climate change impact assessment on hydrology of indian

7/30/2019 Climate Change Impact Assessment on Hydrology of Indian

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BY,

ANEESH MATHEW,ID:2012PCW5182,M.TECH(WRE).



INTRODUCTION Climate change impacts are going to be most severe in the

developing world because of their poor capacity to adopt

climate variability.

NATCOM, the present study has been taken up to quantify

the impact of climate change of the water resources of

Indian river systems.

The study uses the HadRM2 daily weather data todetermine the spatio-temporal water availability in the

river systems. A distributed hydrological model namely

SWAT has been used.



METHEDOLOGY The climate change impact assessment on water resources

can be best handled through simulation of the

hydrological conditions that shall prevail under the

projected weather conditions in an area.

The SWAT water balance model is one such model and

has been used in the present study to carry out the

hydrological modeling of the river basins of the country.



SWAT The SWAT model simulates the hydrologic cycle at daily

time basis.

SWAT is a distributed , continuous, hydrological modelwith an Arc View GIS interface(AVSWAT). The interface

is used for pre and post processing of the data and outputs.

It is used to predict the impact on climate change on the

availability of water resources under GHG with theassumption that land use will not change with time.



DATA



WEATHER DATA



DIGITAL ELEVATION MODEL



DILINEATION OF THE RIVER

BASINS It is done by using DEM as input and the final outflow

point on the drain age of the river basin as the final

pour/drainage point.

River basins have been divided into sub basins using an

arbitrarily selected threshold value.

It also provides the number of the sub basins the river

basins got subdivided into as a result of this threshold. The total area of the river basin as obtained from the

automatic delineation has also been provided.



MODELLED RIVER BASIN ALONG WITH RCM

GRID LOCATIONS



RESULTS OF BASIN ANALYSIS



LAND COVER OR LAND USE LAYER Classified land cover data (13 categories) produced by the

university of Maryland Global land cover facility, using

remote sensing with resolution of 1km grid cell has been

used.



SOIL LAYER Soil map adopted from FAO digital map of the world and

derived soil properties with a resolution of 1:5000000

have been used.



CONTROL CLIMATE

SCENARIO Represents the simulated baseline weather conditions.

Simulated using SWAT model by using this generated

daily weather data (HadRM2). Simulated weather report has been used for control period.

The model represents detailed outputs on flows, actual

evapotranspiration, soil moisture status at daily level.

Additional subcomponents of the total water balance suchas surface runoff, inter flow, sub surface runoff etc.



GHG CLIMATE SCENARIO Using GHG climate scenario data without changing

the land use.

Detailed analysis have been performed on the river

basins to quantify the impacts at the sub basin levels.

Shorter time interval in the month has been used.



SUMMARY RESULTS ON CLIMATE IMPACT

CHANGE ON INDIAN RIVER BASINS



ANNUAL WATER BALANCE COMPONENTS



KRISHNA RIVER BASIN



KRISHNA RIVER BASIN The variation in mean annual water balance components

from control to GHG scenario both in terms of change in

individual values of these components and percentage of

change over control.

Reduction in precipitation by about 20% of the current

value has been predicted in the sub basins of Krishna.

Decrease in water yield over the sub basins is predicted tovary from 30% to 50%.

Actual evapotranspiration is predicted to reduce by about

5% over most of the basins.



DROUGHT ANALYSIS Used for the assessment of drought severity by indicating

relative dryness or wetness.

PDSI is the widely used index that incorporates

information on rainfall, land use and soil properties in the

lumped manner.

PDSI value below 0 indicates the beginning of drought

situation and value below -3 indicates severe droughtcondition.



DROUGHT ANALYSIS



MAHANADI RIVER BASIN




It has been selected as the one which has been

predicted to have maximum impact on account of theflood conditions.




FLOOD ANALYSIS



ADAPTATION ISSUES Strategy for copying with the climate change impacts

on water resources can be no different from the

present day strategy of copying with the ever

increasing demands on the precious resource.

The best way forward is to incorporate such

interventions through a unified framework which can

be conductive to integrated approach.



COPYING ACTIVITIES MAY INCLUDE



GAPS AND FUTURE DIRECTION OF

STUDIES The hotspots have been identified only with respect to

the natural boundaries in the form of sub basins of the

river systems.

Another gap which shall be required to be addressed

in an institutional capacity building at various levels.

The creation of unified framework and its

maintenance shall be a gigantic task which can beachieved only through major policy restructuring of

the institutions at different levels of management.



CONCLUTION



THANK YOU

climate change impact assessment on hydrology of indian

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