Temporal variability of climatic parameters of Yamuna River basin: spatial analysis of persistence, trend and periodicity.

Identification of the precise nature and attributes of the time series of climatological data is very important and is usually the first step for water resources planning and management. Such exercise is very important for hydro-climatic extremes. In many instances, a climatic time series is generally not statistically independent but is comprised of patterns of persistence, cycles, trends or some other non-random components. To see the importance of the subject, this paper de- scribes the statistical approach used to investigate the presence and extent of persistence, trend and periodicity in climatic time series. The methodology was applied to investigate the spatial distribution pattern of the indicative hydro-climatic variables over the Yamuna River basin of India. Hydro-climatic time series used in the analysis were annual rainfall; Monsoon and Non-monsoon rainfall; annual, Monsoon and Non-monsoon rainydays; onset of effective monsoon; and aridity index.