surface water. River. Lakes

The world distribution of surface water resources refers to the uneven distribution of freshwater on the Earth's surface, including lakes, rivers, and reservoirs. This distribution varies greatly from one region to another due to factors such as geography, climate, and human activities. Here's an explanation of the world distribution of surface water resources:

1. Lakes and Rivers:

- North America and Eurasia: These continents have some of the largest freshwater lakes, including the Great Lakes in North America and the Caspian Sea in Eurasia. Major rivers like the Mississippi, Missouri, and Volga flow through these continents, providing significant surface water resources.

- Africa: The African continent is home to several major rivers, such as the Nile, Congo, and Niger, as well as important lakes like Lake Victoria, Lake Tanganyika, and Lake Malawi.

- South America: The Amazon River basin in South America houses the largest river system by discharge in the world. The continent also features extensive freshwater resources in the form of rivers and lakes.

2. Asia:

- South Asia: The Indian subcontinent has the Ganges, Brahmaputra, and Indus rivers, along with large reservoirs like Tarbela Dam. The region heavily relies on these water sources for agriculture and drinking water.

- East Asia: China's Yangtze River and its tributaries, such as the Yellow River, provide essential surface water resources to the most populous country in the world.

- Southeast Asia: The Mekong River flows through several countries in Southeast Asia, serving as a vital waterway and water source.

3. Europe:

- Western Europe: Major rivers like the Rhine and Danube flow through Western Europe, supporting industrial and agricultural activities.

- Eastern Europe: The region has significant freshwater resources, including the Dnieper, Don, and Volga rivers.

4. Australia: While Australia is relatively arid, it has important river systems like the Murray-Darling Basin, which is crucial for agriculture and water supply.

5. Middle East:

- Tigris-Euphrates Basin: The Tigris and Euphrates rivers are essential for Iraq, but they are heavily regulated and impacted by upstream dams in Turkey.

- Nile Basin: The Nile River is a lifeline for Egypt and Sudan, but it's a source of contention among countries upstream that share its waters.

6. Arctic and Antarctic Regions: These regions have abundant surface water in the form of ice caps, glaciers, and ice sheets. However, this freshwater is not readily accessible for human use.

7. Human Impact: Human activities, such as dam construction, irrigation, and pollution, can significantly alter the distribution and quality of surface water resources. These impacts can lead to both water scarcity and water quality issues.

8. Climate Change: Climate change is affecting the distribution of surface water resources through altered precipitation patterns, glacier melt, and changes in river flow.

Understanding the world distribution of surface water resources is vital for managing and conserving these essential freshwater sources. It's crucial for addressing water scarcity, supporting ecosystems, and sustaining human populations in different regions around the globe.

Comments

History of GIS

1. 1832 - Early Spatial Analysis in Epidemiology: - Charles Picquet creates a map in Paris detailing cholera deaths per 1,000 inhabitants. - Utilizes halftone color gradients for visual representation. 2. 1854 - John Snow's Cholera Outbreak Analysis: - Epidemiologist John Snow identifies cholera outbreak source in London using spatial analysis. - Maps casualties' residences and nearby water sources to pinpoint the outbreak's origin. 3. Early 20th Century - Photozincography and Layered Mapping: - Photozincography development allows maps to be split into layers for vegetation, water, etc. - Introduction of layers, later a key feature in GIS, for separate printing plates. 4. Mid-20th Century - Computer Facilitation of Cartography: - Waldo Tobler's 1959 publication details using computers for cartography. - Computer hardware development, driven by nuclear weapon research, leads to broader mapping applications by early 1960s. 5. 1960 - Canada Geograph...

Supervised Classification

Image Classification in Remote Sensing Image classification in remote sensing involves categorizing pixels in an image into thematic classes to produce a map. This process is essential for land use and land cover mapping, environmental studies, and resource management. The two primary methods for classification are Supervised and Unsupervised Classification . Here's a breakdown of these methods and the key stages of image classification. 1. Types of Classification Supervised Classification In supervised classification, the analyst manually defines classes of interest (known as information classes ), such as "water," "urban," or "vegetation," and identifies training areas —sections of the image that are representative of these classes. Using these training areas, the algorithm learns the spectral characteristics of each class and applies them to classify the entire image. When to Use Supervised Classification: - You have prior knowledge about the c...

Accuracy Assessment

Accuracy assessment is the process of checking how correct your classified satellite image is . 👉 After supervised classification, the satellite image is divided into classes like: Water Forest Agriculture Built-up land Barren land But classification is done using computer algorithms, so some areas may be wrongly classified . 👉 Accuracy assessment helps to answer this question: ✔ "How much of my classified map is correct compared to real ground conditions?" Goal The main goal is to: Measure reliability of classified maps Identify classification errors Improve classification results Provide scientific validity to research 👉 Without accuracy assessment, a classified map is not considered scientifically reliable . Reference Data (Ground Truth Data) Reference data is real-world information used to check classification accuracy. It can be collected from: ✔ Field survey using GPS ✔ High-resolution satellite images (Google Earth etc.) ✔ Existing maps or survey reports 🧭 Exampl...

Representation of Spatial and Temporal Relationships

In GIS, spatial and temporal relationships allow the integration of location (the "where") and time (the "when") to analyze phenomena across space and time. This combination is fundamental to studying dynamic processes such as urban growth, land-use changes, or natural disasters. Key Concepts and Terminologies Geographic Coordinates : Define the position of features on Earth using latitude, longitude, or other coordinate systems. Example: A building's location can be represented as (11.6994° N, 76.0773° E). Timestamp : Represents the temporal aspect of data, such as the date or time a phenomenon was observed. Example: A landslide occurrence recorded on 30/07/2024 . Spatial and Temporal Relationships : Describes how features relate in space and time. These relationships can be: Spatial : Topological (e.g., "intersects"), directional (e.g., "north of"), or proximity-based (e.g., "near"). Temporal : Sequential (e....

GIS: Real World and Representations - Modeling and Maps

Geographic Information Systems (GIS) serve as a bridge between the real world and digital representations of geographic phenomena. These representations allow users to store, analyze, and visualize spatial data for informed decision-making. Two key aspects of GIS in this context are modeling and maps , both of which are used to represent real-world geographic features and phenomena in a structured, analyzable format. Let's delve into these concepts, terminologies, and examples in detail. 1. Real World and Representations in GIS Concept: The real world comprises physical, tangible phenomena, such as landforms, rivers, cities, and infrastructure, as well as more abstract elements like weather patterns, population densities, and traffic flow. GIS allows us to represent these real-world phenomena digitally, enabling spatial analysis, decision-making, and visualization. The representation of the real world in GIS is achieved through various models and maps , which simplify...

Vineesh V, Geography

Search This Blog