Rainfall Distribution and its Spatial and Temporal Variability over Arkavathi River Basin under Climate Change Scenario
Knowledge on the spatial variability and temporal trends of mean rainfall is essential for efﬁcient management of water resource and agriculture. Among the climatic elements, the rainfall is the first index, ever through off by formers and climatic analysers as it is the most important single factor which determines the cropping pattern of an area in general and the type of crop to be cultivated and its success or failure in particular. In the recent years, the important scientific challenge faced by researchers worldwide is to have a better understanding about climate change at a regional scale. However, for all the regions the changes are unequal and have localized intensity. Therefore, it should be quantified at a local scale. Precipitation is one of the important climatic variables responsible for climate change and required to be studied thoroughly. In the present study, the Arkavathy sub-basin, which is part of the Cauvery basin, is a highly stressed, rapidly urbanising watershed on the outskirts of the city of Bengaluru. The study is based on 30years of the daily rainfall data for 9 taluks of Arkavathy river basin rain gauge stations. The surface quality tests have also been performed by choosing particular locations to access the portable quality of water. The minimum mean annual rainfall is 646mm at Ramnagara district and maximum mean annual rainfall is 957.5mm at Bangalore north taluk. The maximum mean annual rainfall is recorded at mansoon 600mm at nelamangala taluk and minimum annual rainfall is recorded at winter season 9mm at Kunigal taluk. The entire Aarkavathy river basin experiences an average deficiency and also experiences normal wetness index, from the analysis it is seen that rainfall over Arkavathy river for a 30years of span experiences maximum bad rainfall years.
Keywords - Variability, Precipitation, Rainfall, Deficiency