1. Workshop on Effective Implementation of IWMP
7th and 8th Jan 2014, PUSA, New Delhi
Hydrology for IWMP
7th and 8th Jan 2013
Vaishakh Palsodkar
Geo-Hydrologist, Dept. of Land Resources, MoRD, New Delhi

2. Objectives Understanding the components of hydrologic processes
the quantity and availability of water
the quality of water
the impacts of land use and forest management practices on water resources
the most basic concepts of hydrologic monitoring
Utilizing hydrologic information resources to solve real problems

3. Hydrology
HYDROLOGY is the science of water that is concerned with the origin, circulation, distribution and properties of water of the earth.

4. Watershed /Catchment
WATERSHED, or CATCHMENT, is a topographic area that is drained by a stream, that is, the total land area above some point on a stream or river that drains past that point.
The watershed is often used as a planning or management unit. Natural environment unit.

5. Watershed Hydrology
Physical Hydrology (Rainfall, Topography)
Watershed Water Cycle (infiltration, sedimentation)
Large scale assessment, planning
Human Impacts on Water Resources

6. Physical Hydrology (Watershed Water Cycle)

7. Water Cycle
Due to deforestation, negative impacts are carried downstream in the form of eroded sediments or flooding.
Poor agricultural land management activities like excess fertilizer application convey negative impacts to downstream areas and may change the soil pathology

8. Watershed Water Cycle Based on the conservation of mass:
Input – output = change in storage
P + R + B - F - E - T = ΔS
volumes are measured in units m3, L, ac-ft, f3, gal,
or in & cm over the watershed area

9. Impacts of Development

10. Development Impacts on the Water Cycle
40%
30%
55%
10%
15%
50%
Natural Landscape
Low runoff
High recharge
Healthy summer stream flow
Natural pollutant treatment
Developed
High runoff, Low recharge
- Nuisance flooding
- Lower water tables
Low stream flow

11. Adverse Effect On Shallow Aquifers Due To Irrigation Borewells
RECHARGE - RAINFALL GL
DRY
DRY
DRY
AQUIFER
IMPERVIOUS
DRY
DRY
AQUIFER
IMPERVIOUS
60 M
DRY
AQUIFER
IMPERVIOUS
AQUIFER
90 M
IMPERVIOUS
120 M

12. Importance of Hydrology study
Micro-Watershed at field level
In planning stage it helps to assess the available water
Plan and locate your structure as per the hydrologic assessment.
Water budgeting
Link micro- watershed plans with higher-level watershed or plans
Sub-Watershed
Sub-Basin
Basin

13. Integrated approach Development and Management of ground water is
governed by various disciplines
Topographic survey
Study of Remote Sensing Data
Geomorphological studies
Geohydrological Survey
Community participation and ground water budgeting
Artificial recharge, Rain water harvesting and Conjunctive use

14. Topographic Survey Sound mapping and assessment of the gradient
Peoples participation in project
prioritisation & implementation.

15. Water Budgeting/Auditing
Rain fall Data
Area of watershed
Topography
Soil types
Geology
Governing factors
Cropping pattern
Run off
Evapotranspiration
Recharge
Cumulative draft for different uses
Final balance