Water Cycle Review & Stream Characteristics Powerpoints
Happy Tuesday! October 27th 2015
Today’s Agenda:
• Review what we’ve learned in Unit #3 • Discuss aquifer deple9on & the Ogallala • Jigsaw reading ac9vity
Today’s Objec2ve: EEn 2.4.1
• Explain consequences of aquifer deple9on including subsidence and salt-‐ water intrusion on the coast
WATER CYCLE REVIEW • Water __________ NEVER leaves the Earth
• It is constanly being recycled within the water cycle • The water cycle is driven by energy from the ______ SUN • Liquid water changes into a gas through _____________; evaporation that gas then condenses forming a _cloud _____; when the water becomes to heavy it falls as _precipitation ___________; where it either infiltrates into the ground or ____________ Runs-off the surface.
WATER CYCLE REVIEW • The process of evapora2on from plants is called _Transpiration ____________ • In other words, it’s like plants swea9ng
WATER CYCLE REVIEW • When rain falls on the land, some of the water is absorbed into the ground forming pockets of water called _________________ groundwater • Most groundwater eventually returns to the ________ oceans • Other precipita9on runs directly into streams or rivers; water that collects in rivers, streams, & oceans if called _________ runoff http://perso.orange.fr/prof.danglais/ animations/watercycle/watercycle.htm
EARTH’S WATER BALANCE • Even with all these different processes occurring, Earth’s water cycle is _balanced _______ • Balance in the water cycle means the average annual ____________ precipitation over Earth _______ equals the amount of water that ____________ evaporates • The fact that the ________________________ ocean levels haven’t changed indicates that the system is balanced
STREAMFLOW REVIEW • What force influences the way water makes its way to oceans? Gravity • Streams & rivers carry water downhill from the land to the sea • The 9me this journey takes depends largely on what factor? The stream’s velocity • Velocity is simply _d/t ___ in a given direc9on • The ability of a stream to erodes & transport materials depends on its velocity
STREAM STEEPNESS • The slope or steepness of a stream channel is called its ____________ Gradient
steeper the gradient, the more • The ____________ energy the stream has as it flows downhill Rise over run is the • The phrase _______________ "shorthand" of the formula
CHANNEL CHARACTERISTICS • A __________________ Stream channel is the course the water in a stream follows
• As water flows, it encounters _Friction _______ from the sides & boWom of the channel, which slows down the water • _______ Erosion occurs on the outer bends where water moves fastest • Sediment is _deposited ________ on the inner bends (where water velocity is low) and forms point bars
STREAMS REVIEW
• A meander is just a __________ bend in a river • The _discharge _________ of a stream is the volume of water flowing past a certain point in a given unit of 9me
• A stream ________ profile is a cross-‐sec9onal view of a stream from its source, or headwaters, to its mouth, or the point where the river emp9es into another body of water
STREAM PROFILE 1. Source/ headwater
4. Tributary _________ 5. _Levee ____ Delta 6._____
2. Meander ______ lake 3. Oxbow _________
7. _Mouth _____
STREAM DISCHARGE
• While gradient _decreases _________ between a stream’s headwaters and mouth, discharge ___________ increases
• A Tributary __________ is a stream that emp9es into another steam • ______________ Base level is the lowest point to which a stream can erode its channel
WATER CYCLE REVIEW Condensation Precipitation
Condensation
Surface Run off Evaporation Underground run off Accumulation
Transpiration
STREAM REVIEW • When a stream enters the rela9vely s9ll waters of an ocean or lake, it velocity drops • As a result, the stream deposits sediment & forms a Delta _____ • The side-‐to-‐side cuZng of a stream eventually produces a flat valley floor, called a floodplain __________ • It is appropriately named because during a flood the river overflows its banks and floods the plain
FLOOD REVIEW
FLOODS occur when the discharge of a • ________ stream becomes so great that is exceeds the capacity of its channel and overflows its banks
• There are several control strategies to manage floods including: • Ar2ficial _Levees ______ • Flood control _dams _____ • Placing limits on floodplain _development ___________
FLOOD CONTROL REVIEW • Ar2ficial _Levees ______ are earthen mounds built on the banks of a river
• When Hurricane ___________ Katrina hit New Orleans, over 50 levee breaches occurred resul9ng in many deaths in 2005
• Flood-‐control _dams _____ store floodwater and then let it out slowly • Today many scien9sts advocate sound floodplain management instead of building structures
FLOODING CAN BE DEADLY • Floods have historically been one of the most deadly types of disasters in the U.S.
• Many deaths are due to driving in a flood & consequently _Drowning __________
• Drinking water & recrea9onal waterways can be contaminated with sewage, agricultural waste, chemical pollutants, & animal waste
DISTRIBUTION REVIEW
• Some of the water infiltrates the ground but doesn’t travel far – stays in belt of soil moisture near the surface • Much of the water in soil seeps downward un9l it reaches the zone of _saturation _________ where water fills all of the open spaces in sediment & rock
• ________________ Groundwater is the H2O in this zone • The upper limit of this zone is the water ______ table
WATER TABLE REVIEW
• A water table describes the boundary between water-‐saturated ground & unsaturated ground
• Below the water table, rocks & soil are full of water • Pockets of water exis2ng below the water table are called _aquifers _______ • The amount of groundwater that can be stored depends on the % of the total volume of rock or sediment that consists of pore spaces, which is called _porosity _________
WATER TABLE REVIEW
Permeability of a material is its • The _______________ ability to release a fluid
• Permeable rock layers or sediments that transmit groundwater freely are aquifers • Aquifers are important because they are the source of ______________ Well water
• Good aquifers are those with high permeability such as poorly cemented sands, gravels, or highly fractured rock
AQUIFER DEPLETION • When water is pumped from an aquifer quicker than the rate of recharge, a cone of Depression may form and the water ______________ table level may drop
GROUNDWATER DEPLETION • Groundwater deple2on, or the long-‐term water-‐ level declines caused by sustained groundwater pumping is a key issue • Many areas of the US are experiencing groundwater deple9on
NEGATIVE EFFECTS • Groundwater deple2on is primarily caused by sustained groundwater pumping
• Some of the nega2ve effects of groundwater deple2on: • drying up of wells • reduc9on of water in streams & lakes • deteriora9on of water quality • increased pumping costs • land subsidence
NEGATIVE EFFECTS
NEGATIVE EFFECTS
• Pumping groundwater @ a faster rate than it can be recharged can have some nega9ve effects of the environment & the people who make use of the water • The most severe consequence of excessive groundwater pumping is that the water table below which the ground is saturated with water, can be lowered
For water to be withdrawn from the ground, water must be pumped from a well that reaches below the water table. If groundwater levels decline too far, then the well owner might have to deepen the well or drill a new well
NEGATIVE EFFECTS • Can also lower groundwater levels below the depth that streamside or wetland vegeta9on needs to survive
LAND SUBSIDENCE
• The basic cause of land subsidence is a loss of support below ground • Some9mes, when water is taken out of the soil, the soil collapses, compacts, & drops • Land subsidence is most oYen caused by human ac2vi2es, mainly from the removal of subsurface water
SALT WATER INTRUSION
• One water-‐quality threat to fresh groundwater supplies is contamina2on from saltwater saltwater intrusion • All of the water in the ground is not fresh water • Much of the very deep groundwater and water below oceans is saline • 3.1 million cubic miles (12.9 cubic kilometers) of saline groundwater exists compared to about 2.6 million cubic miles (10.5 million cubic kilometers) of fresh groundwater
SALT WATER INTRUSION • Under natural condi9ons the boundary between the freshwater and saltwater tends to be rela2vely stable • But pumping can cause saltwater to migrate inland and upward, resul9ng in saltwater contamina9on of the water supply In NY state, pumping water for domes9c supply has lowered the water table, reduced or eliminated the base flow of streams, & has caused saline groundwater to move inland
SALT WATER INTRUSION • Salt water intrusion is also an issue in Hilton Head, SC
GROUNDWATER DEPLETION • Groundwater deple2on has been a concern in the Southwest & High Plains for many years • But increased demands on our groundwater resources have overstressed aquifers in many areas of the Na2on
• The Ogallala Aquifer is a shallow water table aquifer located beneath the Great Plains in the US • It is one of the world's largest aquifers • It underlies an area of approximately 174,000 mi² in por9ons of eight states
THE OGALLALA AQUIFER
• Currently, the use of groundwater from the aquifer is unsustainable as withdrawals exceed the natural recharge of the aquifer
• Intensive agricultural & industrial prac2ces threaten the quality & quan9ty of the water
hWps://www.youtube.com/watch?v=XXFsS94HF08
GROUNDWATER DEPLETION
Review • The greatest % of water withdrawn in the Agriculture world is used for ______________ • The water cycle is complete when it Ocean returns to the ___________ • The process of evapora9on from plants is called _Transpiration ____________ • The over drilling for freshwater can lead to land _subsidence __________ & _salt ____ water intrusion
NC RIVER BASINS
• NC has 17 major river basins
• 5 are also part of the Mississippi river basin that drains to the Gulf of Mexico; all the others flow to the Atlan9c Ocean • 11 originate in NC; only 4 are en9rely connected within the state
NC RIVER BASINS
NC RIVER BASINS
• How we treat rivers & the land around them has a direct rela9onship to our quality of life
• A river basin is the land that water flows across or under on its way to a river (drainage area of a river)
• A river basin sends all the water falling on the surrounding land into a central river & out to an estuary or the sea • An estuary is a semi-‐enclosed area where fresh water from a river meets salty water from the sea
DIAGRAMS
NC WATERSHEDS
• A river basin drains all the land around a major river
• Basins can be divided into watersheds, or areas of land around a smaller river, stream, or lake
• Large river basins, such as the Neuse & Cape Fear, are made up of many smaller watersheds • The land is made up of many interconnected watersheds • Within a watershed, all water runs to the lowest point – a stream, river, lake, or ocean
NC GROUNDWATER
• On its way to the lowest point, water travels over the land surface – across farm fields, forestland, suburban lawns, city streets, etc.
• OR, it seeps into the soil & travels as groundwater
• Remember, groundwater is the water found in cracks & pores in sand, gravel, and rock fissures below the Earth’s surface • As water moves downstream, it carries & redeposits gravel, sand, & silt • Water also transfers bacteria, chemicals, and excess nutrients & organic ma^er
NC ECOSYSTEMS
• Whatever happens to the surface water or groundwater upstream will eventually affect downstream systems • Therefore, the health of the aqua2c ecosystem is directly related to ac9vi9es on land • An ecosystem is a natural system linked by living (plants & animals) and nonliving (soil, water, air) things
NC ECOSYSTEMS
• An ecosystem is a natural system linked by living (plants & animals) and nonliving (soil, water, air) things
WATER CYCLE
• The same amount of water on the planet today was present 3 billion years ago: not a drop more or less • Water on Earth circulates con2nuously in the water cycle • Water falls as rain, filters into the ground to recharge aquifers & runs along Earth’s surface as creeks, rivers, & streams • The same water transpires through plants or evaporates from the surface, re-‐enters the atmosphere as vapor & falls again as rain or snow
WATER CYCLE
YOUR ECOLOGICAL ADDRESS • The river basin you live in is one component of your ecological address • Even if you do not live on the waterfront, the land around your house drains to a river, estuary, or lake nearby • Into what river or stream does your land eventually drain? Cape Fear River Basin • Your ecological address is affected by 9 factors: river basin, topography, wetlands, groundwater, biodiversity, soil, air, climate, and energy
YOUR RIVER BASIN
• Remember, everyone lives in a river basin • Even if we don't live near the water, we live on land that drains to a river or estuary or lake • Our ac9ons on that land affect water quality & quan9ty far downstream
1. TOPOGRAPHY
• Topography describes the physical features of a place or the terrain – such as mountains, valleys, and floodplains
2. WETLANDS
• A wetland is an area where the water table is at, near, or above the land surface long enough during the year to support the growth of specially adapted plants • Wetlands help water flow & act like a sponge, filtering pollutants & providing flood control
3. GROUNDWATER
• If your drinking water comes from a well, the source is groundwater • What is the quality of groundwater where you live?
4. BIODIVERSITY
• Biodiversity is the totality of genes, species, & ecosystems in a region • Humans depends on biodiversity for food, medicine, and balanced natural systems
5. SOIL
• The local soil type determines what happens when bare soil is exposed to wind & rain; how ground water percolates; what kinds of plants grow
6. AIR • The quality of air influences forests, crops, & surface water • Pollutants in the air will eventually return to the ground & enter the water supply
7. CLIMATE
• Climate involves all the weather condi9ons prevailing in an area in general or over a long period of 9me
8. ENERGY
• Energy is the ability to do work • Everything we do requires energy • How much water is used to grow the food you eat?
YOUR ECOLOGICAL ADDRESS • A river is the course that water takes as it flows from the highest point in a river basin to the lowest • The river and it surrounding land make up rich & diverse ecosystems that provide habitats for numerous living creatures
• Your ecological footprint is the amount of land & water needed to support one’s lifestyle using current technology
YOUR DAILY IMPACT
NC RIVER BASIN PLANNING • In the 1980s, NC established a water quality management program focused on each of the state’s 17 river basins • The NC Department of Environment & Natural Resources’ Division of Water Quality updates the management plan for each river basin every five years based on data from water quality sampling • In 2014, the EPA approved NPS (Nonpoint source) management plan
NONPOINT SOURCE POLLUTION • Nonpoint source (NPS) pollu2on is any source of pollu9on that enters the environment through some means other than a discrete conveyance • The main form of nonpoint source pollu9on is the polluted runoff that drains into our streams, rivers, lakes and estuaries • Runoff occurs when rainwater, snowmelt, or irriga9on water doesn't soak into the ground & runs off the land into a body of water