 50 days) describes how changes in sea level over the past ~2000 years led to the formation of Vaadhoo (Gaafu Dhaalu atoll) island. This model can provide insight as to what we should expect in our future
Hot off the press - Formation of a large sandy reef island in the southern Maldives over the last 1800 years with multiple sea level fluctuations. Full access is free using the link below for 50 days, which is a great initiative.
A new coastal hazard impact scale which extends the Sallenger waterlevel-based regimes by incorporating coastal
#erosion
impacts.
This extended impact matrix is applicable on coastlines regardless of whether
#storm
impacts are driven by waterlevels or waves.
The overall impact of a storm, based on the combination of flooding hazard and erosion hazard regimes, can then be described using our new Storm Hazard Matrix. Empty cells represent combinations unlikely to occur on sandy beaches. 4/7
@MarcosFTomasi1
Yes, GEE is such a great source of data!
I used the python scripts which have already been developed as part CoastSat. It's a great, easy-to-use open-souce toolbox and has everything you need to get started.
@explorer_mel
The area defined by the beach toe was mapped over time and showed decreasing trend. Higher resolution images and physical marine surveys of the site which followed the initial assessment showed that sand was falling off the NW and W side of the reef crest into deeper water.
@AhmudP
@oxiqamv
@mvoceanhack
@MoEnvmv
Hi Ahmed, it's always good to be critical of work so please allow me to provide some clarity. This particular animation is created using a modified version of the
#CoastSat
toolbox (). The data in the animation was extracted, analysed, and displayed with
Session
#7
: Storm Erosion
Talk title: Do we need pre-storm surveyed bathymetry for operational erosion forecasting? Evaluation of representative and synthetic bathymetry alternatives
@rannamaari
In this case, no. Storm induced changes typically occur over hours/days, whereas the changes seen here take place over years.
The observed change is likely associated with changes in the seasonal wave energy/direction within the lagoon as a result of the dredge material.
@goodebenin
1- it is north-facing.
2- All islands in Maldives display seasonal oscillation as it is caused by changing wave conditions from the Indian Ocean monsoon. The extent of the oscillation varies depending on conditions like reef shape, location in atoll, island shape/size etc
@AndhirinAndhiri
@thalibnaseer
@Msromv
At the moment the tide datum on the site isn't linked to benchmarks but is based on a MSL calculated from 30+years of data at 3 tide monitoring stations across the country.
It should be sufficient for most purposes.
Attaching these readings to PSMs is a possibility as we progress
The profile width last Monday (13th July) was 31m. We are planning on carrying out surveys next Monday (20th July) and will post the actual erosion.
#TakeAGuess
Our
#WRLCoastal
research group are trying to guess amount of erosion caused by latest
#EastCoastLow
at Narrabeen Profile 4. Ensemble mean of crowd-sourced predictions is 30m. Winner takes home a pie at the famous Collaroy Upper Crust pie shop
@ahmedRaxied
The IOD has one of the most direct impacts on the climate of this region, but you are correct in that due to the teleconnections other drivers also have an effect. In fact, an IOD event that coincides with an ENSO event can significantly strengthen/weaken the effects of an IOD!
@explorer_mel
@GeoNadirAu
A really interesting idea.
There's a program in Victoria, Australia doing this with citizen science:
Could be something to possibly try and incorporate into your UAV mapping project
@HasanHalym
Thsy being said, I do however take on projects to develop beach management stratrgies and erosion mitigation measures for islands (ihnabited and resorts). If that is of interest to you please do reach out.
@nihax
For Hulhule specifically, a harmonic analysis is carried out using 27 years of unbroken, quality controlled data and the tide is re-constructed from 184 tidal constituents. Unfortunately I cannot comment on why it differs from the Met website as I am not aware of their method.
@MohamedSharif
In this case the island changed from it's natural east-west orientation to a north-west orientation because of the placement of the dredge material.