IAPRS & SIS, Vol.34, Part 7, "Resource and Environmental Monitoring", Hyderabad, India,2002
ANALYSING SENSITIVITY OF DRY SUSCEPTIBLE LAND USING REMO 1E SENSING
AND GIS
R Jana*, M V Khire
Centre of Studies in Resources Engineering, Indian Institute of Technology,
Powai, Mumbai-400 076, India- rina@csre.iitb.ac.in
KEY WORDS: Climate, Land, Remote Sensing, Temporal Change Detection (Tendency), Variability, Vegetation
ABSTRACT
Both climate variability and human activity have a feedback role, which affects the prolific characteristics of land. This multifaceted
behaviour is more sensitive over a susceptible land causing degradation of land’s capability and productivity. It is attempted to
quantify the tendency of the land and it’s partial relationship with climate variability and population pressure at local level.
In this study the land characteristics, viz., change in land use/land cover, tendency of land’s instability and change in albedo and
Normalised Difference Vegetation Index (NDVI) are assessed and thematic map are generated spatially. The land instability
evaluates the uncertainty in land’s behaviour. The decrease of albedo in dry land gauges the improvement of land quality whereas
it’s increase indicates degeneration of land quality. The NDVI is proved to be the most useful to evaluate the vegetation cover over
the land. On the other hand the temporal climate feature is parametrised through it’s statistical variables. The human population
pressure is represented assuming compound population growth rate. The rational study has been carried out considering triangular
relationship among climate variation, human population pressure and tendency of land entity. The effort has been given to
understand difficulty and simplicity of parametric interdependency through physical analysis. The results evaluate the comparative
sensitivity within the similar susceptible land play a significant role. The study is carried out using two sets of IRS 1A/IB LISS-I
data of same month with about decadal separation.
1. INTRODUCTION
Both climate variability and human activity have a feedback
role, which affects the prolific characteristics of land. The
global climate change usually exacerbates the regional climate
variability which has a significant role in the local
environmental processes. The preliminary results indicate that
the mean ambient temperature during last half-a-century in and
around the study area has been increased by 0.07-0.81°C
climatically. Though the accumulated precipitation is increased
in recent climatic period the vulnerability has been increased in
many stations and it has been observed in coefficient of
variation of precipitation (CV%). Human fallibility and
resource exploitation are most sensitive parameters in the
country like India. It has speeded up the land degradation
process. This multifaceted behaviour is more sensitive over a
susceptible land causing degradation of land’s capability and
productivity. It affects the land reflectance or albedo specially
in arid or semi arid land. Hence, in arid or semiarid land the
reflectance of land surface indicates the land characteristic. In
radiative transfer processes the increase in surface albedo
usually implies that the land is leading towards dryness (Wahab
and Hasanean, 1999).
Robinove et al (1981) described a methodology based on
Landsat Albedo of earth surface in the wavelength range of
0.5um-1.1pm as collected by LANDSAT. Albedo is calculated
using digital brightness, solar irradiance, sun elevation angle,
atmospheric correction. They demonstrated the use of
increment in albedo as an indicator of degradation of land
quality whereas decrease indicate the improvement of the land
quality in arid zone. Pickup and Chewings (1988) developed a
model for forecasting large scale patterns of soil erosion and
deposition from landsat MSS data in arid grazing lands.
The NDVI, indicator of vegetation growth is sensitive to
variation of rainfall (Davenport et al, 1993) or available
irrigated water. Ghosh(1993) gave the revelation towards
development of several indicators for monitoring of land
589
degradation and a solution using RS-GIS tools and ancillary
data.
In view of these observations it is attempted to quantify the
tendency of land’s behaviour and it’s partial relationship with
climate variability and population pressure at local level.
2. PURPOSE OF THE STUDY
The objectives of this study are :
e evaluation of indicators representing land, climate and human
» Relationship among land stress, climate variability and human
pressure
3. DATA AND STUDY AREA
It is attempted to configure the simplest approach of envisaged
technique using two sets of spatial as well as temporal data.
The study is carried out using two sets of IRS 1A/1B LISS-I
data of same month with about decadal separation. It is
attempted to select closest available Julian day for remote
sensing data assuming that such set of temporal data carry least
atmospheric discrepancy in clear sky condition with seasonal
consistency of land's behaviour (table-1). The decadal time
interval between two sets of data is assumed to carry both
climatic and the human stress over the land unit. The climatic
data is procured from India Meteorological Department (IMD)
and the census data is acquired from district level information
centers and web resources.
There are two study zones, Chikalthana and Parbhani (Figure!)
covering two important agricultural belts in semiarid zones of
Western India. In this study, Chikalthana is approximately
bounded by 19°41'N and 20°2'N latitudes, 75°13 E and 75°32E
longitudes. The Parbhani is bounded by 19°12'N and 19°48 N
latitudes, 76°34E and 77°2'E longitudes. The study area of
Chikalthana and Parbhani cover 977.74 Km? and 2468.28 Km?