Humpty Doo Rice Project

The planting of the wet season crop was under way when we arrived and I was allocated the job of carting the rice seed from the mill at the 18 mile (now Coolalinga) to the rice fields. The truck was an S181 International with an Eaton 2 speed axle. It was my pride and joy. The mill manager was Peter van Ryan and his off sider Bob Stewart, Peter was a big man and Bob was small and wiry and we didn't have any elevators to lift the bags so it was all done by hand. I did 2 loads a day for weeks and enjoyed every minute of it. The road from the Stuart Highway was gravel and often corragated, not like the bitumen road that is now the Arnhem highway. Shortly after my arrival, Arthur Parker and I went into Darwin in the Big truck to pick up supplies and we went to the motor registry in Bennett Street so I could get my truck licence. It was situated where the tourist bureau is now, The Police Station was situated opposite. Whilst in town I went to the camera shop and bought an Agfa colour slide camera. It had a hard case and I was able to take it with me while working. After the planting was completed, I was allocated the job of driving the Alice Chalmers Road grader maintaining all the roads on the lease from where the Electricity sub station is now situated. Most days I would take my camera with me on the grader and when I came across an item of interest. I also would go out on my motor scooter on Saturdays and photograph things of interest Saturday was our one day off and the company ran a bus into Darwin for shoppers and back in the afternoon and again in the evening for the pictures.Lee, Beverle

Accounting for uncertainty in volumes of seabed change measured with repeat multibeam sonar surveys

Seafloors of unconsolidated sediment are highly dynamic features; eroding or accumulating under the action of tides, waves and currents. Assessing which areas of the seafloor experienced change and measuring the corresponding volumes involved provide insights into these important active sedimentation processes. Computing the difference between Digital Elevation Models (DEMs) obtained from repeat Multibeam Echosounders (MBES) surveys has become a common technique to identify these areas, but the uncertainty in these datasets considerably affects the estimation of the volumes displaced. The two main techniques used to take into account uncertainty in volume estimations are the limitation of calculations to areas experiencing a change in depth beyond a chosen threshold, and the computation of volumetric confidence intervals. However, these techniques are still in their infancy and, as a result, are often crude, seldom used or poorly understood. In this article, we explored a number of possible methodological advances to address this issue, including: (1) using the uncertainty information provided by the MBES data processing algorithm CUBE, (2) adapting fluvial geomorphology techniques for volume calculations using spatially variable thresholds and (3) volumetric histograms. The nearshore seabed off Warrnambool harbour - located in the highly energetic southwest Victorian coast, Australia - was used as a test site. Four consecutive MBES surveys were carried out over a four-months period. The difference between consecutive DEMs revealed an area near the beach experiencing large sediment transfers - mostly erosion - and an area of reef experiencing increasing deposition from the advance of a nearby sediment sheet. The volumes of sediment displaced in these two areas were calculated using the techniques described above, both traditionally and using the suggested improvements. We compared the results and discussed the applicability of the new methodological improvements. We found that the spatially variable uncertainty derived from the CUBE algorithm provided the best results (i.e. smaller confidence intervals), but that similar results can be obtained using as a fixed uncertainty value derived from a reference area under a number of operational conditions

The interaction of temperature and light on yield and berry composition of Vitis vinifera 'Shiraz' under field conditions

During the growing season, both temperature and light intensity have major impact on plant growth and development. However, the probability of the incidence of high temperatures and/or heat events is likely to increase and become a significant phenomenon in Australian viticulture in the future because of potential climate change. During heat events, high temperature is likely to be exacerbated by the addition of high light intensity or radiant energy/heat which is already a characteristic feature in some Australian vineyards at present and it is expected to continue into the future. Despite its importance, there are few studies on the interactive effects of photon flux densities and temperature of the radiant load on grapevine physiology. This study quantified the impact of temperature and light on grape yield, sugar content and sugar accumulation. We have used Vitis vinifera 'Shiraz' in the field over two seasons under four different light intensities using shade cloth of variable densities. Yield was reduced by 22-40% under the lowest light intensity. Berry sugar content was reduced by 13% under the lowest light intensity in the cooler season (2012-13) and increased by 13% under the highest light intensity in vines exposed to a natural heat event (2013-14 season). Further, sugar accumulation rate declined by 7.7-11.4 mg berry-1 day-1 under the high light intensities. This study has showed that lowest light intensity was a cost for the yield and sugar content during cooler conditions. However, sugar content and sugar accumulation rate under the high light were lower in the warmer conditions