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JAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002 
REMOTE SENSING AND GIS IN THE STUDY OF SOIL RESOURCES 
B.R.M.RAO 
Soils Division, Agriculture &Soils Group, NRSA, DOS, Hyderabad — 500 037 Andhra Pradesh, India 
email:rao_brm@nrsa. gov.in 
KEYWORDS: Soils, mapping, remote sensing, GIS, land evaluation, soil moisture 
ABSTRACT : 
Soil resource information plays a critical role in the management of natural resources and more specifically in the field of 
agriculture. To maintain the present level of soil productivity and to meet the demands of the future, management of soil resources 
on scientific principles is very important. This calls for comprehensive knowledge on soil resources in terms of types of soils, their 
spatial extent, physical and chemical properties and limitations / capabilities. The conventional soil surveys are tedious, time 
consuming and expensive. With the advent of time, new technologies emerged for studying soil resources and space borne remote 
sensing technology proved to be powerful because it enables to study the resources in spatial domain in time and cost effective 
manner. The paper deals with systematic developments in the a 
pplication of remote sensing techniques in the soil resources 
inventory, level and scale of mapping, monitoring of soils and degraded lands, improvements in the interpretation techniques 
employed in deriving information from remotely sensed data. Besides, the applications of Geographical Information System (GIS) 
in the soil resources evaluation and microwave remote sensing techniques for soil moisture study are also discussed. 
1. INTRODUCTION 
Soil is a dynamic living system formed from the combined 
effects of climate, vegetation, soil flora and fauna and time on 
the rocks and parent material. It is a non-renewable natural 
resource whose proper husbandry is essential for both 
continued agricultural productivity and prevention of soil 
degradation. Soil resource information plays a critical role in 
the management of natural resources and more specifically in 
the field of agriculture. To maintain the present level of soil 
productivity and to meet the demands of the future, 
management of soil resources on scientific principles is very 
important. Therefore in recent years increasing emphasis is laid 
on characterisation of soils, accurate mapping of different 
kinds of soils and developing rational and scientific criteria for 
land evaluation and interpretation of soils for multifarious land 
uses. The conventional soil surveys are tedious, time 
consuming and expensive. With the advent of time, new 
technologies emerged for studying soil resources and space 
borne remote sensing technology proved to be powerful 
because it enables to study the resources in spatial domain in 
time and cost effective manner. Besides, the application of 
Geographical Information System(GIS) in the soil resources 
evaluation and microwave remote sensing techniques for soil 
moisture study are also discussed. 
Survey of literature reveals that remotely sensed data from 
space borne sensors like Landsat-MSS / TM , SPOT and IRS - 
LISS-I / II /III etc., were employed to map soils at different 
scales ranging from 1:250,000 scale, 1:50,000 scale. The soil 
information so generated was interpreted for various purposes 
like land capability classification, land irrigability assessment, 
crop suitability studies, management of  watersheds, 
prioritization of watersheds etc. The paper deals with 
systematic developments in the application of remote sensing 
techniques in the soil resources inventory, level and.scale of 
mapping, monitoring of soils and degraded lands, 
improvements in the interpretation techniques employed in 
705 
deriving information from remotely sensed data. Besides, the 
applications of Geographical Information System (GIS) in the 
soil resources evaluation and microwave remote sensing 
techniques for soil moisture study are also discussed. 
2.REMOTE SENSING APPLICATION IN SOIL 
RESOURCES STUDY 
Systematic efforts in the use of remotely sensed data in soil 
  
  
  
  
  
  
  
  
Table .1. soil scales, sensors and levels of soil ma pping 
Soil 
Survey Sensors Soil Classification User 
or 
Scale 
LANDSAT- Resource 
MSS, Subgroups/ Inventory 
1:250,000 | IRS-LISS-I, Families and their at 
WIFS association Regional 
Levet 
District/ 
1:50,000 EI Soil Series and their Sub- 
SPOT association District 
Level 
IRS-IC/ID Block / 
1:25 000 (PAN+LISS-III | Soil Series and their | Taluk / 
[en MERGED association Mandal 
DATA) Level 
1:8000 or IKONOS / TUpes and Phases Village 
larger CARTOSAT Level 
  
  
  
survey had resulted in the development of methodologies for 
operational use in recent times. Table 1 shows the scale of soil 
mapping, level of soil classification and remote sensors useful 
for soil mapping. 
2.1 Interpretation of remotely sensed data 
Visual interpretation of satellite data from various satellites 
namely Landsat, IRS and SPOT, based on photo-elements like 
tone, texture, size, shape, pattern, aspect, association etc., is the 
common method in the preparation of soil maps at various