Abstract:
Drought is a temporary and recurring hydro-meteorological event, which originates from the lack
of precipitation, high temperature, and high evaporation over extended period of time. It is a
normal part of any climate and, perhaps the most complex natural hazard, because it develops
slowly, it is difficult to detect and has many facets in any single region. Drought preparedness
and mitigation depends upon timely information on drought onset, development in time and
spatial extent. This information may be obtained through continuous drought monitoring, which
is normally performed using drought indices. This project work describes drought assessment,
using two different drought indices, SPI (Standardized Precipitation Index) and RAI (Rainfall
Anomaly Index). The Marathwada region of Maharashtra was chosen as the study area and this
region is characterized as a ‘frequently drought prone area’, where drought can be expected
every 6 to 10 years. A comparison of RAI and SPI values were done for determination of
drought severity and temporal extension of drought for planning of mitigation measures for
farmers. Using the SPI and RAI as indicators of drought severity from 1901-2002, the
characteristics of drought were examined. The monthly rainfall data for the period (2012-2016)
was also analyzed and the severity of drought was evaluated as a check with the historical data.
The maximum annual SPI was -2.61 in the year 1920, similarly the RAI values also showed the
same results which was -4.748 indicating the extreme drought conditions in the study area. The
monthly SPI values were also compared with RAI+ and RAI- values for the period under
observation. It was observed that the RAI- is highly correlated with SPI for determining the
characteristics of droughts in the study area. The overall outcome of this study demonstrates that
extreme and severe droughts were experienced in the years 1920, 1972 and 1911, 1912, 1918,
2000, 2001 across the study area leading to unfavourable results on agricultural practices and
water resources in the area.
