Water Resources and Sustainability

Question 1

To adhere to water balances what does precipitation equal

Answer 1

Precipitation= Evapotranspiration+ Infiltration+ Runoff

Question 2

What is the water balance equation

Answer 2

Evapotranspiration + River Outflow + Groundwater Outflow= Precipitation+ River Inflow + Groundwater Inflow +/- change in storage

Question 3

How is water quality measured

Answer 3

-Sediment
-Natural Water Quality
-Contaminants -Discharges, Diffuse Pollutants, Acid Mine Drainage, Urban Runoff, Saline Intrusion

Question 4

What is a renewable peak water limit

Answer 4

Abstracting all available renewable water from a part of the water cycle for human use

Question 5

What is a non-renewable peak water limit

Answer 5

Abstracting water that is not replenished- abstracting faster than recharge

Question 6

What is a ecological peak water limit

Answer 6

Abstracting water from a part of the water cycle in such a way as it has damaging impacts on ecosystems causing loss of biodiversity- total costs of ecological disruptions and damages exceed the total value provided by human use of that water.

Question 7

Brutland Definition for Sustainable Development

Answer 7

Development that meets the needs of the present without compromising the ability of future generations to meet their own needs

Question 8

Safe Yield Definition

Answer 8

Groundwater abstraction should not exceed the long term rate of recharge

Question 9

Why do many people believe the safe yield concept to be a myth

Answer 9

It’s all about the boundaries. Every abstraction has an impact, the question is whether this impact is acceptable. And this is subjective

Question 10

Different Types of Boundaries

Answer 10

-Catchment Boundaries
-Hydrogeological Boundaries
-Recharge to groundwater boundaries
-Groundwater-Surface Water Interaction Boundaries
-Saline Boundary

Question 11

Methods of measuring rainfall

Answer 11

-Daily readings
-Tipping Bucket Rain Gauge
-Calculating Areal Rainfall

Question 12

Methods of measuring evapotranspiration

Answer 12

-Evapotranspiration Pan
-Weighing Lysimeter
-Estimation

Question 13

Define Potential Evapotranspiration

Answer 13

PE= Evapotranspiration that would occur due to weather conditions if soil is at field capacity (fully saturated) for a given vegetation cover.

Question 14

Define Actual Evapotranspiration

Answer 14

AE= Amount of water delivered to the air through evaporation and transpiration, dependent on moisture availability, temperature and humidity. Actual Water Usage AET<=PET

Question 15

Define Soil Moisture Deficit

Answer 15

Demand for water exceeds that which is actually available. Degree to which soil moisture falls below field capacity. PE>AET

Question 16

Measuring River Flows

Answer 16

-Gauging Stations
-Establishes precise
relationship between stage
and flow
-Spot Flow Measurements
-Weirs
-Velocity Area Method
-Current Meter
-Conductivity Meter

Question 17

Measuring Groundwater

Answer 17

-Observation Wells
-Dippers- manual method
-Divers- Automatic method

Question 18

What does Q50 represent

Answer 18

Median Flows

Question 19

What does Q95 represent

Answer 19

Low Flows- 95% of the time flows are larger than this

Question 20

What does Q5 represent

Answer 20

High flows- 5% of the time flows are larger than this

Question 21

What is HER

Answer 21

Hydrologically Effective Rainfall
precipitation-AE

Question 22

Traditional methods of defining sustainable extraction

Answer 22

Protect Low Flows
-Allocation of resources based on minimum flow to be left in the river
-Hands Off Flow Constraints applied as licence conditions