Hydrological modelling improvements required in basins in the Hindukush-Karakoram-Himalayas region

Millions of people rely on river water originating from basins in the Hindukush-Karakoram-Himalayas (HKH), where snow- and ice-melt are significant flow components. One such basin is the Upper Indus Basin (UIB), where snow- and ice-melt can contribute more than 80% of total flow. Containing some of the world’s largest alpine glaciers, this basin may be highly susceptible to global warming and climate change, and reliable predictions of future water availability are vital for resource planning for downstream food and energy needs in a changing climate, but depend on significantly improved hydrological modelling. However, a critical assessment of available hydroclimatic data and hydrological modelling in the HKH region has identified five major failings in many published hydro-climatic studies, even those appearing in reputable international journals. The main weaknesses of these studies are: i) incorrect basin areas; ii) under-estimated precipitation; iii) incorrectly-defined glacier boundaries; iv) under-estimated snow-cover data; and v) use of biased melt factors for snow and ice during the summer months. This paper illustrates these limitations, which have either resulted in modelled flows being under-estimates of measured flows, leading to an implied severe water scarcity; or have led to the use of unrealistically high degree-day factors and over-estimates of glacier melt contributions, implying unrealistic melt rates. These effects vary amongst sub-basins. Forecasts obtained from these models cannot be used reliably in policy making or water resource development, and need revision. Detailed critical analysis and improvement of existing hydrological modelling may be equally necessary in other mountain regions across the world

Arbeid als zwakste schakel : vaste werkzaamheden vragen tussen twee en zeven uur per duizend kilo melk

Signalering van het probleem van een hoge arbeidsdruk in de melkveehouderij, doordat de arbeidsreserve is opgeraakt, waardoor het belang van een ver doorgevoerde efficiëntie nog meer op de voorgrond kom

Energetische landbouw: een kansrijke nieuwe ontwikkeling?

Een kennismaking met de energetische landbouw, die uitgaat van het nut van electromagnetische trillinge

Subpermafrost Groundwater Modelling in Ny-Ålesund, Svalbard:Paper presented at the 11th Northern Res. Basins Symposium/Workshop Prudhoe Bay to Fairbanks, Alaska, USA - Aug. 18-22, 1997

Svalbard is a high arctic archipelago where the permafrost thickness is 150-450 m and almost continuous in ice-free areas. The model work was carried out in Ny-Ålesund, where the subpermafrost aquifers are recharged by water from the bottom of the Vestre Lovénbreen glacier. One main discharge spring is found at the entrance of an old coal mine. The computer code SUTRA has been used to simulate two-dimensional fluid movement and energy transport in the ground under steady state conditions. For the simulation, a cross section with unit thickness parallel to groundwater flow has been chosen. With the resulting output of SUTRA, contour maps of the pressure, hydraulic head, temperature and velocity have been made. Residence times for different situations have been determined to be15 years as a minimum. In general there is a good agreement between the physical reality and the simulation results.</jats:p