water resources engineering (intro)waterinfotech.com/surfwater/les _1 introwr1_2010.pdf ·...

Water Resources Engineering (Intro)

By

Dr.S.S.Rao

Mobile No 9825143747, ssrao1742@gmail.com,

ssriharirao@yahoo.com

Water Resources Engineering (SBST-Syllabus) • Hydrological cycle and its components

– Climate – Precipitation, Interception, evaporation, transpiration,

infiltration, Subsurface water and runoff

• Surface water Hydrology – Basic concepts in surface water hydrology – Detailed analysis of precipitation, evapotranspiration – Stream flow measurements – Runoff, Hydrographs, Floods, Flood routing – Erosion and reservoir sedimentation

• Groundwater Hydrology – Groundwater basics – Aquifer parameters

• Porosity, Specific yield, Storage Coefficient, Coefficient of Permeability, Transmissivity, Specific Capacity and their practical significance

– Darcy’s law – Derivation of aquifer parameters, Pumping test analysis – Quality of water and sea water intrusion – Numerical Techniques in groundwater hydrology – Groundwater management

Applications of water resources Engineering

• Traditional Applications – Irrigation and Scheduling

and Types of Irrigation – Drinking water – Power Generation – Water quality

• Salinity • Pollution of water in

relation to use • Salinity ingression in

coastal aquifers • Modern Applications

– Geographical information system (GIS)

– Statistical & Computer applications in water resources

• Special Applications – Rain water

harvesting – Watershed

Management – Artificial recharge

techniques • Management

– Planning of water resources & Basin Management

– Reservoir planning – Linear and Dynamic

programming in water planning

References

• Engineering Hydrology by K.Subramaniya

• Hydrology by HM Ragunath

• Water resources engineering Franzine, Lindsey

• Engineering Hydrology by R.S.Varshney

• Groundwater by HM Ragunath

• Groundwater Hydrology by Todd

• Groundwater Resources Evaluation by Walton

• Manuals of standards and criteria of planning water resources projects- by economic commissions for Asia and far east, Bangkok

Why should we study water resources?

•2000 million people live under water stress by 2050(UNEP)

•2 out of every 3 persons would live under water stress by 2025

•By 2025, 1.8 billion people will live in countries or regions with absolute water scarcity •Pollution, climate, desertification, water scarcity are the major issues in the next century. •Wars would be fought for water •Already happening in our own country

How wet is our planet?

World Water Resources

Water availability in India Cubic km

Rajasthan

Step wells in Gujarat

Traditional Water Harvesting Marvels of India

Debate on Small vrs Big dams

Dams - Temples of modern India-Nehru

Too much

rain

Too little

rain

River-linking Project:

Physiography of the Region

Major

Diversion

Routes

Design and construction of small dams

Abutment

Body

wall

Side Wall

Toe

Apro

n

Approach

Key

wall

Watershed hydrology

Irrigation and Scheduling and Types of Irrigation

Quality of water

Water contamination

Leaky underground storage tanks

Poorly constructed landfills and septic systems

Improperly abandoned mines and wells

The overuse of fertilizers, pesticides, and road salts

Runoff from livestock confinement areas

Careless industrial and manufacturing organizations

Sea water intrusion

Urban Water harvesting

Stream and pumping well relationship

Ground water in hard rocks

The water levels in

Mehsana are decreasing at

an alarming rate of about

0.5 m in 1981 to 1.5 in

2000 to 3 m per year in

2015 and would further

decrease to about 37 m in

the next 15 years

Rate of water level Decline per year(m) in Mehsana

District

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

1981

1984

1987

1990

1993

1996

1999

2002

2005

2008

2011

2014

2017

Decline per

year(m)

Ground water depletion and other

issues

• Groundwater depletion has emerged as one of the most formidable consequences of agricultural development in the West Indian state of Gujarat over the last five decades

Design of Ground Water Structures

Spacing of Wells

Ground water Management

• Sustainability

• Demand side management

• Supply side management

• Groundwater management in the river basin context:

Categorization of ground

water development Based

on Development in India

Category

Safe up to 70 %

Semi Critical 70- 90 %

Critical >90 %

Over Exploited >100 %

Sustainability

Demand-side management:

• The second step is to put in place an effective system for regulating withdrawals to sustainable levels; such system may include: – Registration of users through a

permit or license system; – Creating appropriate laws and

regulatory mechanisms; – A system of pricing that aligns the

incentives for groundwater use with the goal of sustainability;

– Promoting conjunctive use; – Encouraging water saving devices

Supply-side management

• The third aspect of managing groundwater is augmenting groundwater recharge through:

– [a] mass-based rainwater harvesting and groundwater recharge programs and activities;

– [b] maximizing surface water use for recharge;

– [c] improving incentives for water conservation and artificial recharge

Groundwater management in the river basin context:

Groundwater interventions often tend to be too ‘local’ in their approach. like surface water, the groundwater resource too needs to be planned and managed for maximum basin-level efficiency.

Numerical & Modelling Techniques

INUNDATION MAPPING IN MESHVO & VATRAK RIVER (200 YEARS)

Computer Applications