The further chemistry of ellagic acid III: The effect of wick action upon moisture uptake and movement in ellagate treated Pinus radiata wood
- Authors: Przewloka, Simon , Shearer, B. J.
- Date: 2002
- Type: Text , Journal article
- Relation: Holzforschung Vol. 56, no. 6 (2002), p. 632-638
- Full Text: false
- Reviewed:
- Description: Pinus radiata sapwood stakes were treated with ellagic acid and tetraguanidinium, tetracholine and tetrakis-benzyltrimethylammonium ellagates. The effect of these treatments upon moisture movement and uptake was investigated by wick action. Given that chemical reactions within the wood substrate between nutrients and treatment solutions may alter the properties of the wood with regard to moisture movement, the presence of Cu2+ in the system was also examined. Water-soluble ellagates reduced water loss by 25-35 %, but had no effect upon water uptake. Ellagic acid in N-methylpyrrolidone significantly reduced both water loss and moisture uptake. The effect of Cu2+ upon moisture movement and uptake in the treated stakes was negligible.
- Description: 2003000162
Interaction between a river and its wetland : Evidence from the Murray River for spatial variability in diatom and radioisotope records
- Authors: Grundell, Rosie , Gell, Peter , Mills, Keely , Zawadzki, Atun
- Date: 2012
- Type: Text , Journal article
- Relation: Journal of Paleolimnology Vol. 47, no. 2 (2012), p. 205-219
- Full Text: false
- Reviewed:
- Description: Sinclair Flat is small wetland, located within the gorge section of the Murray River floodplain. situated near Blanchetown, South Australia, the wetland is closely linked to the River and, since regulation, has become permanently inundated. High summer evaporation rates deplete the volume of water within the wetland. However, this is compensated by perennial inflow via a permanent inlet from the River. This site provides an opportunity to explore the relative contribution of river and wetland diatom flora to the sediment record, and the fluvial and aerial contribution of radiometric isotopes to the system. The geochronological and biostratigraphic data provide an insight into the history of the water quality of Sinclair Flat. Evidence exists for the River being a source of sediments and isotopes and of diatom species typical of the main river channel. Prior to 1950, Sinclair Flat was an oligotrophic, oligosaline, clear-water wetland. The wetland shifted gradually to an environment that favoured clear-water benthic species, most likely as a consequence of changes following river regulation in the 1920s, although the capacity to date these sediments is limited. During the 1950s, the wetland became plankton dominated. Peaks in epiphytic diatoms during the 1960s suggest increased emergent macrophyte cover. The contemporary condition is of a connected, turbid, eutrophic and mesosaline lagoon. The ecological condition of Sinclair Flat has diverged considerably from its historical range of condition. This record supports evidence from upstream of widespread state switches in the Murray-Darling Basin floodplain wetlands. This record also lends considerable weight to modern studies attesting to the degraded state of the waterways of the Murray-Darling Basin and the impact of river regulation practices on the water quality of these ecosystems. © 2011 Springer Science+Business Media B.V.
Potential improvements to statistical downscaling of general circulation model outputs to catchment streamflows with downscaled precipitation and evaporation
- Authors: Sachindra, Dhanapala , Huang, Fuchun , Barton, Andrew , Perera, Bimalka
- Date: 2014
- Type: Text , Journal article
- Relation: Theoretical and Applied Climatology Vol. 122, no. 1-2 (2014), p. 159-179
- Full Text: false
- Reviewed:
- Description: An existing streamflow downscaling model (SDM(original)), was modified with the outputs of a precipitation downscaling model (PDM) and an evaporation downscaling model (EDM) as additional inputs, for improving streamflow projections. For this purpose, lag 0, lag 1 and lag 2 outputs of PDM were individually introduced to SDM(original) as additional inputs, and then it was calibrated and validated. Performances of the resulting modified models were assessed using Nash-Sutcliffe efficiency (NSE) during calibration and validation. It was found that the use of lag 0 precipitation as an additional input to SDM(original) improves NSE in calibration and validation. This modified streamflow downscaling model is called SDM(lag0_preci). Then lag 0, lag 1 and lag 2 evaporation of EDM were individually introduced to SDM(lag0_preci) as additional inputs and it was calibrated and validated. The resulting models showed signs of over-fitting in calibration and under-fitting in validation. Hence, SDM(lag0_preci) was selected as the best model. When SDM(lag0_preci) was run with observed lag 0 precipitation, a large improvement in NSE was seen. This proved that if precipitation produced by the PDM can accurately reproduce the observations, improved precipitation predictions will produce better streamflow predictions. © 2014, Springer-Verlag Wien.
Precipitation and evaporative aspects of the terrestrial water balance in Central Victoria and their relationship to large-scale climate drivers during the growing season
- Authors: Marshall, Adam
- Date: 2016
- Type: Text , Thesis , Masters
- Full Text:
- Description: Terrestrial Water Balance (TWB) incorporates the combined effects of precipitation and evaporation, and is an important factor influencing agricultural and hydrological processes and management. This study analyses the TWB components at five stations in central Victoria from 1972 - 2013, a region which spans a range of agricultural and hydrological regimes. These stations represent distinct climatic and geographic locations including the dry inland plains, the Great Dividing Range and the southern coastal area. This research focuses on the „Growing Season‟ from March - November; a period where increased availability of moisture is critical for commencing, maintaining and ceasing a variety of agricultural practices. Moisture surplus is known as „Effective Precipitation‟ and is represented by a Precipitation/Evaporation (P-E) ratio >1. Whilst the combined P-E ratio is significant, an emphasis is placed upon examining individual meteorological components which determine the TWB. Hence rainfall and pan evaporation characteristics are analysed on both monthly and seasonal timescales within the 'Growing Season'. Trends in rainfall are fairly consistent across all stations with ongoing declines generally observed in all months except November, most notable in April, May and October. Pan evaporation displays much more variation between stations with both strong positive and negative trends evident throughout the station network in each season. The varying trends in pan evaporation between the stations suggest that the same large scale conditions can result in vastly different effects locally, owing to topographic and geographic factors. The influence of El Niño - Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) on pan evaporation is widespread and statistically significant during Winter and Spring. The Southern Annular Mode (SAM) displays marked intra-seasonal influence which appears to be highly location dependent. Consistent with the literature, rainfall shows increasing correlations with ENSO and IOD through Winter before peaking in Spring at all stations. Interestingly, despite changes in teleconnection strength over time, these tropical climate drivers display a stronger relationship with pan evaporation than rainfall over the full analysis period. Therefore an opportunity may exist to use such relationships to develop seasonal forecasts of evaporation, similar to what is currently employed for seasonal rainfall forecasting. This is important as Effective Precipitation is significantly influenced by the evaporative component of the TWB. Critically, this study shows that variations in such elements need to be considered on a regional basis, bearing in mind differences in geographic and topographic location, as well as intra-seasonal regimes within the overall Growing Season.
- Description: Master of Applied Science
Estimation of stagnosol hydraulic properties and water flow using uni- and bimodal porosity models in erosion-affected hillslope vineyard soils
- Authors: Filipović, Vilim , Defterdarović, Jasmina , Krevh, Vedran , Filipović, Lana , Ondrašek, Gabrijel , Kranjčec, Filip , Magdić, Ivan , Rubinić, Vedran , Stipičević, Sanja , Mustać, Ivan , Bubalo Kovačić, Marina , He, Hailong , Haghverdi, Amir , Gerke, Horst
- Date: 2021
- Type: Text , Journal article
- Relation: Agronomy (Basel) Vol. 12, no. 1 (2021), p. 33
- Full Text: false
- Reviewed:
- Description: Erosion has been reported as one of the top degradation processes that negatively affect agricultural soils. The study objective was to identify hydropedological factors controlling soil water dynamics in erosion-affected hillslope vineyard soils. The hydropedological study was conducted at identically-managed Jastrebarsko (location I), and Jazbina (II) and (III) sites with Stagnosol soils. Soil Hydraulic Properties (SHP) were estimated on intact soil cores using Evaporation and WP4C methodssoil hydraulic functions were fitted using HYPROP-FIT software. For Apg and Bg/Btg horizons, uni- and bimodal soil hydraulic models could be well fitted to data although, the bimodal model performed better in particular cases where data indicated non-uniform pore size distribution. With these SHP estimations, a one-year (2020) water flow scenario was simulated using HYDRUS-1D to compare water balance results obtained with uni- and bimodal hydraulic functions. Simulation results revealed relatively similar flux distribution at each hillslope position between the water balance components infiltration, surface runoff, and drainage. However, at the bottom profile at Jastrebarsko, bimodality of the hydraulic functions led to increased drainage. Soil water storage was reduced, and the vertical movement increased due to modified soil water retention curve shapes. Adequate parameterization of SHP is required to capture the hydropedological response of heterogenous erosion-affected soil systems.
Modeling water flow and phosphorus sorption in a soil amended with sewage sludge and olive pomace as compost or biochar
- Authors: Filipović, Vilim , Černe, Marko , Šimůnek, Jiří , Filipović, Lana , Romić, Marija , Ondrašek, Gabrijel , Bogunović, Igor , Mustać, Ivan , Krevh, Vedran , Ferenčević, Anja , Robinson, David , Palčić, Igor , Pasković, Igor , Goreta Ban, Smiljana , Užila, Zoran , Ban, Dean
- Date: 2020
- Type: Text , Journal article
- Relation: Agronomy (Basel) Vol. 10, no. 8 (2020), p. 1163
- Full Text:
- Reviewed:
- Description: Organic amendments are often reported to improve soil properties, promote plant growth, and improve crop yield. This study aimed to investigate the effects of the biochar and compost produced from sewage sludge and olive pomace on soil hydraulic properties, water flow, and P transport (i.e., sorption) using numerical modeling (HYDRUS-1D) applied to two soil types (Terra Rosa and Rendzina). Evaporation and leaching experiments on soil cores and repacked soil columns were performed to determine the soil water retention, hydraulic conductivity, P leaching potential, and P sorption capacity of these mixtures. In the majority of treatments, the soil water retention showed a small increase compared to the control soil. A reliable fit with the modified van Genuchten model was found, which was also confirmed by water flow modeling of leaching experiments (R2 0.99). The results showed a high P sorption in all the treatments (Kd 21.24 to 53.68 cm3 g−1), and a high model reliability when the inverse modeling procedure was used (R2 0.93–0.99). Overall, adding sewage sludge or olive pomace as compost or biochar improved the Terra Rosa and Rendzina water retention and did not increase the P mobility in these soils, proving to be a sustainable source of carbon and P-rich materials.