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INTRODUCTION TO GEOGRAPHIC INFORMATION SYSTEMS. Dr. S. A. HALILU. EVERYDAY WE ARE DESCRIBING THE REAL WORLD. What?. WHERE?. EVERYDAY WE are also Describing Events. Fire- What. Time- Stone Age. How- Bush Camp. EVERYDAY WE are also Describing Events. Coordinates- 08.9 N and 07.4E.
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INTRODUCTION TO GEOGRAPHIC INFORMATION SYSTEMS Dr. S. A. HALILU NASRDA, 2010
EVERYDAY WE ARE DESCRIBING THE REAL WORLD What? WHERE? NASRDA, 2011
EVERYDAY WE are also Describing Events Fire- What Time- Stone Age How- Bush Camp
EVERYDAY WE are also Describing Events Coordinates- 08.9 N and 07.4E ADVANCE COMPUTATION LABORATORY
Babylonian Clay Tablet map (and reconstructed drawing) from Ga-Sur, northern Iraq (ca. 2500 B.C.) Images courtesy of HenryDavis.com
“Turin Papyrus” map by Amennakht, royal scribe, showing a portion of Wadi Hammamat in eastern Egypt, prepared for one of King Ramesses IV’s quarrying expeditions (ca. 1150 B.C.) - Egyptian Comparison between Turin Papyrus (left) and modern topographic and geologic maps (right). Images courtesy of James A. Harrell, University of Toledo
Reconstruction of Ptolemy’s “Septima Asiae Tabula”, map of portion of Asia east of the Caspian Sea (ca. 90-168 A.D.) – Roman Egypt Map from Mawang Dui Tombs, Western Han dynasty, China (ca. 2nd century B.C.) Image courtesy of Hong Kong Baptist University Image courtesy of Lombard Maps
Map of Coastal towns in the Caspian Sea Region according to Abuzeide Balkhi, during the Abassid Caliphates (ca. 888 A.D.) Map image courtesy of NASA Image courtesy of Tirdâd Gorgâni (David Gorgan)
Medieval cartographers and scribes copying and drawing out maps by hand based on 2nd-hand data (written accounts, field measurements, complete fantasy) and storing them in a repository archive (later collected as bound atlases after the printing press). T-O style Mappa Mundi from ca. 1130, and T-O diagram from 1472 printing by Guntherus Ziner
details from the “Mapa de Cuauhtinchan”, produced by a Chichimec community from Cuauhtinchan as part of a legal dispute over land with the Spaniards and another Indian community, showing theological beginnings, historical migrations, and the founding of Cuauhtinchan during the twelfth to the fifteenth centuries. (ca. 1580s A.D.) Images courtesy of Washington University in St. Louis, the Mesoamerican Research Foundation, and Harvard University.
Marshall Islanders’ Stick Chart for Navigation (reproduction) showing islands and wave swell refraction and interference patterns Marshall Islanders’ Stick Chart for Navigation showing islands and wave swell and interference refraction patterns Image courtesy of Smithsonian “Ocean Planet” exhibit and NASA’s SeaWifs program. Image courtesy of the Mariners Museum
Section of the Tabula Peutingeriana, detail: Rhodes & detail: Greece, Crete, Turkey (1598 copy of a 12th century MS) Original (lost) copy by Castorius circa 1st century A.D. early road map [painted itinerary] of the imperial highways of the Roman world Images courtesy of HenryDavis.com
Hard Copy Maps are : - static - difficult to update - storage problem - liable to torn, fade, shrink - human to interpret the relationship between features with static data shown on the map …
Geographic Information System Training in GIS includes several components.
Geographic Information System • Geographic– 80% of government data collected is associated with some location in space • Information - attributes, or thecharacteristics (data), can be used to symbolize and provide further insight into a given location • System – a seamless operation linking the information to the geography – which requires hardware, networks, software, data, and operational procedures …not just software! …not just for making maps!
GIS: a formal definition “A system for capturing, storing, checking, integrating, manipulating, analysing and displaying data which are spatially referenced to the Earth. This is normally considered to involve a spatially referenced computer database and appropriate applications software” Chorley Report, 1987 Dr Halilu Ahmad Shaba
What makes data spatial? Grid co-ordinate Placename Latitude / Longitude Postcode Description Distance & bearing Dr Halilu Ahmad Shaba
GIS COMPONENT Dr Halilu Ahmad Shaba
GIS comprises of: • Data input • Storage • Management • Analysis • Output Dr Halilu Ahmad Shaba
IDENTIFICATION LOCATE TRENDS WHAT GIS CAN DO ? PATTERNS MODELS OPTIMAL PATH
Who uses GIS? • International organizations • UN HABITAT, The World Bank, UNEP, FAO, WHO, etc. • Private industry • Transport, Real Estate, Insurance, etc. • Government • Ministries of Environment, Housing, Agriculture, etc. • Local Authorities, Cities, Municipalities, etc. • Provincial Agencies for Planning, Parks, Transportation, etc. • Non-profit organizations/NGO’s • World Resources Institute, ICMA, etc. • Academic and Research Institutions • Smithsonian Institution, CIESIN, etc. Source: Carmelle J. Terborgh, Ph.D.
What can you do with a GIS? • The possibilities are unlimited… • Environmental impact assessment • Resource management • Land use planning • Tax Mapping • Water and Sanitation Mapping • Transportation routing • and more ... Source: Carmelle J. Terborgh, Ph.D.
How does a GIS work? • GIS data has a spatial/geographic reference • This might be a reference that describes a feature on the earth using: • a latitude & longitude • a national coordinate system • an address • a district • a wetland identifier • a road name Source: Carmelle J. Terborgh, Ph.D.
Two fundamental types of data • Vector • A series of x,y coordinates • For discrete data represented as points, lines, polygons • Raster • Grid and cells • For continuous data such as elevation, slope, surfaces • A Desktop GIS should be able to handle both types of data effectively! Source: Carmelle J. Terborgh, Ph.D.
Data Representation Raster Vector Real World Source: Carmelle J. Terborgh, Ph.D.
Questions GIS can answer • Till now GIS has been described in two ways: • Through formal definitions, and • Through technology's ability to carry out spatial operations, linking data sets together. • However there is another way to describe GIS by listing the type of questions the technology can (or should be able to) answer. Location, Condition, Trends, patterns, Modelling, Aspatial questions, Spatial questions. There are five type of questions that a sophisticated GIS can answer:
Questions GIS can answer Aspatial Questions "What's the average number of people working with GIS in each location?" is an aspatial question - the answer to which does not require the stored value of latitude and longitude; nor does it describe where the places are in relation with each other. Spatial Questions " How many people work with GIS in the major centres of Abuja" OR " Which centres lie within 10 Kms. of each other? ", OR " What is the shortest route passing through all these centres". These are spatial questions that can only be answered using latitude and longitude data and other information such as the radius of earth. Geographic Information Systems can answer such questions.
Questions GIS can answer Location: What is at………….? The first of these questions seeks to find out what exists at a particular location. A location can be described in many ways, using, for example place name, post code, or geographic reference such as longitude/latitude or x/y. Condition Where is it………….? The second question is the converse of the first and requires spatial data to answer. Instead of identifying what exists at a given location, one may wish to find location(s) where certain conditions are satisfied (e.g., an unforested section of at-least 2000 square meters in size, within 100 meters of road, and with soils suitable for supporting buildings)
Questions GIS can answer Trends What has changed since…………..? The third question might involve both the first two and seeks to find the differences (e.g. in land use or elevation) over time. Patterns What spatial patterns exists…………..? This question is more sophisticated. One might ask this question to determine whether landslides are mostly occurring near streams. It might be just as important to know how many anomalies there are that do not fit the pattern and where they are located.
Questions GIS can answer Modelling What if……………..? "What if…" questions are posed to determine what happens, for example, if a new road is added to a network or if a toxic substance seeps into the local ground water supply. Answering this type of question requires both geographic and other information (as well as specific models). GIS permits spatial operation.
The benefits of GIS include: • Better information management • Higher quality analysis • Ability to carry out “what if?” scenarios • Improve project efficiency • Quick map delivery Dr Halilu Ahmad Shaba
GIS for planning underdeveloped areas Urban poverty measured in terms of quantity and quality of public space. The lack of public open space. Barrios have a percentage of public space between 5% and 10%. In the average city total space constitute over 30% of the total space. The absence of adequate infrastructure, Urban furniture and maintenance which combined produces unhealthy and insecure conditions. Source: Rosario Giusti de Perez
GIS for planning underdeveloped areas DEALING WITH A COMPLEX MORPHOLOGY REQUIERES: Understanding the existing physical order Identifying the social order conformed by community ties and with no physical evidence Transformation capacity is determined through a detailed review of the built form Source: Rosario Giusti de Perez
GIS for planning underdeveloped areas Analysis of the social network and community ties Sustainability is preserving the small social groups The social network is topology related. Source: Rosario Giusti de Perez
Thanks So Much I Hope I never bored you