Student-produced podcasts as an assessment tool: an example from Geomorphology

The emergence of user-friendly technologies has made podcasting an accessible learning tool in undergraduate teaching. In a geomorphology course, student-produced podcasts were used as part of the assessment in 2008-2010. Student groups constructed radio shows aimed at a general audience to interpret and communicate geomorphological data within the context of relevant social and environmental issues. Questionnaire results suggest that the novel format engaged students, and promoted group working, IT, language and oral communication skills, and a deeper understanding of the context of geomorphic data. For teachers, podcasting technology offers efficient teaching of oral communication, with opportunities for distance and self-directed learning

Diversifying assessment across the ‘Two Cultures’: student-produced podcasts in Geography

Since 2008, following growing collective interest in learning technologies and pedagogy, Geography and History departments at Northumbria and Newcastle Universities have successfully incorporated student-generated podcasting into a mixture of science, humanities and social science modules across all undergraduate levels. This paper presents a number of innovative examples using this approach, with the aim of promoting student creativity and analytical skills in ways different from traditional report- or essay-based assessments. It goes on to consider some of the advantages and challenges of this alternative assessment mode, from both student and tutor perspectives, across the science-humanities divide

The Hydrology, Geomorphology and Quaternary Palaeochannels of the Lachlan Valley, New South Wales

This thesis examines the present-day and Late Quaternary fluvial geomorphology and hydrology of the upper Lachlan Valley in central western New South Wales. The sediments and morphology of the channel and floodplain are described from its principal alluvial reaches: the confined, single channel reach from Cowra to Gooloogong, the unconfined, single-channel reach between Gooloogong and Cadow, and the anabranching reach on the Condobolin Plain. Present-day channel and floodplain morphology in single-channel reaches of the Lachlan River is dominated by the highly variable hydrologic regime, which is accentuated in confined reaches of the river, but is also influenced by inherited channel forms. In confined reaches, where the effective floodplain is <lkm wide, the floodplain is a high-energy surface dominated by large flood features, which elsewhere in the world are attributed to catastrophic flood flows, but which here are forming under the normal regime of the river. Floodplains are characterised by elliptical scour scars, zones of floodplain stripping, chutes and chute bars, compound flood levees and parallel flood channels. In contrast, the channel itself contains low-energy features such as fine-grained, accreting bench deposits which point to remarkable stability of the channel position. Floodplain deposits resulting from fluvial processes operating at a variety of scales are poorly sorted and become coarser with height above the river bed. The hydrologic character of the river, described from streamflow and historical flood records, is consistent with the sedimentary and morphological evidence of a flood-dominated floodplain, and dating evidence indicates that this has been a long-standing characteristic of this river system in this location. In less confined reaches, large flood features are more subdued and channel inheritance locally controls meander patterns and channel slope. Inherited influences increase downstream as confinement of flood flows is less, and channels may become entrenched within highly sinuous palaeomeanders, developing only a narrow floodplain. The effect of variable streamflow is still exhibited in chute channels, scour complexes and zones of stripped floodplain, although the channel itself is governed by bankfull flows. Lateral channel activity increases in the downstream direction, reflected in both the sinousity and width of the active floodplain. These channel and floodplain characteristics continue throughout the anabranching reach on the plains. Hydraulic geometry relationships in both single and anabranching reaches were constructed from streamflow records and surveyed channel cross-sections, and include sediment parameters. The relationship between channel shape and silt-clay content on the Lachlan differs from that described elsewhere. The exponents found for depth and velocity as a function of discharge also exhibit notable departures from trends reported for rivers elsewhere in the world, as the standard relationships are based on rivers which increase in size downstream, while both slope and particle size decrease. The Lachlan presents a reverse situation, where discharge, slope and sediment size all decrease downstream, and illustrates the need to develop regional rather than global relationships to estimate bankfull discharges for ungauged channels with a given set of characteristics. Palaeochannels were described for the Lachlan Valley downstream from Cowra, where they are associated with two major alluvial terraces, and on the Plains downstream from Forbes, where they intersect with each other and with the modern floodplain. Three discrete fluvial systems were defined. The Gulgo Fluvial System is characterised by relatively narrow and deep channels and has a stable, anabranching pattern. A single TL date from point bar sediments of this system suggests these channels were active by at least 57,000 yrs ago and were replaced by channels of the Ulgutherie Fluvial System, characterised by sinuous, regular and scrolled meanders with wide and shallow channels. OSL dates on channel sediments and an overlying source-bordering dune suggests Ulgutherie channel construction and aeolian deflation of fluvial sediments were underway by 34,000 yrs and the system may have declined soon afterwards. Discharge estimates based on several formulae, including relationships developed for the modern river, indicate bankfull discharges of the Ulgutherie system were at least 4 to 7 times those of the present-day river. Ulgutherie channels were replaced by channels of the Nanima Fluvial System, which had a similar morphology to the Ulgutherie channels, with scrolled, regularly sinuous meanders, but smaller channel capacities and width-depth ratios, and sediment characteristics more similar to the modern Lachlan. Radiocarbon dates indicate Nanima channels were active by 6,000 yrs, if not before, and were replaced by smaller, irregularly meandering channels of the present fluvial system soon after 3000 yrs ago. Discharge reconstructions of Nanima channels indicate they carried bankfull discharges 1.5 to 2 times that of the present river. The higher discharges associated with meandering palaeochannels in the Lachlan Valley around 34,000 yrs and from >6,000-3,000 yrs is in good agreement with lake-level and other environmental records within the catchment

Sub‐arctic river bank dynamics and driving processes during the open‐channel flow period

There is growing concern that rapidly changing climate in high latitudes may generate significant geomorphological changes that could mobilise floodplain sediments and carbon; however detailed investigations into the bank erosion process regimes of high latitude rivers remain lacking. Here we employ a combination of thermal and RGB colour time‐lapse photos in concert with water level, flow characteristics, bank sediment moisture and temperature, and topographical data to analyse river bank dynamics during the open‐channel flow period (the period from the rise of the spring snowmelt flood until the autumn low flow period) for a subarctic river in northern Finland (Pulmanki River). We show how variations of bank sediment temperature and moisture affect bank erosion rates and locations, how bank collapses relate to fluvial processes, and elucidate the seasonal variations and interlinkages between the different driving processes.We find that areas with high levels of groundwater content and loose sand layers were the most prone areas for bank erosion. Groundwater seeping caused continuous erosion throughout the study period, whereas erosion by flowing river water occurred during the peak of snowmelt flood. However, erosion also occurred during the falling phase of the spring flood, mainly due to mass failures. The rising phase of the spring flood therefore did not affect the river bank as much as its peak or receding phases. This is explained because the bank is resistant to erosion due to the prevalence of still frozen and drier sediments at the beginning of the spring flood. Overall, most bank erosion and deposition occurrences were observed during the low flow period after the spring flood. This highlights that spring melt, while often delivering the highest discharges, may not be the main driver of bank erosion in sub‐arctic meandering rivers

Mining of nickel laterites – towards more environmentally responsible operations

Primary mining of technology metal ores is needed to enable effective decarbonisation. The use of nickel in rechargeable batteries is expected to increase global demand for nickel rapidly over the coming years. Over 60% of annual global nickel production originates from nickel laterites, with Indonesia and the Philippines leading the market. Mining of nickel laterite ore can adversely affect the environment through the release of CO2 and potentially hazardous elements (PHE), such as hexavalent chromium, or asbestiform minerals. Through our better understanding of the social and environmental impacts of mining operations and the availability of technologies that can potentially mitigate adverse impact, it is paramount to aim for more responsible mining and metal recovery operations. This study focuses on the Sta Cruz nickel laterite deposit in the Philippines. Through a multi-scale and multi-technique analytical programme and drawing on existing knowledge1,2, we appraise the deposit holistically, focusing on (i) the geochemistry and mineralogy of major commodities and trace metals, such as the platinum group elements; (ii) carbonate forming metals, e.g. magnesium and (iii) the presence and ecotoxicity of PHE and minerals. We use this understanding to assess the potential for a circular economy in mining, via complete utilisation of the ore to maximise the metal output and minimise the waste produced. This includes the removal of CO2 through the formation of carbonate minerals (mineral carbonation). We also investigate the potential of carbonates to immobilise chromium crystallographically alongside the CO2. This aspect of mineral carbonation is currently poorly understood. We have carried out laboratory synthesis of chromium-doped carbonates at ambient P-T conditions, which indicates that the most common magnesium carbonates do not readily accommodate chromium. However, other carbonate-bearing minerals, including those belonging to layered double hydroxides, present a viable alternative. The combined PHE-CO2 mineral carbonation, when implemented at different stages of metal recovery, from ore extraction to processing, could lead to a reduction of the volume and toxicity of waste, collectively contributing to the mitigation of the adverse environmental impact of nickel laterite mining. [1] Acquino et al (2022) Minerals, 12(3) [2] Bacuta et al (1990) Journal of Geochem.Exploration, 3

Planned early delivery or expectant management for late preterm pre-eclampsia (PHOENIX): a randomised controlled trial

© 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license Background: In women with late preterm pre-eclampsia, the optimal time to initiate delivery is unclear because limitation of maternal disease progression needs to be balanced against infant complications. The aim of this trial was to determine whether planned earlier initiation of delivery reduces maternal adverse outcomes without substantial worsening of neonatal or infant outcomes, compared with expectant management (usual care) in women with late preterm pre-eclampsia. Methods: In this parallel-group, non-masked, multicentre, randomised controlled trial done in 46 maternity units across England and Wales, we compared planned delivery versus expectant management (usual care) with individual randomisation in women with late preterm pre-eclampsia from 34 to less than 37 weeks' gestation and a singleton or dichorionic diamniotic twin pregnancy. The co-primary maternal outcome was a composite of maternal morbidity or recorded systolic blood pressure of at least 160 mm Hg with a superiority hypothesis. The co-primary perinatal outcome was a composite of perinatal deaths or neonatal unit admission up to infant hospital discharge with a non-inferiority hypothesis (non-inferiority margin of 10% difference in incidence). Analyses were by intention to treat, together with a per-protocol analysis for the perinatal outcome. The trial was prospectively registered with the ISRCTN registry, ISRCTN01879376. The trial is closed to recruitment but follow-up is ongoing. Findings: Between Sept 29, 2014, and Dec 10, 2018, 901 women were recruited. 450 women (448 women and 471 infants analysed) were allocated to planned delivery and 451 women (451 women and 475 infants analysed) to expectant management. The incidence of the co-primary maternal outcome was significantly lower in the planned delivery group (289 [65%] women) compared with the expectant management group (338 [75%] women; adjusted relative risk 0·86, 95% CI 0·79–0·94; p=0·0005). The incidence of the co-primary perinatal outcome by intention to treat was significantly higher in the planned delivery group (196 [42%] infants) compared with the expectant management group (159 [34%] infants; 1·26, 1·08–1·47; p=0·0034). The results from the per-protocol analysis were similar. There were nine serious adverse events in the planned delivery group and 12 in the expectant management group. Interpretation: There is strong evidence to suggest that planned delivery reduces maternal morbidity and severe hypertension compared with expectant management, with more neonatal unit admissions related to prematurity but no indicators of greater neonatal morbidity. This trade-off should be discussed with women with late preterm pre-eclampsia to allow shared decision making on timing of delivery. Funding: National Institute for Health Research Health Technology Assessment Programme

Downstream channel changes on a contracting, anabranching river: The Lachlan, southeastern Australia

Downstream trends in flow, channel morphology, and sediments were investigated over 220 km of the middle and upper alluvial Lachlan River in southeastern Australia. The Lachlan is a perennial river that rises from temperate, humid highlands and flows inland into a semiarid low gradient plain lacking perennial tributaries. Long daily stage records were used to calculate flow parameters and flood frequencies in single and anabranching channel reaches of the river. Morphological trends were based on cross section and height data compiled from new and water authority data, and from particle size trends constructed from bed and bank sediment samples. Mean and peak flows, channel size, and bed particle size all diminish in a downstream direction. In the partially confined piedmont zone, channel and floodplain morphology feature large flood effects and large channel dimensions that reflect extreme flow variability. On the alluvial plains, the unconfined, single-channel contracts with distance downvalley; and anabranches develop at high flow stages. The development of a full anabranching pattern is associated with large flood volume losses. Diminishing flood volumes, mean flows, and channel dimensions is attributed to storage of flood waters in lakes, floodways, and lagoons and through transmission losses during overbank flows. The frequency of bankfull discharge consistently decreases downstream, and may reflect the long duration and lower frequency of floods in the lower reaches of the river. Particle size of bed sediment fines downstream at rates consistent with those reported from sand-bed rivers elsewhere. This is attributed to a combination of hydraulic sorting and low rates of sediment supply from the catchment

Flood channel morphology of a quiet river, the Lachlan downstream from Cowra, southeastern Australia

Detailed geomorphic mapping and sediment analyses of floodplain features were undertaken on a 30-km reach of the Lachlan River in southeastern Australia. The reach is located in the transitional zone between the southern Great Dividing Range and extensive alluvial plains to the west. The channel resembles other fine-grained, low-energy, alluvial channels; it is muddy, narrow and deep, and meanders irregularly. It contains fine-grained accreting bench deposits, and, in places, is influenced by inherited fluvial forms, both of which indicate long-term channel stability. By contrast, the floodplain exhibits features that have been attributed elsewhere to catastrophic flood flows, including elliptical scour scars ("swirl pits"), cobble and gravel deposits, large chutes and chute bars, zones of floodplain stripping, flood levees and multiple flood channels. Sorting and texture of floodplain sediments generally increases with height above the bed, although deposits are variable and poorly sorted. Indications of recent fluvial activity at several levels above the bed are confirmed by aerial photographs dating from 1954, although changes to the channel position have been small. The alluvial facies model displays a compound floodplain, in which a stable, low-energy channel is inset within a high-energy, flood-dominated floodplain. This interpretation is consistent with streamflow and documentary evidence of recurrent large floods since 1839, which have a return period of <10 years on both the partial and annual series. Natural streamflow is characterised by high annual variability and a steep flood growth curve. In such systems, flow variability, together with stream power and sediment characteristics, appears to be an important determinant of floodplain type