Water Resources Flashcards
Natural Resources
Unchanged materials of land, found naturally and used by people in different ways.
Non-Renewable Resources
Limited resources that can run out over time.
For example: fossil fuel, minerals
Renewable Resources
Continuous resources that can be used over and over again. They are sustainable but their value is likely to reduce over time.
For example: sunlight, soil, water
Importance of Rivers
- Tourism
- Fishing
- Domestic Use
- Industrial Use
- Water to desert areas
- Irrigation
- Hydroelectric power generation
- Soil fertility
Hydrological Cycle
Water falls to the ground in the form of precipitation, runs off into streams, lakes, rivers or is absorbed by the soil and by plants, evaporates or transpires as vapour, cools down and condenses in the atmosphere as clouds.
Indus River System
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Importance
Largest river system in Pakistan
Irrigates 60% of cultivated land
Starts at the melting glaciers and snow at the Himalayas and Karakorum Ranges, runs through KPK, Punjab, Sindh, Northern Areas and parts of Balochistan in 5 rivers.
Rivers join at Panjnad and fall into the Arabian Sea.
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It irrigates 60% of cultivated land in Pakistan
Is a source for freshwater fish (fishing makes 3% of the GDP),
Attracts tourists > local income
Provides desert areas with water
Generates HEP
Water used for domestic/industrial purposes
Increases soil fertility
Indus System vs. Baluchistan Rivers
- Indus System has 5 main rivers (Chenab, Jhelum, Indus, Sutlej, Ravi) along with eastern and western tributaries.
Baluchistan has four types of rivers: flow into Indus, flow into sea, absorbed by Sibi Plain or drain into depressions.
- Indus - permanent rivers
Baluchistan - temporary seasonal rivers
- Indus - high discharge and volume
Baluchistan - less discharge and volume
- Indus - covers KPK, Punjab, North, Sindh and parts of Baluchistan
Baluchistan - covers parts of Baluchistan only
Groundwater (WHEN, HOW, WHERE, WHAT, WHY)
Subsoil water is more accessible in the rainy season as the water table rises.
It is accessed through wells, tubewells or the Karez system
Found at foothills of mountains
Useful where canals are not possible.
Types: Sweet (near rivers), Saline (further away from rivers)
Karachi’s groundwater not fir for consumption w/o treatment due to seepage or chemical waste
Domestic Use of Water
Washing, cooking, sanitation, drinking
Industrial Use of Water
Textile: dyeing, washing, printing
Pharmaceuticals: Syrups, medicines, injections, drips
Food Processing: Sodas, juices, mineral water
Steel and Iron: Used to cool furnaces
Agricultural Use of Water (WHAT, HOW MUCH, WHY)
Irrigation is the artificial supply of water to encourage or facilitate plant growth.
90% of PK’s water is used for irrigation
Complex canal system in Pakistan.
Many areas are arid and dry, so water is not easily accessible due to quick evaporation. Other places have a lot of monsoon winds, which result in the water draining away too quickly.
Therefore, a well-developed system ensures water year round.
Types of Irrigation Systems
- Shaduf
- Charsa
- Persian Wheel
- Karez
- Inundation Canals
- Diversion Channels
- Tank Irrigation
MODERN:
- Sprinkler
- Perennial Canals
- Tubewells
- Dams/Barrages
- Link Canals
Shaduf System
V-shaped pole with bucket which is lifted out of well with water. Small area irrigated, rarely used.
Charsa
Powered by animals which lift water out of well. Small area, rare.
Persian Wheel
Powered by blindfolded donkey or bull which makes a wheel turn. The wheel has pots on it which bring out water and spill it in a stream which irrigates a field.
Used in scare water areas.
Karez
Underground system of channels used to utilise subsoil water.
Used in Baluchistan to prevent loss of water due to the heat
Inundation Canals
Seasonal canals which irrigate fields in rainy seasons.
Drawn from river.
Low water level in dry season.
Diversion Channels
Similar to Inundation Canals, but they draw water from a stream in highland areas to irrigate terrace fields
Tank Irrigation
Mud tank stores excess rainwater.
Uncostly and natural but water mixes with silt.
Sprinkler Irrigation
Water is pumped up and sprinkled over fields.
Efficient and quick, easy to operate, uniform water distribution.
However, costly and requires continuous energy supply.
Perennial Canals
Drawn from dams to irrigate fields.
Throughout year, vast area.
Tubewells
Pumps subsoil water,
lowers water table and protects from waterlogging/salinity
Water goes to reservoir/dam
Large Dams VS Small Dams
SMALL: local area irrigation
LARGE: Vast area
SMALL: Supply little/no electricity
LARGE: Produce major amounts of HEP
SMALL: Silting easier to solve
LARGE: Silting harder to solve
SMALL: Cheaper maintenance
LARGE: Costlier maintenance
SMALL: Quick construction and results
LARGE: Slow construction and results
SMALL: Less impact on ecosystem and rivers
LARGE: More impact on ecosystem and rivers
SMALL: Less people evacuated to construct dam
LARGE: More people evac. EG: Mangla Dam > 40,000 people
+ Pakistan needs large dams to generate electricity and for flood control, but small dams are more suitable for the economy (cheaper, silting easier to solve)
What purposes can dams be used for?
- Electricity
- Irrigation
- Domestic/Industrial Purposes
