Wasteland assessment using remotesensing and gis
- 1. WASTELAND ASSESMENT USING REMOTE SENSING AND GIS
- 2. INTRODUCTION •Management of natural resources, especially land resources, is the key to attain food, water and environmental security. •This has special relevance since per capita availability of agricultural land in India is decreasing rapidly due to population growth, industrialization and urbanization.
- 3. WASTE LAND Wasteland is a degraded land which can be brought under vegetative cover, with reasonable effort, and which is currently underutilized and the land which is deteriorating for lack of appropriate water and soil management or on account of natural causes.
- 4. EXTENT AND DISTRIBUTION OF WASTE LAND IN INDIA
- 5. About 63.85 million hectares of land, which account for 20.17% of the total geographical area (328.72 million hectares) exist as wastelands in India . According to the NRSC report, there are 2.42 million hectares (17%) of wasteland in Tamil Nadu.
- 6. REMOTE SENSING AND GIS IN WASTELAND MAPPING To study the spatial dynamics of wastelands, the IRS P6 satellite data(23.5x 23.5 m) and topographical maps are generally used (Scale = 1:50000). The application of remotely sensed data in mapping degraded lands space borne sensors started with the launch of the first Earth Resources Technology Satellite (ERTS-1 / Landsat-1). Later on for better spatial and spectoral resolution -Landsat- TM, SPOT and Indian Remote Sensing (IRS) Satellites are used
- 7. WASTELAND ASSESMENT - METHODOLOGY
- 8. For detection of temporal changes in the wastelands, two period data sets i.e., IRS, Linear Imaging Self-Scanning (LISS III) are used. The geodatabase generated using Arc GIS and on screen digitization techniques, shows the type, extent and spatial distribution of different wasteland categories present in the area.
- 9. In 1991, the Ministry of Environment and Forest (MoEF) embarked upon an ambitious project to apply GIS technology for wasteland management. This was based on prior work carried in 1986 when the Department of Science (DoS) under the National Wasteland Identification Project developed detailed wasteland maps of 147 districts in the country with a 1:50,000 scale. In this project, a Task Force was identified to evolve a suitable wasteland classification system. PROJECT INVOLVED
- 10. WASTE LAND GENERATION PROCESS Water erosion Wind erosion Water logging Salinization / Alkalization Glacial Anthropogenic
- 11. LAND DEGRADATION TYPE COLOUR/TONE (ON FCC) TEXTURE(ON LISS-III DATA) PATTERN Sheet erosion Slightly brighter than surrounding land. Smooth -Medium Contiguous patches Rills brighter than surrounding land. Medium Discrete to contiguous patches Gullies Gray in colour. Medium to slightly course Discrete to contiguous patches Ravines Medium to dark gray Shallow ravine- slightly course Deep ravine- course. Contiguous patches WATER EROSION
- 12. LAND DEGRADATION TYPE COLOUR/TONE (ON FCC) TEXTURE(ON LISS-III DATA) PATTERN Sheet erosion Shades of yellow and light gray Smooth -Medium Contiguous / mottling Partially stabilized dunes Light – medium grey Medium contiguous /discrete patches stabilized dunes • Dry season – medium grey with light yellow tone • Rainy season- pink mottles Medium to course Discrete patches Unstabilized dunes Shades of yellow and light grey Smooth to medium Discrete patches WIND EROSION
- 13. LAND DEGRADATION TYPE COLOUR/TONE (ON FCC) TEXTURE(ON LISS-III DATA) PATTERN Surface ponding Light – dark blue Smooth Discrete patches Sub surface water logging Normal FCC – medium to dark grey FCC with SWIR band(R:G:B = SWIR:NIR:Red) – Various shades of blue smooth contiguous /discrete patches WATER LOGGING
- 14. LAND DEGRADATION TYPE COLOUR/TONE (ON FCC) TEXTURE(ON LISS-III DATA) PATTERN Saline Light grey to white Smooth Discrete patches Sodic Greyish white/ Dull white Smooth discrete patches Saline-sodic •Greyish white to white smooth Discrete patches SALINISATION / ALKALIZATION
- 15. LAND DEGRADATION TYPE COLOUR/TONE (ON FCC) TEXTURE(ON LISS-III DATA) PATTERN Acidic Various shades of green / Black Smooth -Medium Contiguous / discrete /mottled ACIDIFICATION GLACIAL LAND DEGRADATION TYPE COLOUR/TONE (ON FCC) TEXTURE(ON LISS-III DATA) PATTERN Frost heaving Light pink to grey Smooth Contiguous / discrete patches
- 16. LAND DEGRADATION TYPE COLOUR/TONE (ON FCC) TEXTURE(ON LISS-III DATA) PATTERN Industrial effluent affected areas With water- shades of blue Dries – light grey to white Smooth Discrete /contiguous patches Mining and dump areas Shades of white , yellow , red, black Smooth-medium discrete patches Brick kilns Dull white to light yellow smooth Isolated patchesgive rise to mottles ANTHROPOGENIC
- 17. WASTE LAND RECLAMMATION METHODS Gullied and / or ravenous land - Leveling of gullies or ravines construction of check dams Upland with or without shrub – contour bunding, contour trenching,contour terracing Degraded/ underutilsed forest land - Regulate grazing activity, Restrict illegal forest felling Wet land - Passage to the logged water
- 18. CONCLUSION The RS/GIS technology is the master tool in managing the wastelands of the country, starting from mapping, characterization, possible reasons, protection and reclamation of wastelands. At each step of management, RS/ GIS are economically sound, speedy and accurate method. Generation of human resource and skilled personnel having proper training on RS/GIS can contribute a lot in the entire process.
- 19. REFERENCE •NRSA 1991. Guidelines to use wasteland maps. National Remote Sensing Agency, Hyderabad, pp72. •Jain, A.K., Hooda, R.S., Nath, J. and Manchanda, M.L. 1991. Mapping and Monitoring of urban landuse of Hisar Town, Haryana using remote sensing techniques , Journal of the Indian Society of Remote Sensing 6: 133-134.