Prof A. Balasubramanian
Former Dean, Faculty of Science and Technology
Centre for Advanced Studies in Earth Science
University of Mysore, India
Weather and Climate
Climate Variability
Climatic Observations
Climate Projection
Impacts
Mitigation and Adaptation
There is a saying that climate what you expected and weather is what you get
RAPID & DIRECT CONSEQUENCES ON 1. WATER VAPOUR- HUMIDITY
2. SOIL HORIZON + SEGMENTS OF EVAPOTRANSPIRATION
3. SUFACE WATER RESOURCES
4. SNOW-COVERED REGIONS/ SNOW-MELT FED RIVER BASINS
SLOW- PACED EFFECTS ON1. GROUNDWATER RESOURCES- BUT FULLY
DEPENDING UPON SURFACE SOURCES.
2. SALINE INTRUSIONS
The newer findings indicate that warming is more pronounced than expected.
The impact would be particularly severe in the tropical areas, which mainly consist of developing countries, including India (Sathaye, Shukla & Ravindranath, 2006).
Increasing temperature trends of the order of 0.60°C during last 112 years (IMD 2012) and increase in heavy rainfall events and decrease in low and medium rainfall events (Goswami et al. 2006) over India have been observed.
Changes in rainfall and temperatures have also been reported.
To Sustain the Increasing Temperature –Establish Green Belts, Control Fossil Fuel Emissions, adopt Green concepts
Changing Cropping Pattern/ Changing Irrigation Methods
Manage Evapotranspiration
Maintain Soil Moisture-levels- Infiltration Galleries, Compulsory Ploughing of Lands(old method practiced during 1960s and 70s)
Climatic Change-related Factors- reduction in natural recharge during rainfall deficit periods,
High intensity/ short duration RF= No change
Non-climatic Change Factors- Human Induced-Population, Economic Development, LanduseChanges, Irrigation, Agriculture, Etc
Effects are= over-exploitation beyond capacity of storage, depletion of groundwater resources, pollution, deep bore-wells interconnecting deep fissures/fractures- widening storage space
1. Adaptation to global change must include prudent management of groundwater as a renewable, but slow-feedback resource in most cases.
2. Groundwater storage is already over-tapped in many regions, yet available subsurface storage may be a key to meeting the combined demands of agriculture, industry, municipal and domestic water supply, and ecosystems during times of shortage.
The future intensity and frequency of dry periods combined with warming trends need to be addressed in the context of groundwater resources, even though projections in space and time are fraught with uncertainty.
Short-term simulation through modeling
Enhancing the Water Storage Mechanisms
1. Artificial recharge ( Mandatory- Passing a Bill)
2. Managed aquifer storage and recovery projects may become a more important component of many Govt. or local water systems to bank excess renewable-water supplies and provide water for both normal years and those times when resource shortages may develop.
Establishment of large and small surface water storage facilities will benefit from increased runoff.
There is also a fear that higher carbon-di-oxide concentration in the atmosphere may influence dissolution of mineral substances and alter the infiltration sequences of soils.
There is need to store water underground as part of a larger water management strategy, by considering the role of saturated flow and unsaturated flow in artificial recharge.
The Role of Saturated Flow in Artificial Recharge
The Role of Unsaturated Flow in Artificial Recharge
Aquifer recharge and aquifer storage and recovery wells(ASR)(USPA,1999) are used to replenish the water in an aquifer.
AR wells have been utilized to deter salt water intrusion into freshwater aquifers and to control land subsidence(USEPA, 2009).
AR and ASR wells are drilled to various depths depending on the depth of the receiving aquifer.
Drainage wells include all wells that are used to inject surface water directly into an aquifer, or shallow ground water directly into a deeper aquifer, primarily by gravity(Joel 0. Kimrey and Larry D. Fayard,1984).
Effective use of drainage wells requires a source of injection water (a losing aquifer or surface water); prevailing natural downward gradient from the source to the receiving aquifer; and transmission and storage characteristics of the receiving zone that will allow emplacement of the volumes of injection water without head buildup sufficient to decrease severely the downward gradient.
Establishing drainage wells with adequate densities averaging about 2 to 4 wells per ten square km in the rural and suburban and Direct street stormwater-drainage wells in urban areas may enhance to groundwater recharge for a period of 100 years.
Control pollutants through appropriate methods.
The lake-level control wells receive a mix of rainfall, ground-water seepage, and stormwater runoff during the wet seasons and receive mostly groundwater seepage during the dry seasons.
The wetland drainage wells receive short duration, high-intensity rainfall and stormwater runoff and low, but continuous, amounts of ground-water seepage nearly year round.
Green Strategies for Controlling Stormwaterand Combined Sewer Overflows(Natural Resources Defense Council, 2006).
The urban landscape, with its large areas of impermeable roadways and buildings—known as impervious surfaces—has significantly altered the movement of water through the environment.
Once upon a time under JeevanDhara scheme, we dug million wells ( shallow open wells)
Now, not in use. Is it possible to convert them as recharge wells with lateral drill-holes.
Intensive collection of data & creation of databases
Climate Change Impact on Groundwater –Research Groups
Sharing of Simulation Results
Groundwater resources are related to climate change through the direct interaction with surface water resources, such as lakes and rivers, and indirectly through the recharge process.
Therefore, quantifying the impact of climate change on groundwater resources requires not only reliable forecasting of changes in the major climatic variables, but also accurate estimation of groundwater recharge.
GLOBAL CLIMATE CHANGE
GHG- GLOBAL WARMING RISE OF
TEMPERATURELONG/SHORT-TERM TREND-UNDERSTOOD
CHANGE IN WEATHER
CYCLES
EXTREME WEATHER
EVENTS
FLOODS/ DROUGHTS
CHANGE IN PRECIPITATION
PATTERNS
SPATIAL AND TEMPORAL
VARIATIONSUNCERTAINTY IN MAGNITURE AND
INTENSITY
GLOBAL CIRCULATION MODELS(GCM)
WEATHER PREDICTION
MODELS
PRECIPITATION-RUNOFF
HYDROGRAPH MODELS
RIVER BASIN HYDROLOGY
MODELS
SWAT MODEL
FLOOD FORCAST MODELS
GROUDWATER FLOW MODELS/
TRANSPORT MODELS
UNSATURATED ZONE MODELS
STREAM-AQUIFER MODELS
ISLAND/ SEAWATER
INTERFACE SIM MODELS
WATER QUALITY MODELS
INTEGRATION OF MODELING
METHODS
NATIONAL LEVEL
SCALE OF VARIATIONS
MODELING & SIMULATION
PLANET AS A WHOLE
N-S HEMISPHERICAL
CONTINENTAL LEVEL
REGIONAL / STATE LEVEL
RIVER BASIN LEVEL
WATERSHED LEVEL
SPATIAL :X-DIMENSIONY-DIMENSIONZ-DIMENSION
TEMPORAL : Dt
CENTURYDECADEANNUAL
SEASONALMONTHLY
DAILY/ EVENT
As climate change continues to affect our water resources and elevate threats to public health, water resource managers and policymakers must act quickly to enact well-informed, environmentally sound policiesthat address the threats we already face while preparing for the predicted challenges of tomorrow.
Scientific research can, however, play a key role in the nation’s response to climate change.
The Technological solutions are already available.
Thank you…
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