Geodatabase Building Project_Edited

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GEOSPATIAL DATABASES!!

Geodatabase Building Project!!!Monday 17th February 2015!

!!!EXECUTIVE SUMMARY!!The purpose of the project was to design and implement a Geospatial database for the North Central Campus of the University of Glasgow. The geodatabase focussed on buildings and academic units. Data sources and classifications were investigated to provide a dataset to work with. The database structure was designed in the form of a geodatabase schema and entity relationships were assessed and mapped out. The geodatabase was implemented into Esri ArcGIS using ArcCatalog and ArcMap. Initial topographic information was obtained from the Ordnance Survey MasterMap and was built upon throughout the geodatabase implementation. This involved the creation of additional attributes, input of additional tables and the creation of linkages between the related tables.!

Project outputs included a functioning geodatabase structure and a map of the study area.!

!!!!OBJECTIVES!

!• Investigate data sources and their classification!

• Design an appropriate geodatabase schema to allow certain tasks to be carried out!

• Implement the geodatabase

0806514� | �1 16Geospatial Databases

STUDY AREA!!!The chosen study area was the North Central Campus of the University of Glasgow. This area is highlighted in the Google Maps imagery below. The buildings contained within the area and associated attributes were noted. These were split into subtypes including; University, Residential, Research and Other.


Image Adapted From: www.google.co.uk/maps

LEGEND:

North Central Campus Extent

N

Buildings within the area included:

http://www.google.co.uk/maps

http://www.google.co.uk/maps

DESIGN & DATA MODELLING!!The geodatabase design involved the investigation of entities that exist within the study area and their associated attributes. The relationship between these entities was researched and a geodatabase network schema was produced to show the proposed linkages between the tables. !!Entities within the study area were identified and their relationships were assessed and related as follows:!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Note:! M = Many!!!The method of relating the tables is noted to the right of the entity-relationship above (Join or Relate).!!!It became apparent that some buildings carried out other functions not related to the academic branch of the University, this information was to be held in the Services table (ran out of time before this could be fully implemented). This table would have linked to the buildings table on TOID as shown overleaf and would have noted the services that would be available in that particular building. For example, the Accommodation Services at 73 Great George Street. As this was a 1-many relationship the ‘relate’ function would have been used.


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The design was eventually refined to the following tables and attribute linkages:!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!The Building table was the central table as this would be the user point of contact on the GIS. The other tables were either related to or joined to this table. Join was used to bring the Address fields into the Building table and matched on the building ADDRESS_ID. This was done to create a many-to-one relationship for the join to be viable. This meant that when the Identify tool was used on a particular building the address of that building would be visible as building attributes.!!The College and School tables linked to the Building table on building TOID based on the College or School Office. There were no College Offices within the study area so the college office would not show in the related attributes but if this was to be extended to the rest of the campus then results would have been visible.!!School_ID related Subjects to the School table. This showed the subjects taught and other subject attributes within that school in the related attributes when the building was identified.


DATA DICTIONARY AND DOMAINS!!!


TABLE FIELD DATA_TYPE WIDTHALLOW NULL DESCRIPTION DEFAULT DOMAIN

BUILDING BUILDING_ID INTEGER 11 NO Building unique identifier code

BUILDING FEATURE_CODE TEXT 5 Feature code 10021

BUILDING TOID TEXT 15 TOID

BUILDING BUILDING_NAME TEXT 50 Building name

BUILDING ADDRESS_ID INTEGER 11 NO Address unique identifier code

BUILDING BUILDING_TYPE TEXT 14 Building type University

University / Residential / Administration / Other

BUILDING CAMPUS TEXT 11 Campus the building resides in

Main Campus

Gilmorehill / Garscube / Dumfries

BUILDING NO_FLOORS INTEGER 2 Number of floors 1

BUILDING NO_ROOMS INTEGER 2 Number of rooms

BUILDING OPENING_HOURS BLOBLink to a document containing up-to-date building Opening Hours

BUILDING DISBALED_ACCESS TEXT 7 Disabled access availability FULL FULL / PARTIAL /

NONE

BUILDING TOILETS TEXT 3 Toilet facilitiesMale & Female & Disabled

Male / Female / Disabled / Male & Female & Disabled / Male & Female / Male & Disabled / Female & Disabled / None

BUILDING CATERING TEXT 3 Catering facilities NO YES or NO

BUILDING NO_PCS INTEGER 4 Number of PCs

BUILDING NO_PRINTERS INTEGER 2 Number of Printers

BUILDING TELEPHONE TEXT 19 Building Telephone number

BUILDING FAX TEXT 19 Building Fax number

BUILDING EMAIL TEXT 20 Building Email address

BUILDING WEBSITE TEXT 100 Building website

BUILDING WIFI TEXT 3 WiFi Availability YES YES or NO

BUILDING NO_PHOTOCOPIERS INTEGER 3 Number of Photocopiers

BUILDING TECH_FREE_ZONE TEXT 3 Technology free area availability YES or NO

BUILDING NO_GROUP_STUDY_AREAS TEXT 3 Number of group study

areas


TABLE FIELD DATA_TYPE WIDTH ALLOW NULL DESCRIPTION DEFAULT DOMAIN

ADDRESS ADDRESS_ID INTEGER 11 NO Address unique identifier code

ADDRESS BUILDING_NAME TEXT 15 Building Name

ADDRESS NUMBER TEXT 3 Street Number Range Domain: 0-999

ADDRESS STREET TEXT 50 Street name

ADDRESS CITY TEXT 30 City name Glasgow

ADDRESS COUNCIL TEXT 50 Council name Glasgow City

ADDRESS POSTCODE TEXT 7Postcode identifier consisting of letters and numbers

ADDRESS COUNTRY TEXT 50 Country name Scotland

TABLE FIELD DATA_TYPE WIDTH ALLOW NULL DESCRIPTION DEFAULT DOMAINSERVICES SERVICE_ID INTEGER 11 NO Service unique identifier

SERVICES SERVICE_NAME TEXT 30 Service name

SERVICES TOID INTEGER 11 Building unique identifier code

SERVICES TELEPHONE TEXT 19 Service Telephone number

SERVICES FAX TEXT 19 Service Fax number

SERVICES EMAIL TEXT 20 Service Email address

SERVICES WEBSITE TEXT 100 Service website


COLLEGE COLLEGE_ID INTEGER 11 NO College unique identifier code

COLLEGE COLLEGE_NAME TEXT 50 College name

COLLEGE OF ARTS / COLLEGE OF MEDICAL, VETERINARY AND LIFE SCIENCES / COLLEGE OF SCIENCE AND ENGINEERING / COLLEGE OF SOCIAL SCIENCES

COLLEGE COLLEGE_HEAD TEXT 50 Head of college

COLLEGE COLLEGE_OFFICE TEXT 50 College office name

COLLEGE TOID INTEGER 11 Building unique identifier code

COLLEGE TELEPHONE TEXT 19College Office Telephone number

COLLEGE FAX TEXT 19 College Office Fax number

COLLEGE EMAIL TEXT 20 College Email address

COLLEGE WEBSITE TEXT 100 College website



SCHOOL SCHOOL_ID INTEGER 11 NO School unique identifier code

SCHOOL SCHOOL_NAME TEXT 50 School name

SCHOOL OF CRITICAL STUDIES / SCHOOL OF CULTURE AND CREATIVE ARTS / SCHOOL OF HUMANITIES / SCHOOL OF MODERN LANGUAGES AND CULTURES / SCHOOL OF LIFE SCIENCES / SCHOOL OF MEDICINE / SCHOOL OF VETERINARY MEDICINE / SCHOOL OF CHEMISTRY / SCHOOL OF COMPUTING SCIENCE / SCHOOL OF ENGINEERING / SCHOOL OF GEOGRAPHICAL AND EARTH SCIENCES / SCHOOL OF MATHEMATICS AND STATISTICS / SCHOOL OF PHYSICS AND ASTRONOMY / SCHOOL OF PSYCHOLOGY / ADAM SMITH BUSINESS SCHOOL / SCHOOL OF EDUCATION / SCHOOL OF INTERDISCIPLINARY STUDIES / SCHOOL OF LAW / SCHOOL OF SOCIAL AND POLITICAL SCIENCES /

SCHOOL SCHOOL_HEAD TEXT 50 Head of school

SCHOOL SCHOOL_OFFICE TEXT 50 School office name

SCHOOL TOID INTEGER 11 Building unique identifier code

SCHOOL COLLEGE_ID INTEGER 11 NO College unique identifier code

SCHOOL TELEPHONE TEXT 19School Office Telephone number

SCHOOL FAX TEXT 19 School Office Fax number

SCHOOL EMAIL TEXT 20 School Email address

SCHOOL WEBSITE TEXT 100 School website


SUBJECT SUBJECT_ID INTEGER 11 NO Subject unique identifier code

SUBJECT SUBJECT_NAME TEXT 50 Subject name

SUBJECT SUBJECT_HEAD TEXT 50 Head of subject name

SUBJECT SCHOOL_ID INTEGER 11 NO School unique identifier code

GEODATABASE IMPLEMENTATION!!A file geodatabase named ‘Campus_Geodatabase.gdb’ was created in ArcCatalog and two feature datasets were generated within it. The feature datasets were named Features and MasterMap and used the British National Grid spatial reference. Features contained the Building_Data feature class and MasterMap contained the feature classes associated with the OS Topographic MasterMap data, this is highlighted in the screenshot, right:!!!!!The Topography OS MasterMap was downloaded from EDINA DIGIMAP as a file geodatabase and imported into Esri ArcMap. The buildings were selected by OS Building FeatureCode attribute (10021) from the TopographicArea layer and a new layer was created from this selection. Clip was used to extract the data from this new layer for the study area extent only, the resultant layer was named ‘Buildings_Data’.!!Subtypes were created within the Properties of the Building_Data feature class. Subtypes are shown in the screenshot below:!!!!!!!!!!!!!!!!!!!


Domains were created by right-clicking on the geodatabase in ArcCatalog, selecting ‘Properties’ and navigating to the ‘Domains’ tab. The Domains are shown below:!!!!!!!!!!!!!!!!!!!!!!!!!!Additional building attributes shown on the previous page were added as new fields into the Buildings_Data attributes table, refer to screenshot below:!!!


The additional fields were then populated within the Building_Data attributes table using the Editor tool.!!Microsoft excel was used to create and populate the additional tables; Address, College, School, Subject and Services. Domains were updated to include domains for the attributes in these tables.!!These tables were imported into the geodatabase within ArcCatalog using the ‘Import’>’Tables’ function. This is highlighted in the screenshot below:!!!!!!!! !!!!!!!!!The Building_Data and Address table were joined on ADDRESS_ID to enable the user to view the address of a building when selected with the identify tool. The join tool works by joining on fields with the same datatype and attaching the attributes of the matching record from the joined table into the selected table. For example, the Building_Data and Address tables were joined by right-clicking the Buildings_Data layer and selecting ‘Joins and Relates’>’Join’. ADDRESS_ID was selected as the basis that the two tables would be joined on and all records were kept. The method is shown in screenshots below:!!!


E.g. ADDRESS_ID

E.g. Address (Table)

E.g. ADDRESS_ID

All other tables were joined using by ‘relating’ the tables. This was used for the 1-many relationships. An example ‘relate’ is shown in the screenshots below:!!!!!!!!!!!!!!!!!!!!!The Buildings_Data joins and relates are visible within the Layer Properties as shown by the screenshot below. It is possible to add to or remove joins and relates from this section.!!!!!!!!!!!!!!!!!!!!!!!!!!!!The product of joining and relating these tables was that the user was able to interact with all the related information across all tables from the one point of contact instead of looking into each table individually for the information.!!!


ADAM SMITH BUILDING EXAMPLE!!The identify tool was used to select the Adam Smith building and it can be seen from the screenshot of the identify window below that the relations between the tables shows the School, College and Subjects associated with the building.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!


Building

School

College

Associated Subjects

It can also be seen from the buildings attributes that the join is allowing the address attributes of the building to be pulled from the address table and displayed when the building is identified. The screenshots below show the building and address attributes displayed together when the building is selected.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


Building_Data Table Attributes Address Table Attributes

CAMPUS MAP!!Project output included the Campus Map layout from ArcMap shown below. 10k Raster was used as a base map to give a spatial context to the map.!

The OS MasterMap styling was assigned to the Topographic Area layer and clipped to the study area as shown in the ArcMap layout below:


CHALLENGES!!!This section aims to give insight into the challenges that were encountered throughout the project and the methods used to overcome them throughout the database design and implementation phases. This section will also discuss any issues that were unresolved.!!!!• The first challenge of designing the database, other than obtaining and collating the information

about the buildings, was selecting the database model. The relational model appeared to be the best-fit for the dataset. The relational database model that was employed seemed the most efficient and most organised method of dealing with the data as it split each entity into its component parts (attributes) and permitted a simple (once the relationship had been determined) link to another table. However, it is possible that other models may prove to be equally as effective or better.!!!

• One of the biggest issues that arose throughout the design phase involved buildings that were shared by numerous colleges, schools and subjects. In this case these are one-to-many relationships between Building-College, Building-School, and Building-Services. Through research into these types of relationships, it appeared that relating the tables instead of joining them was the better way of handling them instead of redistributing the attributes that were held in the tables. This allowed the related information to appear when the building was identified. However, more research is required into the extent of the user’s interaction with this data.!!!

• A further issue that arose involved the Website field that formed part of the Building, Services, College and Schools tables. As website addresses can be very long the ideal width of the field was unclear.!!!

• Also, the Opening Hours field within the Buildings table could have been split into various days and a start and end time. Using a BLOB data type for the one Opening Hours field and linking to a (pop-up) sheet of opening times for that building may be more efficient if possible? However, the method used to do this was unclear and may require further research.!!!

• Furthermore, when joining and relating tables it transpired that the fields that were being used to link the two tables had to be of the same data type. This was discovered when attempting to relate the Building_Data and Schools tables on TOID. One table had the field defined as an integer and the other defined it as text so when picking the fields to link the tables the other TOID did not appear in the options of fields to relate to. To resolve this a new text field was created and repopulated with the same values.!!


EDUCATIONAL PERSPECTIVE!!This project allowed for deeper research into the methods for database design that were taught in the GIS course in the first semester. !!Overall I experienced mixed levels of success with the project. I found the initial design of the database difficult as I couldn’t visualise what the final product was going to look like at the end and how the different tables were going to link together. I spent a lot of time trying to get this right. I was still making slight refinements even at the implementation stage and I think the lack of previous database design experience contributed to this. However, I definitely feel that I am a lot better prepared for if I was to attempt something similar again. I wouldn’t say that I would breeze through it but I think I have learnt something from the experience, as shown in the learning outcomes below.!!Although it wasn’t perfect, I feel that the implementation of the database was slightly easier and was significantly smoother than the design stage as I had a plan to follow.!!Overall I am pleased with the output of my geodatabase as I found the exercise difficult at times but I am sure there are many improvements that can be made to make it more efficient and more aesthetically pleasing.!!!!Key learning outcomes include:!!!• Ability to examine data sources and their classification !!• Better understanding of entity relationships and Joins & Relates in Esri ArcMap!!• Ability to design a suitable geodatabase schema!!• Ability to deploy a geodatabase in Esri ArcCatalog and ArcMap!!• Ability to use Esri help files!!• Ability to determine Subtypes and Domains in ArcMap for different data types!!• Additional knowledge of Ordnance Survey MasterMap Topographic data!!!!Areas to work on include:!!!• Creating geodatabase schema for different situations!!• Enhancing the geodatabase efficiency!!• Research into BLOB data type


Geodatabase Building Project_Edited

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