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Highlights • Innovative trend analysis (ITA) and Mann-Kendall (MK) determine average trend. • Double-ITA, Triple-ITA, and partial MK are proposed for stability test of trends. • ITA should be used together D-ITA or T-ITA for better trend analysis. • MK should be used together partial MK for better trend analysis. • Comparisons of ITA, D-ITA, T-ITA, classical MK, and partial MK are presented. Abstract The climate change is an important event that affects hydrological, agricultural and water resources planning variables, and therefore, the hydrologists and meteorologists frequently try to identify trend possibilities especially in rainfall, runoff and temperature time series. For this purpose, the classical Mann-Kendall (MK), Spearman's rho (SR), Sen's slope, and linear regression approaches are applied frequently in the literature. Recently, innovative trend analysis (ITA) provides visual inspection and identification of categorical trends, which is one of the main concerns in this paper. On the basis of ITA methodology, several improvements namely double-ITA (D-ITA) and triple-ITA (T-ITA) procedures are suggested using with simple ITA together. These methods are attractive for the trend stability assessment by comparing partial trend components during different sub-periods of a given record series. Furthermore, partial MK test approach is proposed in this paper for the same purpose. These procedures and approach are applied to a set of annual rainfall records at many stations in different regions of Turkey. As a result, the comparison of the suggested methods based on partial sub-series of the same time series helps to improve trend detection with stability identification. [ABSTRACT FROM AUTHOR]

Summary The Mahanadi river basin, a major river basin in eastern India, is expected to be the worst affected river basins in India in terms of the increase in intensity of floods due to climate change. The last decade has already seen five high floods occurring in the Mahanadi basin. Are these recent high floods an indication that Mahanadi floods are already getting worse? If so, is it due to an increase in extreme rainfalls over the basin? To answer these, we analyse the trends of peak discharge at the mouth of the delta at Naraj gauging site (the flow which is responsible for floods in the delta of Mahanadi basin) and peak releases from Hirakud dam in Mahanadi basin. Subsequently, grid based analysis of extreme rainfall is carried out for the entire Mahanadi basin to analyse the spatially varied extreme rainfall trends. Also, a region based (upper and middle regions of Mahanadi basin) analysis of extreme rainfall is carried out using daily mean areal rainfall. The trends of extreme rainfalls are analysed in relation to the trends of peak floods. The entire analysis pertains to post-Hirakud dam construction period. The analysis reveals that the recent incidences of high floods in Mahanadi basin is due to an increase in extreme rainfall in the middle reaches of the basin. [ABSTRACT FROM AUTHOR]