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Chapter 4 & 5: GIS Database & Vector Analysis. Chapter Four: GIS Database 2.

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Presentation on theme: "Chapter 4 & 5: GIS Database & Vector Analysis. Chapter Four: GIS Database 2."— Presentation transcript:

1 Chapter 4 & 5: GIS Database & Vector Analysis

2 Chapter Four: GIS Database 2

3 What is GIS database? Records (formed by rows and columns) Descriptive information about the geographical features A spatial feature consists of a unique record in the database; each distinct feature is defined by unique ID Clicking on a building, the detailed information are shown in the pop-up table 3 Source: www.onemap.sgwww.onemap.sg

4 Working with Tables – Data Type Field & Data Type Different fields will store different kind of values Choice of field type to match with type of data NameDOBAgeHeightSocialSecPicture George Young15/2/1980321.70S8067789J D:/Picture/george.jpg Text/StringDouble Short Date Text/String Hyperlink 4

5 Geospatial data (textual & geometry) e.g. Building 5 Attribute Data Attribute Data Spatial Data Spatial Data GIS manages both spatial & attribute data Attributes Spatial

6 6 BranchRefBranchStaffNumManagerPostcode A0023Novena200Justin Bieber478103 T0247Clementi182Stefanie Sun393910 B0021Bedok126Simon Cowell637456 Table 1 StaffNameJoinDateDeptBranchRef Barb Simpson18 Dec 2002DairyT0247 Randy Jackson29 Jan 2004DairyB0021 Tanya Chua4 Sep 1998VegetablesT0247 Table 2 Which is the common field you can link table 1 and table 2? StaffNumPostcodeBranchRefManager Ans: BranchRef ***Multiple tables can be linked together based on their common keys. Table 1 and table 2 both consists of field named BranchRef. After linking/joining both tables, you would be able to find out which staffs managed by respective branch manager when clicking on the branch location on the map. Branch Locations

7 How many tables would you need to design if you have 3 layers (i.e Building footprints, Roads, Landlots) represented in different form of geometries? 1 table 3 tables 2 tables Ans: 3 tables None of the above answers ***It is not possible to store different geometries within a table. In this scenario, buildings’ layer has its own table (as do other layers). 7

8 Chapter Five: Vector Analysis Proximity Analysis, Route Planning 8

9 Data Analysis – Vector Data In reality, we deal with geographical features everyday. Right at the moment you wake up in the morning, you start to plan your schedule of the day. You might think of going from location A to B, then from B to C to D; what mode of transportation you will use to reach the destinations; what is the estimated duration to reach the destination and so on... GIS helps you to answer these sort of questions more efficiently and visually. To answer the geographical-related questions, you can utilise GIS to analyse single geographical layer or multiple layers. Firstly, you need to understand the Spatial Relationships formed within geographical layers. In reality, we deal with geographical features everyday. Right at the moment you wake up in the morning, you start to plan your schedule of the day. You might think of going from location A to B, then from B to C to D; what mode of transportation you will use to reach the destinations; what is the estimated duration to reach the destination and so on... GIS helps you to answer these sort of questions more efficiently and visually. To answer the geographical-related questions, you can utilise GIS to analyse single geographical layer or multiple layers. Firstly, you need to understand the Spatial Relationships formed within geographical layers. 9

10 Spatial Relationship You can store many geographical layers within GIS system; different thematic layers; both vector and raster data. Each geographical layer has a unique relationship formed with other layers. Example: Roads connects from east to west, shopping mall 1 locates next to post office, buildings are located within particular town boundary etc. How GIS maps geographical entities in real world? Source: www.esri.com 10

11 Satellite Imagery Weather Data Terrain Data Health Data Business Data Demographic Data Property Data Transportation Data Geographical Information System (GIS) 11 You can integrate many thematic data into GIS

12 You can use GIS to:  Find the high density area of residential housing  Locate potential area to set up new childcare centre  How accessible the public transportation system in that specific area (i.e MRT, bus) 12

13 One of the most basic questions asked of a GIS is "what's near what?" How close is this well to a landfill? Do any roads pass within 1,000 meters of a stream? What is the distance between two locations? What is the nearest or farthest feature from something? What is the distance between each feature in a layer and the features in another layer? What is the shortest street network route from some location to another? How many childcare centres that are located within 1 km from my flat? Where are the clinics, hospitals, polyclinics or 24 hrs emergency clinics from my house? Where is the nearest shopping malls from my office? 13

14 Proximity Analysis (Buffer)  Create a circular region around the selected point for proximity analysis  Search within feature or search nearby feature  Select feature from another layer 14 Find buildings near to selected primary school Find schools near to a selected building Source: www.onemap.sgwww.onemap.sg School Query service

15 Route Planning Using GIS Transportation professionals the world over have discovered and embraced GIS as an important tool in managing, planning, evaluating, and maintaining transportation systems. 15 http://www.esri.com/~/media/Files/Pdfs/library/newsletters/transportation-gis- trends/summer-2012.pdf For more reading:

16 Examples: Road Network Analysis What is the quickest way to get from Point A to point B? Which ambulances or patrol cars can respond quickest to an incident? What market areas does a business cover? What are live or historical traffic conditions like, and how do they affect my network analysis result? Source: www.esri.com

17 Using GIS to locate customer catchment AMK Hub & NEX (5, 10, 15 minutes service area)

18 18 Can you get your route planned via OneMap (www.onemap.sg)? Which service on OneMap should you use to find out the list of service bus passing through particular roads? Answer: BusRoute Explorer

19 19 A tourist would like to plan his/her daily tour visiting Singapore places of interest via public transportation mode, which service on OneMap would you suggest him/her to refer to? Answer: Get Directions (*you can choose mode of transportation: drive, bus or combination of Bus & MRT)

20 20 Using OneMap, generate the cheapest route of taking bus from Esplanade to Asian Civilisations Museum. *set 500 m for allowable walking distance. Q1: How much is the cheapest bus fare? Q2: A few solutions are proposed, which solution provides the cheapest and the fastest route to reach Asian Civilisations Museum?

21 21 Q1: How much is the cheapest bus fare? S$0.73 Q2: A few solutions are proposed, which solution provides the cheapest and the fastest route to reach Asian Civilisations Museum? Solution 1: Total travel and wait/walk time = appx 13 minutes


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