Kerala can be divided into three unique rainfall regions, each region having a similar covariance structure of annual rainfall. Stations north of 10.N (north Kerala) fall into one group and they receive more rainfall than stations south of 10.N (south Kerala). Group I stations (table 2) receive more than 65% of the annual rainfall during the south-west monsoon period, whereas stations falling in Group II (table 3) receive 25-30% of annual rainfall during the pre-monsoon and the north-east monsoon periods. Group III stations (table 4) with IIIrd factor as the primary loading, i.e., IIIrd factor greater than Ist and IInd factor.
The meteorology of Kerala is profoundly influenced by its orographical features, however it is difficult to make out a direct relationship between elevation and rainfall. Local features of the state as reflected in the rainfall distribution are also clearly brought out by the study
Abstract of Heaviest Rainfall places in Kerala
-------------------------------------
Neriamangalam 451 cm
Kutiyadi 416
Vythiri 396
Peermade 392
Ponmudi 391
Quilandi 379
Kasargod 355
Hosdurg 351
Karikode 349
Munnar 346
Vellor 345
Irikkur 345
There is a lack of direct relationship between the height of a station and its rainfall from this study. The spatial variability of mean annual precipitation depends upon the topographic factors like exposure of the station to the prevailing wind, elevation, orientation, and slope of the mountain.The study is, however, limited to the number of rainfall stations available and a better network of stations in the region will reflect more local-scale phenomena. The results are useful for mesoscale and synoptic scale atmospheric modelling.
