Managing Water in a Changing World

Water, being a primary element in the diet and a necessary resource for the agriculture, can be considered a basic need for humans. In addition, also industrial practices need a growing amount of water. Since human population is continuously growing at a rate that, in the last two centuries, approximates well the exponential, water demand is increasing. However, the water resources on the Earth are finite. For this reason, even disregarding the potential threats due to the climate change, this situation appears as one of the biggest challenges of the current era. Actually, several small-scale regions already face water sustainability problems, and the scarcity of water resources is expected to spread to wider areas in the near future, if the actual trends of development and population growth do not change. The situation is exacerbated as the climate is already changing, due to the anthropogenic emissions of greenhouse gases in the atmosphere, and its rate is expected to increase by the end of this century. The effects of these changes will increase the natural variability of the climate, exacerbating the extreme climatic phenomena (drought and flood events) and increasing the difficulty of managing water resources, especially in the most vulnerable regions

Radar-Based Analysis of Convective Storms overNorthwestern Italy

Thunderstorms may cause large damages to infrastructures and population, therefore the possible identification of the areas with the highest occurrence of these events is especially relevant. Nevertheless, few extensive studies of these phenomena with high spatial and temporal resolution have been carried out in the Alps and none of them includes North-western Italy. To analyze thunderstorm events, the data of the meteorological radar network of the regional meteorological service of Piedmont region (ARPA Piemonte) have been used in this work. The database analyzed includes all thunderstorms occurred during the warm months (April to September) of a 6-year period (2005–2010). The tracks of each storm have been evaluated using a storm tracking algorithm. Several characteristics of the storms have been analyzed, such as the duration, the spatial and the temporaldistribution, the direction and the distance travelled. Obtained results revealed several important characteristics that may be useful for nowcasting purposes providing a first attempt of radar-based climatology in the considered region

The Occurrence of Cold Spells in the Alps Related to ClimateChange

Author to whom correspondence should be addressed; E-Mail: [email protected];Tel.: +39-011-670-7891; Fax: +39-011-658-444.Received: 23 June 2010; in revised form: 27 July 2010 / Accepted: 27 July 2010 /Published: 2 August 2010Abstract: Climate change is not only a likely prospect for the end of this century, butit is already occurring. Part of the changes will include global warming and increasingtemperature variability, both at global and regional scales. This increased variability wasinvestigated in this paper from the point of view of the occurrence of cold spells in theAlps in the future climate (2071–2100), compared with the present climate (1961–1990).For this purpose, a regionalisation of the climate change effects was performed within theAlps. To avoid possible errors in the estimate of the 2m air temperature, the analysis wasperformed on the soil surface temperature. To get realistic values for this variable, a landsurface scheme, UTOPIA, has been run on the selected domain, using the output of theRegional Climate Model (RegCM3) simulations as the driving force. The results show that,in general, the number of cold breaks is decreasing over the Alps, due to the temperatureincrement. However, there are certain zones where the behaviour is more complicated. Theanalysis of the model output also allowed a relationship to be found between the numberof cold breaks and their duration. The significance of these results over the whole area wasassessed.Keywords: cold spells; climate change; LSPM; UTOPIA; climate extreme

Meteorological and Streamflow Droughts: Characteristics, Trends and Propagation in the Milwaukee River Basin

This study examined meteorological and streamflow droughts for the period 1951-2006 using the Milwaukee River basin in Wisconsin as the study area in an effort to improve the understanding of drought propagation. Specifically, this study aimed to answer the following research questions: (1) What are the temporal trends of meteorological and streamflow droughts identified by drought indicators? (2) How do the drought indicators manifest drought propagation? Meteorological droughts were identified using the Effective Drought Index (EDI), and streamflow droughts were identified using a threshold-level approach. The intensity and duration of both types of drought were found to have decreased over time most likely due to increasing precipitation. Therefore, 22 in the study area, and likely in the larger region, drought has become of less concern. The propagation of meteorological drought into streamflow drought was detected generally after moderate and severe sequences of negative EDI that eventually led to extreme meteorological drought events. The study finds that both EDI and the threshold-level approach are effective in diagnosing meteorological and streamflow drought events of all durations