Department of Geography, School of Geosciences, Bharathidasan University, Tiruchirappalli – 620 024
*Emial: uma888.geo@gmail.com
Online published on 4 January, 2012.
The rainfall is primary source for water and it is characterized by its amount, intensity and distribution in time. The study could form a basis for planning the agricultural activity of the study area. In order to understand the spatial pattern of annual and seasonal rainfall, their variability, precipitation ratio and frequency occurrence of rainfall have been analysed through GIS environs. The study has used the long term (30 years) mean monthly rainfall data for eleven rain gauge stations, located in and around Suruli Ar watershed to analyse its various facets. Accordingly, the mean annual rainfall is about 870 mm which exceeds 1426 mm and drops as much as 638 mm. The mean annual rainfall variability of the watershed is 28.3%. The area in and around Suruli Ar watershed experiences high abnormality as the precipitation ratio is 185% whereas the lowest is about 44.4% at Sothuparai. The entire watershed is subjected to larger temporal fluctuations rather than the spatial distribution of rainfall.
Rainfall, Variability, Abnormality, Precipitation Ratio, Frequency Occurrence and GIS
