ROLE OF REMOTE SENSING AND GIS IN FLOOD MANAGEMENT

AMALKRISHNA

The pace of technological change has been significant over the

past 50 years and has far exceeded the impact of the industrial

revolution. The inconceivable has become the reality with

computers the size of your hand or smaller and the creation of

an online worldwide information resource. The importance of

GIS in Modern Society is clear, GIS now touching on all areas of

society from the environment, to transportation, to government

to enterprise and the general public.

“…a digital map, data located on the map, and a software application (GIS) that links the two together”

INTRODUCTION

GIS is for…

The application of GIS is countless. GIS technology can be used for scientific investigations, resource management, asset management, archaeology, environmental impact assessment, urban planning, cartography, criminology, geographic history, marketing, logistics, mapping and other purposes help to find wet lands and solutions for protection from pollution, town planning. GIS might allow emergency planners to easily calculate emergency response times in the event of any kinds of disasters including natural disasters.

Where is GIS Used?

• Government Agencies GIS used to keep track of the

properties, public works, roads,

and more within their jurisdiction etc.

• Emergency Services Police departments, fire departments and other

emergency services have begun to use GIS to help in their daily operations.

Other Businesses…

• Real estate agents and bankers

are using GIS to track properties,

property values, and tax information. • Health care professionals are using GIS to track the

spread of disease and wellness information.• Communication technology companies use GIS in

planning of their utility expansions. • Weather forecasting also uses GIS technologies. A

host of other businesses use it for marketing purposes.

FLOOD…

FLOOD…

• Flooding is the most

common of all

environmental hazards.• No country is immune from Floods• Floods are natural phenomena common in

many places around the world where either there is river nearby or the local weather can dump large amounts of rain.

ROLE OF GIS

AND REMOTE SENSING

REMOTE SENSING AND GIS IN FLOODMANAGEMENT

GIS plays a prominent role in flood management…

• The unique capabilities of satellites to provide comprehensive, and synoptic coverage of very large areas at regular interval and with quick turn around time have been very valuable in monitoring and managing flood dynamics.

• In fact, it is only space technology, which has for the first time provided the basic information needed in the space, time and frequency domain

Satellites, by virtue of their remote sensing and data transmission capabilities to provide comprehensive multi-date and multi-spectral information on dynamic phenomena covering very large as well as small river basins, have been found to be admirably suited for mapping/monitoring and studying…

ROLE OF SPACE TECHNOLOGYY IN FLOOD MANAGEMENT

The vast capabilities of

communication satellites are

available for timely dissemination of early warning and real-time coordination of relief operations. Satellite communication capabilities, fixed and mobile, are vital for effective communication, especially in data collection, distress alerting, position location and co-coordinating relief operations in the field.

We can use the Techniques for…

• Flood Hazard Zone Mapping

• Flood Plain Management

• Flood Plain Zoning

• Flood Plain Regulation

• Flood Forecasting

• Near Real time Flood Mapping and monitoring

• Bank Erosion Studies

• River morphological studies.

• Digital Elevation Model

The best way to manage flood is use of combination of various measures…

1. FLOOD INUNDATION MAPPING

• To define spatial extent of flood inundation.• To identify the worst flood affected areas.• To evaluate impact of flooding on

environmental concerns, such as, coastlines,

forests, open space etc.• To plan relief operation.• To assess damage.

• Detailed mapping that is required for the production of hazard assessment maps and for input to various types of hydrological models.

 • Developing a larger scale view of the general

flood situation within a river basin with the aim of identifying areas at greatest risk and in the need of immediate

assistance.

2.FLOOD PLAIN ZONING

• Flood hazard zone mapping can be used as a means of non-structural flood control planning of the flood plain and for making policy decisions to regulate the flood plain development activities.

• Using historic satellite data combined with hydrological and close contour data, a flood hazard zone map can be prepared for flood prone basins

3.RIVER MORPHOLOGICAL STUDIES

• To identify the changes in river course over a time period.

• To identify the erosion prone areas along the river course

 • To study the efficacy of flood management structures

The river configuration and flood control works maps can be effectively used.

• This help to identify the vulnerable river reaches and status of the flood control embankments.

• necessary measures can be taken accordingly to avoid breaches.

• The bank erosion maps can be used for planning

bank protection works.

• The study of river configuration will be useful to understand the behavior of the river and can be used for laying physical models.

4.Floodplain management

• GIS is ideally suited for various floodplain management activities.

• such as, base mapping, topographic mapping, and post-disaster verification of mapped floodplain extents and depths.

Example… GIS was used to develop a River Management Plan for the Santa Clara River in Southern California. A GIS overlay process was used to further plan efforts and identify conflicting uses along the river and areas for enhancing stakeholder objectives.

5.Near Real time Flood Mapping and monitoring

• Before the on set of flood season-pre flood satellite data is produced.

• Analyzed and pre-flood river course is delineated.A data base consisting of district boundaries, road/railway net work etc are prepared in GIS

environment.

• The flood situation is continuously monitored.News media, flood report from CWC

• Satellite data checked daily

• If the optical data is cloudy-use microwave data.

• Satellite data is geometrically rectified, classified, and flood layer is delineated.

• This layer is overlaid on map and flood maps are prepared.

• The layer is intersected with the existing database and flood damage statistics like district/block-wise flood inundated area, road/rail affected, damaged houses etc are calculated.

• The flood maps along with the flood damage statistics are sent to user departments in near real time.

• Through this system was sent to user within 5to 6 hours after getting satellite data.

6.Bank Erosion Studies

• Sometimes the bank of the flood prone rivers are subjected to erosion.

• For giving bank protection structures….

• Vulnerable areas subjected to bank erosion along the river are monitored.

• High resolution satellite data acquired at different time intervals have been used to identify and map the the bank erosion.

7.Digital Elevation Model

• DEM can be created by collecting elevations and referencing them to the corresponding points in the mapped area.

• Digital contour lines digitized from the topographic map is the main source of the DEM generation.

Two main steps followed in constructing DEM

The first step is converting contour data containing elevation attribute into the point data.

The second step will generates the surface from the point data created in the first step.

The triangulated irregular network (TIN) are applied in this process

A . Model Development And Execution (H&H)

Floodplain modeling involves two aspects• Hydrologic analysis determines peak flood flows and

hydraulic analysis determines peak water surface elevations.

• This calculation is based on physical characteristics of a drainage area that can be estimated from a GIS database.

• The runoff information from the hydrologic model can then be combined with stream cross-section information in a hydraulic model to determine the depth of flooding.

B . Sub watershed Delineation

• For the purpose of hydrologic design modeling, subdividing the watershed is often necessary.

• The boundary of a watershed is defined by all points that will shed water to the outlet.

Mc Cuen (1998)

Community-Based Flood Risk Assessment Using GIS…

• Traditional methods for flood risk assessment are based on hydrological and hydraulic modeling software packages. These models are useful in depicting the spatial and temporal distribution of floods. However, few are well integrated within spatial

modeling environments

(i.e., GIS) and few are

capable of non-expert

implementation.

Risk Assessment…

• GIS helps to provide an alternative method for a basic flood risk assessment in data-poor environments by combining aerial photo interpretation, data questionnaires in a community-based field data collection campaign, and its subsequent processing and analysis using Geographical Information Systems

Datasets produced by these means and managed under GIS could be used by local authorities to carry out many of the municipal planning activities related to risk management. Moreover, these data could be used for other administrative and decision-making purposes.

Some floodplain mapping and modeling software examples are…

• 1 DHI MIKE Products

 

DHI Inc has three floodplain modeling packages that have GIS linkage capabilities: MIKE 11, MIKE 21, and MIKE FLOOD.

 • 2 HEC-GeoRAS

 

The HEC-RAS system is intended for calculating water surface profiles in a full network of channels, a dendritic system, or a single river reach.

 

Software…

• 3 ArcGIS Hydro Data Model

 

ESRI's ArcGIS Hydro Data Model can be updated to display purely cartographic data, such as the types of data used in creating floodplain maps.

 • 4 GIS Stream Pro

 

GIS Stream Pro from Dodson & Associates) is an ArcView Extension that runs with ArcView 3D Analyst Extension.

Satellite Remote Sensing and

GIS techniques have emerged as

a powerful tool to deal with various aspects of flood management in prevention, preparedness and relief management of flood disaster. They have greater role to play as an improvement over the existing methodologies. GIS is ideally suited for various floodplain management activities such as, base mapping, topographic mapping, and post-disaster verification of mapped floodplain extents and

depths.

REFERENCES

• Revised Guidelines For Providing Central Assistance To State Governments For The Schemes / Proposals Of Flood Control And River Management Works Under Flood Management Programme (2007-12) New Delhi, august 2009 http://mowr.gov.in/writereaddata/linkimages/FMP7870878878.pdf

• Flood management using Remote sensing . www.unesco ihe.org/.../Flood%20Management%20using%20remote

%20sensing.pdf• Remote Sensing Tutorial http://rst.gsfc.nasa.gov/Sect8/Sect8_8.html• Geo Informatics, volume 7, March 2004, Cmedia Productions BV, Page number

14-17.• GIS Development,vol 9, issue 10, October 2005, ISSN 0971-9377, Page number

22-25.• Key Areas in Remote Sensing and GIS, Pregame Planning and Evaluation Group,

National Remote Sensing Centre, Department of Space, Government of India, 2003, Page number 21-23.

Thank you…

Utilize the technologies and increase production to serve our one and only world. Ensure sustainability in every development in every works which meets the needs of present without compromising the ability of the future generation. It also requires knowledge, new ideas for the sustainable development, innovation, willingness to confront challenges openly.