Introduction to Soil Science and Physical Geography
Factors Involved in Soil Formation
Climate, organisms, the overall water balance, time, bedrock, slope, and orientation all contribute to soil formation.
What is Soil from a Pedological Viewpoint?
Soil is a surface layer formed through natural processes. It develops on vegetation cover and consists of mineral and organic fractions. This ground surface layer forms on continents and serves as a foundation for terrestrial life.
What is Soil Structure?
Soil is structured in a series of horizontal layers called horizons, starting from the surface and extending down to the bedrock. Each horizon possesses distinct characteristics based on its composition, structure, and properties. These differences are often visually apparent through variations in color and texture.
Key Features of a Soil Horizon “B”
The B horizon, also known as the subsoil, accumulates mineral elements leached from the upper horizons. It typically exhibits a higher clay content, a lighter color due to the absence of humus, and the presence of iron oxides.
Why is Soil Often Regarded as an Interface?
Soil acts as an interface within the Earth’s system, connecting the four major spheres: the atmosphere, biosphere, hydrosphere, and lithosphere.
What is a Soil Horizon?
A soil horizon is a distinct layer within the soil profile, running parallel to the surface. These horizons, stacked from the surface down to the bedrock, are differentiated by their composition, structure, and properties. The complete set of horizons in a soil is referred to as the soil profile.
Fluvial Processes and Landforms
Defining Load, Capacity, and Competence of a River’s Current
Load: The actual amount of sediment carried by a river at a specific location and time. There are three types of load: bedload, suspended load, and dissolved load.
Capacity: The theoretical maximum amount of material a river can transport, determined by its volume, velocity, and flow regime. Increased flow leads to a higher sediment transport capacity.
Competence: The maximum size of sediment a river can transport as bedload.
What is the Equilibrium Profile of a River?
A river achieves an equilibrium profile when it attains a longitudinal slope that minimizes energy expenditure for water transport. In this state, the river primarily carries water. However, natural rivers rarely reach a perfect equilibrium due to constant environmental changes.
Differences Between an Estuary and a Delta
An estuary is a coastal river mouth where freshwater mixes with seawater. Sediments carried by the river are constantly redistributed by tidal currents and do not accumulate at the mouth.
A delta forms when a river deposits sediments at its mouth, creating an accumulation of sediment that extends into the body of water. Deltas often exhibit a characteristic triangular shape.
Mining and Environmental Impacts
Advantages and Disadvantages of Open-Pit Mining
Open-pit mining offers cost advantages over underground methods. However, it carries significant environmental consequences, including visual and landscape impacts, habitat destruction, and potential for soil and water contamination.
Formation of River Terraces
River terraces are step-like formations along river valleys, representing former floodplains. They form due to cycles of river erosion and deposition. Fluctuations in river flow, often linked to glacial cycles, cause the river to incise its channel, leaving behind remnants of older floodplains at higher elevations.
Geology and Resource Management
Characteristics of Reservoir Rocks for Oil and Gas
Reservoir rocks, such as sandstones and limestones, possess interconnected pores that allow for the storage and flow of fluids like oil and gas. These rocks act as natural underground reservoirs.
Formation and Characteristics of Waves
Waves are generated by wind friction on the ocean surface, transferring energy to water particles and creating a circular motion. Waves act as erosive agents, shaping coastal morphology through processes like abrasion, corrosion, and attrition.
Delta Formation
Deltas form through a sequence of events:
- Intense sedimentation occurs underwater as a river reaches a larger body of water.
- Sediments accumulate and eventually breach the water’s surface, initiating the development of a subaerial delta.
- The delta expands, often starting with a”bird’s foo” shape and gradually evolving into a more triangular form as sediments fill in the spaces between distributary channels.
Major Pollutants from Coal-Fired Power Plants
Coal-fired power plants release significant pollutants, including:
- Sulfur dioxide (SO2): Coal often contains sulfur, which, when burned, releases SO2, a major contributor to acid rain.
- Particulate matter: Coal combustion generates dust and other particles that contaminate the air.
- Heavy metals: Coal can contain heavy metals that are released into the environment through combustion byproducts.
- Leachate: Rainwater percolating through coal ash ponds can carry contaminants into surface and groundwater resources.
Distinguishing Mineral Resources and Reserves
Mineral Resource: The total amount of minerals, rocks, metals, and hydrocarbons present in the Earth’s crust that have the potential for future use.
Mineral Reserve: The economically viable portion of a mineral resource that can be extracted using current technology and market conditions.
The key difference lies in economic and technological feasibility. Reserves are exploitable under current conditions, while resources may become exploitable in the future with technological advancements or changes in market demand.
Remediation of Soil Erosion
: forestry measures: afforestation, improvement of the bush, silvicultural treatments. Measures on agriculture: terracing of slopes, conservation tillage, contour plowing, restore soil fertility, crop abandonment. Hydrotechnics Works: construction of drains, gullies prevent a backflow of
-Differences between nuclear fission and nuclear fusion fission is a nuclear reaction where a heavy nucleus splits in other heavier nuclei, fission is achieved when bombarded with neutrons, this process also releases enough energy and more neutrons are released . In fusion two light nuclei together to form one heavier nucleus, this process also releases a lot of energy and is usually an occasional free neutron, to make this happen is to see a cover of k enrgia.