Gully erosion is a global problem that degrades land and reduces its utility for agriculture, development, and water quality. Quantification of sediment yield and control of sediment sources is essential for environmental protection. Five methods to evaluate erosion rates and sediment yield on an east Tennessee, USA, hillslope were compared: (1) physical measurement by removal of accumulated sediment using 10 L buckets; (2) repeated measurement of erosion pins in gully (erosional) and delta (depositional) areas; (3) geometric model using a combination trapezoidal prism-cylinder segment; (4) geometric model using a series of trapezoidal pyramids; and (5) 3D solid computer modeling. The 3D solid model created in SolidWorks was selected as the reference model and all other methods overestimated sediment yield to varying degrees. Erosion pin methods overestimated sediment yield by 368% in deltas and 123% in gullies. Volumetric measurement of sediment using buckets overestimated sediment yield by 160% due to void space in the buckets. The trapezoidal prism-cylinder segment model overestimated sediment yield by 66% and the trapezoidal pyramids method overestimated sediment yield by 5.7%. For estimation of sediment trapped behind an elliptical or circular silt fence dam, use of the trapezoidal pyramid method provides a good approximation comparable to 3D solid computer modeling.

Background: As the climate warms, many species of reptiles are at risk of habitat loss and ultimately extinction. Locations of suitable habitat in the past, present, and future were modeled for several lizard species using MaxEnt, incorporating climatic variables related to temperature and precipitation. In this study, we predict where there is currently suitable habitat for the genus Pogona and potential shifts in habitat suitability in the past and future. Methods: Georeferenced occurrence records were obtained from the Global Biodiversity Information Facility, climate variables (describing temperature and precipitation) were obtained from WorldClim, and a vegetation index was obtained from AVHRR satellite data. Matching climate variables were downloaded for three different past time periods (mid-Holocene, Last Glacial Maximum, and Last Interglacial) and two different future projections representative concentration pathways (RCPs 2.6 and 8.5). MaxEnt produced accuracy metrics, response curves, and probability surfaces. For each species, parameters were adjusted for the best possible output that was biologically informative. Results: Model results predicted that in the past, there was little suitable habitat for P. henrylawsoni and P. microlepidota within the areas of their current range. Past areas of suitable habitat for P. barbata were predicted to be similar to the current prediction. Pogona minor and P. nullarbor were predicted to have had a more expansive range of suitable habitat in the past, which has reduced over time. P. vitticeps was predicted to have less suitable habitat in the past when examining the region of their known occurrence; however, there was predicted growth in suitable habitat in Western Australia. Both 2070 models predict a similar distribution of habitat; however, the model produced using the 2070 RCP 8.5 climate change projection showed a larger change, both in areas of suitable habitat gain and loss. In the future, P. henrylawsoni and P. microlepidota might gain suitable habitat, while the other four species could possibly suffer habitat loss. Discussion: Based on the model results, P. henrylawsoni and P. microlepidota had minimal areas of suitable habitat during the Last Glacial Maximum, possibly due to changes in tolerance or data/model limitations, especially since genetic analyses for these species suggest a much earlier emergence. The predicted late Quaternary habitat results for all species of Pogona are conservative and should be compared to the fossil record which is not possible at the moment due to the current inability to identify fossil Pogona to the species level. P. nullarbor and P. vitticeps future models predict substantial habitat loss. P. nullarbor could potentially be considered vulnerable in the present since it already has a restricted range, and a conservation plan may need to be considered.

Tsunamis represent significant threats to human life and development in coastal communities. This quantitative study examines the influence of household characteristics on evacuation actions taken by 211 respondents in American Samoa who were at their homes during the 29 September 2009 Mw 8.1 Samoa Islands earthquake and tsunami disaster. Multiple logistic regression analysis of survey data was used to examine the association between evacuation and various household factors. Findings show that increases in distance to shoreline were associated with a slightly decreased likelihood of evacuation, whereas households reporting higher income had an increased probability of evacuation. The response in American Samoa was an effective one, with only 34 fatalities in a tsunami that reached shore in as little as 15 minutes. Consequently, future research should implement more qualitative study designs to identify event and cultural specific determinants of household evacuation behaviour to local tsunamis.

Mmadipudi Hill (CE 550–1200) is an Iron Age site in east-central Botswana approximately 3 km west of Bosutswe, a major Iron Age trade center at the eastern edge of the Kalahari Desert. A 5,000-m2 electromagnetic induction (EMI) survey conducted in 2011 revealed a cattle post arranged in the Central Cattle Pattern, including a central animal kraal with at least three clusters of houses flanking the eastern edge. A test trench confirmed the presence of a Taukome daga structure, possibly a house, 100–150 cm in depth. The EMI survey is one of, if not the first, archaeogeophysical surveys conducted in Botswana. It has proven invaluable as a means to understand the settlement organization and to pinpoint excavations to gain a more detailed understanding of the material culture. The perspective it offered on thorn brush fencing would not have been possible through excavation alone. Although small in scope, the test excavation yielded Taukome and Toutswe artifacts related to the larger sets of issues the Bosutswe region faced as Indian Ocean trade transformed the local political economy. The nature of the relationships between Bosutswe and its surrounding communities likely evolved due to the rise of a prestige goods economy, growing inequality, and environmental degradation around CE 1200. The occupation at Mmadipudi Hill would have immediately preceded these changes. By determining the spatial organization of Mmadipudi Hill, this article begins a crucial first step towards exploring what the local settlement pattern looked like prior to CE 1200 and understanding what the relationships among sites may have been.

Increasing awareness of the impacts of global climate change on marine ecosystems and concerns about shifting bioclimatic and agricultural zones necessitate a reassessment of the geographical distribution of Earths climate types. In recent years, the availability of truly global data-sets has allowed for the application of climatic types, including the Kppen-Geiger system, over the oceans. This research uses NCAR Reanalysis data to create a global Extended Kppen-Geiger climate classification, including the world ocean, for the 1981-2010 averaging period. The percentages of Earths surface covered by tropical rainforest (Af), tropical monsoon (Am), and (especially) the mesothermal-mild summer (Cfc) climate types are much larger than in the terrestrial only analysis. Expanding and contracting terrestrial climate zones are also identified based on the differences in the total area through comparison with maps produced for 1901-1925, 1926-1950, 1951-1975, 1976-2000 and model-output-based predicted Kppen-Geiger types for 2076-2100. Results suggest that hot desert (BWh), hot semi-arid (BSh), and Af climatic types are projected to expand, while the tundra and most mesothermal and microthermal types will decrease in area. These results assist in projecting global impacts of climatic change.

Climate types, biome types, and soil orders are commonly used among physical geographers in research and to describe natural environmental characteristics. However, little attempt has been made to quantify the percentage of global land surface that is covered by combinations of climate types, biomes, and soil orders. This research overlays a world map of 31 climate types produced based on the Köppen-Geiger criteria using gridded NCAR/NCEP reanalysis monthly mean surface air temperature and precipitation data from 1981 to 2010 with global maps of eight biomes adapted from World Wildlife Federation and 12 soil orders from United States Natural Resources Conservation Service. Areas covered by each of the 2976 combinations are then calculated. Results suggest that, as expected, a few climate/biome/soil combinations are most common, such as desert climate/desert biome/entisols, tundra climate/tundra biome/gelisols, and desert climate/desert biome/aridisols. The local nature of soil properties causes small enclaves of unexpected combinations of climate, biome, and soils, and the 10 most extensive climate/biome/soil combinations occupy only one-quarter of the global land surface. The strong correspondence between climate and biome types validates the Köppen-Geiger criteria for categorizing climates based on vegetation realms, even today, despite the general paucity of data available when the criteria were established.

Oyster reefs provide valuable ecosystemservices that contribute to coastal resilience. Unfortunately, many reefs have been degraded or removed completely, and there are increased efforts to restore oysters in many coastal areas. In particular, much attention has recently been given to the restoration of shellfish reefs along eroding shorelines to reduce erosion. Such fringing reef approaches, however, often lack empirical data to identify locations where reefs are most effective in reducing marsh erosion, or fully take into account habitat suitability. Using monitoring data from 5 separate fringing reef projects across coastal Louisiana, we quantify shoreline exposure (fetch + wind direction + wind speed) and reef impacts on shoreline retreat. Our results indicate that fringing oyster reefs have a higher impact on shoreline retreat at higher exposure shorelines. At higher exposures, fringing reefs reduced marsh edge erosion an average of 1.0 m y-1. Using these data, we identify ranges of shoreline exposure values where oyster reefs are most effective at reducing marsh edge erosion and apply this knowledge to a case study within one Louisiana estuary. In Breton Sound estuary, we calculate shoreline exposure at 500 random points and then overlay a habitat suitability index for oysters. This method and the resulting visualization show areas most likely to support sustainable oyster populations as well as significantly reduce shoreline erosion. Our results demonstrate how site selection criteria, which include shoreline exposure and habitat suitability, are critical to ensuring greater positive impacts and longevity of oyster reef restoration projects.

Purpose – Near-field tsunamis provide short warning periods of equal to 30 minutes, which can complicate at-risk individuals’ protective action decisions. In the face of a tsunami, people may turn to individuals such as friends, family, neighbors, or organizations such as the media to obtain warning information to help facilitate evacuation and/or to seek protection from the hazard. To characterize norms for protection action behavior during a near-field tsunami, the purpose of this paper is to explore American Samoan residents’ perceptions of four social stakeholder groups on three characteristics – tsunami knowledge, trustworthiness, and protection responsibility – regarding the September 29, 2009, Mw 8.1 earthquake and tsunami in American Samoa. Design/methodology/approach – The social stakeholder groups were the respondents themselves, their peers, officials, and media. Mean ratings revealed that respondents rated themselves highest for tsunami knowledge and protection against the tsunami but rated peers highest for trustworthiness. In addition, officials had the lowest mean rankings for all three stakeholder characteristics. MANOVA analyses found that there was a statistically significant overall effect for occupation status on respondents’ perceptions of the four stakeholder groups and characteristics. Findings – Employed respondents generally reported higher mean ratings for all stakeholder groups across the three characteristics than those that reported not having an occupation. Given the complexity of evacuation behavior, at-risk individuals may seek the assistance of other community members to support their protective action decisions. Originality/value – The information gathered from this study provides local emergency managers with useful data that could support future disaster resilience efforts for tsunamis.

Climate change will likely have impacts on disease vector distribution. Posing a significant health threat in the 21st century, risk of tick-borne diseases may increase with higher annual mean temperatures and changes in precipitation. We modeled the current and future potential distribution of the Ixodes ricinus tick species in Europe. The Genetic Algorithm for Rule-set Prediction (GARP) was utilized to predict potential distributions of I. ricinus based on current (1990-2010 averages) and future (2040-2060 averages) environmental variables. A ten model best subset was created out of a possible 200 models based on omission and commission criteria. Our results show that under the A2 climate change scenario the potential habitat range for the I. ricinus tick in Europe will expand into higher elevations and latitudes (e.g., Scandinavia, the Baltics, and Belarus), while contracting in other areas (e.g., Alps, Pyrenees, interior Italy, and northwestern Poland). Overall, a potential habitat expansion of 3.8% in all of Europe is possible. Our results may be used to inform climate change adaptation efforts in Europe.

Wild canid populations exhibit different anatomical morphologies compared to domesticated dogs in North America. This is particularly important concerning archaeological sites, which may contain early domesticated species, for the proper identification of osteological remains. Previous studies have indicated domestic dogs exhibit a shorter rostrum accompanied by a crowded tooth row; however, none describe the overall complexity of these changes. Consequently, using a landmark-based geometric morphometric analysis, cranial morphological characteristics were examined in North American wild canids: the gray wolf (Canis lupus), coyote (Canis latrans), red wolf (Canis rufus), and the domestic dog (Canis familiaris). The shape and size of the cranium in lateral and ventral views were compared between the three wild species to the group of domesticated dogs. Wild canids clustered separately from the domestic group in all statistical analyses. Results indicate an expansion of the orbital region, a compression of the rostrum, and an overall warping in the shape and orientation of the skull. In domestic species, there is also a downward shift in the frontal portion of the skull accompanied by the braincase assuming a more upward position. This technique successfully depicted how slight changes in isolated areas of the cranium can have an impact on the overall shape and morphology of the skull. We presume these changes in cranial anatomy reflect the recent selective pressures domestic dogs have undergone since diverging from their wild ancestors.