MAPPING AND MONITORING OF SURFACE WATER BODIES

MAPPING AND MONITORING OF SURFACE WATER BODIES OF GUJARAT STATE Prepared By Enakshi A Dasgupta (MG 1209) Guided By Shashikant A Sharma (Scientist-SF, UPD/UPDG/EPSA)

PROJECT PROFILE  Project Title: Mapping and Monitoring of Surface Water Bodies of Gujarat State  Organization: Space Applications Centre (ISRO)  Tools Used: Arc GIS 9.2, Erdas 9 and Microsoft Office 2007

ABOUT THE PROJECT…  In the arid environment, the systematic mapping and monitoring of water resources is an essential prerequisite for their rational utilization and management.  Satellite remote sensing has been proved to be a cheap and useful tool for mapping and monitoring water resources of large area in comparison with conventional hydrological methods.  As far as is known, very little work has been done on the monitoring of surface water resources.  My area of study has been the Gujarat State.  This research report will serve as an important input for future urban development planning of Gujarat State.

GEOGRAPHY OF GUJARAT Gujarat is located between 20º01' to 24º07' north latitudes and 68º04' to 74º04' east longitude, and covers an area of 195,984 square kilometers. Gujarat, a state in western India borders Pakistan, and Rajasthan to the north-east, Madhya Pradesh to the east, Maharashtra and the Union territories of Diu, Daman, Dadra and Nagar Haveli to the south. The capital of Gujarat is Gandhinagar with Ahmedabad as the largest city. The other major cities are Vadodara, Surat, Rajkot, Bhavnagar and Jamnagar.

CLIMATE OF GUJARAT…  The climate of Gujarat is moist in the southern districts and dry in the northern region.  The average rainfall in Gujarat varies from 33 to152cms.  The southern region of the state has an average rainfall ranging from 76 to 152cms, Dangs district having the highest average of about 190cms.  The northern districts have a rainfall varying from 51 to 102cms.  The rainfall in the southern highlands of Saurashtra and the Gulf of Cambay is approximately 63cms while the other parts of Saurashtra have a rainfall less than 63cms.  The semi-desert area of Kutch has a very low average rainfall.  As the Tropic of Cancer passes through the northern border of Gujarat, the state has an intensely hot or cold climate.

TOPOGRAPHY OF GUJARAT…  Going through the geography of Gujarat, one would know that Gujarat is home to many different topographical features and landscapes.  The geography of Gujarat deals with the following:Climate and Natural Features, Rivers, Dams, National Parks and Major Cities.  The major Rivers flowing through Gujarat are: Narmada, Sabarmati, Tapi and Mahi.  Some major Dams are built on the rivers Narmada, Tapi, Damanganga and Sabarmati.  Gujarat is also rich in Wetland Resources, which are present in the form of: Lakes, Salt marshes, Creeks, Mudflats, Swamps and Reservoirs.

BASICS OF REMOTE SENSING…  Remote sensing is a technique to observe the earth surface or the atmosphere from out of space using satellites (space borne) or from the air using aircrafts (airborne).  Remote sensing uses a part or several parts of the electromagnetic spectrum.  It records the electromagnetic energy reflected or emitted by the earth’s surface.  The amount of radiation from an object (called radiance) is influenced by both the properties of the object and the radiation hitting the object (irradiance).  The human eyes register the solar light reflected by these objects and our brains interpret the colours, the grey tones and intensity variations.  In remote sensing various kinds of tools and devices are used to make electromagnetic radiation outside this range from 400 to 700 nm visible to the human eye, especially the near infrared, middle-infrared, thermal-infrared and microwaves.  Remote sensing, also called earth observation, refers to obtaining information about objects or areas at the Earth’s surface without being in direct contact with the object or area.  Remote sensing imagery has many applications in mapping land-use and cover, agriculture, soils mapping, forestry, city planning, archaeological investigations, military observation, and geomorphological surveying, land cover changes, deforestation, vegetation dynamics, water quality dynamics, urban growth, etc.

SPECTRAL SIGNATURES – WHAT IS IT...  Spectral Signatures are the specific combination of reflected and absorbed electromagnetic (EM) radiation at varying wavelengths which can uniquely identify an object.  Calibration of spectral signatures under specific illumination is collected in order to apply an empirical correction to airborne or satellite imagery digital images.  A measurement of energy commonly used in remote sensing of the Earth is reflected energy coming from land and water surfaces.  The amount of energy reflected from these surfaces is usually expressed as a percentage of the amount of energy striking the objects.  Reflectance is 100% if all of the light striking and object bounces off and is detected by the sensor.  If none of the light returns from the surface, reflectance is said to be 0%.  In most cases, the reflectance value of each object for each area of the electromagnetic spectrum is somewhere between these two extremes.

Spectral Reflectance of Different Remote Sensing Objects

BASICS OF GEOGRAPHIC INFORMATION SYSTEMS (GIS)…

 A geographic information system (GIS), or geographical information system, is any system that captures, stores, analyzes, manages, and presents data that are linked to location.  GIS allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports, and charts  GIS systems are used in cartography, remote sensing, land surveying, utility management, photogrammetry, geography, urban planning, emergency management, navigation, and localized search engines.  GIS technology can be used for scientific investigations, resource management, asset management, archaeology, environmental impact assessment, urban planning, cartography, criminology, geographic history, marketing, logistics, prospectively mapping, and other purposes.

DATA USED FOR THE STUDY…  Toposheets Of Time Period 1920 – 1940 (1:250,000)  Landsat Mss (Multi Spectral Sensor) Data Of Time Period 1972 – 1979 (1:50,000)  Landsat Tm (Thematic Mapper) Sensor Data Of Time Period 1989 – 1992 (1:50,000)  Landsat Etm (Enhanced Thematic Mapper) Sensor Data Of Time Period 2005 – 2006 (1:50,000)

METHODOLOGY…  Scanning And Georeferencing Of Toposheets  Georeferencing Of Satellite Data  Reprojection Of Images (Everything Will Be Put In Lcc Projection Or Wgs-84 Datum.)  Mapping Of Surface Water Bodies Over Temporal Satellite Data  Analysis In Gis  Preparation Of Maps In Gis

AREA COMPARISON OF WATER BODIES OF GUJARAT STATE…

TOTAL NUMBER OF WATER BODIES OF GUJARAT STATE…

AREA COMPARISON AND TOTAL COUNT OF WATER BODIES OF DIFFERENT REGIONS OF GUJARAT STATE

AREA COMPARISON OF WATER BODIES OF CENTRAL GUJARAT REGION…

TOTAL NUMBER OF WATER BODIES OF CENTRAL GUJARAT REGION…

AREA COMPARISON OF WATER BODIES OF NORTH GUJARAT REGION…

TOTAL NUMBER OF WATER BODIES OF NORTH GUJARAT REGION…

AREA COMPARISON OF WATER BODIES OF SOUTH GUJARAT REGION…

TOTAL NUMBER OF WATER BODY OF SOUTH GUJARAT REGION…

AREA COMPARISON OF WATER BODIES OF SAURASHTRA REGION…

TOTAL NUMBER OF WATER BODIES OF SAURASHTRA REGION…

AREA COMPARISON OF WATER BODIES OF KACHCHH REGION…

TOTAL NUMBER OF WATER BODIES OF KACHCHH REGION…

DETAILED ANALYSIS… A CASE STUDY OF VALSAD DISTRICT

AREA COMPARISON OF WATER BODIES OF VALSAD DISTRICT…

TOTAL NUMBER OF WATER BODIES OF VALSAD DISTRICT…

TOPOSHEET OF TIME PERIOD 1920 – 1940 OF VALSAD DISTRICT…

LANDSAT MSS DATA OF TIME PERIOD 1972 – 1979 OF VALSAD DISTRICT…

LANDSAT TM SENSOR DATA OF TIME PERIOD 1989-1992 OF VALSAD DISTRICT…

LANDSAT ETM SENSOR DATA OF TIME PERIOD 2005 – 2006 OF VALSAD DISTRICT…

MAP SHOWING THE DECADAL CHANGE OF WATER BODIES OF VALSAD DISTRICT…

CONCLUSION…  After imposing the Old Water Bodies of the year 1920-1940 on the recent ETM Data of the year 2005-2006, it has been concluded that 92% area of the Old Water Bodies has been converted into Agricultural Land, Fallow Land and Barren Land. 5% area has remained as Water Bodies itself and only 1% of The Old Water Bodies has been used for Urbanisation and Land Use.  Also, it has been observed that the Surface Water Bodies have increased in the Kachchh Region and the Saurashtra Region. Also they have decreased in the Central, North and South Gujarat Region.

THANK - YOU