How does it actually work? Explanation in detail
Bhungroo is a disaster mitigating and climate change (mitigation and adaptation) technology. It assists farmers to get their land free from water logging in peak monsoon period. In post monsoon period, it allows farmer to access best quality irrigation water at their farm gate. This is an added benefit along with water logging solution.
It is a filtrated injection methodology where water from top soil is injected within a pressure through a narrow diameter but high gauge pipe with required perforation length such that higher momentum filtrated water is released in subsoil where water lenses are made to be formed. Created water lenses in peak monsoon period are pressed inside unsaturated zones of the subsoil strata.
How is the water lenses are kept /stored in subsoil?
- This water lenses are formed with filtration leading to natural density, which is invariably different from water present at sub soil.
- In other words water gets collected within the soil present within a depth of 10 to 120 ft below top soil. Conducive optimum pressure along with time bound injection create the water lenses which later placed in horizontal layers
- Water is kept in lenses forms within unsaturated zones
Where is the water kept?
- Water is released underground and it is in kept in lenses forms within subsoil strata which are unsaturated zones.
- This sub soil strata is identified based upon soil testing and available soil strata
- This subsoil strata needs to be at least 1 feet ribbon height
- This subsoil strata can be within a depth of 10 to 120 ft
- The water gets collected in sequence within the unsaturated zones and
- Water can stay over there for longer period
- If needed the water can be lifted from that strata within a period of 45 to 180 days
- It does not need any civil structure underground. Rather here unsaturated soil strata is working as sponge and it allows water to get stored inside in lens forms
How does Bhungroo work in case of multiple floods?
- Based upon Flood momentum and suspended particles within flood water the number of units of Bhungroo needs to be configured.
- The water momentum, duration of water standing at the plot of the lands and locale specific subsoil strata and its instauration will determine the technical design of Bhungroo.
- The flood water needs to be kept idle with an objective of pressure building on the top soil.
- Once pressure is built then that calm flood water is filtered through filtration chamber.
- Then that filtered water is injected through the perforation such that pressure is increased
- That pressured water is passed through the pipe and released in perforated zones in subsoil pipe columns
- In case of series of floods the duration and timeframe of floods needs to be studied. It is needed to understand the technical parameter of the floods in adapting Bhungroo designing as per local situation. Based upon appropriate technology in connection with subsoil strata and water flow dynamics the Bhungroos can be erected and made functional
- Thus in case of multiple floods, Bhungroo design will be modified based upon water quantum, momentum and subsoil water flow. In that context multiple Bhungroos can be erected and flood issues can be tackled
To which extent does Bhungroo depend on the soil condition?
- Bhungroo works in all types of soil strata wherever there is an unsaturated zone is prevailing.
- In any piece of land the unsaturated zones layers will be available– hence we can erect Bhungroo on all soil strata.
- Based upon the level of variance of saturation level in subsoil strata, the water injection momentum will vary. It translates into difference in pace of water injection within subsoil based upon saturation level.
- Thus, types of available local soil strata determines faster and quicker functioning of Bhungroo.
- If soil strata is of stone structure then cost of erection become expensive
- If soil strata is of sandy loam then cost of erection become relatively cheaper
- If top soil is black cotton soil then we might need earth work to get higher water catchment. This will increase the cost of technology erection
What is the relevance of the salinity level?
Salinity level is one of the boosting factors for Bhungroo technology. It is a misconception that Salinity level is the ultimate necessary factor for success of the Bhungroo.
Salt deposition on the top soil makes the soil non porous. When salt gets crystallised then water logging is bound to happen. In that case Bhungroo is easier to erect. And it also makes the process cheaper as in natural water logging water quantum is very high and the stationary water standing is for a longer duration.
In salinity affected areas good results are forthcoming as Bhungroo ensures following:
- It injects water underground from day one owing to good standing water height and its gravitational force
- It also allows storm water (which is non saline) to reach subsoil level
- If the subsoil water salinity is higher than that layer itself works as unsaturated soil zones and it allows low density water to get stored upon the saline water
- This automatically implies water collection at the subsoil level