Land use scenario development and stakeholder involvement as tools for watershed management within the Havel River Basin

The implementation of the European Water Framework Directive (WFD) will address land use issues in river catchments in order to reduce diffuse pollution and work towards the aim of achieving good ecological status, or good ecological potential in surface water bodies. The WFD also requires the active involvement of all interested parties in developing the best approach to achieve its objectives. The paper demonstrates how scenario analysis can be applied to investigate the impacts of land use changes and how stakeholder interviews can be used to evaluate the results of the scenarios.The study was carried out in the Havel Basin in the northeast of Germany. ‘Landscape-ecological spatial units’ were derived from similar characteristics of soil and groundwater conditions, ground relief and inundation to enable spatial allocation of potential land use and link different scales when describing possible changes in land use. As a first step, in three sub-catchments of the Havel River (distinguished by different physical characteristics) detailed surveys were carried out to investigate the various interests of the stakeholders. The interviews were used to identify the key problems of each area with respect to water quality and quantity and facilitated stakeholder engagement with the catchment planning issues in the Havel River Basin. The information from the stakeholder interviews was used to determine the initial conditions for the land use scenarios which were developed to demonstrate possible changes to land use for achieving better water quality. The land use scenarios also were required as an input into the hydrological modelling of their effects on water quality and to calculate their socio-economic effects. In a second survey, the results of the scenarios and the hydrological modelling were presented to the stakeholders. The consultation process identified the priorities of the stakeholders which could then be taken into account when developing management options.     

Seasonal changes in vocalization during behavior of the Atlantic bottlenose dolphin

Four vocalizations (whistles, buzzes, quacks, and pops) were quantified during three behavioral categories (socializing, traveling, and feeding) of the bottlenose dolphin in the Newport River Estuary, North Carolina. This study tested the hypothesis that specific vocalizations of dolphins in this area are associated with specific behavioral categories during the summer and fall. Approximately twice the total number of vocalizations per unit time occurred during the fall as compared to the summer. Each type of vocalization had a distinctive and consistent acoustical structure. The relative frequency of the different vocalization types was significantly dependent on the behavior of the dolphins. Pops were consistently associated with feeding, quacks with socializing, and buzzes with traveling. Whistles, the most common vocalization, were associated with traveling and feeding during the summer and socializing in the fall. Dolphins spent more time involved in undirected activity (socialization) during the summer but spent more time traveling in search of food and feeding during the fall in preparation for migration out of the estuary and movement south.     

Drag of a thin closed fence estimated by the momentum budget technique

Summary In a full-scale field study, the drag coefficient has been estimated of a closed thin fence, which has been attached to the earth's surface. The momentum budget method has been applied to a small and narrow control volume around the fence. It appeared that the drag coefficient was strongly dependent on the thermal stratification of the atmosphere. The result under thermally near-neutral conditions agreed well with an independent direct measuring technique.

---

Zusammenfassung Der Widerstandsbeiwert eines dichten dünnen Zaunes, der am Erdboden befestigt war, wurde bestimmt. Dabei wurde das Impulsbilanzverfahren an einem kleinen und schmalen Kontrollvolumen angewendet. Es zeigte sich, daß der Widerstandsbeiwert stark von der thermischen Schichtung der Atmosphäre abhängig war. Bei thermisch neutralem Zustand stimmte das Resultat gut mit unabhängigen direkten Messungen überein.

---

---

With 7 Figures     

Geophysics 2001

An attempt is made to try and predict those fields of research in geophysics which are most likely to prove rewarding in the next one or two decades. Topics covered are the early history of the Earth, satellite geodesy, mantle convection, geomagnetism, aeronomy and space research.     

The flow around a thin closed fence

A full-scale field study was conducted in order to investigate the flow around a thin closed fence, attached to the Earth's surface. At nine locations around the barrier, mean wind profiles were measured simultaneously. The effect of thermal stratification on the recovery of the profiles was studied. Data of the far wake region, i.e., the region beyond the reattachment point, were compared with the model results of Counihan et al. (1974).     

The role of saline solution properties on porous limestone salt weathering by magnesium and sodium sulfates

Saline solution properties, viscosity in particular, are shown to be critical in salt weathering associated with sodium and magnesium sulfate crystallization in porous limestone. The crystallization of sodium and magnesium sulfate within a porous limestone has been studied at a macro- and microscale using different techniques, including mercury intrusion porosimetry, environmental scanning microscopy and X-ray computed tomography. Such analysis enabled the visualization of the crystallization process in situ, and at high magnification, yielding critical information as to where and how salts crystallize. Sodium sulfate decahydrate (mirabilite) tends to crystallize in large pores as euhedral micron-sized crystals formed at low supersaturation near to the surface of the stone. In contrast, magnesium sulfate heptahydrate (epsomite) tends to precipitate as anhedral wax-like aggregates formed at high supersaturation and distributed homogeneously throughout the stone pore system filling large and small pores. While the former crystallization behavior resulted in scale formation, the latter led to crack development throughout the bulk stone. Ultimately, the contrasting weathering behavior of the two sulfates is explained by considering differences in flow dynamics of solutions within porous materials that are mainly connected with the higher viscosity of magnesium sulfate saturated solution (7.27 cP) when compared with sodium sulfate saturated solution (1.83 cP). On the basis of such results, new ways to tackle salt weathering, particularly in the field of cultural heritage conservation, are discussed.     

Fog Research: A Review of Past Achievements and Future Perspectives

The scientific community that includes meteorologists, physical scientists, engineers, medical doctors, biologists, and environmentalists has shown interest in a better understanding of fog for years because of its effects on, directly or indirectly, the daily life of human beings. The total economic losses associated with the impact of the presence of fog on aviation, marine and land transportation can be comparable to those of tornadoes or, in some cases, winter storms and hurricanes. The number of articles including the word ``fog' in Journals of American Meteorological Society alone was found to be about 4700, indicating that there is substantial interest in this subject. In spite of this extensive body of work, our ability to accurately forecast/nowcast fog remains limited due to our incomplete understanding of the fog processes over various time and space scales. Fog processes involve droplet microphysics, aerosol chemistry, radiation, turbulence, large/small-scale dynamics, and surface conditions (e.g., partaining to the presence of ice, snow, liquid, plants, and various types of soil). This review paper summarizes past achievements related to the understanding of fog formation, development and decay, and in this respect, the analysis of observations and the development of forecasting models and remote sensing methods are discussed in detail. Finally, future perspectives for fog-related research are highlighted.     

Statistical considerations for grain-size analyses of tills

Relative percentages of sand, silt, and clay from samples of the same till unit are not identical because of different lithologies in the source areas, sorting in transport, random variation, and experimental error. Random variation and experimental error can be isolated from the other two as follows. For each particle-size class of each till unit, a standard population is determined by using a normally distributed, representative group of data. New measurements are compared with the standard population and, if they compare satisfactorily, the experimental error is not significant and random variation is within the expected range for the population. The outcome of the comparison depends on numerical criteria derived from a graphical method rather than on a more commonly used one-way analysis of variance with two treatments. If the number of samples and the standard deviation of the standard population are substituted in at-test equation, a family of hyperbolas is generated, each of which corresponds to a specific number of subsamples taken from each new sample. The axes of the graphs of the hyperbolas are the standard deviation of new measurements (horizontal axis) and the difference between the means of the new measurements and the standard population (vertical axis). The area between the two branches of each hyperbola corresponds to a satisfactory comparison between the new measurements and the standard population. Measurements from a new sample can be tested by plotting their standard deviation vs. difference in means on axes containing a hyperbola corresponding to the specific number of subsamples used. If the point lies between the branches of the hyperbola, the measurements are considered reliable. But if the point lies outside this region, the measurements are repeated. Because the critical segment of the hyperbola is approximately a straight line parallel to the horizontal axis, the test is simplified to a comparison between the means of the standard population and the means of the subsample. The minimum number of subsamples required to prove significant variation between samples caused by different lithologies in the source areas and sorting in transport can be determined directly from the graphical method. The minimum number of subsamples required is the maximum number to be run for economy of effort.     

Lacustrine evidence for moisture changes in the Nebraska Sand Hills during Marine Isotope Stage 3

In the central Great Plains of North America, loess stratigraphy suggests that climate during the late Pleistocene was cold and dry. However, this record is discontinuous, and there are few other records of late-Pleistocene conditions. Cobb Basin, located on the northern edge of the Nebraska Sand Hills, contains lacustrine sediments deposited during Marine Isotope Stage 3, beginning approximately 45,000 cal yr BP and continuing for at least 10,000 yr. The lake was formed by a dune dam blockage on the ancient Niobrara River, and its deposits contain a diatom record that indicates changes through time in lake depth driven by changes in effective moisture. During the earliest stages of lake formation, the climate was arid enough to mobilize dunes and emplace dune sand into a blocking position within the Niobrara streambed. Diatom assemblages suggest that lake-level was shallow at formation, increased substantially during a wet interval, and then became shallow again, as arid conditions resumed. By about 27,000 cal yr BP the lake was filled, and a shallow ephemeral river occupied the basin.