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REGIONAL SOIL PROFILE MOISTURE MODELING USING REMOTE SENSING

KrishiKosh

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Title REGIONAL SOIL PROFILE MOISTURE MODELING USING REMOTE SENSING
 
Creator SELVADURAI SUTHAKAR
 
Contributor U. K. Chopra
 
Subject soil water content, layering, irrigation, area, biological phenomena, remote sensing, land resources, soil profiles, physical control, fractionation
 
Description t-8582
The knowledge of regional profile moisture present in agricultural fields is
important for the efficient planning of water resources of that region. In this study,
the prediction of regional profile moisture of a large area (5250 km2
) spread over 3
districts Bulandshahar, Ghaziabad and Goutam Buddha Nagar of the western Uttar
Pradesh, India was carried out based on a remote sensing model and a soil model. A
remote sensing model based on SEBAL (Surface Energy Balance Algorithm for
Land) algorithm was used to estimate the evaporative fraction of energy balance at
soil surface and surface soil moisture of the region. To predict layer wise profile
moisture of the region, a Soil Profile Moisture Estimation (SPME) model was
developed. This model was validated at IARI fields. The inputs required for this
model are initial profile moisture and surface boundary conditions along with a few
soil characteristics parameters. The model predicts the layer wise profile moistures at
the end of a time interval, if the layer wise profile moistures at the beginning of the
period and the surface water fluxes during the period were known for each time step.
Finally, the layer wise moisture content maps of the region were developed. The
performance of the model was tested in IARI field and was found to be very good
with coefficient of determination (R2 = 0.90) and RMSE (0.04) between the
observed and predicted profile moisture content.
The imageries of the study area from MODIS and Landsat satellites were
used to estimate the evaporative fraction at soil surface from SEBAL algorithm. This
was achieved by estimating the net radiation, soil heat flux, sensible heat flux and
latent heat flux of the energy balance equation. This evaporative fraction was
converted to surface evaporative flux and surface soil moisture. This model predicted
the daily evapotranspiration of the study area in the range of 0.2 to 6.8 mm/day (CV
= 19%) for 2009 and 1.3 to 6.9 mm/day (CV = 39%) for 2010. It predicted the
surface soil moisture which was between 1.5 to 40% (CV= 40%) in 2009 and
between 8.5 to 33.4 % (CV=33%) in 2010. The net evaporative flux from SEBAL
was used in SPME model as upper boundary flux. The initial soil profile moistures
were measured from the 50 locations of the study area to get initial conditions for the
SPME model. The layer wise profile moistures were estimated for the next 8 days by
inputting the measured initial conditions and predicted surface fluxes to SPME
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model for all the 50 locations. Then, the layer wise moisture content maps were
developed in the GIS environment of ILWIS software for each day up to next 8 days.
The output of these two models in the form of regional maps of moisture content for
each soil layer provided the quantified information about the soil moisture status of
the agricultural fields in the study area. Linking of the two models predicted that
there was only 4% of the total study area which had the surface moisture content
between 10 to 20% on the day of sampling during 2009 which increased to 88% of
total area at the end of 8th day. During 2010, the surface dried up very fast and by 6th
day of sampling the whole region dried up to moisture content in the range of 10 to
20%. Similar quantified results for other layers were also predicted by linking the
two models. These information are extremely useful in the decision making process
for efficient water use for the region.
 
Date 2016-12-15T10:00:43Z
2016-12-15T10:00:43Z
2012
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/90233
 
Format application/pdf
 
Publisher iari,DIVISION OF AGRICULTURAL PHYSICS