158 research outputs found

    Dynamical properties of the spatial distribution of snow

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    International audienceA simulation exercise has been performed to study the temporal development of snow covered area and the spatial distribution of snow-water equivalent (SWE). Special consideration has been paid to how the properties of the spatial statistical distribution of SWE change as a response to accumulation and ablation events. A distributed rainfall-runoff model at resolution 1 x 1 km2 has been run with time series of precipitation and temperature fields of the same spatial resolution derived from the atmospheric model HIRLAM. The precipitation fields are disaggregated and the temperature fields are interpolated. Time series of the spatial distribution of snow-water equivalent and snow-covered area for three seasons for a catchment in Norway is generated. The catchment is of size 3085 km2 and two rectangular sub-areas of 484 km2 are located within the larger catchment. The results show that the shape of the spatial distribution of SWE for all three areas changes during winter. The distribution is very skewed at the start of the accumulation season but then the skew decreases and, as the ablation season sets in, the spatial distribution again becomes more skewed with a maximum near the end of the ablation season. For one of the sub-areas, a consistently more skewed distribution of SWE is found, related to higher variability in precipitation. This indicates that observed differences in the spatial distribution of snow between alpine and forested areas can result from differences in the spatial variability of precipitation. The results obtained from the simulation exercise are consistent with modelling the spatial distribution of SWE as summations of a gamma distributed variable. Keywords: Snow, SWE, spatial distribution, simulated hydrometeorological field

    THE USE OF COHESIVE DEVICES IN ENGLISH EDUCATION STUDENTS’ WRITINGS

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    This study discovers how cohesive devices used in twelve students’ writing written by four students – two high achiever learners and two low achiever learners – of English Education Program in Indonesian University. With the characteristics of case study approach, the research study applies a qualitative method research design and employs Halliday and Hasan’s (1976) taxonomy of cohesion framework as a ground theory and a tool for text analysis. The findings show that grammatical cohesive devices are used slightly more frequent than the lexical ones. The students frequently used reiteration followed by reference, conjunction, collocation, substitution, and ellipsis with two general functions; to remind the readers about the topic discussed and to show the position of the author within the text. Furthermore, it is realized that to some extent, the way students use cohesive devices is a little bit different; in which at the final point, high achiever learners tend to use more various cohesive devices than the low ones in maintaining their quality of writing. Keywords: Cohesion, Cohesive Devices, Writing Quality Penggunaan Perangkat Kohesif di Tulisan-tulisan Mahasiswa Pendidikan Bahasa Inggris Penelitian ini mengemukakan bagaimana perangkat kohesif digunakan pada dua belas tulisan buatan empat mahasiswa – dua siswa berprestasi tinggi dan dua siswa berprestasi rendah – jurusan pendidikan bahasa inggris di salah satu universitas di Indonesia. Dengan karakteristik pendekatan studi kasus, penelitian ini menerapkan metode kualitatif dan menggunakan taksonomi kerangka kohesi yang diusung Halliday dan Hasan (1976) sebagai teori dasar dan alat untuk menganalisis teks. Temuan menunjukan bahwa perangkat kohesif gramatikal digunakan sedikit lebih sering daripada yang leksikal. Para siswa seringkali menggunakan reiteration diikuti oleh reference, conjunction, collocation, substitution, dan ellipsis dengan dua fungsi umum; untuk mengingatkan pembaca tentang topic yang sedang dibahas dan untuk menunjukan posisi penulis didalam teks. Selanjutnya, disadari bahwa pada titik-titik tertentu, cara siswa menggunakan perangkat kohesif sedikit berbeda; yang mana pada akhirnya, siswa yang berprestasi tinggi cenderung menggunakan perangkat kohesif yang lebih variatif daripada yang digunakan oleh siswa yang berprestasi rendah dalam mempertahankan kualitas tulisannya. Kata Kunci: Kohesi, Perangkat Kohesif, Kualitas Tulisa

    High-quality leader-member exchange and attitudes toward change : the mediating role of mindset

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    Masteroppgave(MSc) in Master of Science in Business, Leadership and Change - Handelshøyskolen BI, 201

    Dynamical properties of the spatial distribution of snow

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    A simulation exercise has been performed to study the temporal development of snow covered area and the spatial distribution of snow-water equivalent (SWE). Special consideration has been paid to how the properties of the spatial statistical distribution of SWE change as a response to accumulation and ablation events. A distributed rainfall-runoff model at resolution 1 x 1 km2 has been run with time series of precipitation and temperature fields of the same spatial resolution derived from the atmospheric model HIRLAM. The precipitation fields are disaggregated and the temperature fields are interpolated. Time series of the spatial distribution of snow-water equivalent and snow-covered area for three seasons for a catchment in Norway is generated. The catchment is of size 3085 km2 and two rectangular sub-areas of 484 km2 are located within the larger catchment. The results show that the shape of the spatial distribution of SWE for all three areas changes during winter. The distribution is very skewed at the start of the accumulation season but then the skew decreases and, as the ablation season sets in, the spatial distribution again becomes more skewed with a maximum near the end of the ablation season. For one of the sub-areas, a consistently more skewed distribution of SWE is found, related to higher variability in precipitation. This indicates that observed differences in the spatial distribution of snow between alpine and forested areas can result from differences in the spatial variability of precipitation. The results obtained from the simulation exercise are consistent with modelling the spatial distribution of SWE as summations of a gamma distributed variable

    Developing and evaluating decision support indicators (DSIs) of climate change impacts on flood and drought: a case study in Western Norway

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    The decision support indicators (DSIs) are specifically designed to inform local and regional stakeholders on the characteristics of a predicted event to facilitate decision-making. They can be classified as conventional, impact-based and event-based DSIs. This study aims to develop methodologies for calculating event-based DSIs and to evaluate the usefulness of different classes of DSIs for climate impact assessment and climate actions by learning about users' perceptions. The DSIs are calculated based on an ensemble of hydrological projections in western Norway under two representative concentration pathway (RCP) scenarios. The definitions, methodologies and results of the indicators are summarized in questionnaires and evaluated by key stakeholders in terms of understandability, importance, plausibility and applicability. Based on the feedback, we conclude that the conventional DSIs are still preferred by stakeholders and an appropriate selection of conventional DSIs may overcome the understanding problems between the scientists and stakeholders. The DSIs based on well-known historical events are easy to understand and can be a useful tool to convey climate information to the public. However, they are not readily implemented by stakeholders in the decision-making process. The impact-based DSI is generally easy to understand and important but it can be restricted to specific impact sectors.publishedVersio

    Spatial and Temporal Variation in the Grilse Proportion of Atlantic Salmon in Norwegian Rivers

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    Variation in the sea age at maturity of Atlantic salmon Salmo salar was studied in 158 Norwegian rivers over large spatial (58–71°N; 5–30°E) and temporal (1983–2000) scales. Age at sexual maturity was expressed as the proportion of grilse (fish with one sea winter) in the nominal salmon catch. No general temporal trend was found in the proportion of grilse in the catches. However, grilse proportion declined significantly in 10 rivers and increased significantly in 11 rivers out of the 55 rivers with data for all 18 years. There were no short-term cycles in grilse proportion within rivers. We found coherence and similarity in the temporal variation in grilse proportion for rivers draining into large fjord systems. Reasons for the temporal variation in grilse proportions must be sought at a river-specific or regional scale. River-specific factors (water discharge, river steepness, and presence of lakes) explained a large percentage of the spatial variation in grilse proportion. Grilse proportion increased with decreasing river size (measured as mean annual water discharge) and with increasing proportion of water discharge occurring during summer (i.e., the migration season). Grilse proportion was higher in rivers located nearer to the open ocean, probably indicating an effect of early feeding on growth and maturation. Even after accounting for environmental variation at the local scale, we found large regional differences in grilse proportion. Region captured this variation more efficiently than latitude, but grilse proportion was higher in the northern part of Norway than in the more southerly part. This variability may indicate large-scale differences in, for example, oceanic migration routes for fish originating from different regions

    Gridded 1 x 1 km climate and hydrological projections for Norway

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    An ensemble of ten EURO-CORDEX GCM/RCM simulations, each representing two alternative emission pathways (RCP4.5 and RCP8.5), were bias-corrected using an empirical quantile mapping method. These corrected datasets covering the period 1971-2100 were then forced with a spatially distributed, gridded version of the HBV model to generate daily time series of different hydrological components. These high-resolution climate and hydrological projections, despite their limitations, represent a valuable data source for different types of climate impact studies at a national and local scale

    Upscaling of methane exchange in a boreal forest using soil chamber measurements and high-resolution LiDAR elevation data

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    Forest soils are generally considered to be net sinks of methane (CH4), but CH4 fluxes vary spatially depending on soil conditions. Measuring CH4 exchange with chambers, which are commonly used for this purpose, might not result in representative fluxes at site scale. Appropriate methods for upscaling CH4 fluxes from point measurements to site scale are therefore needed. At the boreal forest research site, Norunda, chamber measurements of soils and vegetation indicate that the site is a net sink of CH4, while tower gradient measurements indicate that the site is a net source of CH4. We investigated the discrepancy between chamber and tower gradient measurements by upscaling soil CH4 exchange to a 100 ha area based on an empirical model derived from chamber measurements of CH4 exchange and measurements of soil moisture, soil temperature and water table depth. A digital elevation model (DEM) derived from high-resolution airborne Light Detection and Ranging (LiDAR) data was used to generate gridded water table depth and soil moisture data of the study area as input data for the upscaling. Despite the simplistic approach, modeled fluxes were significantly correlated to four out of five chambers with R>0.68. The upscaling resulted in a net soil sink of CH4 of -10 mu mol m(-2) h(-1), averaged over the entire study area and time period June-September, 2010). Our findings suggest that additional contributions from CH4 soil sources outside the upscaling study area and possibly CH4 emissions from vegetation could explain the net emissions measured by tower gradient measurements. (C) 2015 Elsevier B.V. All rights reserved

    Elvetilførsler og direkte tilførsler til norske kystområder – 2016

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    Project manager Øyvind KasteRiverine inputs and direct discharges to Norwegian coastal waters in 2016 have been estimated in accordance with the OSPAR Commission’s principles. Nutrients, metals and organic pollutants have been monitored in rivers; discharges from point sources have been estimated from industry, sewage treatment plants and fish farming; and nutrient inputs from diffuse sources have been modelled. Trends in riverine inputs have been analysed, and threshold concentration levels investigated.Norwegian Environment AgencypublishedVersio
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