7 - Impacts of Agriculture on the Hydrosphere Flashcards
What are the two key impacts of agriculture on the hydrosphere?
- Water Storage and Cycling
- Crop Cover Effects
What is the percentage of Ocean and Saline Lakes vs. Freshwater in the world?
- Oceans and Saline Lakes: 97.4%
- Freshwater: 2.6%
75% of freshwater is tied up in ______________ and ______________.
Ice caps and glaciers
What is a major source of freshwater?
Soil Water (>30%)
What can increase the water storing capacity of agricultural soils?
Cultivation and Management practices
Provide the equation of the Water Budget:
S = I + P + C - ET - DP - R
What are the components of the Water Budget?
- I = Irrigation
- R = Runoff
- S = Storage
- C = Capillary Rise
- P = Precipitation
- ET = Evaporation
- DP = Deep Percolation
What are the two key affects of agriculture on the water cycle?
- Land Preparation
- Irrigatoin
Why does land preparation increase the runoff and drainage of the land?
- Reduced vegetation cover
- Soil compaction from machinery use
- Increase in soil erosion, silting of water bodies.
If groundwater is used from aquifer faster than it is replaced, then the water table will be _____________,
lowered
What are the four examples of agricultural water consumption and water deficits?
- Aral Sea Crisis
- Ogallala Aquifer
- Lake Chad
- Nile, Jordan, and Euphrates-Tigris River Basins
Up until the third quarter of the 20th century, ________ was the worlds fourth largest saline lake.
The Aral Sea
What was the main cause of the Aral Sea crisis?
The soviet government diverted those rivers to irrigate the desert region to grow cotton.
What are the four key effects of the Aral Sea crisis?
- Change in the Sea Surface Temperature. Summer SSTs have increased, while winter SSTs have decreased.
- The Aral Sea region experienced significant desertification during the desiccation period.
- A sharp increase in salinization of lands - one of the most negative consequences of Aral Sea crisis.
- An increase in the number of dust and salt storms in the area.
Where is the Ogallala Aquifer located?
Occupies the High Plains of US, from Texas to South Dakota (450,000km2 of 8 states).
What is the cause of the Ogallala Aquifer crisis?
- Irrigated farming accounts for 94% of the groundwater use, 5.5 million hectares are irrigated in the region (Nebraska = 46%, Texas = 30% and Kansas = 14%)
State governments and local water districts throughout the region have developed what kind of policies?
- To promote groundwater conservation
- Slow or eliminate the expansion of irrigation.
What are the two key causes of the Lake Chad shrinkage?
- Overgrazing resulting in a loss of vegetation
- Deforestation, contributing to a drier climate
- Large and unsustainable irrigation projects built by Niger, Nigeria, Cameroon, and Chad which have diverted water from both the lake and the Chari and Logone rivers.
What three basins are in main focus for water shortages and conflict in the Middle East?
Nile, Jordan and Tigris
Who of the Nile, Jordan, or Tigris reservoir uses the most water?
Starts in Ethiopia, Sudan and Egypt uses most of the water flows in the Nile River.
Ethiopia and Sudan divert water from the Nile, this reduced the amount available to Egypt.
Of the three, Nile, Jordan and Tigris, who is the most water short in the region?
Jordan Basin
Why does Jordan experience a decreased downstream water supply?
From hydro-electricity dams in Syria
What are four proposed solutions to the issues faced by the Nile, Jordan, and Tigris water basins?
- Regional cooperation in allocating water supplies.
- Improve water use efficiency
- Higher water prices (to help increase efficiency)
- Import more grain to cut down the need for irrigation water
_______________ is a major cause of degradation of surface and groundwater resources.
Agriculture
_____________ people die annually from water-borne diseases.
Five million