Hydrology FINAL (Cumulative)

Standard Rain Gauge

Measures depth using a funnel attached to graduated cylinder.

Weighing Recording Gauge

Collects rainwater and measures depth using a spring scale beneath the bucket platform. Doesn’t underestimate intense rain and can measure other precipitation (rain, snow, hail)

Tipping Bucket Rain Gauge

Collects and channels precipitation into a see-saw container, that tips at a certain maximum (and sends an electrical signal). Less expensive, less maintenance, less accurate.

Non-Recording Rain gauge

collecting rainwater: economical, minimum intervention, less maintenance

recording rain gauge

collecting rainwater: more expensive, can be automated, measures intensities, measure accumulation

Satellites

(PERSIANN) measures precipitation

hyetograph

explains temporal distribution of precipitation event during a storm

Infiltration

defined as the flow of water through soil

what is this and what does it do?

ring infiltrometer, measures the rate at which water enters the soil

Van Genuchten/Rosetta

math model estimating soil retention curve

CHEMFLO

computer program that simulates water flow to understand flow and transport

Evaporation pan

oldest and simplest method, how much water evaporates from pan over time

Blaney Criddle

useful for air-temperature datasets available for a site

Jensen-Haise Alfalfa-Reference ET Radiation Method

obtaining 5-day daily ET estimate

Thornthwaite Method

predicts monthly potential ET from mean temperature

Penman Method

accounts for solar energy and a mechanism to remove water vapor; well-watered grass reference crop

Penman-Monteith

Why do we care about runoff?

flooding, low flows, impact assessment of changing land use

WHAT Model

(Web-based Hydrograph Analysis Tool) used for signal analysis and processing to separate high frequency signals and low frequency signals

AMC I

dry conditions, soils are dry [<35 mm rain growing season; <12 mm rain dormant season]

AMC II

normal conditions, [35-53 mm growing; 12-28 mm dormant]

AMC III

wet conditions, heavy rainfall [>53 mm growing; >28 dormant]

Time of concentration (Tc)

the longest time required for water to travel from the boundary to the outlet

Lag time (TL)

the average time for water from all locations to reach the outlet

Rational Method

use to estimate peak runoff for small areas

unit hydrograph

useful for developing hydrographs for ungauged watersheds were a land use change is planned

channel capacity

channel must be able to carry the design discharge at average velocities less than the permissible velocity