Disaster Response, Disaster Risk Reduction, GIS, Imagery, Mapping, Volunteering

Assessing and Responding to the Beirut Blast through the Use of Imagery and Mapping Techniques

My colleague turned his phone to me and said, “Have you seen this?” Thinking that it was just another funny video created by one of the many internet users who are currently in lock-down due to the COVID-19 pandemic, I braced myself. This time however, it was no joke!

On August 4th, 2020, a warehouse at the Port in Beirut, Lebanon, storing approximately 2,750 tonnes of ammonium nitrate, exploded, destroying nearby buildings and causing damage miles away.

Compare the images below by moving the slider. They show images pre-event on June 9, 2020 and post-event on August 5, 2020. In the image the port warehouses, and the grain silos can be seen. The destruction of the 120,000-ton capacity structure of the grain silo and disabling of the port, the main entry point for food imports, exacerbates concerns about food supplies for Lebanon.

Satellite images shows pre and post blast event in Beirut, Lebanon

Coincidentally, during my university days in Edinburgh, Scotland, I shared a flat with two amazing ladies who I grew very close to during my year abroad. Thankfully, I still maintain close contact with them, although it has been more than 16 years since we first met. One of them is from Lebanon and the other from Cyprus. Instinctively, upon realizing the severity of the situation that I witnessed in that video, I reached out to them both. My friend from Lebanon, now resides elsewhere. She indicated however, that many of her family members suffered damage to their homes. My Cypriot friend mentioned that they heard the explosion all the way in Cyprus and that it even felt like an earthquake!

Pictured below is a map showing the proximity of Cyprus to Lebanon, an approximate 265 km distance. I couldn’t help but think of the safety of my friends and their families.

Proximity of Cyprus to Lebanon

As a member of the humanitarian mapping charity – MapAction, I was thankful to learn that a 3 member group was being deployed to help! Even with the rising challenges of operating during the COVID-19 pandemic, this organization, as well as many others are ready to offer support in crisis.

Responding to the Beirut explosion

After being given the opportunity to attend an International Search and Rescue Advisory Group (INSARAG) Earthquake Response Exercise (ERE) in December 2019 in Thailand, I have a deeper understanding and appreciation for the need of collaboration and communication between the teams that are on the ground responding to a disastrous situation. MapAction supports this effort by providing maps to help with co-ordination. The map below shows that in Lebanon, there are several teams on the ground, to include Urban Search and Rescue (USAR), United Nations Office for the Coordination of Humanitarian Affairs (UN OCHA) and the Red Cross. It is quite helpful when co-ordination locations are known by all the teams on the ground.

This is another map that has been provided by MapAction. It shows the area being divided up into more manageable sectors. The locations where bio hazards exist, have been identified and highlighted on the map.

During the past few days, many satellite imagery companies have offered their support to Beirut. This offering is welcomed, as it helps teams on the ground to conduct further damage assessment and provide service delivery to those in need.

The Disasters Charter has also been activated to respond to the Beirut blast. Though clouds obscure parts of this image taken via a Pleides satellite sensor, the map shows emergency shelters being set up, and highlights the location of hospitals in the area.

It is my hope and prayer that Lebanon receives the much needed support and humanitarian relief it requires in the aftermath of this disaster. #prayforlebanon

In my previous blogs I have indicated the importance of up-to-date imagery in responding to a disaster and also what led me to becoming a MapAction Volunteer. You can read them below:

Lavern Rogers-Ryan is a geospatial consultant specialising in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

Disaster Risk Reduction, GIS, Imagery, Mapping, Volcano

My career in GIS was subconsciously influenced 25 years ago by the eruption of Soufriere Hills Volcano

July 2020 marks the 25th anniversary of the eruption of the Soufriere Hills Volcano on Montserrat and presents an opportune moment for reflection.

I was only 13 years old at the time, but I do remember the chaos surrounding these events. It was a very uncertain time for those of us living in Montserrat. At the time I attended the Seventh-day Adventist School in Delvins. I remember exiting the classroom and looking up towards the heavens, like many of my peers. The sky was very dark that day, no one seemed to know what was happening. The picture below is symbolic of what has been etched in my memory.

Emission of ash from Soufriere Hills Volcano, Montserrat
https://www.bgs.ac.uk/discoveringGeology/hazards/volcanoes/montserrat/ash_and_mud.html

I remember the hustle and bustle of parents coming to collect their children. Unfortunately, some of us never had the opportunity to attend school in Montserrat ever again and our childhood friendships and dreams of experiencing life together on Montserrat were dismantled. My mother thought it best to send myself and my brother to live in Antigua with my Aunt because of the uncertainty with schooling and living in Montserrat. Now being a mother myself, I understand her decision.

Just as we began settling into the new norm of life in Antigua, Hurricane Luis, a powerful category 4 hurricane, hit Antigua on September 5th, 1995. This hurricane disseminated the country of Antigua causing damage and destruction to 45% of the residences on Antigua as it passed near 30 miles (48 km) to the north of the island. A recount of Hurricane Luis by Mr. Dale Destin can be found https://268weather.wordpress.com/tag/hurricane-luis/. This storm basically flattened many homes in Antigua, and my Aunt’s home was no exception. Thankfully, to meaningful friendships, my Aunt was able to find accommodation for us and her family elsewhere. So many additional complexities came about from these developments. For example, I remember having to attend school on a shift basis (interestingly, similar to my daughter’s experience during the COVID-19 pandemic now) and spending many nights studying by flashlight and candle light in order to fulfill the requirements for the next day of school.

Although, I was out of Montserrat physically, Montserrat was constantly on my mind. We were always tuned in to ZJB radio to keep abreast of any updates and mostly because my mother was still on island. As a matter of fact, she never migrated!

My brother graduated from secondary school in Antigua in June 1997, and it was around this time that our capital, Plymouth was buried under pyroclastic flows (pictured below). There was no way, that my Mom was going to allow him to go back home. I believe that she was scared even for her own safety! I started thinking about whether or not I will ever be able to identify areas in Plymouth again. Such a tragedy!

Plymouth buried under pyroclastic flows, 1997
Source: https://www.theatlantic.com/photo/2013/05/soufriere-hills-volcano/100509/

After I graduated secondary school in Antigua in a year later, there was still uncertainty in Montserrat. My Mom admonished that it was not the ideal time to return and encouraged me to use the opportunity to continue on to tertiary education. So I ventured even further away from home to pursue a 4 year Computer Science degree in Trinidad. Based on the ongoing situation in Montserrat, I opted to take summer courses which resulted in me completing my degree earlier. Foremost in my mind was how I could make a meaningful contribution to my island home.

I returned home after University graduation in 2002. I was pleased that so many new homes had been built in the north of the island and although businesses were scattered throughout the northern area, things were returning to some sense of normalcy.

New homes built in Lookout, Montserrat (Picture taken in May 2002)
Source:https://www.yachtanju.com/montserrat.htm

I remember having the opportunity to discuss GIS with a consultant who was visiting Montserrat to conduct training. He explained that it was a relatively new field of technology, but it can be used for disaster management along with many other things. He encouraged me to research, applying my knowledge of my recently earned degree to this emerging science.

I delved in, and the rest is history! I completed a Master’s degree in GIS within 3 years of being introduced to the topic. My research topic centered around the “Integration of Remote Sensing Techniques and GIS to Detect and Update Changes in Land Cover as a Result of Intra-island Migration on Montserrat.” Being able to apply my knowledge of GIS to the redevelopment of Montserrat and further assist in disaster management on island, has been my motivation. In retrospect, I can truly say that the eruption of the Soufriere Hills volcano 25 years ago, has influenced my career in GIS to date.

Post Script:

I want to say a hearty thank you to my Mom, who sacrificed everything and ensured that I had a Montserrat to come back home to! I love you Mommy!

Mommy and I.

Learn more about GIS in my previous blog posts below:

Lavern Rogers-Ryan is a geospatial consultant specialising in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

Hydrographic Surveying, Mapping

Hydrographic Surveying: Mapping the Ocean Floor

This week’s focus has been on the World’s Oceans. World Oceans Day is held every year on 8th June to raise awareness of the vital importance of our oceans and the role they play in sustaining a healthy planet.

With that in mind, in order to understand what lies beneath our oceans, hydrographic surveying is usually conducted. Hydrographic surveying involves measuring, describing and mapping physical features that can be found underwater in our oceans, seas, coastal areas, lakes and rivers .

I have been enlightened on the processes and the detailed tasks involved in conducting hydrographic surveying with some training in QPS Qinsy and CARIS (HIPS and SIPS) software programs. In a nutshell, these software programs are used to help with line planning (this helps the surveyor to collect data coherently and also helps with the navigation of the vessel), implementation of the surveys and the post-processing of collected data.

In fact, the technology for collecting underwater data has come a long way, from leadline to sonar (sound navigation and ranging) technology as depicted in the pictures below.

A nostalgic 1985 sketch of hydrographic surveying using leadline
Source: https://en.wikipedia.org/wiki/Hydrographic_survey#/media/File:Cgs01221_-_Flickr_-_NOAA_Photo_Library.jpg
Multibeam sonar used nowadays to map the ocean floor
Source: https://en.wikipedia.org/wiki/Multibeam_echosounder#/media/File:Fis01334_(27555144884).jpg

The experience I gained in hydrographic surveying involved the use of multi-beam sonar technology which was mounted to the front of the vessel. It was really engaging to be able to adjust the swath angles as information is being received from the sensor and to see first hand images of the surface below the water. Some features did amaze and startle me!

Sonar works by transmitting a wide, fan-shaped pulse from a transducer and calculating how long it takes for the echo of that sound wave to be read by the receiver on the vessel. Given that the speed of sound in water is known, using basic trigonometry, the echo can be measured to determine the depth of the area being surveyed.

Video showing the importance of line planning.

This video was captured while the hydrographic survey was being carried out. It highlights the importance of line planning.

The visual provided a clear navigation aid for the captain and also allowed for data to be collected coherently avoiding gaps in the data’s sounding grid.

To ensure that errors were minimized while scanning the ocean floor, the speed of the vessel was reduced when scanning ‘a line”. In addition, when the captain had to make a turn to get on a “new line”, the data collection process was stopped altogether and then restarted after the turn was made. The post-processing of the hydrographic data included, applying tide and sound velocity corrections and removing unwanted data called “outliers”, which can occur from incorrect sea floor detection.

Although hydrographic surveying can be seen as a very time consuming process, there is an amazing project underway, Seabed 2030, which plans to get a full comprehensive map of the entire world’s oceans by 2030 using innovative crowd sourcing methods. Learn more about it below:

Seabed 2030 film 
Source: https://www.youtube.com/watch?v=NNF9NSDKo7c

The resulting data from the post processing is called bathymetric data. Bathymetric data is used most commonly to:

  • Update nautical charts. These charts guide mariners and ensures safety of lives at sea.
  • Inform on the effects of climate change, such as beach erosion and sea-level rise.
  • Determine areas for marine protection. The depth and characteristics of the seabed define the habitat for benthic (bottom-dwelling) organisms. It can help to determine where fish and other sea life will feed, live, and breed.

One of the latest capital projects for the Island of Montserrat required hydrographic surveys to be conducted, allowing the island to benefit from subsea fibre optic cable. More information can be found at this link: https://discovermni.com/2020/01/08/marine-survey-for-montserrats-subsea-fibre-optic-cable-project-begins/.

Knowledge and understanding of our ocean floors will help us all to benefit from our blue economy.

Below I share some images showing some special views that I encountered while conducting hydrographic surveying on the west coast of Montserrat. Happy World Oceans Day 2020 to all!

Lavern Rogers-Ryan is a geospatial consultant specialising in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

COVID-19, GIS, Mapping

Feeling the COVID-19 travel blues? Dispel it by mapping your favorite locations around the world.

My youngest daughter, who insists that she is no longer a baby, made up her very own song about COVID-19. It is shared below for your listening pleasure. Even the youngest among us are aware of COVID-19. That to me signifies the impact that has had on life as we knew it.

The Covid-19 Song

For the past few months all that we have been hearing about is the COVID-19 pandemic and the restrictions it has placed on us all. Now with many borders being closed, and travel restricted to many destinations, I find myself thinking about the places I have been around the world. My most memorable places turns out to be where I have been, in relation to my learning about geospatial technologies. Listed below are my 7 most memorable places and an indication of the “GISsy” things I learnt when I visited.

  1. Dehradun, India – Remote Sensing and Digital Image Processing
  2. A Coruna, Spain – QGIS software training
  3. Chaing Mai, Thailand – Emergency Response
  4. Stanley, Falkland Islands – Spatial Data Management
  5. Merida, Mexico – Marine Spatial Planning
  6. Valetta, Malta – Coastal Resource Management
  7. Belmopan, Belize – Census Mapping

This trip down memory lane convinced me to create a simple map to document these memorable places. Shown below is the dynamic map I created. You can explore this map by zooming, panning and clicking on my location markers. I added images of each location that remains been etched in my mind from my visit.

Would you like to create your own COVID-19 travel blues map? Here’s how you can in 10 easy steps:

  1. Log in to your Google account
  2. Go to Google My Maps: https://www.google.com/mymaps
  3. In the welcome pop-up, select Create a new map
  4. Click the text Untitled map to edit the map title and description.
  5. Type your favorite location in the search box. The map will be panned to that location
  6. Click “+ add to map
  7. You then have the options to style, edit or add an image to tat marker if you so desire using the tools in the pop-up.
  8. You have the option of changing your base image. Try satellite.
  9. You can share your completed map with others by clicking the Share button in the map menu
  10. Under “Add people” at the bottom of the menu, type in the e-mail addresses of the people you’d like to share your map with directly, or choose from your contacts. You can select whether the people you invite can edit the map or just view it.

Congratulations on creating and sharing your very own map!

Lavern Rogers-Ryan is a geospatial consultant specialising in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

Disaster Risk Reduction, GIS, Mapping

COVID-19: Using Geospatial Resources to Understand the Potential Impact on Our Communities.

On Tuesday March 17, 2020 with a cancelled celebration of St. Patrick’s Day, Montserrat received the dreaded news of its first confirmed case of novel coronavirus COVID-19. For many of us that is when the gravity of this situation hit home, literally!

The Ministry of Health and Social Services (MoHSS), in their press release (http://www.gov.ms/first-case-of-new-coronavirus-covid-19-confirmed-in-montserrat/), reminded members of the public to adhere to the following risk mitigation measures:

  1. Refrain from public gatherings
  2. Maintain social distance and
  3. Wash hands regularly with soap and water or using a hand sanitizer.
  4. Limit non-essential travel

In addition, to the guidelines provided above, the utilization of geospatial services and resources can help prepare, manage and deliver an effective response to COVID-19.

President of Environmental Systems Research Institute (ESRI), Jack Dangermond in a letter addressed to its users, highlighted some steps that can be followed in order to understand the potential impact that COVID-19 can have on our community. Five are outlined below:

  1. Map the Cases – map confirmed cases, deaths and recoveries in order to identify where COVID-19 infections exist and have occurred.
  2. Map the Spread – Time enabled maps can reveal how infections spread over time and where interventions can be targeted.
  3. Map Vulnerable Populations – Mapping factors such as social vulnerability and age can help monitor risk groups
  4. Map Capacity to Respond – Map health facilities, medical resources and employees to understand and respond to potential impacts of COVID-19.
  5. Communicate with Maps – Use interactive webmaps, dashboard apps and story maps to help communicate the situation.

Communication with maps have already been used worldwide to map COVID-19. Webmaps, dashboards and story maps help to visualize the evolving situation.

The dashboard app below, powered by GeoTechVision (https://www.geotechvision.com/) shows the COVID-19 outbreak worldwide. It highlights infections, fatalities and most importantly recoveries.

In an effort to amalgamate information related to COVID-19 in one location, the Government of Montserrat created the Montserrat Coronavirus Response Data Hub: https://montserrat-covid-19-response-data-hub-montserratgis.hub.arcgis.com/. Within the site there is also a dashboard which gives relevant data on the current covid-19 statistics for the island.

The story map below details the origins of COVID-19 and gives an account of its geographic spread in an easy to read interactive dialogue.

Communication through map-based dashboards and story maps such as these offers accessible information to people in our communities and around the world eager to protect themselves. These tools improves data transparency and helps authorities disseminate information quickly and effectively.

Lavern Rogers-Ryan is a geospatial consultant specialising in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

Electric Vehicles, GIS, Mapping, Spatial Analytics

How GIS is being used to help alleviate “range anxiety” in the use of Electric Vehicles (EVs)

Range-Anxietycropped

The first fully electric car was unveiled in Montserrat on August 16, 2019.  A truly historical moment which has been captured and shared on this youtube link by Montserrat's Government Information Unit: https://www.youtube.com/watch?v=LjENIlHGWBI&feature=share.

At the unveiling ceremony, a number of discussions surrounded the length of time that a fully charged battery would last and whether or not the electric vehicle (EV) would be able to traverse the winding, steep roads of Montserrat (case in point, Forgarthy Hill) on a full charge.

I have recently come to the understanding that this mindset is referred to as “range anxiety”.

The Oxford Online Dictionary defines range anxiety as “worry on the part of a person driving an electric car that the battery will run out of power before the destination or a suitable charging point is reached”. It has been further noted that this is one of the major hindrances to large scale adoption of all-electric vehicles (https://www.lexico.com/en/definition/range_anxiety).

Four major strategies have been implemented to alleviate range anxiety among electric car drivers:

  1. The development of higher battery capacity at a cost effective price
  2. Battery swapping technology
  3. The use of range extenders
  4. Accurate navigation and range prediction

The utilization of Geographic Information Systems  (GIS) however, and its capability to employ multi-criteria location analytics, provides a solution which would help to alleviate range anxieties for electric car users. Moreover, these tools can assist decision makers in developing a strategic plan for the establishment of a well distributed electric vehicle charging station infrastructure.

In identifying optimal geographic locations for new electric vehicle charging stations, a number of factors should be considered.

  1. Location of likely users of electric vehicles. This can be determined by utilizing census data which contains information on age groups and socio-economic information.
  2. Locations which are high attraction venues to the public. This includes identifying the location of places where persons tend to spend a great deal of time such as, airports, ferry ports, government offices, health care facilities, libraries, places of worship, schools, supermarkets and rum shops.
  3. Availability of GIS data based on appropriate themes - Information contained in datasets such as digital elevation models, land use maps, road networks are pertinent in conducting this type of location analysis.

The output would be a map which displays varying degrees of suitability for the most appropriate locations to install charging stations.

Overall, Electric vehicles (EVs) are both economic and ecological vehicles, since they get their power from rechargeable batteries inside the car. They are advertised as zero emission vehicles, less noisy and more cost effective in the long run.

With the utilization of GIS and location analytics, the main disadvantage of recharge related problems will be curtailed, as vehicle charging stations would be carefully located to maximize electric vehicle usage. The end result would be the reduction in range anxiety of its users.

To put the icing on the cake, it would be absolutely amazing if these charging stations can be fully powered by a source of renewable energy, such as, solar, wind, hydro or geothermal. Then we would be truly making strides to saving our planet!

Lavern Rogers-Ryan is a geospatial consultant specialising in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

GIS, Mapping, Volunteering

Becoming a MapAction Volunteer

When the call came for Caribbean volunteers to apply to MapAction, I was keen to sign up. Having followed the work of this organization and the amazing group of persons who work as volunteers, I saw this as an awesome opportunity for me to contribute to the work of saving lives.

MapAction is a non-governmental, UK based charity, that specializes in providing mapping for humanitarian emergencies. MapAction has the ability to quickly gather crucial data and convey it visually, in the form of maps.  With MapAction’s support, aid agencies, governments and local partners, are in a better position to make informed decisions to deliver aid and emergency supplies to the right place, quickly.

Living in Montserrat, with an active volcano and being privy to how devastating disasters can be, I was grateful for the prospect of being able to use my skills in geospatial technologies to contribute to humanitarian efforts during a disaster. My mind quickly raced back to the impact Hurricanes Irma and Maria had on my neighboring Caribbean Islands, in 2017. I wanted to be in a better position to offer assistance if a situation like that – God-forbid – presented itself again.

I therefore, submitted an application to the organization and not very long after, I was greeted with an email inviting me to an “Assessment Day“. Needless to say, I was very happy to advance to the next stage.

Assessment Day turned out to be very interesting. Surprisingly, during the introductory session, I was reintroduced to the Head of the MapAction Caribbean Section, who reminded me, that we met, while he visited Montserrat in another capacity several years before. Moreover, the gentleman who is the Preparedness Lead for MapAction worked in Montserrat briefly on a project back in the early 2000s. I found it to be very fascinating how unsuspectingly our paths crossed again! In addition, hearing the testimony of a fellow MapAction Volunteer, sort of sealed the deal for me. He explained what being a volunteer all entailed and how my skills can contribute to saving lives.

Overall, this interview process was detailed enough to ensure that I was a good fit for MapAction. Amongst other skills, the panel assessed team spirit, leadership potential and the knowledge and application of Geographic Information Systems (GIS) tools and software.

Receiving another email shortly after assessment day, entitled, “MapAction Caribbean Section – Interview Outcome”, I nervously, but anxiously opened it. The words that bounced from my computer screen, read:

Congratulations, you have been selected to join our Caribbean Team! 

This was awesome news and I am absolutely thrilled to be apart of the MapAction family and being able to contribute to society in this capacity.

I look forward to sharing more about the work of MapAction and my experiences in future blogs.

Learn more about the work of MapAction at www.mapaction.org.

Lavern Rogers-Ryan is a geospatial consultant specializing in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

GIS, Imagery, Mapping

What is GIS?

Learning to read, my youngest daughter looked at her dad proudly as she shouted out the letters on his T-Shirt…“G I S!”. Then she looked at me inquisitively and said “Mommy, G I S?” I responded in the affirmative, “Yes sweetie, G I S!”

So, what is GIS?

This picture which I captured on my return flight to Montserrat, overlooking Davy Hill and Little Bay will help me to explain.

View overlooking Davy Hill and Little Bay, Montserrat

At first glance, buildings, roads, vegetation, hills and the ocean can be seen in my picture. GIS, which stands for Geographic Information System allows you to capture, store, manipulate, analyse, manage and present, this type of geographic data.

The unique aspect about GIS is that it allows you to store additional information, called “attributes”, about each feature. For example, attributes of a road may include its name, type, whether primary or secondary and its length. Similarly, attributes of a building, may include the owner’s name, a category of use, whether it is residential or commercial, the material that the building is made from, for example, wood or concrete, the roof type and also the number of floors.

Attribute data can be obtained from a number of sources or data can be captured specifically for your application. Spatial data can be obtained from satellite images, aerial photographs, scanned maps and similar resources. Essentially, any format of a geographical image with location or co-ordinate points can be used as spatial data.

The combination of spatial and attribute data gives GIS the capability of providing answers to complex questions. It is undeniably, the partnership of these two data types that enables GIS to be such an effective problem solving tool through spatial analysis.

To visualize large amounts of information interactively is one of the most attractive and useful capabilities of GIS. To do this, data is extracted and stored in the form of “layers”.  The image below captures graphically how these layers relate to the real world.

                           Representation of layers in GIS

GIS utilizes two primary data types: vector and raster. Vector data is represented as either points, lines, or polygons. So let’s go back to my picture of Montserrat. In that picture, the location of a particular facility, such as the new location of ZJB Radio in Davy Hill can be captured as a point, other buildings can be represented as polygons, along with the entire settlement area of Davy Hill and the roads can be captured as lines.

Contrastingly, raster data is best suited for information that does not have hard boundaries or locations. So again, let’s revert to the picture which I took. The hills and valleys which you can see are best represented as elevation or terrain modelling surfaces. Raster data is usually used to represent this type of data in a GIS. Data in rasters are viewed as a series of grid cells where each cell has a value representing the feature being observed. 

Unlike, traditional paper maps, GIS is fully interactive. It allows you to add new fields of data,  change the color scheme or form of the map, add text and move symbols around. GIS displays allows you to zoom and pan which offers new perspectives and new insights. These and a host of other capabilities give a user tremendous flexibility and power.

GIS is more than just software. It is a system where trained people and methods are combined with geospatial tools, to enable spatial analysis, manage large datasets, and display information in a graphical form.

GIS Day is celebrated annually, read more in my previous blog: https://lavernrogersryan.com/celebrate-gis-day-annually-and-dont-forget-the-cake/.

Lavern Rogers-Ryan is a geospatial consultant specializing in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

Disaster Risk Reduction, Mapping

Counting the Population is as Easy as 1, 2, 3 with the Help of GIS

 

My three year old is fascinated with counting. Probably one of the most memorable instances of her enthrallment was her sounding off “1, 2, 3, 4” as a family of sisters occupied the bench directly behind us in church. “Four, Mommy, Four!” she shouted as she also pointed it out on her fingers. Seen from my toddlers enthusiasm, there is an innate nature in all of us to know “how many?”.

Conducted on average, every 10 years, the purpose of a census is to gather information about a population’s housing conditions, demographics, social and economic characteristics. It includes collecting data like age, gender, education and employment. It helps us to answer questions like: how many children in your country have completed secondary education? Or how many 20-year olds who live in a particular area and are unemployed? Or how many people in total live on your island? Basic information, such as these, are important for the purposes of planning, development and the improvement in the quality of life for a territory’s citizens.

Counting the population of any country, regardless of the size, can be seen as a daunting task. Geographic Information Systems (GIS), provides a platform, however, to enable data collectors to be more efficient in locating buildings and ensuring that this intimidating work is made a lot more manageable.

In its last count of the population, the Montserrat Statistics department enlisted the use of GIS in the Montserrat 2011 Population and Housing Census to ensure that the enumeration data collected was as accurate as possible. Some visual representations of the data were produced, such as the map below which shows the usual resident population of 4,922 based on gender (male and female) and region (northern, central and southern).

Source: http://www.gov.ms/wp-content/uploads/2011/02/Montserrat-At-A-Glance.pdf

The leader* and the team from the statistics department had a clear vision of how the country should be divided in terms of Enumeration Districts and Areas. Some areas were demarcated using naturally occurring features on the landscape, such as ghauts and mountains, and others were demarcated using man-made features like roads. A total of thirty-six enumeration areas were created and detailed maps were prepared for each area. This allowed the areas to be divided into manageable sections and allowed the data collector, with training in map reading, to be more efficient in canvassing the area. The demarcated enumeration areas now provide a base for the collection of additional data and allows for easy comparison and correlation of datasets in preparation for the 2020 round of censi.

The Montserrat 2011 Population and Housing Census benefited from imagery, which was recently collected in 2010 (see my previous blog at https://wp.me/pa7Lux-7o).  The one-year time difference was considered negligible, allowing for a certain level of confindence in the accuracy of the maps, which were produced. Any missing building footprints were drawn on the map while the area was being canvassed, and then later updated. For any future census activity, access to current imagery will play a huge role in its success. Current imagery can be analysed using tools in GIS which will help to determine changes since the last count. One special way of determining change is to use image classification techniques and compare with previous imagery. Utilising this method, new buildings footprints can be identified and quickly extracted using GIS tools and models.

Furthermore, a census provides data, which is critical for disaster risk reduction. Knowing the spatial distribution of the population and its demographic details is key in increasing a Government’s ability to take appropriate action and reduce the loss of human life. Population density maps provide an outlook to assess risk before and the quantification of a population affected after any disaster.

*This post pays tribute to the late Mrs. Katrina Ryan who was the head of the Statistics Department at the time of the Montserrat 2011 Population and Housing Census in Montserrat. She had an endearing passion for the accuracy of statistical data. May her soul rest in eternal peace.

Lavern Rogers-Ryan is a geospatial consultant specialising in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.

Disaster Risk Reduction, Imagery, Mapping

Satellite Imagery is A Powerful Visual Aid in GIS and Disaster Response

The earthquake events of August 21, 2018 which shook Venezuela, Trinidad and other neighbouring countries (https://www.usgs.gov/news/magnitude-73-earthquake-venezuela) reminded me that not all disasters can be predicted or come with a warning. Videos which showed the impact of the earthquake quickly filled my social media timeline, causing me to reflect on the training I had undergone as project manager for the International Charter Space and Natural Disasters (https://disasterscharter.org). This organization, once registered with, provides a series of support through the use of satellite imagery to assist in the aftermath of a disaster.

Satellite imagery is a form of remotely sensed data with proves useful in the occurrence of an unforeseen event and provides a powerful visual aid when utilized with a geographic information system (GIS). Disaster risk managers are better able to assess their region’s risk when they are able to compare pre and post disaster images.  This type of analysis enables relief workers to identify changes in the landscape, such as buildings which are no longer standing and roads which are obstructed. It is an efficient way to identify damage and conduct rapid impact and needs assesments. GIS supports the use of satellite imagery to locate damaged facilities, identify the type and amount of damage and begin to establish priorities for action.

As satellite sensors improve, satellite imagery is becoming more useful. One of my favourite places to explore satellite data is the USGS Earth Explorer Portal (https://earthexplorer.usgs.gov/). It provides an interface where one can search the available sensors to see the data that is available for a particular area of interest. The advantage of the USGS Earth Explorer is that it houses data from the Landsat Programme which has a 40+ year track record of image acquisition. It allows for free downloading of data over chronological timelines while providing a long list of satellites to choose from.

Additionally, capturing my interest for hours on end is the USGS Earth Now Viewer (https://earthnow.usgs.gov/observer). This viewer is truly remarkable as it shows the position of the Landsat sensor in real-time. It also gives a visual of the satellite images being collected when the sensor scans the earth.

The Landsat Program began with Landsat-1 in 1972 and Landsat- 9 is planned for 2023. Over the years, Landsat has enhanced the number of spectral bands, spatial resolution and spectral resolution. Landsat 1-3 sensors collected data in only 4 bands and at 60 meter resolution. Over time, this has improved, as Landsat 8 now collects in 11 spectral bands varying from 15 meter to 100 meter.

The Sentinel Satellites of the Copernicus Programme also provide free satellite imagery which can be downloaded at the Copernicus Open Access Hub (https://scihub.copernicus.eu/dhus/#/home). The Sentinel-2 provides some improvement to the Landsat data with sharper imagery of up to 10 meters. Sentinel-2 monitors more frequently with a revisit time of 5 days and captures land changes in 12 spectral bands, each ranging from 10 – 60 meters pixel size. The USGS Sentinel2Look Viewer (https://landsatlook.usgs.gov/sentinel2/viewer.html) allowed me to browse through some sentinel-2 imagery. I found relatively cloud free imagery of Montserrat (shown below) which was acquired on 12th April 2018. This is a plus as cloud-free imagery is not always available due to our location and climate.

With the assistance of a skilled technician, satellite imagery can be utilized effectively in disaster management especially during the response stages. By combining spectral bands and performing image classification techniques the capabilities of remotely sensed data can be fully utilized in disaster management.

 

Lavern Rogers-Ryan is a geospatial consultant specialising in disaster risk management and recovery. She is currently head of the GIS Centre within the Government of Montserrat. Learn more about geospatial services in disasters at www.lavernrogersryan.com.