Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2024
Sammendrag
Climate change stands as one of the most pressing challenges confronting global ecosystems and human livelihoods. The agriculture sector of Anuradhapura district, Sri Lanka, well renowned for its pivotal role in the nation’s food production, faces an increasing threat from the changing climate. This study aims to incorporate the indicator system method which uses a set of indicators to assess the agricultural vulnerability (AV) to climate change in Anuradhapura district. The AV assessment used in this study involves three principal components exposure, sensitivity, and adaptive capacity. The indicators are normalized to allow spatial analysis and smooth integration within a geographic information system (GIS) framework. The AV of Anuradhapura district ranged from 0.32 to 0.67 and was divided among five levels very low, low, moderate, high, and very high. The findings suggest that Anuradhapura’s agricultural sector was significantly impacted by climate change as the majority of the total area was found to have very high, high, and moderate levels of AV with 25, 28, and 24%, respectively. The results obtained from this study are essential for formulating plans to improve Anuradhapura’s agricultural sector resilience and adaptability to ensure food security and livelihood sustainability considering the ever-changing climate.
Forfattere
C. Jayasuriya C. Palliyaguru V. Basnayake R.K. Makumbura Miyuru Gunathilake U. RathnayakeSammendrag
Det er ikke registrert sammendrag
Forfattere
Zumry Niyas Charuni I. Madhushani Miyuru Gunathilake Vindhya Basnayaka Komali Kantamaneni Upaka RathnayakeSammendrag
Det er ikke registrert sammendrag
Forfattere
Randika K. Makumbura Prasad Dissanayake Miyuru Gunathilake Namal Rathnayake Komali Kantamaneni Upaka RathnayakeSammendrag
This study presents the first attempt in Sri Lanka to generate a forest fire risk map covering the entire country using a GIS-based forest fire index (FFI) model. The model utilized seven parameters: land use, temperature, slope, proximity to roads and settlements, elevation, and aspect. All these parameters were derived using GIS techniques with ArcGIS10.4 and QGIS3.16. Data from Remote Sensing sources, particularly the MODIS hotspot real-world dataset, were employed to gather fire count information for the year 2020. Validation was conducted through the merging hotspot technique and kernel density estimation (KDE). The research findings highlight the districts in the Central and Uva provinces, such as NuwaraEliya (10.3 km2), Kandy (2.74 km2), and Badulla (10.41 km2), as having a “very low risk" of forest fire potential. Conversely, districts like Hambanthota (0.1 km2), Kaluthara (0.04 km2), and Kurunegala (0.2 km2) exhibit a “very high risk" of forest fire potential, although it is negligible compared country's total area. Overall, the study suggests that Sri Lanka is not currently facing a significant threat of forest fires and is a “medium risk" of forest fires as 49.49% of land falls under this category. These results are of immense value to relevant authorities, including the Ministry of Wildlife and Forest Resources Conservation, in formulating effective strategies to manage and mitigate forest fire risks in the country.
Sammendrag
I Norge, som mange andre steder, har menneskers bruk av arealer til matproduksjon, transport og bosetning, ført til store endringer i landskapet. Disse endringer/påvirkninger har blant annet resultert i økt erosjon og flom, og redusert økologisk kvalitet i mange elver og bekker. Grønne løsninger", eller naturbaserte tiltak er aktuelt for å redusere disse problemene i landskapet. Dette innebærer blant annet å gi elver og bekker mer plass i landskapet, slik at de kan holde tilbake (fordrøye) vann og redusere farten på vannet i flomperioder. Men, det er også et ønske om å bruke naturbaserte løsninger der erosjonssikring er nødvending. Denne rapporten er en del av det nordiske prosjektet N4S og gir en kunnskapssammenstilling om erosjonssikring av bekkekanter, med særlig fokus på områder med sand og leire. Ulike former for naturbasert kantsikring, som innebærer bruk av naturlige materialer og metoder for å stabilisere elve- og bekkekantene, forhindre erosjon, gjenopprette vegetasjonen, absorbere energien fra vannstrømmen og fremme biologisk mangfold, gjennomgås i rapporten. Rapporten gir også en vurdering av lovverket som er komplekst og ikke nødvendigvis tilpasset denne typen tiltak. Søknadsprosessen er tidkrevende og kan bli kostbar. Derfor er det viktig å sette av nok tid og penger til planlegging og søknadsprosesser ved gjennomføring av naturbaserte prosjekter.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Rolf David Vogt Øyvind Aaberg Garmo Kari Austnes Øyvind Kaste Ståle Haaland James Edward Sample Jan-Erik Thrane Liv Bente Skancke Cathrine Brecke Gundersen Heleen de WitSammendrag
Rising organic charge in northern freshwaters is attributed to increasing levels of dissolved natural organic matter (DNOM) and changes in water chemistry. Organic charge concentration may be determined through charge balance calculations (Org.−) or modelled (OAN−) using the Oliver and Hruška conceptual models, which are based on the density of weak acid functional sites (SD) present in DNOM. The charge density (CD) is governed by SD as well as protonation and complexation reactions on the functional groups. These models use SD as a key parameter to empirically fit the model to Org.−. Utilizing extensive water chemistry datasets, this study shows that spatial and temporal differences in SD and CD are influenced by variations in the humic-to-fulvic ratio of DNOM, organic aluminum (Al) complexation, and the mole fraction of CD to SD, which is governed by acidity. The median SD values obtained for 44 long-term monitored acid-sensitive lakes were 11.1 and 13.9 µEq/mg C for the Oliver and Hruška models, respectively. Over 34 years of monitoring, the CD increased by 70%, likely due to rising pH and declining Al complexation with DNOM. Present-day median SD values for the Oliver and Hruška models in 16 low-order streams are 13.8 and 15.8 µEq/mg C, respectively, and 10.8 and 12.5 µEq/mg C, respectively, in 10 high-order rivers.
Forfattere
Ståle Haaland Josef Hejzlar Bjørnar Eikebrokk Geir Orderud Ma. Cristina Paule‐Mercado Petr Porcal Jiří Sláma Rolf David VogtSammendrag
Over the past four decades, an increase in Dissolved Natural Organic Matter (DNOM) and colour, commonly referred to as browning, has been noted in numerous watercourses in the northern hemisphere. Understanding the fluctuations in DNOM quality is a prerequisite for gaining insights into the biogeochemical processes governing DNOM fluxes. Such knowledge is also pivotal for water treatment plants to effectively tailor their strategies for removing DNOM from raw water. The specific ultraviolet absorbance (sUVa) index has been a widely applied measurement for assessing DNOM quality. The sUVa index is the UV absorbance (OD254) of water normalized for DNOM concentration. We have used a long-term dataset spanning from 2007 to 2022, taken from the Malše River in South Bohemia, to model DNOM and the sUVa index. We have applied regression models with a process-oriented perspective and have also considered the influence of climate change. Both DNOM and the sUVa index is positively related to temperature, runoff and pH, and negatively related to ionic strength over the studied period. Two distinct model approaches were employed, both explaining about 40% of the variation in sUVa over the studied period. Based on a moderate IPCC monthly climate scenario, simulations indicate that both DNOM and the sUVa index averages remain fairly stable, with a slight increase in winter season minima projected towards the year 2099. A slight decline in summer season maxima is simulated for DNOM, while the sUVa summer maximum remain stable. These findings suggest a robust resilience in both DNOM and the sUVa index against anticipated changes in temperature and runoff for the Malše River in South Bohemia.
Sammendrag
In this study, the influence of riverbed silting on the groundwater regime in a lowland area was investigated. The study area is situated at the Rye Island (Žitný Ostrov) in Slovakia, along the Gabčíkovo – Topoľníky canal, which is part of the drainage-irrigation canal system constructed in this locality. The Rye Island is an area with very low slope (0.25 10–4) and good climatic conditions for aquatic vegetation, therefore the canals are influenced by intensive silting processes. The spatial and temporal patterns of surface water – groundwater exchange are significantly influenced by the thickness of riverbed sediments and their permeability. The aim of this study was to evaluate the thickness and hydraulic conductivity of bed sediments in the Gabčíkovo – Topoľníky canal and to examine their influence on the groundwater – surface water interaction in the area. The hydraulic conductivity of the sediments was assessed from undisturbed samples by the falling head method. The obtained data were used for numerical simulations of groundwater heads by the TRIWACO model for different drainage and infiltration resistance conditions in the area of interest. The results of this study can support the planning of canal maintenance.
Sammendrag
The objectives of the study was to 1) investigate soil-plant-water interactions based on field measurements of plant reflectance and soil water content (SWC) in different inter-row managed vineyards, and 2) modeling changes in the SWC due to differences in soil physical parameters among slope positions and management methods. The study explored the impact of three different soil management practices on grapevine growth and soil health in vineyards: tilled (T), cover crops (CC), and perennial grass (NT) inter-rows. Data was collected for 2022 and 2023. At each study slopes, we had two measurement points along a slope section. To continuously monitor soil water and temperature conditions, sensors were strategically positioned at two depths of 15 cm and 40 cm below the soil surface along the slopes, both at the upper and lower points of the vineyard, while topsoil SWC was measured bi-weekly. Normalized Difference Vegetation Index (NDVI) and Photochemical Reflectance Index (PRI) sensors were used to measure leaf reflectance, while handheld instruments were used to measure additional NDVI and leaf Chlorophyll contents (SPAD). For the hydrological modeling we used SWAP (Soil-Water-Atmosphere-Plant), where the rswap R-package was used for calibration (2020 15 and 40cm data), validation (2021 15 and 40cm data), and statistical evaluation. In 2022, all three slopes showed a significantly higher SWC content for the higher points compared to the lower, while in 2023 the grassed slope upper point showed higher SWC (0.18 vs 0.15%). The highest NDVI values were measured for the cover cropped vineyard site (0.68). However, we found no significant differences among NDVI values based on inter-row management or slope position, only the grassed inter-row vineyard had differences in the NDVI values at the lower and upper points (p=0.034). The highest leaf chlorophyll contents were measured for the cover cropped vineyard site (305). Most of the leaf Chlorophyll values were not significantly different among slope positions. Using the SWAP model, data from the cover cropped inter-row vineyard was used for calibration and validation. We found good model fitting (NSE > 0.52; d_daily > 0.81). Reduced-tillage (RT) and drought tolerant plant (DTP) management scenarios were run to simulate SWC changes over time. Preliminary data shows that DTP significantly reduced, while RT did not significantly affect our site’s SWC.