Rainfall Climatology Average annual precipitation 30-year normal precipitation.

Slides:



Advertisements
Similar presentations
Hydrology Rainfall - Runoff Modeling (I)
Advertisements

Analysis of Hydrographs
Hydrologic Statistics
CHARACTERISTICS OF RUNOFF
Rainfall-Runoff Modeling
Engineering Hydrology (ECIV 4323)
Forest Hydrology: Lect. 18
Hydrograph Interpretation.
I am sure you have heard about the farmer in Sidell, Illinois. After that fiasco with the cheese being left standing alone taking the blame for polluting.
Infiltration Infiltration is the process by which water penetrates from ground surface into the soil. Infiltration rate is governed by: rainfall rate hydraulic.
Hydrologic Theory One of the principal objectives in hydrology is to transform rainfall that has fallen over a watershed area into flows to be expected.
River Hydrographs Why do we use hydrographs?
Construction And Analysis Of Hydrographs. Hydrograph Record of River Discharge over a period of time River Discharge = cross sectional area rivers mean.
Analysis of Hydrographs
Upper Brushy Creek Flood Study – Flood mapping and management Rainfall depths were derived using USGS SIR , Atlas of Depth Duration Frequency.
International Institute for Geo-Information Science and Earth Observation (ITC) ISL 2004 RiskCity Introduction to Frequency Analysis of hazardous events.
Start Audio Lecture! FOR462: Watershed Science & Management 1 Streamflow Analysis Module 8.7.
Precipitation statistics Cumulative probability of events Exceedance probability Return period Depth-Duration-Frequency Analysis.
Chapter 3 -Hydrology Hwk#3 - pp ,4,7,11 Hydrologic Cycle Runoff - Ground Surface Water Infiltration - Ground Penetration (percolation) Transpiration.
Construction Analysis Hydrographs
Urban Hydrology and Water Budget Calculation Geog310 Urban Climatology.
Hydrology & Water Resources Engineering
Analyses of Rainfall Hydrology and Water Resources RG744
Statewide Map-based IDF Analysis Norman Gonsalves for Caltrans.
Estimation of Areal Precipitation from point measurements Most often interested in quantifying rainfall over an entire watershed. Has to be inferred from.
I am sure you have heard about the farmer in Sidell, Illinois. After that fiasco with the cheese being left standing alone taking the blame for the failure.
WinTR-20 SensitivityMarch WinTR-20 Sensitivity to Input Parameters.
Flood hydrographsHydrosphere. Flood hydrographs show the effect that precipitation has on the water levels in a river. After a storm the water levels.
Construction And Analysis Of Hydrographs Hours from start of rain storm Discharge (m 3 /s) Base flow Through flow Overland.
Construction And Analysis of Hydrographs ©Microsoft Word clipart.
Precipitation Types Important for Real Time Input and Forecasting
James River in Richmond, Virginia looking upriver from the Robert E. Lee bridge. Belle Isle is on the right, November What is happening in this.
Urban Storm Drain Design: Rainfall-Runoff relations.
Frequency Analysis and Data Reading: Applied Hydrology Sections
CE 424 HYDROLOGY 1 Instructor: Dr. Saleh A. AlHassoun.
Construction And Analysis of Hydrographs ©Microsoft Word clipart Ballakermeen High School.
DES 606 : Watershed Modeling with HEC-HMS Module 8 Theodore G. Cleveland, Ph.D., P.E 29 July 2011.
Rick Cruse, Matt Helmers, Greg Brenneman, and John Laflen Iowa Water Center, and Iowa State University Extension.
WinTR-20 SensitivityFebruary WinTR-20 Sensitivity to Input Parameters.
Fluvial Geomorphology GRG 338-C Streamflow (Discharge)
Engineering Hydrology Discussion Ch. #6 Hydrographs
Watershed Pauline Demerjian Mariela Gonzalez Rodolfo Salgado Anthony Blanco Kevin Albanes Diana Perez.
Basic Hydrology: Rainfall-Runoff – I
Introduction to Urban Hydrology
Surface Water Applied Hydrology. Surface Water Source of Streamflow Streamflow Characteristics Travel Time and Stream Networks.
VERIFICATION OF A DOWNSCALING SEQUENCE APPLIED TO MEDIUM RANGE METEOROLOGICAL PREDICTIONS FOR GLOBAL FLOOD PREDICTION Nathalie Voisin, Andy W. Wood and.
Module 10: Average Rainfall Theodore G. Cleveland, Ph.D., P.E, M. ASCE, F. EWRI August 2015 Module 10 1.
-1 DR. S & S. S GHANDHY GOVT. ENGINEERING COLLEGE, SURAT. SUB : HYDROLOGY & WATER RESOURCES ENGINEERING ( ) TOPIC : HYETOGRAPH & HYDROGRAPH ANALYSIS.
Analyses of Rainfall Hydrology and Water Resources RG744 Institute of Space Technology October 09, 2015.
STORMWATER MASTER PLAN TASK FORCE November 20, 2006.
Nicolson Institute - Geography Department The objectives of this PowerPoint presentation and the accompanying work sheet are to - introduce storm hydrographs.
HYDROGRAPHS: CONSTRUCTION AND ANALYSIS 01/10/2016.
Precipitation Measurement
HYDROLOGY Lecture 10 Unit Hydrograph
Rainfall-Runoff modeling
Analysis of Hydrographs
HYDROSPHERE 2.
Construction Analysis Hydrographs
Basic Hydrology & Hydraulics: DES 601
Flood Frequency Analysis
Introduction to Urban Hydrology
Chapter 3 -Hydrology Hwk#3 - pp ,4,7,11 Hydrologic Cycle
Analysis of Hydrographs
Precipitation Analysis
Hydrologic Statistics
Hydrology CIVL341.
Weekly lesson objectives
Analysis of Hydrographs
Analysis of Hydrographs
Hydrology CIVL341 Introduction
Presentation transcript:

Rainfall Climatology Average annual precipitation 30-year normal precipitation

Rainfall Climatology

Characteristics of individual storms

Rainfall Climatology TIMECU RAIN TIME IN. RAINDUR.MAX. RN INT

Rainfall Climatology

Intensity-Duration-Frequency Analysis Extreme-value distribution

Rainfall Climatology Recurrence interval (RP) P = exceedence probability; chance that the annual maximum event of any year (e.g. 5-minute maximum) will equal or exceed some given value 5% probability that in any year the annual maximum 24-hour rainfall will equal or exceed 88 mm 1 n + 1 T = = p m

Rainfall Climatology

HOW CAN WE HAVE TWO "100-YEAR FLOODS" IN LESS THAN TWO YEARS? This question points out the importance of proper terminology. The term "100-year flood" is used in an attempt to simplify the definition of a flood that statistically has a 1-percent chance of occurring in any given year. Likewise, the term "100-year storm" is used to define a rainfall event that statistically has this same 1-percent chance of occurring. In other words, over the course of 1 million years, these events would be expected to occur 10,000 times. The amount of rainfall in the city of Charlotte and Mecklenburg County and the subsequent flooding in August 1995 had no influence on the events of July These events, as well as any recurring events, are assumed to be statistically independent of each other. Therefore, each year begins with the same 1-percent chance that a 100-year event will occur.

Rainfall Climatology DOES A 100-YEAR STORM ALWAYS CAUSE A 100-YEAR FLOOD? No. Several factors can independently influence the cause-and-effect relation between rainfall and streamflow. When rainfall data are collected at a point within a stream basin, it is highly unlikely that this same amount of rainfall occurred uniformly throughout the entire basin. During intensely localized storms, rainfall amounts throughout the basin can differ greatly from the rainfall amount measured at the location of the raingage. Some parts of the basin may even remain dry, supplying no additional runoff to the streamflow and lessening the impact of the storm. Consequently, only part of the basin may experience a 100-year rainfall event. Existing conditions prior to the storm can influence the amount of stormwater runoff into the stream system. Dry soil allows greater infiltration of rainfall and reduces the amount of runoff entering the stream. Conversely, soil that is already wet from previous rains has a lower capacity for infiltration, allowing more runoff to enter the stream. Another factor to consider is the relation between the duration of the storm and the size of the stream basin in which the storm occurs. For example, a 100-year storm of 30-minutes duration in a 1-square-mile (mi2) basin will have a more significant effect on streamflow than the same storm in a 50-mi2 basin. Generally, streams with larger drainage areas require storms of longer duration for a significant increase in streamflow to occur.