Abstract:
This paper proposes a methodology for assessment of drought vulnerability at
spatial and temporal scales using physiographic, climatic and hydrologic factors by integrating
relative influence of different factors at the scale of hydrologic response units
(HRUs). In the proposed methodology, an index termed as ‘‘Integrated Drought Vulnerability
Index (IDVI)’’ is devised as an indicator of vulnerability to drought. The SWAT
model has been applied to demarcate HRUs and estimation of soil moisture in the study
basin. Spatial information of different influencing factors is categorized into various subclasses,
and maps have been prepared using ArcGIS. In this analysis, monthly rainfall
departure is considered as climatic factor and Soil Moisture Deficit Index as hydrologic
factor. The applicability of the proposed methodology is demonstrated on the Ken River
basin, located in the Bundelkhand region in central India. Using the proposed methodology,
maps showing spatial distribution of relative vulnerability to drought have been
obtained at the level of HRU. The HRUs with higher value of IDVI represent the areas with
relatively high degree of vulnerability to drought and vice versa. The maps thus obtained
have been validated using the documented information. The present methodology provides
better insight for drought mitigation actions.
