Trends in Extreme Precipitation Events in the Indus River Basin and Flooding in Pakistan

In the absence of a sufficiently dense network of climate stations covering all topographic regions of the Indus River basin and delivering high quality data over the last 30 years or more, daily precipitation data were obtained from the National Centers for Environmental Prediction-Department of the Enviornment (NCEP-DOE) Reanalysis 2 dataset for the period 1979 to 2011. The daily precipitation data were transformed into time series of frequency of extreme precipitation events of 1-day and 10-day durations defined in terms of 90th and 99th percentile threshold exceedances. The non-parametric Mann-Kendall trend test was applied to determine whether statistically significant changes in precipitation extremes occurred over time, in due consideration of autocorrelation in the data.

Extreme precipitation showed a high spatial variability, with the highest daily and 10-day precipitation totals, and thus highest 90th and 99th percentiles, in the southeastern lowlands at the foot of the Himalayas and the lowest in the Karakorum. Significantly decreasing trends in extreme precipitation were observed in the western part of the Indus River basin; significantly increasing trends were mainly detected in the very high mountainous regions in the east (Transhimalaya and Himalayas) and in the north (Hindu Kush and Karakorum) of the Indus basin. High precipitation rates are not common in the arid climate of these high mountainous regions. Future flood management plans need to consider the increasing trends in extreme precipitation events in these areas.     

Influence of water-level elevation and tidal range on the sedimentation in a German tidal flat area

The nearshore region of the German Bight is characterised by a large tidal flat area of 7500km², which is a wedge of alluvial material lying in front of the coast. The elevation of a flat depends on the long-term water-level and currents. As a result of the rising water-level, the flats are migrating over an inclined Pleistocene basement. This migration depends on the balance of sedimentation versus erosion which is a function of water depth. Regular measurements of the water-level have been made since the middle of the 19th century. From the observations of the MHW it is estimated that the water-level has risen to approximately 30cm in the past hundred years. Recent investigations show that the change of the half-tide water-level is less than that of MHW. The increasing tidal range also changes the sedimentation processes over the tidal flats. The quantitative influence of the altered tidal range on the sedimentation and the morphology of the Wadden Sea is as important as that of the influence of mean water-level elevation. Changes in the elevation of the coastal plain caused by tectonic forces or subsidence cannot be determined. Extensive investigations were conducted to determine quantitatively the sedimentation processes which have taken place since 1936. The sediment budget of the Flackstrom basin (low macrotidal coast) is presented. With respect to the MHW datum plane, sedimentation of 20 × 10⁶m³ has taken place in this area. This is equivalent to a mean silting-up of 30cm over the past 46 years, an average 0.7cm/year. The sedimentation process is dependent upon the mean elevation of the flat. Most of the sedimentation has taken place above the half-tide water-level. Therefore, the flanks of the flats have risen more than the tops and the sand-ridges, which certainly reflects the very small long-term water-level elevation change of only 3cm which occurred during the period investigated (1936 to 1982). Recent investigations of the present state show a relationship between the tidal range and the height of the main sedimentation-zone. Comparisons of the Flackstrom (tidal range approximately 3.40m) and parts of the Dutch Wadden Sea (tidal range approximately 1.80m) indicate that the main sedimentation-zone moves down-shore from half-tide water-level to mean-low-water with the decrease of the tidal range, due to differences in the general course of the hypsometric curves over the tidal flat areas.     

Vegetative Reproduction in Posidonia oceanica

Abstract. An investigation was conducted on transplantation in the Mediterranean seagrass, Posidonia oceanica. The effects of rhizome length and season of transplantation were investigated over the first year of growth in relation to survival and development in orthotropic shoots. Twelve batches, each composed of 36 transplants bearing one leaf bundle, were detached and planted at the same site and depth. They were fixed horizontally to mesh supports. These twelve batches, comprising three classes of rhizome length (10, 15, and 20 cm), were transplanted at four times of year. Mortality was highest for transplants made in early summer, when temperatures exceeded 20°C, and lowest for those made in autumn. Although initial rhizome length had no discernible effect on subsequent mortality, it was positively related to the length of the necrosed portion one year later. The most successful transplants, made in autumn with 10 to 15 cm long rhizomes, gave survival rates of 92 to 97%. These results should help to develop transplantation techniques for restoring damaged sites.     

Introduction: Toward More Inclusive and Comparative Perspectives in the Histories of Geographical Knowledge

Over the past three decades, feminist historiography of geography has begun to situate women's contribution to the production of geographical knowledge within the histories of geography, at times against the conviction of skeptical colleagues. In this Focus Section introduction, we renew Domosh's (1991a Domosh, M. 1991a. Beyond the frontiers of geographical knowledge. Transactions of the Institute of British Geographers 16 (4): 488–90.[Crossref], [Web of Science ®] , [Google Scholar], 1991b ———. 1991b. Toward a feminist historiography of geography. Transactions of the Institute of British Geographers 16 (1): 95–104.[Crossref], [Web of Science ®] , [Google Scholar]) call for creating more inclusive feminist histories of geography by situating the three focus section articles on the careers and contributions of women in twentieth-century geographical practice and knowledge production in the United Kingdom and the United States within wider debates about diverse, unfamiliar, and previously hidden aspects of geographical knowledge production. We argue that feminist historiography of geography and feminist historical geography could benefit from continuously diversifying inclusive and comparative research perspectives, and from unlocking diverse archives, to enhance understanding of why and how some male and some female gatekeepers have been more supportive of women than others.     

Feminizing the University: The Mobilities,Careers, and Contributions of Early Female Academics in the University of Cambridge, 1926–1955

This article examines the role of early female academics at the University of Cambridge in the production and dissemination of knowledge between 1926 and 1955. A statistical comparison of women's use of academic leave of absence with that of their male colleagues reveals that, across disciplines, women were less integrated into (inter)national knowledge networks and thus less visible in their epistemic communities than men because women focused their academic leaves more on research, rarely attended conferences, traveled overseas less often than men, and went more frequently to destinations within Europe than the United States as the new economic hegemon. Biographical case studies of these early female academics demonstrate the importance, variously, of their upper middle-class background, academic excellence, and familial and nonfamilial patronage in developing their careers, overcoming multiple hurdles, and producing intellectual contributions of equal quality to that of their male peers. Conceptually, this article calls for the inclusion of academic travelers from disciplines other than geography into feminist histories of geographical knowledge and argues that rather than stereotyping gender differences, greater comparative research on the experiences of female and male academics is needed to understand the mechanisms of gender inequality within the university.     

Effects of Tidal Flooding on Juvenile Willows

Tidal wetlands are affected by sea level rise. In the tidal freshwater stretches of estuaries in the temperate zone, willows (Salix spp.) form tidal freshwater forests above the mean high water level. Willows tolerance to prolonged periodic flooding in riverine systems is well documented, whereas effects of tidal flooding on willows are largely unknown. Flooding stress may play a major role in regeneration failure of willows in tidal forest stands along estuarine shores, and juvenile willows might be specifically affected by partial or total submergence. To assess the tolerance of juvenile willows to tidal flooding, we conducted a mesocosm experiment with cuttings from Salix alba and Salix viminalis, which are both characteristic species for tidal freshwater forests in Europe. Cuttings originating from either fresh or brackish tidal forest stands were grown under four tidal treatments with up to a tidal flooding of 60 cm. A general tolerance to a tidal flooding of 60 cm was observed in chlorophyll fluorescence, growth rates, and biomass production in both willow species. Overall, S. alba showed higher leaf and shoot growth, whereas S. viminalis produced more biomass. S. alba with brackish origin performed worst with increasing tidal flooding, suggesting a possible pre-weakening due to stressful site conditions in tidal wetlands at the estuarine brackish stretch. This study demonstrates that juvenile willows of S. alba and S. viminalis tolerate tidal flooding of up to 60 cm. It is concluded that tidal inundation acts as a stress by causing submergence and soil anaerobiosis, but may also act as a subsidy by reestablishing aerobic conditions and thus maintaining willows performance. Therefore, we suggest investigations on Salix tidal flooding tolerance and possible effects of willows on tidal wetland accretion under estuarine field conditions.     

Can Jupiters be found by monitoring Galactic bulge microlensing events from northern sites?

In 1998 the EXPORT team monitored microlensing event light curves using a charge-coupled device (CCD) camera on the IAC 0.8-m telescope on Tenerife to evaluate the prospect of using northern telescopes to find microlens anomalies that reveal planets orbiting the lens stars. The high airmass and more limited time available for observations of Galactic bulge sources make a northern site less favourable for microlensing planet searches. However, there are potentially a large number of northern 1-m class telescopes that could devote a few hours per night to monitor ongoing microlensing events. Our IAC observations indicate that accuracies sufficient to detect planets can be achieved despite the higher airmass.     

Mapping the narrative positions of new political groups under the UNFCCC

Since the mid-1990s, the aim of keeping climate change within 2?°C has become firmly entrenched in policy discourses. In the past few years, the likelihood of achieving it has been increasingly called into question. The debate around what to do with a target that seems less and less achievable is, however, only just beginning. As the UN commences a two-year review of the 2?°C target, this article moves beyond the somewhat binary debates about whether or not it should or will be met, in order to analyse more fully some of the alternative options that have been identified but not fully explored in the existing literature. For the first time, uncertainties, risks, and opportunities associated with four such options are identified and synthesized from the literature. The analysis finds that the significant risks and uncertainties associated with some options may encourage decision makers to recommit to the 2?°C target as the least unattractive course of action.     

Solid state CPMAS C and N NMR spectroscopy in organic geochemistry and how spin dynamics can either aggravate or improve spectra interpretation

Because the ongoing discussion about the reliability of solid state cross polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectroscopy still leaves uncertainty with respect to its usefulness in organic geochemistry, the present work provides a brief introduction into the basic principles of this technique and gives some explanation about the potential source of non-quantitative results. In addition, relaxation data are supplied which are necessary for the correct adjustment of NMR acquisition parameters. High contents of paramagnetics or moisture indeed affect the CP dynamics, complicating quantification of solid state NMR data obtained with a standard protocol. Whereas the latter can be avoided by carefully drying the sample, the first is often circumvented by demineralization with hydrofluoric acid (HF). Although this can yield considerable organic matter loss, the given examples demonstrate that differences in the intensity distribution of the spectra before and after HF treatment are most likely due to a selective alteration of the relaxation kinetics of protons closely interacting with paramagnetics. It is further shown that single pulse excitation does not necessarily provide quantitative data, since some geopolymers (e.g. cellulose) relax extremely slowly. At high magnetic fields and low spinning speeds, spinning side bands can overlap with relevant signals and obscure the intensity distribution. At spinning speeds >6 kHz, the range of the correct Hartmann-Hahn match is reduced, resulting in a preferential intensity loss of weakly coupling carbons which can be avoided by the application of special pulse sequences. In principal, the acquisition of quantitative CPMAS NMR data from geochemical samples is possible, although this often requires an in depth analysis of the relaxation parameters. Further, the latter also represents a powerful tool for the identification of geochemical compounds by providing additional information about their physical status and their spatial relationships to each other.