Skip to main content

Geographic phenomena fields objects boundaries.


In geography, geographic phenomena refer to features or processes that can be observed and studied on Earth's surface. These phenomena can be classified into three main categories: fields, objects, and boundaries. Each category has distinct characteristics, representations, and applications in Geographic Information Systems (GIS).

1. Fields

A field represents continuous, spatially varying data where a value is present at every location within the study area. It describes conditions that exist across a geographic area.

Characteristics:

  • Continuity: Fields have no discrete boundaries; the data is continuous.
  • Gradual Variability: The values of a field change gradually across space.
  • Representation: Typically modeled using raster data in GIS, where a grid structure assigns a value (e.g., temperature or elevation) to each cell.

Examples:

  • Temperature Map: Shows temperature variation across a region.
  • Rainfall Distribution: Displays rainfall levels over a large geographic area.
  • Elevation Data: Represents the height of land at every point in an area.

2. Objects

An object is a discrete geographic feature with a clearly defined location and boundaries. Objects are identifiable entities that exist as "whole" within a space.

Characteristics:

  • Discrete Entities: Objects are separate from their surroundings.
  • Defined Boundaries: Each object has clear limits.
  • Representation: Modeled using vector data in GIS, which represents objects as points, lines, or polygons.

Examples:

  • A City: Represented as a polygon or point on a map.
  • A River: Represented as a line feature in GIS.
  • A Building: Mapped as a point or polygon feature.

3. Boundaries

A boundary is the line or zone that marks the separation between different geographic features, fields, or phenomena. Boundaries can be sharp or gradual, natural or human-made.

Characteristics:

  • Sharp Boundaries: Distinct separation, such as a political border between two countries.
  • Gradual Transitions: Zones of change, such as a gradient from forest to grassland.
  • Representation: Typically represented as lines or polygons in GIS.

Examples:

  • Natural Boundary: Coastlines, rivers, or mountain ranges.
  • Human-Made Boundary: State or country borders, property lines.
  • Ecological Boundary: Transition zones between ecosystems, like a forest edge.

Key Differences Between Fields and Objects

AspectFieldsObjects
NatureContinuous data across spaceDiscrete entities with defined boundaries
RepresentationRaster dataVector data
ExamplesTemperature, elevation, rainfallCities, rivers, buildings
ChangeGradual changes across spaceFixed, defined locations


Fyugp note 
GIS second semester 

Comments

Post a Comment

Popular posts from this blog

History of Geography.

Chronological sequence and categorized by era and region. I. Introduction & Etymology •  Etymology : The term "Geography" derives from the Greek γεωγραφία (geographia) , meaning "Earth-writing" (description or writing about the Earth). •  First Use : Eratosthenes (276–194 BC) was the first person to use the word. •  Pre-Term Practices : Recognizable geographic practices like cartography (map-making) existed prior to the coining of the term. II. Antiquity & Ancient Civilizations 1. Ancient Egypt (Pre-Classical) •  Cosmology : Ancient Egyptians viewed the Nile as the center of the world, with existence based upon "the" river. •  Geographical Knowledge : •  Oases : Known to the east and west, considered locations of various gods (e.g., Siwa for the god Amon ). •  Kushitic Region : Lay to the south, known as far as the 4th cataract . •  Punt : A region located south a...
Post a Comment
Read more

Building Topology in GIS, Data Query in GIS, Geoprocessing and Automation in GIS

A Geographic Information System (GIS) is more than a digital mapping tool. It is a comprehensive system for capturing, storing, managing, analysing, querying, and visualising spatial (geographic) and non-spatial (attribute) data . To maintain accurate spatial data and perform advanced analyses, GIS relies on three important concepts: Building Topology Data Query Geoprocessing and Automation These concepts ensure data integrity, efficient data retrieval, and automated spatial analysis , making GIS an indispensable tool in geography, environmental science, urban planning, disaster management, transportation, agriculture, and resource management. 1. Building Topology in GIS Topology is the mathematical and logical framework that defines the spatial relationships between geographic features such as points, lines, and polygons. It ensures that spatial data maintain correct geometric relationships even after editing or analysis. Simple Definiti...
Post a Comment
Read more

Historical Development of Geography in the Ancient Period

The Ancient Period marks the earliest stage in the evolution of geographical thought, extending from approximately 3000 BCE to the 5th century CE . During this period, geography evolved from simple descriptions of the Earth's surface to systematic scientific inquiry. Early civilizations developed geographical knowledge to meet practical needs such as navigation, trade, agriculture, military expansion, taxation, and administration . The greatest contributions came from the Mesopotamian, Egyptian, Indian, Chinese, Greek, and Roman civilizations , with the Greeks laying the foundations of scientific geography . Meaning Terminology: Historical Development Historical development refers to the gradual evolution of geographical knowledge, concepts, methods, and theories over time. Concept Geographical knowledge evolved through: Observation of the natural environment Exploration and travel Cartography (map-making) Astronomical observations ...
Post a Comment
Read more

Development of Health Geography

Health Geography (formerly Medical Geography ) is the branch of geography that studies the relationship between health, disease, environment, place, and healthcare systems . The discipline has evolved over more than 2,500 years through contributions from physicians, geographers, epidemiologists, microbiologists, and public health experts. The development of Health Geography can be divided into the following periods: Ancient Period Medieval Period Renaissance and Pre-Modern Period Nineteenth Century (Pre-World War Era) World War Period Post-World War Period Modern Health Geography 1. Ancient Period (5th Century BC – 500 AD) Characteristics Health closely linked with the natural environment. Diseases explained through climate, water, air, and seasons. No knowledge of microorganisms. Medical observations were descriptive. Major Concepts Environmental Determinism Disease Ecology Climate and Healt...
Post a Comment
Read more

Ph.D. or M.Sc. Assistantship in Hyperspectral Remote Sensing of Biodiversity Oklahoma State University

Ph.D. or M.Sc. Assistantship in Hyperspectral Remote Sensing of Biodiversity Oklahoma State University Description: We invite applications for a Ph.D. or M.Sc. position in the field of remote sensing at Oklahoma State University. The successful candidate will use airborne and spaceborne hyperspectral data (from DLR's DESIS sensor), as well as in-situ measurements (functional traits and species diversity) to (1) map grassland diversity and (2) detect the spread of an invasive alien species in the Joseph H. Williams Tallgrass Prairie Preserve. The position will be housed in the Department of Geography at Oklahoma State University. The target start date is August 2021. Qualifications: Applicants with a masters' degree or bachelor's degree (at the time of appointment) in physical sciences (remote sensing, ecology, environmental science, geography, plant biology), engineering (environmental, optical), or other related fields with relevant research or work experience (e.g., hyper...
Post a Comment
Read more