Popular in Geology
Popular in Geology
verified elite notetaker
This 3 page Study Guide was uploaded by Monica Huang on Sunday April 12, 2015. The Study Guide belongs to Geol370 at San Francisco State University taught by Dr.Sklar in Fall. Since its upload, it has received 220 views. For similar materials see Geology in Geology at San Francisco State University.
Reviews for Geology 370
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 04/12/15
Study guard of exam 2 Week 7 Watersheds Rivers and Floods Watersheds o How is a watershed de ned 0 Watershed components divide outlet channel network tributary junctions o lnter basin water transfers what are they Examples in California 1Definition of a Watershed All the land that drains to a given point along the ver 2 Watersheds are composed of Hillslopes and Channels 3 quotlnterBasin Water Transfersquot 1Trinity River Water Goes to Sacramento River 2 Eel River Water Goes to Russian River Hillslope ow paths 0 Overland flow shallow subsurface flow saturated overland flow groundwater ow How does water get from hill slope to the river 4 types of runoff from hill slopes 1 Surface or overland flow happens when precipitation exceeds in ltration depends on storm intensitv soil prooerties 2 Shallow subsurface flow happens because water moves through soil more easily than through rock 3 Saturated surface or overland flowhappens when soil becomes saturated and water ows out of soil 4 Groundwater Flow water ows throuoh saturated rock and soil to enter river throuoh bed and banks Basic river concepts 0 Channel crosssection components Bank bed thalweg oodplain 0 River ow Discharge Q Width W x Depth D x Velocity V o How is discharge measured 1 From a bridge when Q is too large to wade 2 Measuring Discharge from Cableway 3 The relationship between stage and discharge at a cross section of a river is called the stagedischarge rating curve 4 Measuring Discharge Continuously USGS stream gaging station 0 How do Q W D V change from headwaters to mouth of river 1 From river headwaters to river mouth how do these attributes change Discharge depth width and velocity ALL INCREASE o Hydrograph what is it Hydrograph Graphic representation of a river s discharge over time River morphology 0 River systems from mountain to ocean o Sediment transport bedload suspended load 0 Panform patterns Straight meandering braided Straight channel Usually steep channels ln mountain headwaters Debris ows happen Meandering Stream Panform Point bar deposition versus Cut bank erosion o Meander development cut bank point bar oxbow lake Oxbow Lakes when the former meander becomes isolated from the rest of the river Flooding 0 De nition of ood and relation to river stage Flooding Overbank ow condition Discharge Q greater than channel39s holding capac y Factors that affect ooding rain intensity rain amount soil condilons in ltralon rates basin characteristic Stage The height of the water level in a river at a given location and time Flooding stage is higher than top of channel banks 0 Types of ooding upstream vs downstream duration recurrence interval By stream location 0 Upstream ood Shorter duration smaller area 0 Downstream ood Longer duration greater magnitude larger area By duration Q Flash ood High volume of ooding water in very short duration characteristic short lag time usually in upstream Non ash ood What does it mean when R 100 years 10 years 500 years By magnituderecurrence interval 0 100year 50year 25year 10year oods Recurrence interval R in years R N 1M N is the number of years of record M is the rank of individual ow within the recorded years ex if R 500 we say a 39500 year ood event39 0 Probability P Relationship to Recurrence interval Probability 1Rx100 The probability P of a given magnitude ood What does it mean when P 10 10 02 etc P 1R Ex P 1500 0002 02 in any year P 1R Ex P 1100 001 10 in any year Statistical ooding probability verses reality Statistical probability One 100year ood on average once every 100 years or 1 in any year
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'