Hydrology in the context of "Antarctic Convergence"

In hydrology, discharge is the volumetric flow rate (volume per time, in units of m/h or ft/h) of a stream. It equals the product of average flow velocity (with dimension of length per time, in m/h or ft/h) and the cross-sectional area (in m or ft). It includes any suspended solids (e.g. sediment), dissolved chemicals like CaCO
₃(aq), or biologic material (e.g. diatoms) in addition to the water itself. Terms may vary between disciplines. For example, a fluvial hydrologist studying natural river systems may define discharge as streamflow, whereas an engineer operating a reservoir system may equate it with outflow, contrasted with inflow.

A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creation of a river delta occurs at the river mouth, where the river merges into an ocean, a sea, or an estuary, into a lake, a reservoir, or (more rarely) into another river that cannot carry away the sediment supplied by the feeding river. Etymologically, the term river delta derives from the triangular shape (Δ) of the uppercase Greek letter delta. In hydrology, the dimensions of a river delta are determined by the balance between the watershed processes that supply sediment and the watershed processes that redistribute, sequester, and export the supplied sediment into the receiving basin.

River deltas are important in human civilization, as they are major agricultural production centers and population centers. They can provide coastline defence and can impact drinking water supply. They are also ecologically important, with different species' assemblages depending on their landscape position. On geologic timescales, they are also important carbon sinks.

Geology is a branch of natural science concerned with the Earth and other astronomical bodies, the rocks of which they are composed, and the processes by which they change over time. The name comes from Ancient Greek γῆ (gê) 'earth' and λoγία (-logía) 'study of, discourse'. Modern geology significantly overlaps all other Earth sciences, including hydrology. It is integrated with Earth system science and planetary science.

Geology describes the structure of the Earth on and beneath its surface and the processes that have shaped that structure. Geologists study the mineralogical composition of rocks in order to get insight into their history of formation. Geology determines the relative ages of rocks found at a given location; geochemistry (a branch of geology) determines their absolute ages. By combining various petrological, crystallographic, and paleontological tools, geologists are able to chronicle the geological history of the Earth as a whole. One aspect is to demonstrate the age of the Earth. Geology provides evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates.

The Mississippi River System, also referred to as the Western Rivers, is a mostly riverine network of the United States which includes the Mississippi River and connecting waterways. The Mississippi River is the largest drainage basin in the United States. In the United States, the Mississippi drains about 41% of the country's rivers.

From the perspective of natural geography and hydrology, the system consists of the Mississippi River itself and its numerous natural tributaries and distributaries. The major tributaries are the Arkansas, Illinois, Missouri, Ohio and Red rivers. Given their flow volumes, major Ohio River tributaries like the Allegheny, Tennessee, and Wabash rivers are considered important tributaries to the Mississippi system. Before the Mississippi River reaches the Gulf of Mexico, it runs into its distributary, the Atchafalaya River.

Groundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer. This process usually occurs in the vadose zone below plant roots and is often expressed as a flux to the water table surface. Groundwater recharge also encompasses water moving away from the water table farther into the saturated zone. Recharge occurs both naturally (through the water cycle) and through anthropogenic processes (i.e., "artificial groundwater recharge"), where rainwater and/or reclaimed water is routed to the subsurface.

The most common methods to estimate recharge rates are: chloride mass balance (CMB); soil physics methods; environmental and isotopic tracers; groundwater-level fluctuation methods; water balance (WB) methods (including groundwater models (GMs)); and the estimation of baseflow (BF) to rivers.

Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish itself. The term applies to various natural resources such as water aquifers, grazing pastures and forests, wild medicinal plants, fish stocks, and other wildlife.

In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at an unsustainable rate, given their natural rates of mortality and capacities for reproduction. Such practices can result in extinction at the population level and even extinction of whole species. In conservation biology, the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term is also used and defined somewhat differently in fisheries, hydrology, and natural resource management.

Wildlife management is the management process influencing interactions among and between wildlife, its habitats and people to achieve predefined impacts. Wildlife management can include wildlife conservation, population control, gamekeeping, wildlife contraceptive and pest control.

Wildlife management aims to halt the loss in the Earth's biodiversity, by taking into consideration ecological principles such as carrying capacity, disturbance and succession, and environmental conditions such as physical geography, pedology and hydrology. Most wildlife biologists are concerned with the conservation and improvement of habitats; although rewilding is increasingly being undertaken. Techniques can include reforestation, pest control, nitrification and denitrification, irrigation, coppicing and hedge laying.

Anthropocene is a term that has been used to refer to the period of time during which humanity has become a planetary force of change. It appears in scientific and social discourse, especially with respect to accelerating geophysical and biochemical changes that characterize the 20th and 21st centuries on Earth. Originally a proposal for a new geological epoch following the Holocene, it was rejected as such in 2024 by the International Commission on Stratigraphy (ICS) and the International Union of Geological Sciences (IUGS).

The term has been used in research relating to Earth's water, geology, geomorphology, landscape, limnology, hydrology, ecosystems and climate. The effects of human activities on Earth can be seen, for example, in regards to biodiversity loss, and climate change. Various start dates for the Anthropocene have been proposed, ranging from the beginning of the Neolithic Revolution (12,000–15,000 years ago), to as recently as the 1960s. The biologist Eugene F. Stoermer is credited with first coining and using the term anthropocene informally in the 1980s; Paul J. Crutzen re-invented and popularized the term.

In physical geography and hydrology, a channel is a landform on which a relatively narrow body of water is situated, such as a river, river delta or strait. While channel typically refers to a natural formation, the cognate term canal denotes a similar artificial structure.

Channels are important for the functionality of ports and other bodies of water used for navigability for shipping. Naturally, channels will change their depth and capacity due to erosion and deposition processes. Humans maintain navigable channels by dredging and other engineering processes.