Geographic Information Systems (GIS) concepts simplified

Ilana's today we actually going to look at the GIS concepts simply find now we don't know why so many learners have such fear for GIS and in fact is can be one of the easiest sections available in geography so yes I must say that we get lots of material concepts etc as ArcGIS which gives us long definitions I mean many books you see the wrong definitions appearing which are professional GIS books but we can simplify it in order to what we need in grade 12 so I'm gonna go through this important thing and only just the concepts that is stipulated in our exam guideline in fact and let me go forward get my little button down here again you know that this is the area that we're going to cover anything your guideline all right all these concepts from this where we look at GIS many of these concepts I'm not gonna go through a whole list because I will be dividing them in each slide many of these concepts you've done already alright with a few like data standardization etc that is maybe new formatting but we will simplify in fact if I go forward I will find that the longest definition is and the more complex definition is GIS itself okay that is your very very I would say not even convinced by most complex that we are from the others and it's very simple so let's look at me do need to look at what is G is of course we know it's a computer system alright that's what uses programs use a computer system which captures stores checks and displays data related to positions on the Earth's surface so when we look at this we know we have to use a computer for for this we know it captures data all right when we do it to from remote sensing we capture data or we capture data from any other data source example number of people or the crime rates in different areas you can get it from statistics so you should can store the data you can check it you can display it and you can add it up like data layering you learnt you understand you want to look at where is the best place to to put your farm you get a data layer of fertile land you download it you use your computer then you get a data layer of flatland and you get that data also and then you get a data data on water supply and you put all the data together and you will find that he must farm there okay because it's the most fertile land the flat land etc okay so it's doing all that and as you can see here all this information coming into computers with his curious apps maps analysis software all is used in data so this is a fairly good and comprehensive definition of GIS so when we look at G is we look at Geographic that's all right geographic information systems that what it means in place on earth spatial where something is on earth you got it colorless right so we have to look at space sure first the location etc okay information that's geography information systems this is data for facts put together you can layer them one on top of to make a double graphic map makes sense okay when I put things together all right we're spoke about where you're gonna farm you understand makes information more useful example the number of schools using a road for congestion all right data is using GIS can be can be using a following we can use the maps from a load sensing spatial resolution spectral resolution I come to these concepts later so tip used in so many ways it's information all right which is data which is layers like for instance road networks etc and the last thing is system integrated interrelated information using data to make it mean something right that's a system that will put it together now okay you've got data as I said let's go back to example you got out of fertile soil you can you just use that data to then say I'm going to found it you also need other data for Ag land water supply transport and all of a sudden if you tell relate that data and put it together it becomes more useful you mean something that's a better area to farm or back the area to put in my factory so this is what it is geography Geographic spatial information is data and systems that put the information together alright that's the simplest way that I could put in this GIS concept so you can see it in the top here computer system capturing storing checking this plane but data related to the Earth's surface alright and this is how we do it okay so general definition now let's get to the other concepts remote sensing you can see the satellite here you can see the aeroplane here it's taking images of the earth okay can you see taking images of the earth from a distance now watch out learners this definition is updated now we say getting information about the Earth's surface from a vertical distance all right this has changed from a vertical distance or from above so please note learners you must be specific on that most things now tell you it's just a distance so that has changed now many of us just focus on this watchout learners if you say it is getting information of the from about the Earth's surface from a satellite then you give me an example you must say vertical distance above if you want to give an example then it's satellite because not only satellites can take images there's other examples aeroplanes hot-air balloon all these things take images of the earth all right from a vertical distance so anything that takes from a vertical distance can be considered remote sensing okay so we've got that concept let's move to the next one a pixel a pixel all right now what is a pixel it's the smallest unit of digital image or graphic that can be displayed or represented as a digital display device okay so it's a smallest it's one of those pixels made together make the picture okay so the more the pixels all right the clearer and the clarity and the quality in terms of clarity the images are better okay so if say Grannis it refers to digital grid cells we'll accept it all right I gave you the full definition but I'm showing you how it can be simplified so this in a picture is a pixel can you see here this is now all these little pixels come together and they make a picture alright and it has to be it's an image so it has to be your raster data working with images photographs and that is why some people both woo my camera is a 16 pixel and each year it went up it's a 32 pixels okay make a pixel alright meaning that it takes clearer pictures okay so you must have heard that before my commands got so many pixels in it okay so the clearer the image if there are more pixels alright now let's go further resolution refers to the clarity of the image let's look at these ones this is pixels are very big a and it's not much so it's not very clear let's go down where it is smaller so the resolution is higher in this one therefore you can see the picture is far more clearer than this picture because it has a higher resolution please note I know sometimes I see this question which has a high resolution the topographic map on auto photo the topographic map does not have a resolution all right it's not an image it's made all right points lines and polygons okay so the image makes the bit it determines the pixels all right so the more the pixels the clearer the image this is what we picked up but just now it's a first-rate clarity of image - there are some wrong definitions this is fine okay and the clearer the more the pixels that we have the image okay took another one spatial resolution alright refers to the detail of an image determined by the size and number of pixels all right okay the detail you can see more detail you look at this alright less pixels okay you see it but you don't see the full detail yeah you see a better detail how it bends you can't see all that yet alright can you see the real bending of it yet that little piece here but as the pixels improve and L as the spatial resolution improves more details so it's not just about clarity it's about detail okay so I can see something about clear but I can't see the detail that's shown in this case can you see it alright there's a little more detail from your head today all right you can see even ya can see the little bend you know that is why we see people go and they buy you guys more than me I'm just a poor teacher you buy this television mooches UHD and a dremel now it's le HD whatever and you see whoa I can see the wrinkles around the person's eyes brilliant high spatial resolution okay that gives you a better idea about this okay now these examples of just giving you alright the definition is this detail of any week determine - size and number of pixels but even if you know detail of an image already to give you as a shortage it is still fine I would still prefer send determined by the size and number of pixels like example the size of a smallest feature can be detected by satellite sensor and displayed as a satellite image it can even smallest of features you know you can see a dot I'm taking doing remote sensing etc where you pick up that satellite sensor and as you shoot you can get right into that it's a person that's lying down the ice whatever you can actually see brilliant all right the next one that we look at is spatial data it refers to information about the location and shapes of features okay example your current reference that is spatial data we want to know exactly where something is located 25 degrees 15 minutes 30 seconds South 24 degrees 18 minutes 16 seconds East that is location that is spatial data also you can see the shape of this okay so if I had a grid here and special I had my seconds and minutes I would know exactly where it's located and I would also pick up the shape of it so spatial location GIS okay let's go further attribute data now this is further information about the area of feature in addition to its location so it's descriptive data and reality learner's every day we dealing with this your teachers in class I'm going to use a golf course I know it is to conference is located I think we've got the good reference if I have the information to a graphic map whatever now I want activity data further descriptive data about this place example I state to the temperature if I've got a temperature map it will give me now what else can I see on this photograph it has a lot of green grass they are ponds or lakes they are pikas can you see it all right how many holes are they I know this 18 of course they are trees on this golf course can you see that is describing the golf course so the golf course is located at so many degrees minutes whatever South and East and what else do we look at it what describes it okay all the different features that is asked to be data it is descriptive data all right oh it gives you further information about an area in addition to its location good definition but if you want it just simply do what it actually does descriptive data about a feature okay right let's go on spatial objects you've done this before all right I know for many years from Britain onwards you've done this points which can be your trig beacon your spotlight this symbols like Church whatever those are your points then you've got lines which can be the railway line your rubbers all right roads those are line features and then you got polygons sailing like maths all right your features that irregular an enclosed okay like the dam yeah built-up area cultivated land all right those are polygons and these are the three spatial objects that you have gotten before but we actually going through all we're not taking any chances now where is spatial objects used it's used on a map correct on a topographic map you see here you'll see all these secondary roads yeah all right there is a dam yet the road would be a lie the dam will be a polygon you'll see cultivated land here that's your polygon all right you'll see the dual reservoir that's your point this farmstead is a point can you see it right there's your spot idea which is your point there's a dot thing so we know polygon line point all right that is your special objects can you see it super learners vector data little refers to representation of a geographic feature using points lines and polygons so vector data is not an image it's it's a representation vector Delta beautiful you'll always be using it is your topographic map can you see as I showed you before there's polygons use them like your damn your cultivated land there's lines like your roads there's lots a points like your your reservoir so all these being used not everything needs to be used at one time all right but as long as you've got these things is vector data topographic map remember that you will not forget to the name if you remember that topographic map vector data raster data is a represented representation of a geographic feature using rectangular grid cells also referred to as pixels or picture elements beautiful is your topography not your topographic my to apologize is your auto photo map all right it's an image that is why it's using pixels it's using grid or also known as blood cells all right but the best is the word pixels okay and therefore it becomes an image or a picture that's your last the data so vector data is representation points lines polygons all right it's like a topographic map raster data is a picture okay like your auto photo map alright I'm messing up this one let me go on then data layering yeah we put different types of information or data layers are projected on to one another or we can say it's placed on top of one another so we take the thin data layers like one gotta lay could be dreamy or you're rivers etc another data layer could be infrastructure roads and things or transport alright another day data layer could be vegetation and you take all those data layers and put it together but you put them on top of one another alright don't forget to put them together and what do you have your best example of data layering that you will be using even in the final exam is your topographic map can you see different layers there's a river straining there's the cultivated lands agriculture can you see your own networks your transport all put on top of one another in order to create a topographic map this is data Larry don't go too far I know there'll be a lot of examples a lot of scientific examples you stick simply you know please on top of one another is a topographic map ok let's go on then data integration refers to the combining of two or more data layers now data layer data integration you see is it that combining what's the difference remember in data layering you putting layers on top of one another alright in data integration yes you will put layers on top of one another but it doesn't necessarily have to be on top of one another it can mean different things you can take figures you understand and bring them together and work out where is the highest crime in an area okay how many robberies are me robberies are they you can bring statistics like that and put it together I stopped putting it on top one another so data integration data living is one type of data integration okay and it gives you an example here you get satellite data data from digital alright other from dust that you're gonna use that you're playing from people all right you're gonna use tables read digital maps and eventually you're gonna take all this put them together and make this map oh you're gonna get figures how much hijacks within in all the areas hijacking how many robberies were they I mean house breaks they work you're going to put all the data to determine which is the safest area that's also data integration not putting it onto one an other or top of one another okay you understand the difference between those two then the five components I knows oh not a gate alright but it's part of how much Excel curriculum let's just go over a little bit you know it's hardware its software its data its people its organizations with an S okay it's a bag that's a process and methods okay so let's look here if we don't have the hard way the computer etc we can do GIS okay then if we don't have the software like the earth program etc a computer is not just gonna get it like that we need software alright to be used with the hard way okay then the day time the information that we're gonna use like those statistics I told you we need to get information about where's the crime are much hijacking was day if you don't have the information you're not going to be able to do G is also then you need the methods by a data layering data integration whatever okay all that and eventually if you don't have people to do it who's gonna do it I don't know the future maybe computers will do all these things I don't know but now even computers have to be designed by man okay so oh by humankind I do apologize I'm being chauvinist there it's not just man it's humankind all right so all these things work together to create the gis all right that's why it's five important components let me know stuff you will see the word sources of information and you say what is this is just basically telling you will we get sources of information from for GIS so do not get confused I know even some of my learners and IP sources of information are what are they okay look at this they have general sources for spatial data that's what we're dealing with spatial data location and descriptions of the locations etc hardcopy maps that you have can be used aerial photographs that use wherever photographs turned into your auto photo maps remote sensing imagery that you get from the computers point data all right samples from surveys pre-existing digital files can you see information that exists all right samples that somebody took as a survey you want to use that to determine okay existing map sometimes refers to an analog Maps okay most popular source of GIS project all right these maps that you use so it's where we get our information can be from research can be from other digital information that's already been stored whatever as resources and we can person based on this learners look at what sources they talking about they okay this sauce was taken from from a survey done you understand on an area so you if they ask you the type of source of information then you talk about surveys okay and there we go again I must mix it up okay apologies for that learners let's go next one data manipulation okay yeah data is processed or converted making it easier to use all we can say more useful information okay that's a diffusion easier to use it's processed it's converted it's changed so it makes it easier to use all right let's take this we talked about example here correcting distortions sharpening definitions of the picture all right this had many lines we don't really clearly see the shape the lines crossing etc alright what we've done here we want to see the outlines we've removed all that and we just have a map and now it's clearly seeing where they meeting yeah we don't know you're right it looks as if they're meeting totally their lines running across so we made them we corrected that distortions in this all right now look at this okay we made it more useful we use different colors etc okay to show that this lighter color is three hundred two hundred and six to three hundred forty six meters okay the very light color is zero to two hundred five meters in terms of elevation can you see what will be we manipulating the data to see the imagery okay so this is what happens yeah all right proceed to convert making it easier to use okay remember there will be slightly differences if you use different words wrong you mean the same thing is fine and all these are concepts data integration involves combining layers of information I think I've repeated this okay creating and making it more useful there's another definition combining lace or Telly's making information more useful okay but I did cover this before but I think the slide is not listed because we've got another simple definition okay let's look at the next one buffering now watch out learners if you want to get your full 1 mark I know so but it's one mark why am i happy to work so much always even a definition for one mark you must give the full definition many learners right it's a demarcation of any area it's so veiny around what what limitation ok so you have to be specific it's imitation of an area around a feature oh you couldn't right location now I put geo graphic in in brackets that's the correct but if you wrote it's a demarcation of an area around a feature you got your mark ok don't write around an object please an object is my coffee mug here alright that's an object you must say feature or you can say location look at this alright this is a road or a river so buffering around a line alright maybe this was a river and it could flood therefore we buffered and said no development here this is buffering around a point ok where you actually look at maybe it's a nature reserve we don't know alright whatever but Nature Reserve beginner net maybe school ok and you want to know from which area do we have the feeder zone to come to the school you know feeder areas all right this is buffering around a polygon which could be your Nature Reserve now you buffered and said no development around this Nature Reserve alright so we stopped development yet we keep this for conservation then there's various points where you can above him so is demarcating an area various things to stop flooding to stop this just that you understand just of urban development okay but it's demarcation of an area around a feature o location then query what is that of course you query is ask okay but let you ask and answer questions about geographic features and they attributes and the relationship between them quite a long money even ask questions about geographic features okay attributes is referring to their descriptions about the data and how they related okay now let's look at this I'm just gonna make hypothetical system here all right I want to know using my GIS all the data that I have etc I want to ask which area is a crime hot spot okay so I'm going to look at the features of the area and their attributes or there's this area yeah this area yeah whoo this greasing here hardly any crime here hardly any crime here because my query is crime where is it Ryan eyes and suddenly I find yeah woo lots of murders and lots of break-ins lots of this I'm sorry I'm using the crime thing as an example but I all the time but I used it before also this is a hot spot I can mark that off based on firstly my query and then looking at all the features and descriptions in terms of getting my answer okay statistical analysis is interpreting various forms of statistics in relation to a query that might not be obvious simply by looking at a map okay so yet it involves figures etc okay so let's look at it my query here is I've got different suburbs all right I've got town Hill I've got mountain rise I got Priscilla alright I'm pronouncing that correctly my apologies and I'm looking at two things car hijacking and housebreaking all right and I'm gonna see which one is having a higher crime rate okay further the topographic map is not going to give me that so therefore I look at statistics that's why it's not obvious by looking at a map okay I have to look at statistics can you see statistical analysis and then analyze it whoa yeah it's 80% in town you 11.3% alright yeah twenty three point four percent okay for that place all right car hijackings can you see one hundred hundred and seventy seven point eight percent okay thirty six I can work out which place has a higher which place is lower and then determine where my crime rate is high or low can you see using figures statistical analysis nothing is difficult in GIS then data standardization transforming a variable into a more analytical and useful form okay making data more interchangeable lots of heavy words there let's make sense of this take Maps in South Africa let's say each map made as different symbols some maps alright for cultivated land they had circles okay some maps had little lines like that some map said crosses okay then for each map you'd have to have own reference right but what if you this is the most correct one okay but what happens yeah if you decided to create a reference all right and all South African Maps will have little green lines for cultivated lands national roads will be a red and blue all right railway or lines and station will have that symbol what have you done you have standardized the data I don't need a topographic maps of South Africa I don't even need to have the reference day if land is know if people know the reference all right take it just look at see those little beam lines is cultivated land all right thick red line is your National Road this is data standardization your Maps have data standardization don't get into any other complex things so we taking a variable this could be a variable if we use different symbols and into more analytic and useful so we took this variables with each one may have different symbols for cultivated lands and we made a common one which becomes more useful and more interchangeable you understand it can be shared anything okay data standardization your topographic map data sharing okay a GIS system that allows others to use your data I said space your non facial but if you said allows others to use your data alright I think maybe you should mention your spatial and non-spatial because it would be odd just use your data means you've got data on your phone twenty megabytes you understand and somebody else uses it okay so allow somebody else to use your spatial or not now cloud its its Tandy he became use it understand the Internet okay allows you to share information at this stage we find when when people are not able to go to school due to various things like covert etc over nineteen this information you shared through zoom through whatsapp isn't it it allows systems that allow you to share data okay data sharing data security refers to restricting the availability of data to certain people or organizations like here we've got a very difficult one where we look at how this data gets sauce it goes to web client its they can only get the information all right let's take something so common let's leave all that all right let's take this computer okay you may have data in here alright you may give people access I'm just using not totally the best example but it makes you understand it better all right you may allow people to open that up with a data as a code on it of that computer has a code honey you open it up and you say oh you may put codes on different articles that only some men send people the code from your computer to say this is the code you open you think it's confidential information alright so they're gonna think the information but they won't be able to open it if you don't give them the code gets data security your cell phone you know some of you zip around with all the fingers or you type out something when you put your finger somewhere or you put your face and that's what you can open all right so certainly they put an open it alright so data security and must know your parents can open it don't think they don't know Tia yes all right paper GIS people get so confused with this lens it's something simple let me just use this alright in this past paper what happened was he said use the three data layers below it was taken from the map the three blocks all right and make a paper GIS all right so this represented your Ray this represented your Nova and this represented the contour lines all right so what you do you to take all of this and put it together yeah it was there to determine where's the best place to put a factory so obviously I mean for transport river for water supply contours in terms of flat land and you have to put all that together to create a paper das so the word seems more complicated than anything else now look what you have to do for this question there is this one here all right the rain you put it exactly where it's supposed to be then you just copied it from there then Enola can you see that you took it and put it here exactly where it was the contour lines exactly where it was and now you see Oh places like a su hija de River near the river line and it's generally flatland good place to put my factory so you actually do the paper GIS to sort of T query the query was where's the best place to put your factory yeah it was near the water the other way Liana Rama learners GIS is simple you just need to consider it yourself all right people get confused buffering I say we do buffering we determine how far from the school can learn has come to that school isn't that lovely your feeder area you understand okay you look at various things so GIS is and daily use through your computers through your cell phones you always getting data you want to do a project there's a geographic project to get a map can you go and get data you understand from different sources so GIS is a pleasure to have all the best lettuce keeper [Music]

Channel: Geography with Dave

Views: 25,883

Rating: 4.8912621 out of 5

Keywords: GIS, Remote sensing, - Resolution, pixels, Spatial resolution, Spatial and attribute data, Vector and raster data, Spatial objects, - Points/nodes, lines, area/polygons, Concept of layering of information, Components of GIS, Sources of information for GIS, Data manipulation and analysis:, - Concept of data manipulation, data integration, buffering, querying, statistical analysis, Data standardisation, Data sharing, Data security

Id: ybXfc30a5XM

Length: 40min 50sec (2450 seconds)

Published: Thu Jun 04 2020