Linking pattern to process in reef sediment dynamics at Lady Musgrave Island,southern Great Barrier Reef

Linking surficial sediment patterns in reef environments to the processes that underlie their depositional dynamics enables predictions to be made of how environmental changes will influence reef‐associated sedimentary landforms, such as islands and beaches. Geomorphic linkages between sediment deposition patterns and the biophysical processes that drive them are often poorly resolved, particularly at broad landscape scales where tangible statements can be made about structural changes to landforms. The present study applies geospatial techniques to link patterns in reef sediment dynamics at Lady Musgrave Island to the underlying processes driving them. In situ calcification is characterized by developing a high resolution map of the surficial calcium carbonate producing communities inhabiting the reef platform, and associated sediments across the reef flat are analysed for grain size, kurtosis, sorting and threshold bed shear stress to explore transport pathways across the reef flat and lagoon. Wave energy is modelled across the entire reef platform as a potential driver of sediment dynamics, and morphometric linkages are empirically defined between wave energy and grain size. Findings indicate that carbonate sediments are primarily sourced from calcifying communities colonizing the outer periphery of the reef platform and that sediment grain size can be reliably linked to wave energy by virtue of a linear model.     

Improved atmospheric circulation over Europe by the new generation of CMIP6 earth system models

Global Climate Models (GCMs) generally exhibit significant biases in the representation of large-scale atmospheric circulation. Even after a sensible bias adjustment these errors remain and are inherited to some extent by the derived downscaling products, impairing the credibility of future regional projections. In this study we perform a process-based evaluation of state-of-the-art GCMs from CMIP5 and CMIP6, with a focus on the simulation of the synoptic climatological patterns having a most prominent effect on the European climate. To this aim, we use the Lamb Weather Type Classification (LWT, Lamb British isles weather types and a register of the daily sequence 736 of circulation patterns 1861-1971. METEOROL OFF, GEOPHYS MEM; 737 GB; DA 1972; NO 116; PP 1-85; BIBL 2P1/2, 1972), a subjective classification of circulation weather types constructed upon historical simulations of daily mean sea level pressure. Observational uncertainty has been taken into account by considering four different reanalysis products of varying characteristics. Our evaluation unveils an overall improvement of salient atmospheric circulation features consistent across observational references, although this is uneven across models and large frequency biases still remain for the main LWTs. Some CMIP6 models attain similar or even worse results than their CMIP5 counterparts, although in most cases consistent improvements have been found, demonstrating the ability of the new models to better capture key synoptic conditions. In light of the large differences found across models, we advocate for a careful selection of driving GCMs in downscaling experiments with a special focus on large-scale atmospheric circulation aspects.

     

Application of Binary Permeability Fields for the Study of $${\hbox {CO}_{2}}$$ Leakage from Geological Carbon Storage in Saline Aquifers of the Michigan Basin

The feasibility of geological carbon storage (GCS) sites depends on their capacity to retain safely \({\hbox {CO}_{2}}\). While deep saline formations and depleted gas/oil reservoirs are good candidates to sequester \({\hbox {CO}_{2}}\), gas/oil reservoirs typically have a limited storage capacity compared to ideal targets (\(\sim \) 1 Mt/year) considered for \({\hbox {CO}_{2}}\) disposal (Celia et al. in Water Resour Res 51(9):6846–6892, 2015. doi: 10.1002/2015WR017609). In this respect, deep saline aquifers are considered more appropriate formations for GCS, but present the disadvantage of having limited characterization data. In particular, information about the continuity of the overlying sealing formations (caprock) is often sparse if it exists at all. In this work, a study of \({\hbox {CO}_{2}}\) leakage is conducted for a candidate GCS site located in the Michigan Basin, whose sealing properties of the caprock are practically unknown. Quantification of uncertainty on \({\hbox {CO}_{2}}\) leakage from the storage formation is achieved through a Monte Carlo simulation approach, relying on the use of a computationally efficient semi-analytical leakage model based upon the solution derived by Nordbotten et al. (Environ Sci Technol 43(3):743–749, 2009), which assumes leakage occurs across “passive” wells intersecting caprock layers. A categorical indicator Kriging simulator is developed and implemented to represent the caprock sealing properties and model the permeability uncertainty. Binary fields of caprock permeability are generated and exhibit mostly low permeability, with sparsely-occurring local high permeability areas where brine and \({\hbox {CO}_{2}}\) may leak out of the storage formation. In addition, the feasibility of extending the use of the semi-analytical model to large-area leakage pathways is studied. This work advances a methodology for preliminary uncertainty quantification of \({\hbox {CO}_{2}}\) leakage at sites of GCS with little or no information on the sealing properties of the caprock. The implemented analysis shows that, for the considered site, \({\hbox {CO}_{2}}\) leakage may not be negligible even for relatively low (\(\sim \) 1%) probabilities of finding permeable inclusions in the caprock and highlights the importance of being able to characterize caprock sealing properties over large areas.     

Recommendation system to determine suitable and viable hiking routes: a prototype application in Sierra de las Nieves Nature Reserve (southern Spain)

This paper describes a system for recommending hiking routes to help manage hiking activities in a protected area. The system proposes various routes, based on five criteria that maximize some aspects of hikers’ requirements (by analyzing the viability and difficulty of the trails) and also those of protected areas managers (by proposals to relieve congestion in areas already used for hiking and to promote awareness of new ones, as a contribution to environmental education). The recommendation system uses network analysis, multi-criteria decision analysis and geographic information system by free software tools: PgRouting, PostgreSQL and PostGIS. This system has been tested in Sierra de las Nieves Nature Reserve (Andalusia, Spain). Of the 182 routes obtained by the system, 62 (34%) are considered viable for hikers in Sierra de las Nieves, taking into account the type of user most likely to visit this protected area. Most routes have a high difficulty level, which is coherent with the mountainous character of the protected area.     

Exploring the interactions between vulnerability,resilience and adaptation to extreme temperatures

Natural Hazards - Proposed ways of improving adaptation to climate change have most often been supported by narrowly framed and separate analysis. This article investigates how different levels of...     

Risk perception in Unión Juárez,Chiapas, Mexico

The proximity to the Tacaná volcano, to the subduction zone between the Cocos and North America plates, to the Mexican coast, and to the active geologic Polochic-Motagua fault makes the population of Union Juarez (UJ), Chiapas, Mexico, exposed to many natural hazards including hurricanes, earthquakes, landslides, and volcanic eruptions. We assessed the risk perception of UJ, and our findings indicate that the community has moderate level of risk perception according to the scale of the National Center for Disaster Prevention of Mexico. The UJ’s risk perception is mainly dependent on gender and religion because females unlike males in case of disasters and emergencies: (1) believe that it is necessary to improve their preparedness; (2) trust the local civil protection authorities; (3) would know how to respond; (4) would follow the established protocols; and (5) would not relocate. On the other hand, non-religious people know better the protocols to follow in the event of disasters than the religious population. Besides, the community of UJ reasonably perceives earthquakes and extreme rains as the main hazards that they are exposed to, while volcanic hazards are considered less important although the town is located very close to the Tacaná volcano that has been active during the last 30 years. The local population lacks of proper knowledge and resources to develop adequate disaster mitigation plans. Surprisingly, the work of the local civil protection is considered poor. Our results can be used for local authorities as a tool to strength the disaster prevention actions in UJ.

     

Characterization of a landslide-triggered debris flow at a rainforest-covered mountain region in Brazil

Natural Hazards - Debris flows represent great hazard to humans due to their high destructive power. Understanding their hydrogeomorphic dynamics is fundamental in hazard assessment studies,...     

A combined structural and seasonal approach to assess wildfire susceptibility and hazard in summertime

Natural Hazards - Wildfire susceptibility and hazard models based on drivers that change only on a multiyear timescale are considered of a structural nature. They ignore specific short-term...     

Nine nations,one ocean: A benchmark appraisal of the South Western Indian Ocean Fisheries Project (2008–2012)

Coastal and island states of the Western Indian Ocean lack scientific and management capacity to draw sustainable benefits from their Exclusive Economic Zones. Declining ecosystem services and unregulated fishing has prompted nine riparian countries to develop a regional framework for capacity building and scientific development towards collective management of shared resources. Supported by the Global Environment Facility (GEF), the Agulhas and Somali Currents large marine ecosystems programme consists of three inter-related modules, supported by different agencies: land-based impacts on the marine environment (UNEP); productivity, ecosystem health and nearshore fisheries (UNDP) and transboundary shared and migrating fisheries resources (World Bank). The latter is the South Western Indian Ocean Fisheries Project (SWIOFP), a 5-year joint data gathering and fisheries assessment initiative. SWIOFP is a prelude to long-term cooperative fisheries management in partnership with the newly established FAO–South Western Indian Ocean Fisheries Commission (SWIOFC). We describe the development of SWIOFP as a model of participatory regional scientific cooperation and collective ocean management.     

Climate change and human occupation in the northernmost Chilean Altiplano over the last ca. 11 500 cal. a BP

This interdisciplinary study represents an approximation towards understanding how regional human cultural systems may have been affected by climate change in the northernmost Chilean Altiplano (>3600 m) over the last ca. 11 500 cal a BP. We compare the archaeological record from Hakenasa cave with the lake record from Lago Chungará sediment cores, located 50 km to the south. By integrating both of these archives in conjunction with regional palaeoclimate and archaeological data, we provide new evidence for the role of changing environmental and climatic conditions in human settlement patterns. The first human occupation of the entire Altiplano occurs at Hakenasa and is dated to 9980 ± 40 ¹⁴C a BP (11 265–11 619 cal. a BP), and took place under wetter regional climate conditions. An archaeologically sterile deposit occurs at Hakenasa between 7870 and 6890 cal. a BP. Constituted by sands and gravels, these sediments are interpreted as a flood event. This time period is synchronous with alternating short dry and wet events recorded in the Lake Chungará sedimentary sequence. Human activity resumes and increases in importance at Hakenasa by ca. 6000 cal. a BP. This corresponds to wetter conditions indicated by the Chungará record. Even though the lake record indicates intense volcanic activity over the last 6000 cal. a BP, this had little or no impact on the human population present at Hakenasa. This study shows that even in this extreme environment human settlement patterns do not always respond in a linear fashion to environmental change. Copyright © 2008 John Wiley & Sons, Ltd.