Water

Question 1

Define, Hydrosphere

Answer 1

The hydrosphere is made up of large bodies of water, such as: The oceans, lakes, icecaps and rivers that are mobilised by the Sun and gravity. It is also known as the hydrological cycle and it involves water in its three states (liquid, solid and gas).

Question 2

Define, Hydrology.

Answer 2

Hydrology studies the mobilisation of ground and surface water, including its physical and chemical content.

Question 3

What are the two main types of water in the hydrological cycle?

Answer 3

• Meteoric: Water derived from atmospheric condensation that, joins the larger body of the hydrosphere as surface and groundwater.
• Saline: The waters of oceans and lakes

Question 4

What is residence time?

Answer 4

The length of time during which a substance is suspended at a location.

Question 5

What is interception?

Answer 5

Interception is the percentage of water, that after precipitation, does not reach the ground due to vegetation.

Question 6

At what tempature does evaporation take place under normal atmospheric pressure?

Answer 6

Evaporation at normal atmospherioc pressure can take place at any temperature.

Question 7

What increases the rate of evaporation? And what reduces it?

Answer 7

Rising temperature and wind can increase the evaporation of water.

While humidity can decrease it.

Question 8

What are the inputs of the water balance equation?

Answer 8

Precipitation (P) and groundwater flow (∆G)

Question 9

What are the outputs of the water balance equation?

Answer 9

evaporation (E), streamflow (Q) and groundwater (∆G)

Question 10

What drives the water cycle?

Answer 10

The Sun’s energy and the Earth’s gravity.

Question 11

Define water table.

Answer 11

The water table, can be defined as the level at which the geology of the ground is fully saturated.

Question 12

What properties affects the hydraulic conductivity of water?

Answer 12

The permeability of the rock will affect any liquid that passes through, be it water or oil.

The properties of the liquid, will also affect it’s hydraulic conductivity. A temperature change from 5c to 30c will double the hydraulic conuctivity of water.

Question 13

Define permeable and impermeable rocks.

Answer 13

A rock with hydraulic conductivity of 1m per day or more is permeable

A rock with hydaulic conductivity of 10^-3m per day is classed as impermeable

Question 14

What is the difference and relationship between porosity and permeability?

Answer 14

The difference is that porosity, is a measurement of the rocks ability to hold water, while permeability is the measurment of the rocks ability to allow water to pass through.

The relatiomship they have it permeability is fully dependant on porosity.

Question 15

What is the difference between a rock that is isotropic and a rock that is anisotropic?

Answer 15

Anisotropic rock would mean that the physical properties of the rock differ depending on the direction to which you measure it (i.e a piece of wood that is stronger along the grain than against it)

Isotropic would mean that the rock performs the same no matter which direction you measure it.

Question 16

What is the basic balance water equation?

Answer 16

inflow = outflow + change in storage

Question 17

What is quickflow?

Answer 17

Quickflow is the visible reaction to a river from rainfall, whereby it increase in either height and speed, due to an influx of quick throughflow and overland flow.

Question 18

What is Hewlett’s theory?

Answer 18

Hewlett’s theory build upon Horton’s theory by saying that saturated overland flow, occurs in variable areas, for example, ones that are more likely to be humid with water tables closer to the surface.

Question 19

What is Horton’s theory?

Answer 19

Horton’s theory depends on the rate of rain fall (light, medium or heavy) and also the level of ground infiltration. Thus is most applicabe to areas of low vegetation, arid areas or culitvated fields.

Question 20

What is the equation? And what does it mean?

Answer 20

The amount of run off from a catchment or river is a product of its cross-sectional area. Thus the average speed and run off from an area, is calculated by:

Q =Av
A = Width x Depth
v = distance/time

Question 21

What is meant by “lag time”?

Answer 21

It is the time between maximum precipitation and peak discharge rates.

Question 22

Name this seldom type of flow.

Answer 22

Laminar

Question 23

What is an Ion?

Answer 23

An atom or molecule with a net charge due to the loss or gain of an electron.

Question 24

Explain the meaning of the superscript symbol Ca²⁺

Answer 24

This is an atom with a particular amount of charge. That amount of charge is denoted by the ’+’ sign and the amount of charge it has is denoted by the ‘2’.

Question 25

What are ions with a plus sign called?

Answer 25

cations

Question 26

what are ions with a negative charge called?

Answer 26

anions

Question 27

What is ionic bonding and what are ionic materials?

Answer 27

ionic bonding is the bond between atoms or molecules with positive and negative charge.

Materials held together with such a bond, are called ionic materials

Question 28

When is the level of dissolved oxygen in a river likely to be at its highest and its lowest?

Answer 28

Vegetation is a key player in the extraction and circlation of CO² in the water and atmosphere through photosynthetic processess.

Thus a river with aquatic plants, will have its highest concentrations of dissolved oxygen during a warm summer afternoon. As oxygen is given off by plants via photosynthesis.

Question 29

What gas is produced in the oxidisation of organic matter?

Answer 29

Carbon Dioxide

Question 30

What does he presence of Ammonia, indicate?

Answer 30

Ammonia is the break down of animal and plant matter and is harmfull to aquatic life. So a polluting substance.

IF the concentration of nitrates NO₃− is higher than 50 mg/l then it can become dangerous for aquatic life.

Question 31

What is the meaning of Turbidity?

Answer 31

Cloudy or opaque sample

Question 32

Name some heavy metals, that bioaccumulate. Further more, explain bioaccumulation.

Answer 32

Mercury (Hg), Arsenic (As), Cadmium (Cd) and Lead (Pb)

Bioaccumulation is the build up of heavy metals within an organism which leads to degrading health within animals highest in the food chain.

Question 33

what does ICP-AES stand for?

Answer 33

inductively coupled plasma-atomic emission spectroscopy.

Question 34

Describe endocrine disruptor

Answer 34

endocrine disruptor was used as a pesticide before the EU Directive brought in standards for drinking water.
.

Question 35

What are OCPs?

Answer 35

OCPS are a class of organochlorine pesticides I

dieldrin - an insecticide now banned - mimics hormones, and causes immunodisfunction, parkinsons and other health defects

Question 36

How many calibration standards should be prepared, before plotting a calibration curve?

Answer 36

An analyst will usually prepare 5 standard calibration samples.

Question 37

What is a stock solution?

Answer 37

A concentrated solution that gets diluted into progressively lower concentrations for use.

Question 38

What is the maximum TDS of irrigation water?

Answer 38

3000mg l^-1 But varies depending on crops

Question 39

Are the parameters for this natural water, okay for irrigation?

Answer 39

No, as the sodium content of the water is higher than the combined magnesium and calcium content. This would be bad for soil, as it reducres permeability by making it sticky when wet, and solid when dried.

Question 40

Name some water treatement processess

Answer 40

• Ion exchange
• Activated Carbon
• Softening
• Reverse Osmosis

Question 41

What is Ion Exchange?

Answer 41

Ion exchange is used to ‘soften’ water and remove nitrate from it. It is very similar to the domestic water process where water is passed through a bed of special resin particles

Question 42

What is the process of activated carbon?

Answer 42

Used to get rid of organic substances in the water, which are then absorbed on the surface of the carbon.

Question 43

What is softening?

Answer 43

It is the removal of calcium or magenisum in water, through ion exchange via chemical intervension or precipitation.

Question 44

Reverse Osmosis

Answer 44

Osmosis is where a solution passes through a membrane. Pore size of the membrane allows only water molecules to pass through. Osmosis pressure dictates the movement of solution.

Reverse osmosis, is the introduction of artifical pressure, to allow only water molecules to pass through.

Just like a super fine filitration system.

Question 45

What features of weather have an affect on water evaporation and why??

Answer 45

Humidity, wind, temperaturel.

The humudity is a measure of the atmospheres saturation level. Low humidity means low saturation, allowing more water to evaporate into the atmosphere, than high humidity which means high saturation, allowing less water to evaporate into the atmosphere.

High temperatures encourage the breaking up of water molecule bonds, causing them to enter the evaporation phase.

Wind circulates air around, pushing away saturated air and bringing in unsaturated air. .

Question 46

What is the equation that describe the latent heat of vaporisation of water?

Answer 46

R = H + G + E

H = heating air above land surfaced

G = heating soil, veg and surface water

E = Latent heat evaporation

Question 47

What are the main reservoirs in the water cycle?

Answer 47

Oceans, Underground, atmospheric water, in the rivers, ice caps, soil and lakes.

Question 48

What does the result of the hydraulic conductivity equation tell us?

Answer 48

The result tells us about the permeability of the rock, by calculating the volume of water that will flow through a unit cross-sectional area of rock per unit of time.

Rocks with hydraulic conductivites of 1m a day or more, are regarded as permeable

Rocks with a hydraulic conductivity of 10^-3 m per day are usually regarded as impermeable.