PROJECTS

Master Plan Preparation

Six towns falling in either AMRUT or SmartCity project required to bring all the data to a GIS database for planning, monitoring and analysis. The GIS database was therefore created with village and town cadastral maps that were verified for the landuse using high resolution satellite imagery.

Various thematic maps on parameters like census/demography, physical & social infrastructure, transportation network, etc were created in the GIS. Land suitability analysis with weighted overlay indicated land suitable for the development of the planning areas in the six LPAs. The suitability analysis along with other non-spatial information provided the planner with information to plan the proposed landuse among other things.

City Regional Plan:

The use of GIS in this project is mainly for the Settlement Pattern Analysis and Decision making process. The methodology of the GIS process for this project mainly comprises of the following:
• Conversion of cadastral paper maps to GIS with georeferencing.
• Designing Geo-Database structure
• Creating various thematic layers
• Preparing Existing Landuse Status
• Field verification of Landuse
• Analysis of Catchment & Water Flow, Landuse patterns on transport corridors, etc.
• Preparing Maps for Future Plans

In the Sriperumbudur Region there are a number of water bodies of which Sriperumbudur, Pillaipakkam and Gunduperumbedu Lakes are larger than other lakes. Unfortunately these water resources are not able to store and serve for the domestic purpose of this region. Most of the water bodies dry up during summer season. Chembarambakkam Lake has the major catchment in this region.

SRTM data was used in ArcGIS Spatial Analyst software Hydrology tools to delineate the catchments at the watershed level. The arrows shown in the watershed map indicate the direction of flow of water.

DPR for Storm Water Drain:

The aim of GIS in the “Preparation of DPR for Storm Water Drainage” project was: 1) To organize the data output by the total station survey into a GIS database with attributes captured during survey 2) delineating the catchments that shall provide an understanding of the water flow over the topography and 3) preparing a landuse map using Satellite Images and field verification.
Topographic surveys were executed by surveyors after staking out sufficient GCPs in each of the six municipalities using DGPS survey. The GCPs provided the starting points for Total station surveys and acted as a Geodetic control to validate the survey. Hence, the surveyed data is inherently geo-referenced to UTM Zone 44N under the Traverse Mercator System on WGS 1984 ellipsoid/datum.

The use of GIS in this project with regard to storm water is to be able to use topographic information in the form of contour or DEM (Digital Elevation Model) to delineate the catchment area, a “catchment” that accumulates water during a rain event and allows it to flow into pathways to the pour point or otherwise the confluence of a higher order stream/river.

Cartosat-1 (2.5m resolution) Panchromatic data was used to prepare the landuse/land cover map for estimation of runoff factor. The maps so prepared were verified in the field before being used for estimating factors of runoff.

DGPS / DGNSS surveys:

DGNSS surveys were performed with Dual Frequency Dual Constellation GNSS Leica and Trimble receivers. In the absence of both Geodetic GCPs in the vicinity and an RTK Network infrastructure, controls were established with 24 hours’ data logs and post-processed with IGS’s precise ephemeris data including that of IISC, Earth Rotation parameters among others. The resultant position is taken as control coordinate and rovers used this as control for RTK or post-processed corrections.

Surveys were performed in unforgiving hilly terrains and forested areas to establish cadastral records and forest – revenue boundaries.

Other surveys, were performed in urban and peri-urban areas for asset mapping.

Green India Mission:

Kolli Hills of Namakkal District, Tamilnadu. Kolli hills stand at about 1400m M.S.L. and is unique in its Physiography – an undulating plateau like landform towering over the plains. Its rich soil and conducive climate support a wide variety of plant species. This Level 1 landform was broken down into Level 2 landforms based on its geomorphology, watersheds and administrative boundaries.

The project outcome was the Forest type and Forest density mapping of the Level 2 landform – viz. the classification of satellite images for forest type and density and identification of areal extent of plant species. Some of the species present in Ariyursholai Level 2 landscape (in the Evergreen, Deciduous and Scrub forest) are, Memecylon edule, Neolitsea scrobiculata, Persea macraantha, Vernonia arborea.