Water Cycle Actions Evaporation Condensation Precipitation Run off

Water Cycle Actions: • Evaporation • Condensation • Precipitation • Run off • Infiltration Storage: • Oceans • Lakes • Glaciers • Groundwater

Groundwater Movement • One of the most abundant sources of fresh water on the planet • Motion is controlled by two variables: – Porosity – Permeability

Porosity • Amount of empty space within a material – Material: sediment, fractured rock, sponge, etc • Affected by roundness and sorting of unconsolidated sediments • Expressed as a percent of total volume of substance – Porosity = (volume of pore space)/(total volume) * 100%

Permeability • Ability of water to flow through material – Cohesion, Adhesion? • Affected by pore size and connectedness of spaces • Small pores constrict water flow • Lack of connection between pores reduces/eliminates water flow

Capillary Action • Is the upward motion of ground water • Influenced by particle size – Smaller particles = higher water • Caused by adhesion of water to particles • As pore space gets larger, gravity takes over, pulling the water down • This is why you can dig in the sand near a beach and hit water above the height of the surface of the lake

What is a Budget? • A way to keep track of input/output of a system – Bank account – Water storage • Take the amount coming in, see if you owe anything, pay it, check your balance. If you don’t have enough, then you go into deficit (a la USA, $8, 000, 000).

Lab 25: Local Water Budget • P = Precipitation • Ep = potential evapo-transpiration • DSt = change in storage (same as amt of P-Ep, unless there wasn’t enough in storage from previous month) • Ea = actual evapo-transpiration; why could actual ever be less than potential? • S = surplus, equals (P-Ep)-DSt • D = deficit, the difference between Ea and Ep • St = storage; storage is expressed as a percentage (0 -100)

• When would storage of groundwater be at its maximum? • Start with a month you KNOW will either be full (100 St) or empty (0 St) • Finish this lab so you can use it on the next lab!

Think work 1/28 • Describe a sediment in which water would flow quickly. • Identify the names of all sediment sizes. • What property of sediments allow water to flow upward? • What happens to porosity with increased grain size? • What happens to permeability with increased grain size?

Bell work 1/26 • A region is experiencing a deficit of groundwater and 100 mm of rain falls. There is a potential of 250 mm of evapotranspiration. – How much water evaporates? – How much deficit does the region experience that month? • Monday: using computers to assemble your review sessions! Who still needs to sign up? ?

Climate • The characteristic weather of a region. • Primarily based on temperature (which leads to potential evapotranspiration) and precipitation. – Ratio of P: Ep • Weather is what happens short-term. Climate is the long-term trend of weather.

Other factors affecting climate • • • Latitude (insolation) Location of water and land areas Precipitation patterns Ocean currents Wind belts Vegetation

Climate Classification • Based on moisture, temperature: – Moisture: arid (<. 4), semiarid (. 4 -. 8), subhumid (. 8 -1. 2), humid (>1. 2) • Those numbers are climate ratios – Temperature: polar, subtropical, tropical – Vegetation: desert, grassland (steppe, taiga), deciduous forest & coniferous forest, rain forest • Climate Ratio = P/Ep • Calculate your climate ratios for budget lab

Effect of land/water on temperature • For a given latitude, temperature will vary less with proximity to water; -water has a moderating effect. • Example: San Francisco vs St. Louis Winter: SF=49, SL=32 Summer: SF=64, SL=78

Climographs • Show temperature and precipitation of a region. • Can be used to classify a region’s climate type. – How could you tell if you were in the southern hemisphere?

2/9 1. Norway has an annual precipitation of 1250 mm, and an annual potential evaporation of 1120 mm. Classify Norway in terms of climate zone. 2. What 2 effects do ocean currents have on Norway? 3. Why do large bodies of water have a moderating effect on annual temperature ranges?

What is the effect of ____ on climate? • • • Latitude? Bodies of water? Winds? Ocean circulation? Elevation? Mountains?

• Effect of _____ on climate? • Prevailing Wind patterns – Notice high pressure at 30 degrees? – High pressure = ? ? ? weather • Porosity/Permeability/capillary action – What affects these? – How does water flow faster? – Porosity is independent of particle size! • But what about mixing sizes together? • • Rainfall vs. output (evap, runoff, etc) Factors affecting runoff Reading a water budget (surplus, usage, deficit, recharge) Climate types, ratios