Usage of GIS and remote sensing for tank and land-use studies

Abstract

This work, jointly led by the IFP and the Institute of Geography of the University of Provence (France) integrates all the available information in a GIS spatialized and geo-referenced database, covering an area of 60 by 80 kms (district of Villupuram and Pondicherry) with a 1/10,000 precision level.

The objective of this work is threefold:

• To analyze and quantify the evolution of tank-fillings through remote-sensing
• To delimit homogenous land-usage zones, and to determine if these zones are linked by the access to water (of surface via tanks, and underground by pumping) or to any other explaining factor.
• To spatialize all the information and results in order to analyze the influence of environmental factors in the zone-delimiting of these phenomena and to emit hypothesis on the importance of social and socio-economical factors.

For that, a database has been made, associating
* 3 main vectorial layers
  Tanks: the contour of nearly 2000 tanks has been registered (according to topographical maps of 1916 and 1931) with additional information on the management characteristics (according to PWD and own field surveys with farmers).
  Village revenue: one thousand villages have been punctually geo-localized and attributed information with data from the 1991 and 2001 census.
  Village surface area: the contour of communal perimeters were redrawn and established.

* Groups of multi-spectral satellite images spread on 6 dates (Jan. 1977, Jan. 1991, Feb 2000, Oct 2000, Jun 2002, Feb 2004), which were rectified and merged with a 100 m² resolution and worked upon in order to produce maps of the state of surface of agricultural zones.

* Diverse data on the environment (geology, geomorphology, pedology, rainfall) that was digitized and rectified.

The setup of this base allowed

• To make zone-delimitings of landscape units with strong personalities and to produce statistics on the state of surfaces of agricultural zones.
• To characterize the spatial organization of tanks
• To produce statistics on the evolution of tank fillings

By crossing all these results, we are looking for a pattern of evolution of the management of tank water, given the massive diffusion of electrical pumping since the 1970s. This experimentation provides a knowledge base that requires to be complemented by the integration in GIS of other information of hydro-geological, social and socio-economical nature.

Speakers

Géraldine SAVIN & Wichy MEAS, University of Provence, France

Organisers

Department of Social Sciences, “Social Management of Water” project, French Institute of Pondicherry

Venue

Jawaharlal Nehru Conference Hall, French Institute of Pondicherry, 11, Saint Louis Street, Pondicherry - 605 001

Time

10h30