A warming climate is expected to have an impact on the magnitude and timing of river floods; however, no consistent large-scale climate change signal in observed flood magnitudes has been identified so far. We analyzed the timing of river floods in Europe over the past five decades, using a pan-European database from 4262 observational hydrometric stations, and found clear patterns of change in flood timing. Warmer temperatures have led to earlier spring snowmelt floods throughout northeastern Europe; delayed winter storms associated with polar warming have led to later winter floods around the North Sea and some sectors of the Mediterranean coast; and earlier soil moisture maxima have led to earlier winter floods in western Europe. Our results highlight the existence of a clear climate signal in flood observations at the continental scale.
COBISS.SI-ID: 8122721
The paper presents an extension of a recently developed fully coupled elastoplastic method (Pulko and Logar, 2016) for the analysis of a poroelastic thick-walled soil cylinder around an elastoplastic endbearing stone column to account for the influence of an elastic geosynthetic encasement. The method was developed in the framework of Biot's consolidation theory (Biot, 1941) and is based on a unit cell concept, wherein the column encasement is modeled as a thin elastic membrane, which can only sustain tension and acts in the radial direction. Analytical closed-form expressions for excess pore pressures, stresses, strains, displacements and encasement forces were derived in the Laplace domain. The final elastoplastic solution in time domain was obtained numerically by using efficient numerical scheme for the inverse Laplace transform. The validity of the solution was checked against finite element analyses and compared with previously developed analytical methods. The results show the influence of column encasement on transient state of settlements, strains, excess pore pressures and encasement forces under instantaneous or time dependent load.
COBISS.SI-ID: 8176481
This study presents a novel decentralized sanitary separation system as a zero-discharge solution for blackwater (BW) (faeces, urine and toilet paper) treatment for remote tourist facilities located in sensitive areas. The system operates with low water and energy consumption, enables safe operation and requires low maintenance. The BW was collected from two vacuum toilets (VTs) (0.8 L flush water) and separated in peat filters (PFs) to obtain a liquid fraction (LF) and a solid fraction (SF) of the BW. The LF from the PFs was thereafter treated in a biofilter (BF) and finally evaporated in the evaporation module (EM) powered by solar vacuum collectors (SVC). In the PFs, particles larger than 1 mm from the BW were reduced by 96.5%. Furthermore, the total suspended solids (TSS) mass removal efficiency of the PFs averaged 51.5%. Reduction of ammonia through nitrification was noticeably enhanced after 100 days of the system operation (max. 55.8%). 21.2% or 0.54 kg of total phosphorus (TP) was retained in the PFs, to be further composted and reused for agricultural purposes. An additional 5% or 0.10 kg of TP was retained in the BF. The final step of the LF treatment was in the EM at a sanitizing temperature of )60 °C to prevent the release of human pathogens into environment. With a total electricity consumption of 9.1 kWh/day and a heat consumption of approximately 5.1 kWh/day gained by the SVC, the system successfully integrated different approaches to treating the BW.
COBISS.SI-ID: 2312039
Evapotranspiration is an important element of the water cycle and possible trends in the evapotranspiration can, among others, influence on the water management and agricultural production. Since actual evapotranspiration values are rare and difficult to estimate, reference evapotranspiration was examined in order to document changes in the climatic conditions that affect evapotranspiration. The daily reference evapotranspiration data calculated using the Penman-Monteith method from 18 meteorological stations located in three different climate types in Slovenia was examined in this study. 55 years of data from 1961 until 2016 was analysed. The Mann-Kendall test was applied in order to detect trends in different samples that were defined based on the daily reference evapotranspiration data. Relationship between the evapotranspiration and influencing factors was also investigated using the generalized boosted regression trees model. The calculated trends for different samples are mostly increasing and statistically significant while no consistent trend could be detected for all 18 stations. The maximum increase in the daily reference evapotranspiration for the observed period was 0.5mm and the maximum decrease -0.4mm. Moreover, upward trend was detected for two mountain stations and downward for one sub-Mediterranean station. No uniform trend could be found for the stations located in the temperate continental climate. Furthermore, generalized boosted regression trees model indicated that solar radiation has the largest impact on the reference evapotranspiration values, generally followed by air temperature, saturation vapour pressure deficit and wind speed.
COBISS.SI-ID: 8465249
The effects of five commercially available hydrolytic enzyme additives on methane yields from dehydrated paper pulp sludge (DPPS) were determined in 5L pilot-scale reactors operated in semi-continuous mode for 60 days. Methane production was 40% and 43% higher in reactors receiving Novozymes and Novalin additives, respectively, compared to controls. Effects of time of DPPS inclusion on bacterial and archaeal microbial communities were many times larger than effects of enzyme type as enzyme addition did not produce rearrangements larger than random fluctuations observed in reactors receiving only DPPS. The ratio between volatile organic acids and alkalinity signified progressive decrease in process stability until day 45 irrespective of enzyme supplementation. Complementation with clarified pig slurry (1.5% vol.) for subsequent 15 days effectively stabilized process parameters and was sufficient for microbial communities to maintain DPPS hydrolytic capacity and process additional carbon flow derived from hydrolytic activity of enzyme additives. Consequently, initially unadapted full-scale biogas plant inoculum was capable of significantly increased methane yields from DPPS. Based on annual DPPS availability in EU the potential for additional energy recovery was estimated to be in the range of nearly 1 TJ.
COBISS.SI-ID: 3874696