2.2 Perform Hydrological Analysis/ Interpret Ecological Analysis Flashcards
Includes rainfall, snowfall, and hail. The annual amounts, temporal distribution, and intensity or ___ vary geographically.
Percipitation
___ occurs on land and water surfaces. _____ from plants also returns water to the atmosphere
evapotranspiration (evaporation, transpiration)
This is percipitation that runs off the lands surface and flows downhill. Percipitation , soil type, slope, and vegetation all influence the amount of this
Surface Runoff
How are impervious surfaces detrimental to they hydrologic system?
- Significantly reduce groundwater recharge
- Subsequently lower the water table
- Depelete groundwater supplies
- Reduce ecologically important baseflow to streams and wetlands
Refers to water that infiltrates the lands’ surface and percolates downward to the underlying water table
Recharge
Water that is present in saturated ground, where all the pore spaces are completely filled with water
ground water
What is the term where groundwater discharged to streams, lakes, wetlands, or the ocean?
baseflow
What are some long-term negative effects from pumping a water supply or irrigation wells?
Wetland losses, diminished stream flows, depleted aquifers
Elements of natural hydraulic systems
Lakes, springs, rivers, aquifers, ocean
Land area that contributes surface water to a given location; defined and delineated by surface topography.
Watershed
What are the 5 watershed scale terms?
- Basin
- Subbasin
- Watershed
- Subwatersheds
- Catchment area
Defines major river, estuary, or lake drainage area that covers several thousand square miles. May cover major portions of a state or group of states.
Basin
Smaller in area than a basin, ranging from several hundred square miles in area
Subbasin
Subbasin is combosed of a set of even smaller watersheds, usually in the range of tens to a few hundred square miles.
Watershed
water shed is composed of ___ typically ranging in size from a few to several square miles. Often defined as the land are above the confluence of two second-order streams.
Subwatersheds
Measured in acres and can be defined as the land above a given point that drains to the first intersection of a stream
Catchment area
Where are impervious cover characterizations most noticeable?
Small streams and rivers
Watercourses that receive water input
Receiving Waters
What are examples of receiving waters?
Rivers, streams, lakes, oceans, reservoirs, aquifers, or other watercourses
What is of primary concern when creating a watershed plan for a stream?
Channel morphology, water quality, riparian cover, and temperature (think ecosystems within the stream)
What is of primary concern when creating a watershed plan for a freshwater lakes and reservoirs?
Phosphorous loading, sediment inputs, bacterial loading, and shoreline erosion (think standing water. bacteria, sediment, and phosphorous can really change the water)
What is of primary concern when creating a watershed plan for a coastal system?
Nitrogen, pathogens, and viruses
What is of primary concern when creating a watershed plan for a groundwater aquifer?
recharge rates, soluble pollutants, pathogen inputs, and connection between surface activities and groundwater
What are 4 watershed restoration techniques?
- Environmental site assessments and remediation (contaminated soils/ remediation)
- Preservation of natural remnants (think smart growth, avoiding fragmented natural systems)
- Restoration of impaired aquatic systems (habitat restoration, wetlands etc)
- Reuse and adaptation of existing buildings and infrastructure (don’t disturb ground further)
Subsurface areas that hold groundwater from which significant quantities of groundwater can be extracted
Aquifers
Three main types of aquifers
- Sand and gravel
- Fractured rock
- Limestone or Karst formations
What are some effects of having certain land uses overlaid on aquifers?
- Impervious surfaces preclude direct aquifer infiltration and reduce recharge
- Aquifers are highly permeable and can be easily contaminated (septic tanks, landfills)
- Landuses that demand large quantities of groundwater supplies (like golf) can caue land subsidence
What are some regulatory techniques available to protect aquifers?
-Zoning and subdivision ordinacnes and health regulations can all be developed to prohibit or limit certain land uses deemed to present unacceptable risks to underlying aquifers.
- ex. zoning can be used to preclude high-risk uses such as chemical manufacturing
- ex. wellhead protection areas can be mapped
What are some non regulatory techniques available to protect aquifers?
Land acquisition within identified aquifer areas, or posting signage to notify when entering a protection area
The amount of water that can be withdrawn from an aquifer without significant ecological impacts
Safe yield
1 acre to a depth of 1 foot
43,560 cubic feet
Large buildup of sediment in the channel that can induce channel instability; areas downstream may be sediment- starved, and cases the stream bed to erode and lower its elevation
channel downcutting
Flat bottomlands adjacent to river channels; accomodate floodwaters in excess of channel capacity, store floodwater, and thereby attenuate peak flows downstream
Floodplain
Bands of vegetation that flank a channel or lake
Riparian Corridor
Required in many areas to filter sediment from diffuse runoff, reduce nutrient concentrations through uptake by plants, contribute leaf litter and insects to the channel from riparian trees; provide wood to the channel as undercut trees fall in; and provide habitat for many species
Buffers
Typical widths for buffers
20-300 feet
- 100 feet minimum to filter pollutants
- 300 feet to protect wildlife habitat
Buffer depend on what you are buffering/ setting back
What are the three buffer zones?
Streamside - should be left as much undisturbed as possible
Middle - can accommodate some clearing for trails, bike paths
Outer - additional setback of 25 feet before first structure. Good for athletic fields, gardens
What are the major wetlands?
- Marshes
- Non tidal marshes
- Tidal Marshes
- Swamps
- Bogs
- Fens
Characterized by emergent soft-stemmed vegetation adapted to saturated soil conditions.
pH is normally neutral (more plants and wildlife)
Marshes
Adjacent to lakes, ponds, rivers, and streams, and also poorly drained areas where surface or groundwater can collect
Characterized by highly organic, mineral-rich soils of sand, silt and clay.
Vegetation - cattails, bulrushes, reeds
Nontidal marshes
Influenced by Ocean tides
Most often brackish but may be saline (salty) or even fresh.
Highly biological productivity
Help to reduce storm damage to coastlines, absorb excess nutrients and pollutants before they reach oceans and estuaries
Tidal Marshes
Include any wetland dominated by woody plants, such as trees or shrubs.
Saturated soils or standing water during certain times of the year
Highly organic soils
Dominance of woody plants
Swamps
Thick covering of sphagnum moss, spongy peat deposits, and acidic waters
Receive water from percipitation
Prevents water from leaving the surface
Acidic peat is main charactersitic
Bogs
Receive their water from groundwater and surace water
Because they receive water from sources other than precipitation, water is less acidic and have higher nutrient levels than bogs
More diverse flora and fauna
Emergent soft-stemmed vegetation
Fens
3 Ways designers deal with wetlands
- )Design development minimizes impact of natural wetlands
- ) Existing wetlands are degraded and need wetland restoration
- ) Constructed wetlands may be needed where none exist
Moss prevents water from leaving the surface
Plaudification
Coarser grain sizes have a ___ profile for beach slope
steeper
Finer grain soils have ___ profiles at the beach
flatter
Primary dune
Marks the seaward extent of dune stabilizing vegetation
Fore dune
Where are federal policies towards beaches and dunes primarily found
Coastal Zone Management Act (CZMA)
Transitional aquatic zone between freshwater river systems and open ocean
Estuary
Four types of estuary classification by geologic features
- ) Flooded river valleys; caused by sea level rise(Ex. Chesapeake Bay)
- ) Tectonic estuaries; caused by subsidence (Ex. SF Bay)
- ) Fjords; caused by glacial movement. Deeply cut valleys (ex. only found in alaska in US)
- ) Bar-built estuaries; creation by formation of barrier islands that create protected aquatic systems behind them (ex. Sound of Galveston Bay)
Three types of estuary mixes (salt & fresh water)
- ) Stratified (fresh and salt are largley separate)
- ) Partially Mixed (large areas of brakish, range of water salinities
- ) Fully Mixed (salinity levels constant throughout)
