Acid environments and drought Flashcards
What are arid environments
Places which normally have very low rainfall
Eg deserts
What is a place called that normally has very low rainfall
Arid environments
Characteristics of arid environments
-… growth is … due to lack of …
—>plants are … & there are few … trees
-… is s…, d…, d… and not …
—>no … fall and …
-…, plants and … have … to cope with … water …
-very …
-plant growth is sparse due to lack of rainfall
—>plants are short & there are few tall trees
-soil is shallow, dry, dusty and not fertile
—>no leaves fall and decompose
-animals, plants and people have adapted to cope with limited water supplies
-very hot
What is drought
A severe shortage of water where there is less rainfall that usual over a long period of time
What happens to water supplies during drought
They become … because they are … used but there isn’t enough … for them to be …
They become depleted because they are constantly used but there isn’t enough rainfall for them to be replenished
How does high temperatures in drought deplete water resources even faster
High temps increase the rate of evaporation and demand for water
Where can droughts happen
Anywhere
Drought hazards
-… of water … leads to … and … water … in lakes, rivers etc causing … and plants to …
-lakes and … become … and there is less … water to … waste …, therefore … the risk of … leading to … of … like cholera
-… of water can … crops and harm l…, leading to food … causing hunger, … and …, and hurting …
-soil … out and … die, leaving the soil … to l.. by wind and
.., making its hard to grow … again
—>making food … worse causing …
-soil … and sewers become …, this can cause … when it’s finally …, damaging … and …
-… becomes very … making … more likely
-depletion of water supplies leads to shortages and lower water levels in lakes, rivers etc causing animals and plants to die
-lakes and rivers become stagnant and there is less fresh water to dilute waste materials, therefore increasing the risk of contamination leading to outbreak of diseases like cholera
-lack of water can damage crops and harm livestock, leading to food shortages causing hunger, malnutrition and famine, and hurting farmers
-soil dries out and plants die, leaving the soil vulnerable to erosion by wind and rain, making its hard to crop crops again
—>making food shortages worse causing starvation
-soil hardens and sewers become blocked, this can cause flooding when it’s finally rains, damaging infrastructure and farmland
-vegetation becomes very dry making wildfires more likely
Causes of drought
-m
-h
-h
-meteorological
-hydrological
-human
Meteorological causes of drought
-can cause … to get … rainfall than …
-changes in … circulation can mean it doesn’t … much in an … for … or years
-changes in … circulation can also make the … rains …
—>eg … rains don’t come
-… rainfall is also caused when … pressure … systems stop … (weather … that cause …) from entering an …
-can cause area to get less rainfall than average
-changes in atmospheric circulation can mean it doesn’t rain much in an area for months or years
-changes in atmospheric circulation can also make the annual rains fall
—>eg monsoon rains don’t come
-low rainfall is also caused when high pressure weather systems stop depressions (weather systems that cause rain) from entering an area
Hydrological causes of drought
-r…, l…, r… and a… are all part of the … system
-a … of … in these … can lead to …
-drought is more … in areas that … on … and stores of … water eg …, rivers
-in … dry … surface water … quickly so it gets … faster than in …
-… factors can take a … to have an … but can have … lasting …
-once stores are … they can take … to be …
-rivers, lakes, reservoirs and aquifers are all part of the hydrological system
-a lack of water in these stores can lead to drought
-drought is more likely in areas that rely on rainfall and stores of surface water eg lakes, rivers
-in warm dry conditions surface water evaporates quickly so it gets depleted faster than in aquifers
-hydrological factors can take a while to have an effect but can have long lasting impacts
-once stores are depleted they can take years to be replenished
Human causes of drought
-… farming … water supplies by using large … of water for …, and farming … animals also … a lot of water
-building … across … creates … which provide … for … people, but this can … the … of water …, causing …
-… reduces the amount of water that can be … in the … so land … out more …
-… release a lot of … into the … through their …, so … can make the … drier
—>contributing to … causes
-intensive farming depletes water supplies by using large volumes of water for irrigation, and farming livestock animals also demands a lot of water
-building dams across rivers creates reservoirs which provide water for local people, but this can reduce the flow of water downstream, causing drought
-Deforestation reduces the amount of water that can be held in the soil so land dries out more quickly
-trees release a lot of moisture into the air through their leaves, so deforestation can make the atmosphere drier
—>contributing to meteorological causes
What areas are more vulnerable to drought
-the areas which experience the most … droughts are normally found at …o N and … of the …
—>eg. Northern & Southern …, the … East, a…, N… A… etc
-the … of droughts can be explained by … atmospheric …
-cool … air … at …o … and S of the …, creating a … of high … with very little …
-some … suggest climate
.. has caused droughts to be more … and …
-the areas which experience the most severe droughts are normally found at 30o N and S of the equator
—>eg. Northern & Southern Africa, the Middle East, Australia, North American etc
-the pattern of droughts can be explained by global atmospheric circulation
-cool dry air sinks at 30o N and S of the equator, creating a belt of high pressure with very little rainfall
-some scientists suggest climate change has caused droughts to be more frequent and severe
