mapping of degraded lands using remote sensing and

May 1, 2023 Sethupathi S, M.Sc.,(soil Science). 1

Role Of Remote Sensing In Soil Resource Mapping

Soil Resource InventorySoil Resource Inventory : Land resource information plays a key role in the management of natural resources. Management of soil resources on scientific principles is essential to maintain the present level of soil productivity and to prevent soil / land degradation.Mapping of different kinds of soils and developing rational and scientific criteria for land evaluation and interpretation of soils for multifarious land uses.The remote sensing technology is found to be more efficient and economical than conventional surveGIS is a powerful and sophisticated tool for displaying and analyzing spatial relationships between geographic phenomena in the form of vectors and images.


Role Of Remote Sensing In Soil Resource Mapping

The synoptic and repetitive coverage of satellite over large areas Remote sensing technique have reduced the field work to a considerable extent and soil boundaries are more precisely delineated than in conventional methodsAerialphotographs were being used as a remote sensing tool for soil mapping. Subsequently satellite data in both digital and analog forms have been utilized for preparing small scale soil resource maps. During mid eighties landsat thematic maps and IRS-LISS II data were used by the scientists to map soils at 1:50,000 scale. At this scale soil could be delineated at association of soil series or family level. Indian remote sensing satellites (IRS IA, IB, IC and ID) provide state-of-the art database for natural resource inventories.


Many researches have been conducted to explore the potential of LISS I and LISS II data for soil resource mapping both at 1:250,000 and 1:50,000 scale .

The successful launching of a series of operational earth observation satellites viz., IRS satellites series (IA, IB, IC, ID, P3, P4 OCEANSAT/ P6- RESOURCESAT-1), CARTOSAT 1, 2, 2A and most recently IMS 1, RISAT-2 and OCEANSAT-2 significant progress has been made in soil and land cover mapping, land degradation studies and soil and water resource development and management.


Role of remote sensing in land use studies

Information on the existing land use / land cover pattern and its distribution is a pre-requisite for better understanding of land aspects and also plays a vital role in developmental planning.

With the advent of remote sensing techniques (both aerial and satellite) it has been possible to prepare land use maps at various levels showing categories of land under different uses both in spatial and statistical form.

The FCC of thematic mapper data were used for identifying and delineating wastelands.

Wastelands were identified and mapped on1:250,000 scale. Compared land-use / land cover change of watershed using remote sensing data and GIS software.

which made an attempt to study the changes in the land use pattern.


Maharana and Nepal Singh (2001) characterized degraded landforms of Arid Western Rajasthan using IRS-IB imagery of February 1995. Land use land cover classes in Gaur Ganga Watershed in Uttaranchal state was analysed by Bisht and Kothyari (2001) using toposheet and visual interpretation of Landsat 5 TM image bands 2, 3 and 4 using Simple Macro Language (SML) in ARC/ INFO software. Loss of vegetation cover was estimated to be 5.07 and 8.1 per cent during 1963- 1996 and 1986 -1996 respectively.


Role Of GIS In Thematic Mapping

Geographic information system has emerged as a powerful tool for spatial analysis of natural resources and data base management. It is an efficient and versatile tool to automate the transformation of soil data in to soil information.


Mapping of Degraded Lands Using Remote Sensing and GIS

Techniques

Introduction “Desertification”. As the increasing world population places more demands on land for food production etc., Conventional soil surveys provide information on and degradation ; the new technologies emerged for studying natural resources, remote sensing and GIS are effective technologies for detecting, assessing, mapping, and monitoring the land degradation.

The development of well established methodologies for mapping and monitoring of various degraded land in a cost effective manner.


SPACE BORNE SENSORS ERTS-1 / landsat-1. LANDSAT-TM, SPOT and IRS-LISS-III Indian remote sensing satellites (INSAT’s) are being employed to mapping the soils at different scales ranging from 1:250,000 to 1:50,000. Better spatial and spectral resolution, enabled to map and monitor degraded lands more efficiently.

REMOTE SENSING Parker defined “Remote sensing as covering the collection of data about object which are not in contact with the collecting device”. The synoptic view of the area allows better monitoring capability, especially when the coverage is repetitive, interval is short, and resolution of the image is high. Remote sensing provides data in several discrete bands, enabling creation of FCC and the interpretation accuracy.


LAND DEGRADATION MAPPING

The objective of the mapping is to generate realistic information on degraded lands and their spatial distribution to undertake developmental planning.

Importance of Land Degradation Mapping Ministry of Agriculture initiated the land degradation mapping during Eighth Five-Year Plan based on the following factors.No realistic database on degraded lands is available in the country


Varying nomenclature to describe the land degradationTechniques of data acquisition differsStrategic planning to combat the menace of land degradation Land development with scientific means for sustained agricultural production and eco-developmentStatistics produced by several agencies on degraded lands vary widely

LEGEND Legend development is a state of art in land resource mapping to depict the various land information on map in a comprehensive manner.


Conceptualization of Mapping

The mapping has been conceptualized as a four-tier approach comprising

Kind of degradation, Severity of degradation, Degradation under major land use and major landform.

The various causative factors both natural and biotic degradation processes, viz., water and wind erosion, waterlogging, salt affliction, shifting cultivation, mining, etc. The methodology for land degradation mapping has been developed accordingly.


Methodology

The methodology for land degradation mapping using remote sensing techniques developed by the organization is based on the expertise in the field of soil survey and remote sensing acquired since inception.

Multi-date False Colour Composite (FCC) generated out of IRS LISS II sensor has been used for interpretation purposes.

Standard procedure of image interpretation techniques covering the steps i.e., recognition, identification, analysis and inferences have been followed for mapping purposes.


Legend Development• Legend development is a state of art in land resource mapping

to depict the various land information on map in a comprehensive manner.

• According to the conceptualization of mapping, various kinds of degraded lands have been symbolized alphanumerically.

• For example water erosion has been symbolized as “We” whereas degradation due to water logging has been denoted as “Wl”.

• The kind of degraded lands have further been segregated based on degree of severity and have been denoted by suffixing a numerical 1 to7.


Legend for Land Degradation Mapping


Flow diagram for generation of land degradation mapMay 1, 2023 Sethupathi S, M.Sc.,(soil Science). 20

STUDY AREA GIS proved to be an effective tool in handling spatial data available at different scales. Voluminous point data such as soil information, rainfall, temperature, socio-economic data and to perform integrated analysis of data on various resources of any region and to arrive at optimum solutions for various problems.

Representative sample sites were selected for ground truth data collection. During field visits, features of topography and soil profiles were studied; site characteristics and soil samples were also collected for laboratory analysis. The preliminary interpreted maps were modified using field data and soil chemical analytical data; final maps were prepared with appropriate legend.


Location map of study areaMay 1, 2023 Sethupathi S, M.Sc.,(soil Science). 23

LAND USE / LAND COVER Land use is defined as to the human activity or economy related function associated with a specific piece of land, while the The over-exploitation and mismanagement of land resources have resulted in the degradation of land. Nearly 175 million hectares of land in India is subject to one or other kind of degradation process.


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Land use /cover mapMay 1, 2023 Sethupathi S, M.Sc.,(soil Science). 26

Assessment of Soil Erosion

False Colour Composite (FCC) Based on soil, slope, land use/land cover, current soil erosion

status was mapped. Visual interpretation involves identification and delineation of

degraded lands that are manifested on false colour composite (FCC).

Sheet, Stony waste and gullied erosion on satellite image


Creation of Digital Data Base of Degraded Lands

Though voluminous information on degraded lands in the form of maps and attributes (physical and chemical properties, geographic location, current land use, etc.) is available with various organizations, there is no organized digital data base available at the district or state level to the concerned users in M.P. Thus, a centralized digital database in a Geographic Information System (GIS) domain on degraded lands was

Soil erosion map of the study areaMay 1, 2023 Sethupathi S, M.Sc.,(soil Science). 29

Global Positioning System (GPS) with adequate accuracy. It would enable studying the variations in properties of degraded lands in space and time.


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mapping of degraded lands using remote sensing and

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