Earth systems & resources

Overview
Forums
More

Surface runoff of water
Surface Runoff If the amount of water falling on the ground is greater than the infiltration rate of the surface, runoff or overland flow will occur. Runoff specifically refers to the water leaving...
- View More
Groundwater
In the broadest sense, groundwater refers to all subsurface water. The term more commonly refers to water beneath the surface of the earth which saturates the pores and fractures of sand, gravel,...
- View More
Freshwater biomes
Introduction Freshwater is defined as having a low salt concentration — usually less than 1%. Aquatic plants and animals in freshwater regions are adjusted to the low salt content and would...
- View More
River
Introduction to Rivers Rivers are of immense importance geologically, biologically, historically and culturally. Although they contain only about 0.0001% of the total amount of ...
- View More
Stream
Introduction Streams alter the Earth's landscape through the movement of water and sediment (Figure 1). Streams are powerful erosive agents moving material from their bed and banks. In mounta...
- View More
Seawater
Seawater is a mixture of various salts and water. Most of the water in the ocean basins is believed to originate from the condensation of water found in the early atmosphere a...
- View More
Ocean circulation
Surface Ocean Currents An ocean current can be defined as a horizontal movement of seawater in the ocean. Ocean currents are driven by the circulation of wind above surface waters, interac...
- View More
Surface water management
Introduction Surface water is precipitation that does not infiltrate into the ground or return to the atmosphere by transpiration or evaporation. It may be loosely defined as water that st...
- View More
Aquifer
Introduction An aquifer is a geologic formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water ...
- View More
Aquifer depletion
Scores of countries are overpumping aquifers as they struggle to satisfy their growing water needs, including each of the big three grain producers—China, India, and the United States. These ...
- View More
TCE contamination of groundwater
Trichloroethylene (TCE) is a man-made chlorinated solvent, used primarily to remove grease from metal parts and textiles. In addition to TCE, related chlorinated solvents, or volatile organics compoun...
- View More
Effect of climate change and land use change on saltwater intrusion
Introduction Fresh water is a scarce resource. According to the World Meteorological Organization, only 2.5 percent of the total water volume on the Earth is fresh water an...
- View More
Water resources
Introduction Water resources are used in various ways including direct consumption, agricultural irrigation, fisheries, hydropower, industrial production, recreation, navigation, environme...
- View More
Water governance
Abstract The water sector worldwide is increasingly characterized in terms of a crisis situation. The unique and complex characteristics of the water resource entail complex social, political, and e...
- View More
Governance of water resources in Africa
Introduction Governance is the central issue for water resources, especially in the light of water scarcity and environmental change, and is critical for maximizing available opportunities. Threats ...
- View More
Society and water resources
Water is central to survival—without it, plant and animal life would be impossible. Water is a central component of Earth’s ecosystems, providing important controls on the weather and climate. Wat...
- View More
Water profile of Kuwait
Geography and Population Kuwait, with a total area of 17,820 square kilometers (km2), lies at the head of the Persian Gulf. It is bordered in the north and north-west by Iraq, in the south and south...
- View More
Transborder conservation
Transborder, or transboundary, conservation can be loosely defined as the subset of international relations focusing on particular international borders and border regions. To some degree, the word t...
- View More
Rock cycle
The rock cycle is a general model that describes how various geological processes create, modify, and influence rocks (Figure 1). This model suggests that the origin of all rocks can be ultimately...
- View More
Soil forming factors
The Russian geologist Vasily Dokuchaev (1846–1903), considered the father of soil science, was the first to identify and discuss, at the end of 19th century, what we know today as the “factors of ...
- View More
Composition of rocks
Table 1: Common elements found in the Earth's rocks. Element Chemical Symbol Percent Weight in Earth's Crust ...
- View More
Soil erosion and deposition
Introduction Erosion is defined as the removal of soil, sediment, regolith, and rock fragments from the landscape. Most landscapes show obvious evidence of erosion. Erosion is responsible ...
- View More
Student Assignment 100
Introduction: This assignment presents the requirements and key dates for a proposal, interim and final deliverables for a term p...
- View More
Soil & soil dynamics
Global water resources & use
The Atmosphere
Earth science concepts