1. PRESENTATION ON
RAIN WATER HARVESTING
BY:
RAGHAV SINGLA
VII-B
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2. What Is Rainwater Harvesting?
RWH consists of simple systems to collect, convey, and store rainwater. Rainwater capture is accomplished primarily from roof-top, surface runoff, and other surfaces.
RWH either captures stored rainwater for direct use (irrigation, production, washing, drinking water, etc.) or is recharged into the local ground water and is call artificial recharge.
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3. Why Rainwater Harvesting?
Conserve and supplement existing water resources
Supply water at one of the lowest costs possible for a supplemental supply source.
Commitment as a corporate citizen - showcasing environmental concerns
Replenishing local ground water, where lowering of water tables has occured
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4. Why Not RWH? Not applicable in all climate conditions over the world
Collected water quality might be affected by external factors
Performance seriously affected by climate fluctuations that sometimes are hard to predict
Collected rainwater can be degraded with the inclusion of waste water runoff
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5. Let’s take a look at The Water Cycle Condensation Precipitation
Evapotranspiration
Evaporation
Infiltration
Narration: The hydrologic or water cycle is the continuous flow of water between reservoirs at or near the earth’s surface. As water falls to the ground as precipitation, it may develop as surface runoff into nearby surface waters or infiltrate into the ground and become stored as groundwater. Water stored in open areas, know as surface water, can evaporate into the atmosphere. In addition, water used by plants for normal growth or transpiration is also returned to the atmosphere. Once in the atmosphere water can condense into clouds and precipitate as rain or snowfall, initiating the cycle over again. Water is a renewable resource that, managed properly, can sustain the activities in the watershed for an indefinite period of time.
Animation: shows water cycle
Surface Runoff
Surface Water
Consumption
Groundwater
Sea water intrusion
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6. Condensation
Average Rainfall
Average Annual and Monthly Precipitation – Average rainfall over one year period and monthly intervals and usually based on global atmosphere
Precipitation
Narration: The hydrologic or water cycle is the continuous flow of water between reservoirs at or near the earth’s surface. As water falls to the ground as precipitation, it may develop as surface runoff into nearby surface waters or infiltrate into the ground and become stored as groundwater. Water stored in open areas, know as surface water, can evaporate into the atmosphere. In addition, water used by plants for normal growth or transpiration is also returned to the atmosphere. Once in the atmosphere water can condense into clouds and precipitate as rain or snowfall, initiating the cycle over again. Water is a renewable resource that, managed properly, can sustain the activities in the watershed for an indefinite period of time.
Animation: shows water cycle
Consumption
Groundwater
Surface Water
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7. Storage Storage devices may be either above or below ground
Different types include
Storage Tanks
Water Containers
Lagoons or Lined Ponds
Size based on rainfall pattern, demand, budget and area
The collection device usually represents the biggest capital investment of an RWH system. It therefore requires careful design- to provide optimal storage capacity while keeping the cost as low as possible.
While above-ground structures like tanks are easily purchased or made with a variety of designs, and water extraction is in many cases by gravity; they also are expensive, require more space and are prone to attack from the weather.
Below-ground structures like cisterns, lagoons etc. are generally cheaper due to lower material requirements and unobtrusive. However, water extraction often requires a pump, contamination is more common, and present a potential danger to children and small animals if left uncovered.
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8. Establishing the need in India…
A news article says that ground water levels in New Delhi are falling and RWH will become mandatory.
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9. SO AS WE ALL ARE THE HUMAN BEINGS
AND ITS OUR RESPONSIBILTY TO SAVE OUR GROUND WATER LEVEL
AND MAKE THEM RECHARGE AT TIME TO TIME
BY RAIN WATER HARVESTING
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