Download presentation

Published byArmando Kenderdine Modified over 2 years ago

1
**Topics for 9/6 Annual water balance and the Budyko curve**

Project progress

2
**Water Balance Ratios can be used to “characterize” watersheds**

Q/P, ET/P… Energy limited vs Water limited systems Budyko (1974) Climate and Life

3
**Physical Controls on Water Balance at Catchment Scales**

Treat as a lumped system Receives rainfall at the rate p(t), loses water through evapotranspiration e(t), and runoff q(t) dS/dt = p(t) – q(t) – e(t) Where S is the storage of water at any time (t) At the annual scale we assume there is no carry over from year to year and P = Q + E where P, Q, and E are annual totals We will investigate the “partitioning” of the water balance at the annual scale Key Point: Annual water balance is controlled by climate

4
**Bucket Model Assumptions**

p and e are uniform through the year e occurs at potential rate as long as water is available No runoff if bucket is less than full

5
**Two Scenarios Case 1: Dry Climate (arid) Ep>P, and ep(t) > p(t)**

… Actual E is controlled by the amount of rainfall Water limited system S/Sb= 0 No water storage, no vegetation…adverse to life

6
**Two Scenarios Case 2: Wet Climate (humid) P>Ep, p(t) > ep(t)**

What happens to the bucket? E = Ep, Q = P – Ep Upper limit to e(t) is the evaporation demand Energy limited S/Sb = 1 Too wet, adverse to life

7
**Budyko Diagram Consider the limits Plot E/P vs Ep/P**

If E = Ep (wet climate)… If E/P = 1 (dry climate) … E/P is a measure of actual water balance Ep/P is a measure of climate, called dryness index

8
**Limits of Budyko Diagram**

Whole world can be divided in to “energy limited” and “water limited” areas Why doesn’t empirical curve match theoretical?

Similar presentations

OK

Estimating ET Type of method used will be determined by: 1. Type of surface (e.g. open water vs. leaf) 2. Availability of water for evaporation 3. 4. 5.

Estimating ET Type of method used will be determined by: 1. Type of surface (e.g. open water vs. leaf) 2. Availability of water for evaporation 3. 4. 5.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on film industry bollywood life Ppt on nestle india ltd company Ppt on non biodegradable waste pictures Ppt on 2nd world war pictures Ppt on impact of french revolution Ppt on tcp ip protocol architecture definition Ppt on conservation of momentum formula Mba ppt on body language Free download ppt on the road not taken Ppt on column chromatography set