In water scarce areas, policy makers frequently opt for water conservation and saving technologies (WCSTs) as a measure to ensure resource use sustainability, although this policy is subject to scientific and political debate. This work presents an application of an integrated methodological approach for analysing the costs and benefits of using WCSTs to achieve water policy objectives. The focus is on the measures aimed at reducing irrigation water abstraction under the 1⁠st and 2⁠nd cycle of Water Framework Directive implementation in the Guadalquivir River Basin (Southern Spain). The method is a combination of a multicriteria assessment of the main effects of water-saving investments at basin level, estimated using a selected group of indicators. In a second stage, a cost-benefit analysis is conducted. The study finds a benefit-to-cost ratio of 4.1/1 for the Guadalquivir River Basin, thus concluding that irrigation modernization in this case study has been a good social investment. The method can be extended to other hydrological systems (aquifer basins) to draw general conclusions.

To reduce the impact of droughts and increase the resilience of regional water systems, various demands, such as hydropower, supply and irrigation, need to be reconciled. In this perspective, designers and practitioners must be able to use information tools to define the hydrological constraints for a sustainable management of the resource. In this work, a web-based open-source geoinformation system is presented, that allows to estimate Flow Duration Curves (FDCs) in ungauged basins. The regional statistical model used, developed by Ganora et al., 2013 [1] in North-Western Italy, is based on the characterization of the FDC in a parametric framework where parameters depend on topographic, climatic, land use and vegetation descriptors computed at the basin scale. The software tool, accessible both by web browsers and GIS desktop (e.g. QGIS), pilots the estimations steps by computing the spatial descriptors and applying relations needed to estimate the full FDC via Burr distribution. The developed server-side scripting provides users with always updated data and procedures, being free from software client compatibility issues.

Currently, there is general concern about the non-stationary behaviour of flood series. Consequently, several studies have been conducted to identify large-scale patterns of change in such flood series. In Spain, a general decreasing trend was found in the period 1959-2009. However, a multi-temporal trend analysis with varying starting and ending years showed that trend signs depended on the period considered. Flood oscillations could influence the results, especially when flood-rich and flood-poor periods are located at the beginning or end of the series. In Spain, a flood-rich period in 1950-1970 seemed to lead to the generalised decreasing trend, as it was located at the beginning of the flood series. Nevertheless, the multi-temporal test can only find potential flood-rich and flood-poor periods qualitatively. A methodology has been developed to identify statistically significant flood-rich and flood-poor periods. The expected variability of floods under the stationarity assumption is compared with the variability of floods in observed flood series. The methodology is applied to the longest streamflow series available in Spain. Seven gauging stations located in near-natural catchments with continuous observations in the period 1942-2014 are selected. Both annual maximum and peak-over-threshold series are considered. Flood-rich and flood-poor periods in terms of flood magnitudes and the annual count of exceedances over a given threshold are identified. A flood-rich period in the beginning of the series and a flood-poor period at its end are identified in most of the selected sites. Accordingly, a flood-rich period placed at the beginning of the series followed by a flood-poor period influence the generalised decreasing trend in flood series previously found in Spain.

China is in a period of rapid urbanization, which is forming a number of highly urbanized regional clusters, such as the Pearl River Delta region and the Yangtze River Delta region. The urban development has also profoundly changed the local environment, including local climate conditions, underlying topography, municipal & water conservancy facilities, which increases the risk of flood & waterlogging disasters. Due to the high concentration of population and industries in these areas, the loss of urban flood and waterlogging has also increased at an unprecedented rate. Therefore, it is of great significance to strengthen the analysis and evaluation of the characteristics and impact of flood & waterlogging disasters in highly urbanized areas. Based on the comprehensive analysis of domestic and foreign related studies, this study quantitatively analyzed the vulnerability of flood & waterlogging disaster-bearing bodies in highly urbanized areas of China, considering the characteristics of different disaster-bearing bodies, such as industry and commerce, surrounding agriculture, housing, traffic, lifeline facilities (like water, gas and electricity), etc. The disaster-causing mechanism and response of different disaster-bearing bodies to flood & waterlogging events were analyzed, and the mechanism curve of flood & waterlogging loss rate and submergence degree was established. The study on the quantitative method of vulnerability of flood disaster-bearing bodies in highly urbanized areas will provide theoretical support for dynamic assessment of flood & waterlogging disaster losses and it could also provide technical support for scientific flood control and disaster reduction in China for the future.

and volume and duration should be taken into account in a multivariate framework. The primary goal of this study is to compare univariate and joint bivariate return periods of extreme precipitation that all rely on different probability concepts in selected meteorological stations of Cyprus. Pairs of maximum rainfall depths with corresponding durations are estimated and compared using annual maximum series (AMS) for the complete period of the analysis and 30-year subsets for selected data periods. Marginal distributions of extreme precipitation are examined and used for the estimation of typical design periods. The dependence between extreme rainfall and duration is then assessed by an exploratory data analysis using K-plots and Chi-plots, and the consistency of their relationship is quantified by Kendall’s correlation coefficient. Copulas from Archimedean, Elliptical and Extreme Value families are fitted using a pseudo-likelihood estimation method, evaluated according to the corrected Akaike Information Criterion and verified using both graphical approaches and a goodness-of-fit test based on the Cramér-von Mises statistic. The selected copula functions and the corresponding conditional and joint return periods are calculated and the results are compared with the marginal univariate estimations of each variable. Results highlight the effect of sample size on univariate and bivariate rainfall frequency analysis for hydraulic engineering design practices.