Temporal Variability in Rangeland Erosion Processes

Author(s):  
J. R. Simanton ◽  
William E. Emmerich
2021 ◽  
Vol 13 (23) ◽  
pp. 13355
Author(s):  
Tanja Micić Ponjiger ◽  
Tin Lukić ◽  
Biljana Basarin ◽  
Maja Jokić ◽  
Robert L. Wilby ◽  
...  

Estimation of rainfall erosivity (RE) and erosivity density (ED) is essential for understanding the complex relationships between hydrological and soil erosion processes. The main objective of this study is to assess the spatial–temporal trends and variability of the RE and ED in the central and southern Pannonian Basin by using station observations and gridded datasets. To assess RE and ED, precipitation data for 14 meteorological stations, 225 grid points. and an erosion model consisting of daily, monthly, seasonal, and annual rainfall for the period of 1961–2014 were used. Annual RE and ED based on station data match spatially variable patterns of precipitation, with higher values in the southwest (2100 MJ·mm·ha−1·h−1) and southeast (1650 MJ·mm·ha−1·h−1) of the study area, but minimal values in the northern part (700 MJ·mm·ha−1·h−1). On the other hand, gridded datasets display more detailed RE and ED spatial–temporal variability, with the values ranging from 250 to 2800 MJ·mm·ha−1·h−1. The identified trends are showing increasing values of RE (ranging between 0.20 and 21.17 MJ·mm·ha−1·h−1) and ED (ranging between 0.01 and 0.03 MJ·ha−1·h−1) at the annual level. This tendency is also observed for autumn RE (from 5.55 to 0.37 MJ·mm·ha−1·h−1) and ED (from 0.05 to 0.01 MJ·ha−1·h−1), as for spring RE (from 1.00 to 0.01 MJ·mm·ha−1·h−1) and ED (from 0.04 to 0.01 MJ·ha−1·h−1), due to the influence of the large-scale processes of climate variability, with North Atlantic Oscillation (NAO) being the most prominent. These increases may cause a transition to a higher erosive class in the future, thus raising concerns about this type of hydro-meteorological hazard in this part of the Pannonian Basin. The present analysis identifies seasons and places of greatest erosion risk, which is the starting point for implementing suitable mitigation measures at local to regional scales.


2020 ◽  
Vol 655 ◽  
pp. 185-198
Author(s):  
J Weil ◽  
WDP Duguid ◽  
F Juanes

Variation in the energy content of prey can drive the diet choice, growth and ultimate survival of consumers. In Pacific salmon species, obtaining sufficient energy for rapid growth during early marine residence is hypothesized to reduce the risk of size-selective mortality. In order to determine the energetic benefit of feeding choices for individuals, accurate estimates of energy density (ED) across prey groups are required. Frequently, a single species is assumed to be representative of a larger taxonomic group or related species. Further, single-point estimates are often assumed to be representative of a group across seasons, despite temporal variability. To test the validity of these practices, we sampled zooplankton prey of juvenile Chinook salmon to investigate fine-scale taxonomic and temporal differences in ED. Using a recently developed model to estimate the ED of organisms using percent ash-free dry weight, we compared energy content of several groups that are typically grouped together in growth studies. Decapod megalopae were more energy rich than zoeae and showed family-level variability in ED. Amphipods showed significant species-level variability in ED. Temporal differences were observed, but patterns were not consistent among groups. Bioenergetic model simulations showed that growth rate of juvenile Chinook salmon was almost identical when prey ED values were calculated on a fine scale or on a taxon-averaged coarse scale. However, single-species representative calculations of prey ED yielded highly variable output in growth depending on the representative species used. These results suggest that the latter approach may yield significantly biased results.


2013 ◽  
Vol 14 (4) ◽  
pp. 393-398

The occurrence of trihalomethanes (THMs) was studied in the drinking water samples from urban water supply network of Karachi city that served more than 18 million people. Drinking water samples were collected from 58 locations in summer (May-August) and winter (November-February) seasons. The major constituent of THMs detected was chloroform in winter (92.34%) and summer (93.07%), while the other THMs determined at lower concentrations. Summer and winter concentrations of total THMs at places exceed the levels regulated by UEPA (80 μg l-1) and WHO (100 μg l-1). GIS linked temporal variability in two seasons showed significantly higher median concentration (2.5%-23.06%) of THMs compared to winter.


2020 ◽  
Author(s):  
Jaroslaw Roman Lelonkiewicz ◽  
Chiara Gambi

While language production is a highly demanding task, conversational partners are known to coordinate their turns with striking precision. Among the mechanisms that allow them to do so is listeners’ ability to predict what the speaker will say, and thus to prepare their response in advance. But do speakers also play a role in facilitating coordination? We hypothesised that speakers contribute by using coordination smoothers – in particular by making their turns easier to predict. To test this, we asked participants to type definitions for common English words, either on their own (n = 26 individuals) or interacting with a partner (n = 18 pairs), and we measured the timing with which they produced the definitions. In a post-test, additional participants (n = 55) attempted to predict the final word of these definitions and rated them for quality. We found that interacting speakers initiated their turns with less variable delays than solo individuals. In contrast, our post-test measures suggested that jointly produced definitions were in fact of lower predictability and quality than those produced by individuals, but the analysis revealed these findings were likely confounded by task difficulty. We propose that the reduction in temporal variability observed for interacting speakers may facilitate prediction and thus act as a coordination smoother in linguistic interactions. [NOTE: Please cite this paper as: Lelonkiewicz, J. R., & Gambi, C. (2020). Making oneself predictable in linguistic interactions. Acta Psychologica, 209, 103125. https://doi.org/10.1016/j.actpsy.2020.103125 ]


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