A map is a symbolic representation of selected characteristics of a place, usually drawn on a flat surface. Maps present information about the world in a simple, visual way. They teach about the world by showing sizes and shapes of countries, locations of features, and distances between places.
A good physical or digital map should be clear and easy to understand. The colour contrast and symbols should be simple and easy to understand and interpret. The style as well should be very simple without elements of complexity.
Most maps contain the same common elements: main body, legend, title, scale and orientation indicators, inset map, and source notes. Not all are necessary or appropriate for every map, but all appear frequently enough that they’re worth covering.
Title – This is the description of the map and what it contains. The title should be short and concise.
Legend: This shows what the symbols on a map mean.
The scale is the value of an actual distance on the map. It can be measured like about 1cm on the map is to 1km on the ground. This may not be appropriate if the coordinate system used does not preserve distance across the map’s extent.
Border – These are the edges of the map.
Orientation – This explains what direction is north (up, down etc).
Graticules: These are lines showing parallels of latitude and meridians of longitude for the earth. Graticules can be used to show location in geographic coordinates (degrees of latitude and longitude)
Source Notes: This tells us where the map comes from and who produced it.
A good map establishes a visual hierarchy that ensures that the most important elements are at the top and the least important are at the bottom. Typically, the top elements should consist of the main map body, the title (if this is a standalone map) and a legend (when appropriate). Ordering your maps right makes it easier for the person who will read the map to glean information in a short amount of time.
Difference between drone surveying and manual land surveying.
Surveying is a means of making relatively large-scale, accurate measurements of the Earth’s surfaces.
Land Survey involves the scientific process of measuring the dimensions of a particular area of the earth’s surface, including its horizontal distances, directions, angles, and elevations. Artificial structures, such as a road or building, may also be noted during a survey.
A Drone Survey refers to the use of a drone, or unmanned aerial vehicle (UAV), to capture aerial data with downward-facing sensors, such as RGB or multispectral cameras, and LIDAR payloads.
What are the Differences?
DRONE SURVEYING
Capturing topographic data with a drone is up to five times faster than with land-based methods and requires less manpower. With PPK geo-tagging, you also save time, as placing numerous GCPs is no longer necessary. You ultimately deliver your survey results faster and at a lower cost.
Drone maps created using good quality drone equipment, careful flight planning, commercial grade GPS ground control points and commercial grade processing software can potentially be accurate to around 2-3cm horizontally and around 5-6cm vertically.
Compared to other surveying methods, drone surveys can be completed in less time, as drones are able to cover large areas of land within a short period.
Typically, drone surveys can produce high-quality photographs and video recordings in a couple of hours.
TRADITIONAL LAND SURVEYING
While drones are agile and reliable, they can’t deal well with high winds. Drones are lightweight and small; high winds can blow them off course and make it impossible for them to get consistent readings. This is unlike traditional Land surveying equipment and instruments which are tethered to the ground.
The brick-size batteries used by drones are heavy and can get used up quickly unlike total stations which have better battery capacity. Although “the newer the model, the stronger the battery” according to Our In-house GIS Analyst, Mr Boluwatife Williams.
Traditional methods involve staff manually traversing a site to collect data points, whereas drones can collect this data with staff far away from potentially dangerous areas.
Manual surveying methods are incredibly accurate, the accuracy of the drone surveying is only threatened if the pilot is a greenhorn.
Geological Maps are special purpose maps that show the geological properties of land – rock types, rock age, bedding planes, shale, coal, and other naturally occurring phenomena.
Geo Maps can be used for many different purposes, including assessing ground-water quality and contamination risks; predicting an earthquake, volcano, and landslide hazards; characterizing energy and mineral resources and their extraction costs; rock formation and types present; land management and land-use planning.
Information obtained from geological maps has been used for both private and public decision-making processes. It helps in the siting of highways and provides information about the structural deposition of rock types in the proposed area to determine what kind of construction risks can’t be taken.
FEATURES OF GEOLOGICAL MAPS
Features can include types of rocks, faults, minerals, and groundwater. From studying a geologic map the user can better understand possible dangers like the potential for floods or earthquakes and help locate important deposits of energy resources, such as water, oil, natural gas, and minerals.
For example, an extensive geo map of Nigeria will show where several types of natural resources and minerals can be found. Geoinfotech’s Geostore contains several examples of geological maps including cities such as Lokoja, Jos, Enugu, etc.
5 USES OF GEOLOGICAL MAPS
Geologists measure features where outcrop or surficial materials are exposed, then infer geologic contacts based on these measurements. A variety of lines, symbols, and text convey information in the form of a geologic map.
Measurements taken at the surface are used to predict the location of geologic units and structures at depth and these predictions are shown on cross-sections.
A geo map is a major tool for communicating geological information to other geologists and the public.
Geological maps are useful to paleontologists because they indicate the age of the rock bodies in which fossils and other discoverable historic items are found.
Colors are used to showcase and differentiate the different features from each other.
Geo maps provide information for a better understanding of Earth. By studying geologic maps, users can identify potential natural hazard areas for floods, earthquakes, landslides, etc. These maps can also provide data on important deposits of energy resources such as oil, natural gas, and coal
Lagos takes new survey mapping, following the APPSN housing scheme, changing the measurement parameters that affected the Certificate of Occupancy (C of O) issued 40 years ago.
Now the physical location of the property to a small degree has been adjusted and surveyors can thereby take accurate measurements through different technological equipment.
The chairman of the Lagos chapter, Rafiu Adaranijo, Private Practising Surveyors of Nigeria (APPSN), a subgroup of the Nigerian Institution of Surveyors, made it known during the yearly general meeting and Luncheon, themed: “Professionalism and Longevity: Addressing the Dimensions of Wellness and Personal Health,” advised residents to seek information on the new Lagos survey mapping.
He also went further saying: “They remapped the whole of Lagos, using the new technology to solve problems like location shift as a result of a new owner wanting to do a change of title”.
“We realized that the state government has improved its mapping and changed the coordinates.
“That is why we created a new Continuously Operating Reference Station (CORS) in Lagos State and with that, there is no way we can use the old instruments.”
Rafiu said the procurement of instruments was a challenge. And so the association’s partnered with instrument vendors to acquire RTK Multiband GPS (Emlid). Enabling receiver for members to pay in installments.
“This instrument procurement scheme to date has about 45 subscribers, while over 120 surveyors are currently accessing the CORS service even from the Office of the State Surveyor-General,” he said.
Property owners were urged by Rafiu to seek clarification from surveyors on how to reassess every mapping activity done.
Speaking on the proposed Surveyors Estate, he said, over 520 practicing surveyors in Lagos deserved decent and affordable homes, adding that the project would take off before July.
Rafiu said the association was adopting measures to ward off quacks while appealing to Governor Babajide Sanwo-Olu to ensure surveyors are engaged in all projects.
Summoning the attention of all tiers of government, Rafiu said partnering with surveyors in projects will inhibit building collapse and construction failure across the nation.
Well, for the time being, the guest speaker and Associate Professor at the Lagos University Teaching Hospital (LUTH), Dr. Okezie Kanu, advised surveyors to shun isolation.
And that embracing interactions and engaging in regular exercises to improve mental health and wellness.
He also said mental health is the foundation of all wellness, hence, professionals should remain healthy physically and mentally for efficiency.
Earlier, the National President of the Nigerian Institution of Surveyors (NIS), Dr. Oluwamotemi Olukayode, represented by Mr. Adewebi Vincent, encouraged surveyors to be the best they could be health-wise and emotionally.
He also makes a closing remark saying, “Your greatest asset is yourself. That is why you must take care of your health,”
In tackling insurgency using drone technology. The Surveyor-General of the federation Abdul Ganiyu Adebomehin, while addressing journalists in Abuja yesterday, says his office has been able to purchase the latest drones technology and other equipment used in mapping and surveying.
While also calling on other surveyors and non-surveyors outside to partner with his office on this, he said: “we’ve used drones to map 1 in 500 and 1 in 1,000. Where you can see everything clearly, there’s no ambiguity in everything we do”.
Further addressing how his office is tackling insurgency using drone technology, he said the drones could also be deployed in the fight against insurgency raving the country by tracing, identifying, and eliminating bandits and insurgents.
This he said thus:” We can also use this to tackle the menace of insecurity, the insurgency, and banditry that is disturbing us.
We can use this at about 15 – 20km away from the den of the bandits to carry out surveillance on the bandit’s hideouts.
We can also use this to track them if they decide to move away from where they were, you can tell the system this picture you have on, track them. So, there is no route for anyone if we were sincere to face the battle”
