Earth’s Landscapes: Formation, Factors, and Modeling
The landscape is characterized by a portion of space with a combination of physical, ecological, biological, and historical influences that come together to configure the appearance of that portion of space. We are looking for ways and forms of relief modeling. Relief modeling involves descriptive expressions and an analysis of the topography.
Factors Shaping the Landscape
The forms of relief (cliffs, dunes), the weather, density of human presence, and the type of vegetation and wildlife (desert, meadow) influence the landscape. The extent of the ground view of the spectator and subjective aspects, such as memories, also play a role.
Geological Agents and Landscape Modeling
Geological agents contribute to the modeling of the relief produced as part of a landscape:
- Rivers: River water and flora cause river modeling.
- Glaciers: Ice causes groundwater modeling, leading to sinkholes.
- Sea: Waves shape the seashore.
- Wind: Wind causes wind modeling.
Climate’s Influence on the Landscape
Climate influences geological modeling, vegetation, fauna, and weather situations. Human activities and land use are also factors that shape the territory.
Climate Factors
- Geological agent: Acting and more effective forms of relief (waves).
- Meteorology: Influences how the landscape is perceived in certain weather situations.
- Vegetation: Determines what can grow in the area.
- Fauna: Characteristic animals of the region.
- Human activities: These include possible crops.
The Role of Energy in Landscape Formation
Energy causes various effects: The Earth warms and provides a temperature. Shallow water evaporates and starts the water cycle. Energy maintains geological agents that carry out relief, used for modeling by photosynthetic beings.
Solar Energy
Solar energy maintains the Earth’s atmospheric dynamics and the water cycle, as well as the agents and the biosphere.
Consequences of Solar Energy
Solar energy produces large differences regarding the amount of atmospheric moisture between zones of the planet (climate) and time differences. The temperature difference between the equator and the poles gives rise to air flow and thermal ocean currents.
Weather and Climate
Weather is the science that studies atmospheric phenomena. Climate is a broad concept, referring to the average values of temperatures and rainfall obtained over many years.
Sedimentary Rocks
Sedimentary rocks are formed from existing rocks that were subjected to the action of atmospheric agents and the activity of certain organisms. They are altered (weathered), then eroded by the action of water, wind, or ice. These geological agents transport the sediment through different forms of transport: floating, drag, saltation, suspension, and dissolution (only if water and other liquids such as precipitated sulfur and sodium chloride are involved). Finally, the geological agent, either by loss of energy or gravitational deposition of sediment, or by chemical precipitation of dissolved sediment, accumulates the transported sediment particles in a process called sedimentation.
Two effects of sedimentation: Increasing pressure and temperature rise.
Sedimentary basins: Large areas where the crust is slowly sinking.
Lithification: The process that transforms a sediment into a sedimentary rock.
- Detrital: Clay, sandstone, conglomerate.
- Evaporitic: Salt, gypsum.
- Carbonate: Limestone, marl.
- Organic: Coal, oil.
Soil Formation
Detritus: Result of rock weathering, influencing composition and structure.
Atmospheric Dynamics
When warm air rises, it forms clouds, and precipitation occurs. Depressions tend to move slowly as the mass of warm air loses heat and humidity.
An anticyclone is a hub of high atmospheric pressure. Isobar lines connect points of the same atmospheric pressure.
Landscape Changes and Topographic Maps
Changes: The main element of the landscape that contains much information on geological agents. These changes are relevant for public works projects (roads, power lines), mining operations (management of quarries and gravel pits), territory management (agricultural areas), and forecasting geological risks (assessment of environmental impacts).
Topographic maps: A reduced and simplified representation of all elements that exist on the Earth’s surface, including topography, hydrography, land use, settlements, communications, etc. They represent administrative boundaries with contour lines.
- Numeric scale: Indicates the ratio between the map and reality.
- Graphic scale: Indicates the length that a segment drawn on the map would represent in reality.
Weathering Processes
Weathering is the process of decomposition or alteration of surface rocks by the action of the atmosphere, water, and living beings.
Factors Influencing Weathering
Moisture, oxygen, temperature changes, freezing water, and living things.
Types of Weathering
Chemical weathering: The chemical alteration of rocks is caused by oxygen, carbon dioxide in the atmosphere, and water. It may occur primarily by oxidation, dissolution, carbonation, and the action of living beings.
Mechanical weathering: Causes erosion of rocks without changing the composition of minerals.
Biological weathering: Living beings within roots help introduce themselves into cracks.
Fluvial, Torrential, Glacial, Karst, and Coastal Modeling
Fluvial Modeling
Canyons and gorges: Narrow river valleys. Flood plains: Easier for human occupancy. Meandering rivers: Help shape the land.
Torrential Modeling
Wild waters: Cause sinkholes to form in canyons. Alluvial fans: Highly valued landscape features.
Glacial Modeling
Glacial cirques: Amphitheater-shaped areas. Glacial valleys: U-shaped. Accumulation of snow during winter can support winter sports.
Karst Modeling
Surface modeling: Due to dissolution of the roof, forming cavities. Underground: Caves and tunnels.
Coastal Modeling
Coastal modeling is a form (generated by external geological agents) that occurs at the contact between land and sea, influenced by waves, tides, and the action of certain animals such as corals that construct structures. It also involves the interaction between marine waters and continental areas or river wetlands or lagoons.
Wind Modeling
Erosion: Wind carries away clay particles and sand grains. Sedimentation: Where a field of dunes forms.