6 research outputs found
Soil moisture monitoring for climate research: Evaluation of a low-cost sensor in the framework of the Swiss Soil Moisture Experiment (SwissSMEX) campaign
Social media in the hospitality industry: An empirical study how hotel managers deal with user-generated content
Master's thesis in International hotel and tourism managementSocial media has gained in importance in the last years. With the revolution of the World Wide Web from simple tool to complex platform, user-generated content and online customer reviews have had a great impact on both consumers and businesses. This study explores the ways hotel managers deal with social media and user-generated content. Qualitative methods are employed through the analysis of in-depth interviews conducted with hotel managers in the Stavanger region in Norway. The research provides empirical evidence of the ways hotel managers make use of social media and user-generated content in their operations. Special emphasis is placed on analysing the strategic implementation of social media into the current operations and the future planning processes of the hotels in question. The findings of the study indicate that hotel managers consider social media and user-generated content important, but little effort and few resources are employed. In addition, there is a significant lack of knowledge of social media practices and explicit strategies are scarce. Yet, managers see social media as an opportunity rather than a threat and believe it to gain importance in the future
A new perspective on the spatio-temporal variability of soil moisture: Temporal dynamics versus time invariant contributions
Knowledge about the spatio-temporal variability of soil moisture is essential to understand and predict processes in climate science and hydrology. A significant body of literature exists on the characterization of the spatial variability and the rank stability (also called temporal stability) of absolute soil moisture. Yet previous studies were generally based on short-term measurement campaigns and did not distinguish the respective contributions of time-varying and time-invariant components to these quantities. In this study, we investigate this issue using measurements from 14 grassland sites of the SwissSMEX soil moisture network (spatial extent of approx. 150 × 210 km) over the time period May 2010 to July 2011. We thereby decompose the spatial variance of absolute soil moisture over time in contributions from the spatial variance of the mean soil moisture at all sites (which is time-invariant), and components that vary over time and are related to soil moisture dynamics. These include the spatial variance of the temporal soil moisture anomalies at all sites and the covariance between the site anomalies to the spatial mean at a given time step and those for the temporal mean values. The analysis demonstrates that the time-invariant term contributes 50–160% (on average 94%) of the spatial soil moisture variance at any point in time, while the covariance term generally contributes negatively to the spatial variance. On the other hand, the spatial variance of the temporal anomalies, which is overall most relevant for climate and hydrological applications because it is related to soil moisture dynamics, is relatively limited and constitutes at most 2–30% (on average 9%) of the total variance. Nonetheless, this term is not negligible compared to the temporal anomalies of the spatial mean. These results suggest that a large fraction of the spatial variability of soil moisture assessed from short-term campaign may be time-invariant if other regions present a similar behavior. Moreover, we find that the rank (or temporal) stability concept, when applied to absolute soil moisture at the sites, mostly characterizes the time-invariant patterns. Indeed, sites that best represent the mean soil moisture dynamics of the network are not the same as those that best reflect mean soil moisture at any point in time. Overall, this study shows that conclusions derived from the analysis of the spatio-temporal variability of absolute soil moisture need not generally apply to temporal soil moisture anomalies, and hence to soil moisture dynamics.ISSN:1027-5606ISSN:1607-793
Continuous simulation for flood estimation in ungauged mesoscale catchments of Switzerland – Part II: Parameter regionalisation and flood estimation results
Flood estimations for ungauged mesoscale catchments are as important as they are difficult. So far, empirical and stochastic methods have mainly been used for this purpose. Experience shows, however, that these procedures entail major errors. In order to make further progress in flood estimation, a continuous precipitation–runoff-modelling approach has been developed for practical application in Switzerland using the process-oriented hydrological modelling system PREVAH (Precipitation– Runoff–EVApotranspiration-HRU related model). The main goal of this approach is to achieve discharge hydrographs for any Swiss mesoscale catchment without measurement of discharge. Subsequently, the relevant flood estimations are to be derived from these hydrographs. On the basis of 140 calibrated catchments (Viviroli et al., 2009b), a parameter regionalisation scheme has been developed to estimate PREVAH’s tuneable parameters where calibration is not possible. The scheme is based on three individual parameter estimation approaches, namely Nearest Neighbours (parameter transfer from catchments similar in attribute space), Kriging (parameter interpolation in physical space) and Regression (parameter estimation from relations to catchment attributes). The most favourable results were achieved when the simulations using these three individual regionalisations were combined by computing their median. It will be demonstrated that the framework introduced here yields plausible flood estimations for ungauged Swiss catchments. Comparing a flood with a return period of 100 years to the reference value derived from the observed record, the median error from 49 representative catchments is only -7%, while the error for half of these catchments ranges between -30% and +8%. Additionally, our estimate lies within the statistical 90% confidence interval of the reference value in more than half of these catchments. The average quality of these flood estimations compares well with present empirical standard procedures, while the range of deviations is noticeably smaller. Additionally, the availability of complete hydrographs and the process-oriented background bear potential for analyses that go beyond the mere estimation of peak flows