Wadi

A wadi is a dry riverbed or valley that only fills with water during periods of heavy rainfall or snowmelt.  These watercourses are typically found in arid or semi-arid regions, where precipitation is infrequent and unpredictable.  The term “wadi” comes from the Arabic word for valley or channel, and these features can range in size from small, shallow depressions to deep canyons.  Wadis are important features of desert landscapes, as they provide vital habitats for plant and animal species, and can also serve as corridors for human travel.

Wall Rock

Wall rock refers to the rock that surrounds and encloses an ore body or mineral deposit.  This rock is often different in composition and texture from the ore itself, and can provide valuable information about the geological processes that led to the formation of the deposit.  Wall rock can also be an important factor in determining the economic viability of a mineral deposit, as it can affect the cost and efficiency of mining operations.

Water Balance

Water balance refers to the relationship between the amount of water entering and leaving a particular system, such as a river basin, lake, or ecosystem.  This balance is determined by the interaction of various factors, including precipitation, evaporation, infiltration, and runoff. A positive water balance occurs when the amount of water entering a system exceeds the amount leaving it, resulting in increased water storage.  A negative water balance occurs when the opposite is true, leading to decreased water storage and potential water scarcity.

Water Cycle

The water cycle, also known as the hydrologic cycle, is the continuous movement of water through the Earth’s atmosphere, oceans, land surface, and subsurface.  This cycle involves a complex series of processes, including evaporation, condensation, precipitation, infiltration, and runoff.  These processes are driven by solar energy and the Earth’s rotation, and play a crucial role in regulating the planet’s climate and supporting life.  The water cycle is closely linked to other natural cycles, such as the carbon and nitrogen cycles, and is affected by human activities such as land use change and pollution.

Water Gap

A water gap is a geological feature that occurs when a river or stream cuts through a ridge or mountain range, creating a narrow valley or gap.  Water gaps are often formed over millions of years as erosion gradually wears away the rock and soil, leaving a deep channel in its wake.  These features can be found in many different types of terrain, from the rugged mountains of the Appalachian Range to the rolling hills of the Midwest.  Water gaps can provide important habitats for plant and animal species, as well as opportunities for outdoor recreation such as hiking and fishing.

Water Table

The water table is the level at which the ground is saturated with water. This level can vary depending on factors such as precipitation, soil type, and topography, and can be located at different depths throughout a given area.  The water table is an important concept in hydrology, as it affects the availability of groundwater for human use and the health of ecosystems that depend on this resource.  Groundwater is often accessed by drilling wells into the aquifers that lie below the water table.

Watercourse

A watercourse is any natural or man-made channel that carries water, such as a river, stream, or canal.  Watercourses are an important feature of many landscapes, as they provide habitats for aquatic and riparian species, as well as opportunities for human recreation and transportation.  The characteristics of a watercourse can vary widely depending on factors such as slope, flow rate, and sediment load.  Human activities such as damming and diversion can also have a significant impact on the ecology and hydrology of watercourses.

Waterfall

A waterfall is a natural feature that occurs when a river or stream drops over a vertical or nearly vertical cliff, creating a dramatic cascade of water. Waterfalls are found all over the world, from the towering falls of Niagara to the remote and secluded cascades of the Amazon rainforest.  These features can be a popular destination for tourists and nature lovers, as well as an important source of hydroelectric power.  Waterfalls can also provide habitats for unique plant and animal species that have adapted to the challenging environment of the falls and the surrounding area.

Watershed

A watershed is an area of land that drains water into a common outlet, such as a river, lake, or ocean.  This area is defined by the topography of the land, with higher elevations forming the boundary of the watershed.  The water that flows into a watershed can come from precipitation, groundwater, or surface runoff, and can have a significant impact on the quality and quantity of water available downstream.  Watersheds are an important concept in hydrology, as they provide a framework for understanding the movement and storage of water in natural systems.

Watershed Map

A watershed map is a type of map that shows the geographic boundaries of a watershed, which is an area of land where all the water drains into a particular body of water, such as a river or lake.  Watershed maps are important for understanding the movement of water across the landscape and the potential impacts of human activities on water quality and availability.  They are used by environmental scientists, urban planners, and policymakers to study the effects of land use changes, such as urbanization and deforestation, on water resources.  Watershed maps can also be used to identify areas where conservation efforts are needed to protect sensitive ecosystems and endangered species.  In addition, they are useful for emergency management planning, as they can help predict the path and magnitude of floods and other water-related disasters.

Wave

A wave is a disturbance that travels through a medium, such as air or water, causing oscillations in the particles of that medium.  In the context of water, waves are often created by wind or other disturbances, and can vary widely in size and intensity.  Waves can have a significant impact on coastal ecosystems and infrastructure, as well as providing opportunities for recreation such as surfing and boating.  The study of waves is an important field of research in physics, fluid mechanics, and oceanography.

Wave-cut Platform

A wave-cut platform is a flat, rocky surface that forms at the base of a sea cliff as a result of wave erosion.  These features are created as waves pound against the base of the cliff, undercutting the rock and causing it to collapse into the sea.  Over time, this process can create a broad, level platform that extends out from the base of the cliff.  Wave-cut platforms can provide important habitats for intertidal species, as well as offering opportunities for scientific research and recreational activities such as tidepooling.

Wave-cut Terrace

A wave-cut terrace is a horizontal or gently sloping surface that forms above a wave-cut platform as a result of continued wave erosion.  These features are created as waves undercut the rock at the base of the cliff, causing it to collapse and creating a new cliff face. Over time, this process can result in the formation of a series of terraces at different elevations above the sea.  Wave-cut terraces can be found in many coastal areas, and can provide important insights into the geological history and processes of the region.

Wavelength

Wavelength is the distance between two consecutive points on a wave that are in phase, meaning that they are at the same point in their oscillation cycle. In the context of topography, wavelength can refer to the distance between successive peaks or troughs of a topographic feature, such as a series of sand dunes or ocean waves.  Wavelength is an important concept in physics, as it is related to the frequency and speed of a wave, and can be used to characterize a wide range of phenomena.

Weather

Weather refers to the current atmospheric conditions in a specific location, including temperature, humidity, precipitation, wind speed and direction, and other factors.  Weather is constantly changing and can be influenced by a wide range of factors, including the season, topography, and global weather patterns.  Weather can have a significant impact on human activities and infrastructure, as well as on natural systems such as ecosystems and watersheds.

Weathering

Weathering is the process by which rock and soil are broken down by physical, chemical, or biological means.  This process can be caused by a wide range of factors, including temperature changes, water, wind, and plant roots.  Weathering can have a significant impact on the topography of a region, as it can lead to the formation of new landforms such as canyons, valleys, and rocky outcrops.  The study of weathering is an important field of research in geology and earth science, as it can provide insights into the history and formation of the Earth’s crust.

Wedge

In topography, a wedge is a triangular-shaped landform that is formed when two geologic plates converge and one is forced upward.  This process is often associated with tectonic activity and can lead to the formation of mountain ranges, such as the Himalayas.  Wedges can also be formed by the deposition of sediment in a triangular shape, such as in the case of alluvial fans or river deltas.  The formation and study of wedges is an important area of research in geology, as it can provide insights into the movement and structure of the Earth’s crust.

Welded Tuff

A welded tuff is a type of volcanic rock that forms when hot ash and pumice are ejected from a volcano and settle on the ground.  Over time, these materials can become compacted and cemented together by the heat and pressure of the surrounding rocks, forming a solid, dense mass.  Welded tuffs can be found in many volcanic regions around the world and are often used as building materials due to their strength and durability.

Well

A well is a man-made hole in the ground that is dug to access water or other resources, such as oil or gas.  Wells can be found in many different contexts, including residential, agricultural, and industrial settings.  The depth and design of a well can vary widely depending on the location and the purpose for which it is intended.  Wells are an important source of water for many communities around the world and play a critical role in agriculture and industry.

Wetland

A wetland is a type of ecosystem that is characterized by the presence of water, either seasonally or permanently.  Wetlands can be found in a wide range of environments, including coastal regions, floodplains, and mountain valleys.  They are important habitats for a wide range of plant and animal species, many of which are unique to wetland environments.  Wetlands also provide a number of important ecosystem services, including water filtration, flood control, and carbon sequestration.

Whole Rock Analysis

Whole rock analysis is a technique used in geology to determine the composition and properties of rocks.  In this technique, an entire rock sample is crushed and then analyzed to determine its mineral content, chemical composition, and other properties.  This technique is often used in the study of igneous rocks, such as volcanic rocks, as well as in sedimentary and metamorphic rocks.  Whole rock analysis is an important tool in the study of geology, as it can provide insights into the formation and history of rocks.

Wind

Wind is the movement of air across the surface of the Earth.  It is caused by differences in temperature and pressure between different parts of the atmosphere, as well as the rotation of the Earth.  Wind can have a significant impact on the environment, shaping landscapes and affecting weather patterns. It can also be harnessed for energy generation through wind turbines.

Wind Gap

A wind gap is a geological feature that occurs when a river changes its course, leaving behind a narrow gap in a ridge or mountain range.  Over time, wind can erode the rock and widen the gap, creating a passageway for air to flow through.  Wind gaps are often found in areas where the rock is resistant to erosion, such as sandstone or limestone.

Windbreak

A windbreak is a physical barrier, such as a wall or row of trees, that is designed to protect an area from the damaging effects of wind.  Windbreaks are commonly used in agricultural and horticultural settings to protect crops and other plants from wind damage.  They can also be used in residential and commercial settings to provide shelter from strong winds.  Windbreaks are an important tool in the management of the environment, as they can help to prevent erosion and conserve soil moisture.

Windward

Windward is a term used to describe the side of a mountain or other terrain feature that faces the prevailing wind.  In this position, the windward side is exposed to higher levels of precipitation, which can lead to the formation of lush forests and other vegetation.  The opposite side of the terrain feature is known as the leeward side, which tends to be drier and less vegetated.

Winter Solstice

The winter solstice is an astronomical event that occurs on or around December 21st each year in the Northern Hemisphere, and June 21st in the Southern Hemisphere.  It marks the shortest day and longest night of the year, as the tilt of the Earth’s axis causes the Sun to appear at its lowest point in the sky.  The winter solstice has been celebrated in many cultures throughout history, as a symbol of the return of light and the triumph of life over darkness.

Wishbone Diagram

A wishbone diagram is a tool used in engineering and product design to identify and analyze the various factors that contribute to a specific problem or issue. It is named for its resemblance to the shape of a wishbone, with the problem or issue at the top and the contributing factors branching out below. The diagram can help to identify the root cause of a problem and guide the development of solutions.

Wolframite

Wolframite is a mineral that is commonly used as a source of tungsten, a metal with a wide range of industrial and technological applications.  It is typically found in granitic and metamorphic rocks, as well as in hydrothermal veins.  Wolframite is valued for its hardness and high melting point, which make it useful in the production of alloys, electrical contacts, and other products.

Woodland

Woodland is a type of ecosystem characterized by a dense growth of trees and other woody vegetation.  It is typically found in areas with moderate rainfall and fertile soil, and can range from tropical rainforests to temperate deciduous forests.  Woodland ecosystems provide habitat for a wide variety of plant and animal species, and can also provide important ecosystem services such as carbon sequestration and water filtration.

World Map

A world map is a representation of the Earth’s surface that shows the continents, oceans, and other major features.  There are many different types of world maps, including political maps that show national borders and cities, physical maps that show topography and landforms, and thematic maps that show specific data such as population density or climate zones.  World maps are important tools for understanding the geography and history of the world, and can be used for a wide range of educational, scientific, and practical purposes.