/pdf/remote-sensing-of-the-environment-4yfxjaaswe.pdf

Remote sensing of the environment

https://oss.deltares.nl/documents/48999/59759/Roelvink_2009.pdf

Modelling storm impacts on beaches, dunes and barrier islands

Climate Change 1995 is a scientific assessment that was generated by more than 1 000 contributors from over 50 nations. It was jointly co-ordinated through two international agencies; the World Meteorological Organization and the United Nations Environment Programme. The assessment was completed by the Intergovernmental Panel on Climate Change (IPCC) with a primary aim of reviewing the current state of knowledge concerning the impacts of climate change on physical and ecological systems, human health, and socioeconomic factors. The second aim was to review the available information on the technical and economic feasibility of the potential mitigation and adaptation strategies.

Climate Change 1995

Wind speeds over the world’s oceans have increased over the past two decades, as have wave heights. Studies of climate change typically consider measurements or predictions of temperature over extended periods of time. Climate, however, is much more than temperature. Over the oceans, changes in wind speed and the surface gravity waves generated by such winds play an important role. We used a 23-year database of calibrated and validated satellite altimeter measurements to investigate global changes in oceanic wind speed and wave height over this period. We find a general global trend of increasing values of wind speed and, to a lesser degree, wave height, over this period. The rate of increase is greater for extreme events as compared to the mean condition.

https://researchbank.swinburne.edu.au/file/bca43746-6f16-4ad2-a4b7-27f8d8d60fed/1/PDF (Published version).pdf

Global trends in wind speed and wave height over the past 25 years

Recent accelerated climate change has exacerbated existing environmental problems in the Mediterranean Basin that are caused by the combination of changes in land use, increasing pollution and declining biodiversity. For five broad and interconnected impact domains (water, ecosystems, food, health and security), current change and future scenarios consistently point to significant and increasing risks during the coming decades. Policies for the sustainable development of Mediterranean countries need to mitigate these risks and consider adaptation options, but currently lack adequate information — particularly for the most vulnerable southern Mediterranean societies, where fewer systematic observations schemes and impact models are based. A dedicated effort to synthesize existing scientific knowledge across disciplines is underway and aims to provide a better understanding of the combined risks posed.

/pdf/climate-change-and-interconnected-risks-to-sustainable-18gsp1lank.pdf

Climate change and interconnected risks to sustainable development in the Mediterranean

The predictability of cross-shore bed evolution of sandy beaches at the time scale of storms and seasons using process-based Profile models

Hydraulic behaviour of horizontal subsurface flow constructed wetlands with different aspect ratio and granular medium size

The Ebro River is the largest freshwater course of Spain with a discharge (in the lower course) that has been reduced in the last few decades due to the construction of several dams and the corresponding increase of water demand and river regulation. The lowest stretch of this river (about 42 km) behaves most of the time as a highly stratified estuary with a salt wedge. The dynamics of this salt wedge are important from the ecologic and economic points of view and depend mainly on the river discharge, although other factors (like bathymetry and climatology) play a non-negligible secondary role. The wedge dynamics would also be affected by the planned river diversion scheme towards other areas of Spain. This diversion plan would mean a reduction of about 15% of the annual discharge (in the Ebro lower course) and the corresponding impact should be carefully assessed.



With that aim a two-layer hydrodynamic numerical model has been employed to evaluate the role of flow regulation in the Ebro salt wedge dynamics, with particular emphasis on the potential discharge reduction due to the planned water diversion. The model has been calibrated with data acquired during four field campaigns (one per season) carried out during 1999 and 2000. Different scenarios of discharge reduction have been studied. Model results suggest a significant increase of salt wedge extent and permanence associated with the planned diversion scheme. This would entail an increase of saltwater intrusion problems both for aquifers and crops. Copyright © 2003 John Wiley & Sons, Ltd.

Effects of discharge reductions on salt wedge dynamics of the Ebro River

[1] Projected future regional wave climate scenarios at a high temporal-spatial scale were obtained for the NW Mediterranean Sea, using five combinations of regional-global circulation models. Changes in wave variables were analyzed and related to the variations of the forcing wind projections, while also evaluating the evolution of the presence of the different types of sea states. To assess the significance of the changes produced, a bootstrap-based method was proposed, which accounts for the autocorrelation of data and correctly reproduces the extremes. For the mean climate, relative changes of Hs up to ±10% were obtained, whereas they were around ±20% for the extreme climate. In mean terms, variations of Hs are similar to those associated with wind speed but are enhanced/attenuated, respectively, when fetch conditions are favorable/unfavorable. In general, most notable alterations are not in the Hs magnitude but rather in its direction. In this regard, during the winter season, it is interesting to note that the significant deviations between the results derived from the two global circulation models are larger than those between regional models. ECHAM5 simulated an enhanced west wind flow that is translated into more frequent W-NW waves, whereas the HadCM3Q3 global model gives rise to the east component, which contributes to a higher intensity and number of storms coming from such a direction and directly affects the wind-sea/swell distribution of coastal stretches that face east, like the Catalan coast. Different patterns of change were obtained during the summer when a common rise of NE-E waves was found.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/jgrc.20233

Joan Pau Sierra

Papers

The predictability of cross-shore bed evolution of sandy beaches at the time scale of storms and seasons using process-based Profile models

Hydraulic behaviour of horizontal subsurface flow constructed wetlands with different aspect ratio and granular medium size

Effects of discharge reductions on salt wedge dynamics of the Ebro River

Projected future wave climate in the NW Mediterranean Sea

Wave energy resource assessment in Lanzarote (Spain)