510 research outputs found

    HESPER web - development and reliability evaluation of a web-based version of the humanitarian emergency settings perceived needs scale

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    Background: The Humanitarian Emergency Settings Perceived Needs Scale (HESPER) assesses a wide range of physical, psychological and social perceived needs across 26 questions, and can be used in humanitarian emergencies and disasters for needs assessment or research studies. The original HESPER collects data through individual interviews. Today, a large number of people have access to the internet, including in humanitarian emergencies and disasters. Therefore, this paper aimed to report the development, reliability evaluation and feasibility evaluation of the HESPER Web. Methods: First, the original HESPER was developed into a web based survey. Thereafter, alternate forms reliability between the HESPER and HESPER Web, and test-retest reliability for the HESPER Web, was evaluated using a study sample of 85 asylum seekers in Sweden in total. Results: The alternate forms reliability evaluation showed that the HESPER Web was a reliable instrument to assess perceived needs. Intraclass correlation coefficient (ICC) for total number of serious needs was 0.96 (CI 0.93–09.98, p <0.001). Cohen’s κ was used to analyse the alternate forms reliability between the HESPER and HESPER Web item per item; the correspondence between HESPER and HESPER Web varied between 0.54 and 1.0 for the 26 questions. There was a strong nominal association in first priority need between the HESPER and HESPER Web (Cramer’sV 0.845, p <0.001). In the test-retest reliability evaluation of HESPER Web, ICC was 0.98 (CI 0.97–0.99, p <0.001), and Cohen’s κ varied between 0.53 and 1.0. There was a strong nominal association in first priority need between test and re-test (Cramer’s V 0.93, p <0.001). The HESPER Web was experienced as easy and safe to use and was found less time consuming than the original HESPER interview, according to the study participants. Conclusion: The HESPER Web is a reliable and usable instrument to assess perceived needs. It can reduce a number of practical challenges both for needs assessment in disasters or humanitarian emergencies as well as in research

    Perceived needs among asylum seekers in Sweden: a mixed methods study

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    The health and well-being of asylum seekers in high-income countries is a concern from both individual and community perspectives. This study aims to describe the perceived needs of adult asylum seekers in Sweden. A mixed methods study was conducted that combined a non-randomized descriptive cross-sectional assessment of perceived serious needs using the Humanitarian Emergency Settings Perceived Needs Scale (HESPER) Web with 85 adult asylum seekers and focus group discussions with 14 adult asylum seekers in Sweden. Descriptive and comparative statistics were used for the quantitative part, and thematic analysis for the qualitative part. The total number of perceived serious needs reported by respondents ranged from zero to 13 needs per person with a mean of four needs (SD 2.71). The most commonly perceived serious needs were related to income or livelihood, separation from loved ones, being displaced from home, distress, and concerns about accessing adequate health care services. Many of the perceived needs appeared to be related to experiences of being dependent, in limbo, and vulnerable. Addressing people’s current perceived needs can contribute to resilience and well-being and therefore should be considered in health care systems that cater to immigrants

    Water Availability and Land Management Control Catchment‐Scale Agricultural Nitrogen and Phosphorous Use Efficiencies

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    In arable systems, large amounts of nutrients, particularly of nitrogen (N) and phosphorus (P), are not efficiently converted into harvestable products and are lost from agricultural systems, with negative consequences for agricultural productivity and the environment. These nutrient losses are mediated by hydroclimatic processes causing nutrient leaching and volatilization. We quantify over the period 1987–2012 how water availability through the evaporative ratio (actual evapotranspiration divided by precipitation) and irrigation, agricultural practices, and edaphic conditions jointly affect nutrient use efficiencies in 110 agricultural catchments in the United States. We consider N and P use efficiencies (nitrogen use efficiency [NUE] and phosphorous use efficiency [PUE]) defined as ratios of catchment-scale N and P in harvested products over their respective inputs, as well as the NUE/PUE ratio, as an indication of catchment-scale N and P imbalance. Both efficiencies increase through time because of changes in climate and agronomic practices. Setting all else at the median value of the data set, NUE and PUE increased with evaporative ratio by 0.5% and 0.2% when increasing the evaporative ratio by 20% and by 4.9% and 18.8% in the presence of irrigation. NUE was also higher in catchments where maize and soybean were dominant (increasing by 2.3% for a 20% increase in maize and soybean fractional area). Soil properties, represented by mineral soil texture and organic matter content, had only small effects on the efficiencies. Our results show that both climatic conditions and crop choice are important drivers of nutrient use efficiencies in agricultural catchments

    An observation-based constraint on permafrost loss as a function of global warming

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    This is the author accepted manuscript. The final version is available from Nature Research via the DOI in this recordPermafrost, which covers 15 million km 2 of the land surface, is one of the components of the Earth system that is most sensitive to warming. Loss of permafrost would radically change high-latitude hydrology and biogeochemical cycling, and could therefore provide very significant feedbacks on climate change. The latest climate models all predict warming of high-latitude soils and thus thawing of permafrost under future climate change, but with widely varying magnitudes of permafrost thaw. Here we show that in each of the models, their present-day spatial distribution of permafrost and air temperature can be used to infer the sensitivity of permafrost to future global warming. Using the same approach for the observed permafrost distribution and air temperature, we estimate a sensitivity of permafrost area loss to global mean warming at stabilization of million km 2 °C â '1 (1σ confidence), which is around 20% higher than previous studies. Our method facilitates an assessment for COP21 climate change targets: if the climate is stabilized at 2 °C above pre-industrial levels, we estimate that the permafrost area would eventually be reduced by over 40%. Stabilizing at 1.5 °C rather than 2 °C would save approximately 2 million km 2 of permafrost.European Union Seventh Framework ProgrammeNatural Environment Research Council (NERC)Swedish Research CouncilResearch Council of NorwayUK DECC/Defra Met Office HadleyEuropean Unio

    The permafrost carbon inventory on the Tibetan Plateau : a new evaluation using deep sediment cores

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    Acknowledgements We are grateful for Dr. Jens Strauss and the other two anonymous reviewers for their insightful comments on an earlier version of this MS, and appreciate members of the IBCAS Sampling Campaign Teams for their assistance in field investigation. This work was supported by the National Basic Research Program of China on Global Change (2014CB954001 and 2015CB954201), National Natural Science Foundation of China (31322011 and 41371213), and the Thousand Young Talents Program.Peer reviewedPostprin

    Effect of Terrain Characteristics on Soil Organic Carbon and Total Nitrogen Stocks in Soils of Herschel Island, Western Canadian Arctic

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    Permafrost landscapes experience different disturbances and store large amounts of organic matter, which may become a source of greenhouse gases upon permafrost degradation. We analysed the influence of terrain and geomorphic disturbances (e.g. soil creep, active-layer detachment, gullying, thaw slumping, accumulation of fluvial deposits) on soil organic carbon (SOC) and total nitrogen (TN) storage using 11 permafrost cores from Herschel Island, western Canadian Arctic. Our results indicate a strong correlation between SOC storage and the topographic wetness index. Undisturbed sites stored the majority of SOC and TN in the upper 70 cm of soil. Sites characterised by mass wasting showed significant SOC depletion and soil compaction, whereas sites characterised by the accumulation of peat and fluvial deposits store SOC and TN along the whole core. We upscaled SOC and TN to estimate total stocks using the ecological units determined from vegetation composition, slope angle and the geomorphic disturbance regime. The ecological units were delineated with a supervised classification based on RapidEye multispectral satellite imagery and slope angle. Mean SOC and TN storage for the uppermost 1 m of soil on Herschel Island are 34.8 kg C m-2 and 3.4 kg N m-2, respectively. Copyright © 2015 John Wiley & Sons, Ltd

    Vertical pattern of organic matter decomposability in cryoturbated permafrost-affected soils

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    Permafrost thaw will release additional carbon dioxide into the atmosphere resulting in a positive feedback to climate change. However, the mineralization dynamics of organic matter (OM) stored in permafrost-affected soils remain unclear. We used physical soil fractionation, radiocarbon measurements, incubation experiments, and a dynamic decomposition model to identify distinct vertical pattern in OM decomposability. The observed differences reflect the type of OM input to the subsoil, either by cryoturbation or otherwise, e.g. by advective water-borne transport of dissolved OM. In non-cryoturbated subsoil horizons, most OM is stabilized at mineral surfaces or by occlusion in aggregates. In contrast, pockets of OM-rich cryoturbated soil contain sufficient free particulate OM for microbial decomposition. After thaw, OM turnover is as fast as in the upper active layer. Since cryoturbated soils store ca. 450 Pg carbon, identifying differences in decomposability according to such translocation processes has large implications for the future global carbon cycle and climate, and directs further process model development

    Carbon and nitrogen pools in thermokarst-affected permafrost landscapes in Arctic Siberia

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    Ice rich Yedoma-dominated landscapes store considerable amounts of organic carbon (C) and nitrogen (N) and are vulnerable to degradation under climate warming. We investigate the C and N pools in two thermokarst-affected Yedoma landscapes – on Sobo-Sise Island and on Bykovsky Peninsula in the North of East Siberia. Soil cores up to three meters depth were collected along geomorphic gradients and analysed for organic C and N contents. A high vertical sampling density in the profiles allowed the calculation of C and N stocks for short soil column intervals and enhanced understanding of within-core parameter variability. Profile-level C and N stocks were scaled to the landscape level based on landform classifications from five-meter resolution, multispectral RapidEye satellite imagery. Mean landscape C and N storage in the first meter of soil for Sobo-Sise Island is estimated to be 20.2 kg C m−2 and 1.8 kg N m−2 and for Bykovsky Peninsula 25.9 kg C m−2 and 2.2 kg N m−2. Radiocarbon dating demonstrates the Holocene age of thermokarst basin deposits but also suggests the presence of thick Holocene aged cover layers which can reach up to two meters on top of intact Yedoma landforms. Reconstructed sedimentation rates of 0.10 mm yr−1–0.57 mm yr−1 suggest sustained mineral soil accumulation across all investigated landforms. Both Yedoma and thermokarst landforms are characterized by limited accumulation of organic soil layers (peat). We further estimate that an active layer deepening by about 100 cm will increase organic C availability in a seasonally thawed state in the two study areas by ~ 5.8 Tg (13.2 kg C m−2). Our study demonstrates the importance of increasing the number of C and N storage inventories in ice-rich Yedoma and thermokarst environments in order to account for high variability of permafrost and thermokarst environments in pan-permafrost soil C and N pool estimates

    Approaching the potential of model-data comparisons of global land carbon storage

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    Abstract Carbon storage dynamics in vegetation and soil are determined by the balance of carbon influx and turnover. Estimates of these opposing fluxes differ markedly among different empirical datasets and models leading to uncertainty and divergent trends. To trace the origin of such discrepancies through time and across major biomes and climatic regions, we used a model-data fusion framework. The framework emulates carbon cycling and its component processes in a global dynamic ecosystem model, LPJ-GUESS, and preserves the model-simulated pools and fluxes in space and time. Thus, it allows us to replace simulated carbon influx and turnover with estimates derived from empirical data, bringing together the strength of the model in representing processes, with the richness of observational data informing the estimations. The resulting vegetation and soil carbon storage and global land carbon fluxes were compared to independent empirical datasets. Results show model-data agreement comparable to, or even better than, the agreement between independent empirical datasets. This suggests that only marginal improvement in land carbon cycle simulations can be gained from comparisons of models with current-generation datasets on vegetation and soil carbon. Consequently, we recommend that model skill should be assessed relative to reference data uncertainty in future model evaluation studies
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