Combining Optical Remote Sensing, McFLI Discharge Estimation, Global Hydrologic Modeling, and Data Assimilation to Improve Daily Discharge Estimates Across an Entire Large Watershed

Remote sensing has gained attention as a novel source of primary information for estimating river discharge, and the Mass-conserved Flow Law Inversion (McFLI) approach has successfully estimated river discharge in ungauged basins solely from optical satellite data. However, McFLI currently suffers from two major drawbacks: (1) existing optical satellites lead to temporally and spatially sparse discharge estimates and (2) because of the assumptions required, McFLI cannot guarantee downstream flow continuity. Hydrological modeling has neither drawback, yet model accuracy is frequently limited by a lack of discharge observations. We therefore combine McFLI and models in a data assimilation framework applicable globally. We establish a daily “ungauged” baseline model for 28,998 reaches of the Missouri river basin forced by recently published global runoff data, which we do not calibrate. We estimate discharge via McFLI using ∼1 million width measurements made from 12,000 Landsat scenes and assimilate McFLI into the model before validating at 403 USGS gauges. Results show that assimilated discharges did not impair already accurate baseline flows and achieved median improvements of 28% normalized root mean square error, 0.50 Nash–Sutcliffe efficiency (NSE), and 0.23 Kling–Gupta efficiency where baseline performance was poor (defined as baseline negative NSE, 225/403 reaches). We ultimately improved flows at 92% of these originally poorly modeled gauges, even though Landsat images only provide McFLI discharges at 1.5% of reaches and 26% of simulated days. Our results suggest that the combination of McFLI and state-of-the-art hydrology models can improve flow estimations in ungauged basins globally

The role of social networking services in eParticipation

A serious problem in eParticipation projects is citizen engagement – citizens do not necessarily become more willing to participate simply because net-services are provided for them. Most forms of eParticipation in democratic contexts are, however, dependent on citizen engagement, interaction and social networking because democratic systems favour the interests of larger groups of citizens – the more voices behind a political proposition, the greater its chances of success. In this context of challenges the study of social networking on the internet and social network theory offers valuable insights into the practices and theories of citizen engagement. Social network theory focuses on the chains of relationships that social actors communicate and act within. Some social networking services on the internet attract large numbers of users, and apparently sustain a great deal of interaction, content-generation and the development of loosely-coupled communities. They provide the forum for much discussion and interaction. In this respect social networking could contribute to solve some of the problems of engaging their users that eParticipation services often struggle with. This paper investigates the potential of Social Networking Services for the eParticipation area by defining social networking services, introducing the driving forces behind their advance, and discusses the potential use of social networking software in the eParticipation context

Search for a scalar top quark using the OPAL detector

Contains fulltext : 124482.pdf (preprint version ) (Open Access

A search for doubly charged higgs production in z0 decays

Contains fulltext : 124394.pdf (preprint version ) (Open Access