Agricultural Drought in Bangladesh - Monitoring and Predicting Agricultural Drought: A Global Study - page 319

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(NOAA). The AVHRR data, received in five different channels, are digitally
processed at the SPARRSO, primarily to analyze formation of cyclones
and depressions in the Bay of Bengal. To analyze changes in vegetation
cover, the radiometric information (% reflectance) received by the NOAA
satellite is plotted against the wavelength of the radiation. From standard
curves, verified by “ground truthing” with local conditions, the condition
of vegetation with regard to growth can be determined. This information
is then analyzed using GIS technology to get a spatial view of the analy-
sis (SPARRSO, 1999). The technique was tried jointly by SPARRSO and
BARC and has proved useful.
Unfortunately, AVHRR data can only be obtained when there are no
clouds in the sky over Bangladesh (i.e., only during the winter season). Syn-
thetic Aperture Radar (SAR) data (chapters 7 and 8) should ideally be used
during the monsoon season because it can penetrate through clouds. Un-
fortunately, SPARRSO operates with very limited funding that does not al-
low it to procure SAR data from international agencies and data providers.
Moreover, the organization does not have the mandate to monitor drought
conditions. Its sole responsibility is to monitor cyclone formations. When
there are fears of wide-scale loss of Aman due to the postmonsoon drought,
SPARRSO is requested by the Ministry of Agriculture to analyze the situ-
ation.
Given the technological capacity of SPARRSO, it is possible to monitor
drought on a regular basis for all the cropping seasons provided that the
ministries involved coordinate with each other and allocate funds to pro-
cure information, engage personnel for ground-level data collection and
analysis, and enhance the capacity to validate models. In the absence of a
proper institutional mechanism, the country has been deprived of valuable
information useful to drought monitoring.

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D rought Mitigation in Bangladesh
Since ancient times, farmers have practiced irrigation using surface water
from nearby sources for a variety of crops including Aman and a number
of nongrain Rabi crops. There have been local Aman species/cultivars that
required very low levels of supplementary irrigation. Traditional irrigation
techniques have been used extensively. With the advent of green revolution
in the mid-1960s and with the development of HYV seeds, people began
to irrigate lands heavily. The initial results have been excellent in terms
of grain yields. However, over the years, the requirement for fertilizers
and irrigation has increased significantly due to the gradual deterioration
in land quality due to the erosion of major nutrients, micronutrients, and
organic carbon contents from the topsoil.
The surface water systems of the country are largely dependent on up-
stream countries: India, Nepal, Bhutan, and China. Increasing water with-
drawal upstream and the diversion of water from the main transboundary
courses reduced the flow in Bangladesh significantly during the dry months