| Words | Definition | Source |
| Alluvial Soil | Alluvial soils are soils deposited by surface water, found near rivers, floodplains, and streams. They are an important category of soils. They provide many functions in our ecosystem. Alluvial soils remove sediments and nutrients flowing in the adjacent water. They can also remove other contaminants from rivers and improve water quality for downstream communities | Link |
Anaerobic | When the soil or substrate has little to no available oxygen. | Link |
| Aquifer | An aquifer is a body of porous rock or sediment saturated with groundwater. Groundwater enters an aquifer as precipitation seeps through the soil. It can move through the aquifer and resurface through springs and wells. Thus, an aquifer is an underground formation of permeable rock or loose material that can produce useful quantities of water when tapped by a well | Link |
| Atoms | It is the smallest constituent unit of matter that possess the properties of the chemical element. Atom is the basic of all matter. They are very small and consist of even tinier particles. Neutrons, Protons, and Electrons are the basic particles making up the atom | Link |
Basin outlet | The most downstream point of a drainage basin past which all flow from an upstream watershed flows. | Link |
Biogeochemical processes | The term biogeochemical is derived from “bio” meaning biosphere, “geo” meaning the geological components and “chemical” meaning the elements that move through a cycle. | Link |
Catchment | The area contributing surface water flow to a point on a drainage or river system | Link |
Constructed wetlands | Specifically designed features installed in the landscape that use naturally occurring physical, ecological and chemical processes to treat polluted water | Link |
Cross connections | Any situation where foul water can get into the surface water system, these include dual manholes, where the two systems share a manhole chamber, and piped connections, which were sometimes installed to reduce the risk of sewer flooding, as well as misconnections | Link |
Daylighting | Daylighting rivers or streams is the process of removing obstructions (such as concrete or pavement) that are covering a river, creek, or drainage way and restoring them to their previous condition | Link |
Desalination | Process that removes salts from water | Link |
Dew | Dew is the moisture that forms at night when objects or the ground outside cool down by radiating, or emitting, their heat | Link |
| Ecotones | An ecotone is a border zone, where ecological systems meet and mingle, sometimes forming a new and different community. Ecotones occur at edges and physical boundaries, where fresh water meets salt water and water meets land, where tides roll up and down coasts, where woodlands become pastures and the fir trees of taiga forests give way to the lichen and grass of tundra | Link |
| Estuary | An estuary can be defined as a partially enclosed body of water formed where freshwater from rivers and streams mixes with seawater as the tides advance and recede. | Link |
| Eutrophication | Water pollution caused by high nutrient levels which stimulate algal growth, excessive algal growth (or ‘blooms’) use up oxygen, resulting in reduced water quality | Link |
| Evaporation | Evaporation is the process that changes liquid water to gaseous water (water vapor) | Link |
| Evapotranspiration | Evapotranspiration is the sum of all processes by which water moves from the land surface to the atmosphere via evaporation and transpiration. Evapotranspiration includes water evaporation into the atmosphere from the soil surface, evaporation from the capillary fringe of the groundwater table, and evaporation from water bodies on land. Evapotranspiration also includes transpiration, which is the water movement from the soil to the atmosphere via plants | Link |
| Flood | To overflow or cover in water or another liquid. | |
| Flood Plain | A floodplain is a lowland area that is susceptible to flooding from an adjoining watercourse, ocean, lake or other body of water. | Link |
| Frost | Frost is water vapor, or water in gas form, that becomes solid. Frost usually forms on objects like cars, windows, and plants that are outside in air that is saturated, or filled, with moisture | Link |
| Ghost Stream | Buried beneath the pavement , an invisible network of waterways flows through. These are called ghost streams | Link |
Groundwater | Groundwater, a vital natural resource, resides within aquifers beneath the Earth’s surface. It is found underground in the spaces between particles of rock and soil, or in crevices and cracks in rock. Groundwater is not confined to only a few channels or depressions in the same way that surface water is concentrated in streams and lakes. Rather, it exists almost everywhere underground. The level below which all the spaces are filled with water is called the water table. Above the water table lies the unsaturated zone. Here the spaces in the rock and soil contain both air and water. Water in this zone is called soil moisture. The entire region below the water table is called the saturated zone, and water in this saturated zone is called groundwater | Link |
| Hail | Ice stones falling from the sky – is known as hailstone. Any thunderstorm that results in the falling of hailstones is called hail. Hail generally ranges from pea- to softball-sized and can damage property and injure people. Hail forms when warming at the Earth’s surface causes water to evaporate and rise, eventually reaching freezing temperatures higher in the atmosphere | Link |
Hydric soil | Soils formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part of the soil profile. In wetlands, hydric soil supports the growth and regeneration of vegetation that has adapted to grow in saturated/inundated and low-oxygen conditions. Oftentimes the soil can be used to help identify a wetland type for purposes like wetland delineation. Scientists can study soil to better understand wetland ecosystems that can support conservation and restoration purposes | Link |
Hydrophytes | Wetland plants are hydrophytes (hydro = water, phyte = plant). These are plants growing in water or on soil that at least periodically is deficient in oxygen due to excessive water content. | Link |
| Hydroponics | Method of farming or where plants can be grown in nutrient-fortified water, instead of in soil | Link |
| Hygroscopic | Material/substances that adsorb water vapor from the air and absorb liquid water from the environment | Link |
| Hypoxic zone | Low oxygen zones in oceans and lakes. This occurs because of a process called eutrophication, which happens when a body of water gets too many nutrients, such as phosphorus and nitrogen | Link |
| Ice | Ice is water in its frozen, solid form. Ice has different properties than most room-temperature liquids do in their solid form. | Link |
| Ice sheet | An ice sheet is a mass of glacial land ice extending more than 50,000 square kilometers (20,000 square miles). Like a glacier, an ice sheet forms through the accumulation of snowfall in areas where annual snowfall exceeds annual snowmelt. Over thousands of years, layers of snow build up, becoming more dense and transforming into glacial ice. The ice thickens to such a point that the pressure of the accumulated ice triggers movement, forming a flowing sheet of ice tens to thousands of meters thick and tens to thousands of kilometers across. | Link |
| Iceberg | An iceberg is ice that broke off from glaciers or shelf ice and is floating in open water. | Link |
| Interception, Interception loss | That part of the precipitation on the canopy that doesn’t reach the ground, because it evaporates from the canopy (canopy interception loss) and from near-ground plants and leaf litter (litter interception loss) or, to a lesser extent, is absorbed by plants | Link |
| Levee | A levee is a natural or artificial wall that blocks water from going where we don’t want it to go. Levees may be used to increase available land for habitation or divert a body of water so the fertile soil of a river or seabed may be used for agriculture. They prevent rivers from flooding cities in a storm surge. But if a levee breaks, the consequences can be disastrous. | Link |
| Molecules | A group of two or more than two atoms of the same or different elements that are chemically bonded together is called a molecule. | Link |
| Peat | Peat is the surface organic layer of a soil that consists of partially decomposed organic matter, derived mostly from plant material, which has accumulated under conditions of waterlogging, oxygen deficiency, high acidity and nutrient deficiency. | Link |
| Peatland | In temperate, boreal and sub-arctic regions, where low temperatures (below freezing for long periods during the winter) reduce the rate of decomposition, peat is formed mainly from bryophytes (mostly sphagnum mosses), herbs, shrubs and small trees. | Link |
Periglacial environment | The periglacial environment is a cold climate, frequently marginal to the glacial environment, and is characteristically subject to intense cycles of freezing and thawing of superficial sediments. Permafrost commonly occurs within this periglacial environment. | Link |
| Permafrost | Permafrost, also known as perennially frozen ground, is generally considered to be a thickness of soil, surficial deposits, or bedrock at a variable depth below the surface of the earth in which the temperature of the matrix has existed below the freezing point of water for a period of at least several years. Permafrost therefore may consist of frozen soil, frozen bedrock, and clear ice. | Link |
| Permeable | Material contains interconnected cracks or spaces that are both numerous enough and large enough to allow water to move freely | Link |
Porous media | Aquifers consisting of aggregates of individual particles such as sand or gravel | Link |
Precipitation | Precipitation is any liquid or frozen water that forms in the atmosphere and falls back to the earth. It comes in many forms, like rain, sleet, and snow. Along with evaporation and condensation, precipitation is one of the three major parts of the global water cycle | Link |
Rainfall runoff | Water that flows over the land surface over impermeable (e.g. concrete yards) or permeable (e.g. fields, gardens) surfaces | Link |
Saline water | Water that is saline contains significant amounts (referred to as “concentrations”) of dissolved salts, the most common being the salt we all know so well—sodium chloride (NaCl). | Link |
Salinization | Salinization is an increase in the total dissolved solids (TDS) of the aquifer caused by natural or anthropogenic factors. The processes and sources of salinization vary for inland and coastal aquifers | Link |
Sleet | Sleet occurs when snowflakes only partially melt when they fall through a shallow layer of warm air. These slushy drops refreeze as they next fall through a deep layer of freezing air above the surface, and eventually reach the ground as frozen rain drops that bounce on impact. Depending on the intensity and duration, sleet can accumulate on the ground much like snow. | Link |
| Snow | Snow, by a simple definition, is a group of loosely connected ice crystals; ice is the solid form of water. Numerous factors influence snow production, including pollution in the air, wind speed, humidity and altitude. Snowflakes take on many different shapes depending on how the ice crystals come together as they fall from clouds through the atmosphere. | Link |
Transpiration | Transpiration is the process in which water is lost as water vapor from the aerial parts of the plants through stomata. Transpiration is essentially evaporation of water from the leaves of the plant | Link |
Vernal pools | Vernal pools, or seasonal pools, are a unique type of wetland habitat. They are typically small, shallow, ephemeral water bodies, and unlike a pond or a lake, they have no permanent inlet or outlet. They are filled each spring by rain and snow melt, then dry up for a period of time during the summer. | Link |
Cultivating a Hydrologic Imagination in Environmental Design