Evolution of karst conduit networks in transition from pressurized flow to free-surface flow
Summary: This is the first modeling study of conduit network evolution in karst aquifers under pressurized and free surface turbulent flow conditions. Under pressurized flow, the evolution is governed by the feedback between the distribution of hydraulic head and the growth of conduits, as has been already revealed by earlier models. We demonstrate the final selection of stable flow paths on the scale of individual junctions, during and after transition to the free-surface flow regime.
Summary: This study introduces the theory of networks, and in particular complex networks, to examine connections in streamflow dynamics. Monthly streamflow data from a network of 639 stations in the United States are studied. The connections are examined primarily using the concept of clustering coefficient, which quantifies the network’s tendency to cluster. The clustering coefficient analysis is performed with several different threshold levels based on correlations in streamflow between the stations.
Spatial analysis of precipitation in a high-mountain region: exploring methods with multi-scale topographic predictors and circulation types
Summary: The question of how to utilize information from the physiography/topography in the spatial interpolation of rainfall is a long-standing discussion in the literature. In this study we test ideas that go beyond the approach in popular interpolation schemes today. The key message of our study is that these ideas can at best marginally improve interpolation accuracy, even in a region where a clear benefit would intuitively be expected.
Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap system
Summary: Natural patterns of water levels in the Mekong are changing as a result of hydropower and irrigation development. Since 1991, significant changes in water level fluctuations and rising and falling rates have occurred along the lower Mekong. The changes were linked to temporal and spatial trends in water infrastructure development and can lead to impacts on ecosystem productivity. Climatic change is also important, but it has not been the main cause of the key water level alternations.
Climate change and wetland loss impacts on a western river's water quality
Summary: We demonstrate a framework to assess system sensitivity to combined climate and land cover change scenarios. In the western United States study watershed, findings suggest that mid-21st-century nutrient and sediment loads could increase significantly or show little change under no wetland losses, depending on climate scenario, but that the combined impact of climate change and wetland losses on nutrients could be large.
Evaluation of the satellite-based Global Flood Detection System for measuring river discharge: influence of local factors
Summary: One of the main challenges in global hydrological modelling is the limited availability of observational data for calibration and model verification. The aim of this study is to test the potentials and constraints of the remote sensing signal of the Global Flood Detection System (GFDS) for converting the flood detection signal into river discharge values. This work also provides a first analysis of the local factors influencing the accuracy of discharge measurement as provided by this system.
Mobilisation or dilution? Nitrate response of karst springs to high rainfall events
M. Huebsch, O. Fenton, B. Horan, D. Hennessy, K. G. Richards, P. Jordan, N. Goldscheider, C. Butscher, and P. Blum Hydrol. Earth Syst. Sci., 18, 4423-4435, 2014 AbstractFinal Revised Paper (PDF, 1447 KB)Discussion Paper (HESSD)
05 Nov 2014
Inundation and groundwater dynamics for quantification of evaporative water loss in tropical wetlands
J. Schwerdtfeger, M. S. Johnson, E. G. Couto, R. S. S. Amorim, L. Sanches, J. H. Campelo Jr., and M. Weiler Hydrol. Earth Syst. Sci., 18, 4407-4422, 2014 AbstractFinal Revised Paper (PDF, 1539 KB)Discussion Paper (HESSD)
05 Nov 2014
Comment on "Technical Note: On the Matt–Shuttleworth approach to estimate crop water requirements" by Lhomme et al. (2014)
Summary: This paper explains the Matt-Shuttleworth approach clearly, simply and concisely. It shows how this approach can be implemented using a few simple equations and provides access to ancillary calculation resources that can be used for such implementation. If the crop water requirement community considered it preferable to use the Penman-Monteith equation to estimate crop water requirements directly for all crops, this could now be done using the Matt-Shuttleworth approach.