Remote-Sensing Technologies and Data Processing Algorithms - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 153

Practice has shown that, irrespective of the climatic zone, microwave radiome-
ters need to be used to achieve acceptable precision when reconstructing the vertical
pro

le of moisture in a soil layer to a depth of one meter. There is a priori
information about average soil moisture for depths 50 cm (W s2 ) and 100 cm (W s3 ).
The value W s1 is estimated by means of microwave radiometers with wavelengths
ʻ

= 10 and 30 cm. Then the following approximation W s ð z Þ ¼az 3 þ bz 2

þ cz þ d

is considered, where unknown coef cients are calculated from the condition of

minimal deviation between the W s ð z i Þ and W si (i = 1, 2, 3). For this to be done
conditions ( 2.5 ) have to be realized. This methodology allows soil moisture to be
determined by remote monitoring over large areas with an error no greater than
0.3 g cm − 3 for a biomass of vegetable cover no smaller than 2 kg m − 2 and with an
error up to 0.07 g cm − 3 for a biomass greater than 2 kg m − 2 .
The knowledge of function W s (z) allows to use the model of water balance of
territory to reconstruct the dynamical soil properties and other water balance ele-
ments as the functions of geophysical and ecological parameters. Experimental
valuation of thickness of upper soil layer on the lower boundary of which every
6 days after rain or watering the capillary connections breaking is taken place
(Fig. 2.13 ). Typical thickness of this dried up layer oscillates between 3 and 5 cm.

Fig. 2.13 Fragment of the vertical profile of soil moisture (%) calculated on basis of monitoring
data in framework of International hydrophysical experiment on the Bulgarian territory in the 2007
summer (Krapivin and Shutko 2012; Verba et al. 2013)