Poisonous (1)


Behaviour that is learned from previous generations and passed on to the next generation (13)


Crossing a border from one country to another (14)


Plants take up liquid water and give off water vapour through pores in their leaves (4)


International agreement that creates legal rights and duties (14)


Cloudiness of water, a measure of water clarity (4)

Urban heat island

Effect caused by heat energy radiated from hard surfaces in large cities that raises temperature relative to surrounding rural areas, especially at night (6)


Increase in the number of people living in towns and cities relative to rural areas (5)

Urban planning

Designing towns and cities so they function effectively and meet the needs of people living in them (6)


Animals such as mosquitoes, flies, fleas, rats and dogs that transmit disease-causing agents from one host to another (11)


Susceptibility of individuals, a population or system to the effects of harm (12)

Waste hierarchy

Waste management options listed in order of desirability as follows: reduce, reuse, recycle, recover, dispose (8)

Waste optimisation

Reducing the quantity of waste produced by adopting the options in the waste hierarchy (8)

Water cycle

(also known as hydrological cycle) continuous circulation of water between oceans, atmosphere and land (4)

Water pollution

Presence of excess physical, chemical or biological substances that degrade water quality and are capable of causing harm to living organisms (7)


Countries/regions with less than 1,000 m3 per person per year for all purposes (1)


Countries/regions with less than 1,700 m3 of water per person per year for all purposes (1)

Water table

Top of the groundwater below the land surface (4)

Water-washed diseases

Diseases that occur as a result of poor personal hygiene mainly due to water scarcity (11)


Temperature, rainfall, wind, sunshine etc that we experience from hour to hour and day to day (9)

Last modified: Tuesday, 7 June 2016, 6:27 AM