‘Any place could be home’: Embedding refugees’ voices into displacement resolution and state refugee policy

This article explores refugees’ views about the ‘durable solutions’ or three Rs – Voluntary Repatriation, Local or Re-Integration and Resettlement – underscoring the need for refugees’ voices to inform policy actions taken on their behalf. Central to discourses on the right to return and the policy practice of voluntary repatriation is the salience accorded the nation-state of which territorial boundaries are an important defining feature. Drawing on ethnographic interviews with Liberian refugees in the Gomoa-Buduburam camp in Ghana, this article elucidates the effects of essentialist assumptions about territory, nation-state, home and enforced repatriation on the rights of refugees. By studying practices around and responses to the so-called solutions to displacement, especially VR, insights are gained into various ways in which space is reproduced and contested by international/local implementers and refugees, respectively, in the search for solutions. Importantly, the extent to which the views of displaced persons are allowed to shape such practices is highlighted. The article concludes by encouraging an embedding of refugees’ views about the three Rs into reformulating state policy expressions in displacement interventions. Including refugees as active participants in resolving their own problems, it is suggested, is one sustainable way to address the canker of protracted displacement in our times.     

Using panel data to estimate the effect of rainfall shocks on smallholders food security and vulnerability in rural Ethiopia

Ethiopia??s agriculture is predominantly rainfed and hence any irregularity in weather conditions has adverse welfare implications. Using panel data, this paper analyzes the effect of rainfall shocks on Ethiopian rural households?? food security and vulnerability over time while controlling for a range of other factors. To this end, we generate a time-variant household food security index which is developed by principal components analysis. Based on this index, households are classified into relative food security groups and their socioeconomic differences are assessed. The exploratory results show that compared to the less secured households, the more secured ones have male and literate household heads, tend to have a greater number of economically active household members, own more livestock, experience better rainfall outcome, and participate in local savings groups. Using the food security index as the dependent variable, we use a fixed effects instrumental variable regression model to identify determinants of households?? food security over time and find that rainfall variability is an important factor. Moreover, household size, participation in local savings groups, and livestock ownership positively affect food security. Results from multinomial logistic regression model complement the fixed effects instrumental variable regression results by showing that the level and variability of rainfall are important determinants of persistent food insecurity and vulnerability. The results highlight the need for efficient risk reduction and mitigation programs to improve risk exposure and coping ability of rural households. Careful promotion of investment in infrastructure to support irrigation and water resources development is one aspect worth considering.     

Exploring weathering and regolith transport controls on Critical Zone development with models and natural experiments

The architecture of the Critical Zone, including mobile regolith thickness and depth to the weathering front, is first order controlled by advance of a weathering front at depth and transport of sediment at the surface. Differences in conditions imposed by slope aspect in the Gordon Gulch catchment of the Boulder Creek Critical Zone Observatory present a natural experiment to explore these interactions. The weathering front is deeper and saprolite more decayed on north-facing than on south-facing slopes. Simple numerical models of weathering front advance, mobile regolith production, and regolith transport are used to test how weathering and erosion rates interact in the evolution of weathered profiles. As the processes which attempt are being made to mimic are directly tied to climate variables such as mean annual temperature, the role of Quaternary climate variation in governing the evolution of Critical Zone architecture can be explored with greater confidence.     

Impact of mega-scale sand extraction on tidal dynamics in semi-enclosed basins: An idealized model study with application to the Southern North Sea

Long-term considerations of repeated and increasing sand extraction on the Netherlands Continental Shelf (North Sea) may lead to the creation of a mega-scale extraction trench in front of the Dutch coast (length hundreds of km, width over 10 km, depth several m). We investigate the impact of such a huge topographic intervention on tidal dynamics, which is a key aspect in hydrodynamics, and indirectly also affecting morphodynamics and ecology.     

Reconstructing recent sedimentation in two urbanised coastal lagoons (NSW,Australia) using radioisotopes and geochemistry

In this study, we combined grain size and geochemical analyses with radioisotope analysis of lead-210 (²¹⁰Pb), caesium-137 (¹³⁷Cs) and radiocarbon (¹⁴C) ages to reconstruct the sedimentation history of two urbanised coastal lagoons in south-east Australia. Towradgi and Fairy Lagoons were both found to exhibit slow initial sedimentation of less than 1 mm year⁻¹ prior to anthropogenic influences. Land clearing in the catchments increased runoff and erosion in the creeks feeding into the estuaries, and has resulted in progradation of fluvial material into the estuarine systems with a marked increase in sedimentation to between 2 and 7 mm year⁻¹. The upper 20–50 cm of the sediment column in both lagoons contained elevated concentrations of heavy metals such as Pb, Cu, Ni and Zn. This pollution trend was found to be consistent with the history of industrialisation and urbanisation in the region, which expanded rapidly post World War 2. The total metal concentrations were consistent with other urbanised/industrialised estuaries around the world. Despite the fairly disturbed nature of these coastal lagoons, the use of ²¹⁰Pb, ¹³⁷Cs and ¹⁴C dating in combination with bulk geochemical analyses allowed detailed reconstruction of sedimentation history.     

Origin of Tertiary to Recent EM- and subduction-like chemical and isotopic signatures in Auca Mahuida region (37°–38°S) and other Patagonian plateau lavas

The alkaline volcanic rocks of the 1.8–0.9 Ma Auca Mahuida and post-mid-Pliocene Rio Colorado backarc volcanic fields east of the Andean Southern Volcanic Zone at ~37°–38°S have pronounced intraplate-like chemical signatures with some striking similarities to oceanic DM-EM1-like lavas of the south Atlantic Tristan da Cunha type. These backarc lavas are considered to have formed as a series of mantle batches typified by 4–7 % melting, with decompression melting initiating in a garnet-bearing mantle above a steepening subduction zone, and final equilibration occurring near the base of a ~65- to 70-km-thick lithosphere at temperatures of ~1,350–1,380 °C. Evolved Auca Mahuida mugearite to trachytic samples are best explained by crystal fractionation with limited mixing of partial melts of recently underplated basalts, in line with isotopic signatures that preclude significant radiogenic contamination in a preexisting refractory crust. Higher Ba/La and subtly higher La/Ta ratios than in nearby ~24–20 Ma primitive basalts or oceanic (OIB) lavas are attributed to the residual effects of slab fluids introduced during a shallow subduction episode recorded in the arc-like chemistry of the adjacent 7–4 Ma Chachahuén volcanic complex. Positive Sr, K and Ba spikes on mantle-normalized patterns of both primitive Auca Mahuida and ~24–20 Ma basalts, like those in EM-like OIB basalts, are attributed to mixing of continental lithosphere into the asthenosphere. In Patagonia, this mixing is suggested to have peaked as the South America continent accommodated to major late Oligocene plate convergence changes, as similar Sr, K and Ba spikes and DM-EM1 signatures are absent in ~50–30 Ma backarc lavas north of 51°S, and all of those south of 51°S. Introduction of an EM1-like component associated with lateral mantle flow of a Tristan da Cunha source is largely precluded by its Cretaceous age and distance to Patagonia.     

Assessing Nitrogen Dynamics Throughout the Estuarine Landscape

Assessing nitrogen dynamics in the estuarine landscape is challenging given the unique effects of individual habitats on nitrogen dynamics. We measured net N₂ fluxes, sediment oxygen demand, and fluxes of ammonium and nitrate seasonally from five major estuarine habitats: salt marshes, seagrass beds (SAV), oyster reefs, and intertidal and subtidal flats. Net N₂ fluxes ranged from 332?±?116 μmol?N-N₂?m^?2?h^?1 from oyster reef sediments in the summer to ?67?±?4 μmol?N-N₂?m^?2?h^?1 from SAV in the winter. Oyster reef sediments had the highest rate of N₂ production of all habitats. Dissimilatory nitrate reduction to ammonium (DNRA) was measured during the summer and winter. DNRA was low during the winter and ranged from 4.5?±?3.0 in subtidal flats to 104?±?34 μmol?¹⁵NH ₄ ⁺ ?m^?2?h^?1 in oyster reefs during the summer. Annual denitrification, accounting for seasonal differences in inundation and light, ranged from 161.1?±?19.2 mmol?N-N₂?m^?2?year^?1 for marsh sediments to 509.9?±?122.7 mmol?N-N₂?m^?2?year^?1 for SAV sediments. Given the current habitat distribution in our study system, an estimated 28.3?×?10⁶?mol of N are removed per year or 76 % of estimated watershed nitrogen load. These results indicate that changes in the area and distribution of habitats in the estuarine landscape will impact ecosystem function and services.     

Pyrite paragenesis and multiple sulfur isotope distribution in late Archean and early Paleoproterozoic Hamersley Basin sediments

The sulfur isotope record in late Archean and early Paleoproterozoic rocks is of considerable importance because it provides evidence for changes in early Earth atmospheric oxygen levels and potentially constrains the origin and relative impact of various microbial metabolisms during the transition from an anoxic to oxic atmosphere. Mass independently fractionated (MIF) sulfur isotopes reveal late Archean and early Paleoproterozoic sulfur sources in different pyrite morphologies in Western Australia's Hamersley Basin. Multiple sulfur isotope values in late Archean pyrite vary according to morphology. Fine grained pyrite has positive sulfur MIF, indicating a reduced elemental sulfur source, whereas pyrite nodules have negative sulfur MIF, potentially derived from soluble sulfate via microbial sulfate reduction. The Hamersley Basin δ³⁴S–Δ³³S record suggests that the extent of oxygenation of the surface ocean fluctuated through the Late Archean from at least 2.6 Ga, more than 150 million yr before the Great Oxidation Event. In the early Paleoproterozoic, there is less distinction between pyrite morphologies with respect to sulfur isotope fractionation, and pyrite from the Brockman Iron Formation trends toward modern sulfur isotope values. An important exception to this is the strong negative MIF recorded in layer parallel pyrite in Paleoproterozoic carbonate facies iron formation. This may suggest that deeper water hydrothermal environments remained anoxic while shallower water environments became more oxidised by the early Paleoproterozoic. The results of the current study indicate that sulfide paragenesis is highly significant when investigating Archean and early Paleoproterozoic multiple sulfur isotope compositions and sulfur sources.     

Overview of integrative tools and methods in assessing ecological integrity in estuarine and coastal systems worldwide

In recent years, several sets of legislation worldwide (Oceans Act in USA, Australia or Canada; Water Framework Directive or Marine Strategy in Europe, National Water Act in South Africa, etc.) have been developed in order to address ecological quality or integrity, within estuarine and coastal systems. Most such legislation seeks to define quality in an integrative way, by using several biological elements, together with physico-chemical and pollution elements. Such an approach allows assessment of ecological status at the ecosystem level ('ecosystem approach' or 'holistic approach' methodologies), rather than at species level (e.g. mussel biomonitoring or Mussel Watch) or just at chemical level (i.e. quality objectives) alone. Increasing attention has been paid to the development of tools for different physico-chemical or biological (phytoplankton, zooplankton, benthos, algae, phanerogams, fishes) elements of the ecosystems. However, few methodologies integrate all the elements into a single evaluation of a water body. The need for such integrative tools to assess ecosystem quality is very important, both from a scientific and stakeholder point of view. Politicians and managers need information from simple and pragmatic, but scientifically sound methodologies, in order to show to society the evolution of a zone (estuary, coastal area, etc.), taking into account human pressures or recovery processes. These approaches include: (i) multidisciplinarity, inherent in the teams involved in their implementation; (ii) integration of biotic and abiotic factors; (iii) accurate and validated methods in determining ecological integrity; and (iv) adequate indicators to follow the evolution of the monitored ecosystems. While some countries increasingly use the establishment of marine parks to conserve marine biodiversity and ecological integrity, there is awareness (e.g. in Australia) that conservation and management of marine ecosystems cannot be restricted to Marine Protected Areas but must include areas outside such reserves. This contribution reviews the current situation of integrative ecological assessment worldwide, by presenting several examples from each of the continents: Africa, Asia, Australia, Europe and North America.     

Recent water quality trends and a comparison to sediment-core records for two riverine lakes of the Upper Mississippi River basin: Lake St. Croix and Lake Pepin

Long-term water quality monitoring data from two riverine lakes in the Upper Mississippi River basin, Lakes St. Croix and Pepin, were analyzed to compare the long-term average water quality conditions and land use distributions, water quality trends and loads at lake inlets and outlets, trends from long-term versus short-term monitoring records, and the ability of paleolimnological cores to accurately infer lake water quality conditions. During the 1976–2004 period, the long-term average concentrations of nutrients, suspended solids, and chlorophyll-a were consistently lower at the Lake St. Croix inlet versus the Lake Pepin inlet, which drains a greater proportion of urban and agricultural runoff. Despite these differences, nutrient trends were similar at the inlets to both lakes; reductions in total phosphorus and ammonium concentrations were attributed to improvements in point source technologies, whereas increasing nitrate concentrations were attributed to both point source changes and nonpoint source increases. Despite improvements in several water quality variables, nitrate concentrations are increasing in both lakes, sediment trends indicate persistent nonpoint source inputs to Lake Pepin, and current total phosphorus concentrations remain well above pre-1950s levels in both lakes. Since urban development and agriculture are increasing in the Lake St. Croix and Lake Pepin Watersheds, continued point source regulation and additional nonpoint source control efforts will be needed to further improve water quality in these lakes. The 1976–2004 trends for most water quality variables were similar at inlet versus outlet sites on Lake St. Croix. Trends at Lake Pepin inlet versus outlet sites were less similar, but data availability limited the comparison to the 1993–2003 period. While the truncated data record highlighted short-term trends in both lakes, the full data record was most useful for exploring general patterns in water quality. Length of monitoring record affected our ability to detect trends at the inlets to both lakes, and altered the magnitude of detected trends. During the two decades of the 1980s and 1990s, paleolimnological estimates of retained phosphorus loads were similar to those estimated from recent water quality monitoring. These similarities support the use of paleolimnological approaches to infer past water quality conditions in Lakes St. Croix and Pepin. This is one of eight papers dedicated to the “Recent Environmental History of the Upper Mississippi River” published in this special issue of the Journal of Paleolimnology. D. R. Engstrom served as guest editor of the special issue.