Journal articles on the topic 'Rain and rainfall Victoria'
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1
Holland, J. E., T. H. Johnston, R. E. White, and B. A. Orchard. "An investigation of runoff from raised beds and other tillage methods in the high rainfall zone of south-western Victoria, Australia." Soil Research 50, no. 5 (2012): 371. http://dx.doi.org/10.1071/sr11200.
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For many years, the poor physical and hydraulic properties of the soils in south-western Victoria have restricted crop production due to waterlogging. In this region of predominantly winter rainfall, raised beds have become popular with farmers to overcome these difficulties; however, little has been reported on the hydrology of raised beds compared with other tillage systems for cropping in the rain-fed environment of south-western Victoria. This study measured rainfall characteristics, runoff volumes, and soil properties such as the soil water content, bulk density, and hydraulic conductivity for three tillage treatments (raised beds, conventional cultivation, and deep cultivation) over 6 years on a Sodosol at a field site near Geelong, Victoria. Runoff was regressed against rainfall variables such as the amount per event, hours of rainfall, rainfall intensity, and maximum rainfall intensity to determine the significance of any differences between the treatments. The relationship between runoff and rainfall amount was best described with an exponential model. Raised beds significantly increased the amount of runoff relative to the other treatments when above-average rainfall was received, but there was little difference in runoff in years of below-average rainfall. No consistent effect of runoff on crop biomass was detected nor could any differences in runoff be attributed to differences in soil water content, hydraulic conductivity, and bulk density between treatments. The most important factor appeared to be the furrows between the raised beds, which acted as conduits for the flow of surface water during the larger storm events. During such events, runoff is an important hydrological process in cropping land in south-western Victoria.
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Cullen, B. R., R. P. Rawnsley, R. J. Eckard, K. M. Christie, and M. J. Bell. "Use of modelling to identify perennial ryegrass plant traits for future warmer and drier climates." Crop and Pasture Science 65, no. 8 (2014): 758. http://dx.doi.org/10.1071/cp13408.
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Potential exists to select pasture species better adapted to anticipated warmer temperatures and lower rainfall, associated with increasing atmospheric carbon dioxide (CO2) and other greenhouse gas concentrations, to maximise pasture yields and persistence. This study assessed the effect of increasing three plant traits in perennial ryegrass (Lolium perenne L.) to adapt to future climates: root depth; heat tolerance, defined as the ability of plant to grow at high temperatures; and responsiveness to elevated CO2 concentrations. Pasture production was simulated using the Sustainable Grazing Systems Pasture model at three sites with temperate climates in south-eastern Australia: Hamilton, Victoria (medium rainfall); Ellinbank, Victoria (high rainfall); and Elliott, Tasmania (high rainfall). Two future climate scenarios were created at each site by scaling the historical climate (1971–2010) by +1°C with –10% rain (435 ppm CO2) and +2°C with –20% rain (535 ppm CO2). A genotype × environment interaction suggested that the plants traits most effective at increasing pasture yield differed depending on the local climate. Increased root depth was the most effective change in a single trait that increased pasture harvested at Elliott, increased heat tolerance was most effective at Ellinbank, whereas increasing all three individual traits was similarly effective at Hamilton. At each site, the most effective traits increased pasture growth during the period between late spring and mid-summer compared with the current cultivar. When all three traits were increased at the same time, the pasture production advantage was greater than the additive effects of changing single traits at Hamilton and Ellinbank. Further consideration of the feasibility of selecting multiple traits and the effects of a broader range of climate projections is required. Nonetheless, results of this study provide guidance to plant breeders for selection of traits adapted to future climates.
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Adhikary, Sajal Kumar, Nitin Muttil, and Abdullah Gokhan Yilmaz. "Improving streamflow forecast using optimal rain gauge network-based input to artificial neural network models." Hydrology Research 49, no. 5 (December 5, 2017): 1559–77. http://dx.doi.org/10.2166/nh.2017.108.
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Abstract Accurate streamflow forecasting is of great importance for the effective management of water resources systems. In this study, an improved streamflow forecasting approach using the optimal rain gauge network-based input to artificial neural network (ANN) models is proposed and demonstrated through a case study (the Middle Yarra River catchment in Victoria, Australia). First, the optimal rain gauge network is established based on the current rain gauge network in the catchment. Rainfall data from the optimal and current rain gauge networks together with streamflow observations are used as the input to train the ANN. Then, the best subset of significant input variables relating to streamflow at the catchment outlet is identified by the trained ANN. Finally, one-day-ahead streamflow forecasting is carried out using ANN models formulated based on the selected input variables for each rain gauge network. The results indicate that the optimal rain gauge network-based input to ANN models gives the best streamflow forecasting results for the training, validation and testing phases in terms of various performance evaluation measures. Overall, the study concludes that the proposed approach is highly effective to achieve the enhanced streamflow forecasting and could be a viable option for streamflow forecasting in other catchments.
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Sivapragasam, Chandrasekaran, Poomalai Saravanan, Saminathan Balamurali, and Nitin Muttil. "Ascertaining Time Series Predictability in Process Control – Case Study on Rainfall Prediction." MATEC Web of Conferences 203 (2018): 07002. http://dx.doi.org/10.1051/matecconf/201820307002.
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Rainfall prediction is a challenging task due to its dependency on many natural phenomenon. Some authors used Hurst exponent as a predictability indicator to ensure predictability of the time series before prediction. In this paper, a detailed analysis has been done to ascertain whether a definite relation exists between a strong Hurst exponent and predictability. The one-lead monthly rainfall prediction has been done for 19 rain gauge station of the Yarra river basin in Victoria, Australia using Artificial Neural Network. The prediction error in terms of normalized Root Mean Squared Error has been compared with Hurst exponent. The study establishes the truth of the hypothesis for only 6 stations out of 19 stations, and thus recommends further investigation to prove the hypothesis. This concept is relevant for any time series which need to be used for real time process control.
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Broecker, Wallace S., Dorothy Peteet, Irena Hajdas, Jo Lin, and Elizabeth Clark. "Antiphasing between Rainfall in Africa's Rift Valley and North America's Great Basin." Quaternary Research 50, no. 1 (July 1998): 12–20. http://dx.doi.org/10.1006/qres.1998.1973.
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The beginning of the Bølling-Allerød warm period was marked in Greenland ice by an abrupt rise in δ18O, an abrupt drop in dust rain, and an abrupt increase in atmospheric methane content. The surface waters in the Norwegian Sea underwent a simultaneous abrupt warming. At about this time, a major change in the pattern of global rainfall occurred. Lake Victoria (latitude 0°), which prior to this time was dry, was rejuvenated. The Red Sea, which prior to this time was hypersaline, freshened. Lake Lahontan, which prior to this time had achieved its largest size, desiccated. Whereas the chronologic support for the abruptness of the hydrologic changes is firm only for the Red Sea, in keeping with evidence obtained well away from the northern Atlantic in the Santa Barbara Basin and the Cariaco Trench, the onset and end of the millennial-duration climate events were globally abrupt. If so, the proposed linkage between the size of African closed basin lakes and insolation cycles must be reexamined.
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Onyango, Augustine O., Haiming Xu, and Zhaohui Lin. "Diurnal cycle of rainfall over Lake Victoria Basin during the long‐rain season based on TRMM satellite estimate." International Journal of Climatology 40, no. 10 (January 29, 2020): 4622–37. http://dx.doi.org/10.1002/joc.6479.
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Villalta, O. N., W. S. Washington, G. M. Rimmington, and W. E. MacHardy. "Environmental factors influencing maturation and release of ascospores of Venturia pirina in Victoria, Australia." Australian Journal of Agricultural Research 52, no. 8 (2001): 825. http://dx.doi.org/10.1071/ar00093.
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The influence of moisture, light, and temperature on Venturia pirina ascospore maturation and discharge was studied during 1992–99 in 2 pear-growing regions in Victoria. In each year and site, mature ascospores were trapped over a 3-month period beginning a few days before or at the green-tip stage of pear tree development in early September and ending in late November, with the majority of ascospores ((>80%) trapped between green-tip and petal-fall. Ascospore discharge was associated with rain and dew, with 90–98% of the season’s total number of ascospores trapped during rain events and 2–10% trapped during dew events in the 12 data sets examined. Most ascospores were trapped (82.5– 99.9%) during daytime (0600–1800 hours). The 0.1–17.5% of ascospores detected during night time (1900–0500 hours) were trapped mainly within 1–3 h of dawn or dusk. There were linear relationships between the logit of cumulative percentage of ascospore maturation and temperature accumulation (above 0 degree-days), calculated both daily and for days with >= 0.2 mm of rainfall. Six linear regression equations were formulated with 10 years of field data and using the 2 methods of accumulating degree-days, to predict the cumulative percentage of matured ascospores. Predictions were compared with additional field and laboratory observations not used in the formulation of the linear equations. The importance of the temperature-based linear equations is discussed in relation to the prediction of pear scab ascospore maturity for use in a pear scab management program.
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Myers, BA, DH Ashton, and JA Osborne. "The Ecology of the Mallee Outlier of Eucalyptus behriana F. Muell. Near Melton, Victoria." Australian Journal of Botany 34, no. 1 (1986): 15. http://dx.doi.org/10.1071/bt9860015.
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An outlier of mallee vegetation occurs south of the Great Dividing Range in Victoria in a rain shadow region (annual rainfall approx. 500 mm) about 50 km west of Melbourne. A Eucalyptus behriana open-scrub with a sparse understorey of chenopods, mosses, lichens and some grasses occurs on solonetz soil on lateritized Tertiary sandy clays and on skeletal soils on Ordovician slates and sandstones. The dryness of the mallee site is probably exacerbated by the smaller rate of water infiltration and greater salinity of the solonetz soil under E. behriana compared with the solodic soil, in the moister area further north, under an open-forest of E. microcarpa. The multistemmed habit of E. behriana appears to be partly genetically fixed. Hollow lignotuberous rings, filled to a depth of about 15-25 cm with brown, nutrient-rich humus, are common. Pattern analysis of the distribution of stems of E. behriana indicated strong clumping at about 9 m², due to the multistemmed habit, and weaker clumping at about 600 m², which correlated with the size of groups of dense, spindly individuals of E. behriana, resulting from a past phase of gap regeneration.
9
Khan, S. I., P. Adhikari, Y. Hong, H. Vergara, T. Grout, R. F. Adler, F. Policelli, D. Irwin, T. Korme, and L. Okello. "Observed and simulated hydroclimatology using distributed hydrologic model from in-situ and multi-satellite remote sensing datasets in Lake Victoria region in East Africa." Hydrology and Earth System Sciences Discussions 7, no. 4 (July 22, 2010): 4785–816. http://dx.doi.org/10.5194/hessd-7-4785-2010.
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Abstract. Floods and droughts are common, recurring natural hazards in East African nations. Studies of hydro-climatology at daily, seasonal, and annual time scale is an important in understanding and ultimately minimizing the impacts of such hazards. Using daily in-situ data over the last two decades combined with the recently available multiple-years satellite remote sensing data, we analyzed and simulated, with a distributed hydrologic model, the hydro-climatology in Nzoia, one of the major contributing sub-basins of Lake Victoria in the East African highlands. The basin, with a semi arid climate, has no sustained base flow contribution to Lake Victoria. The short spell of high discharge showed that rain is the prime cause of floods in the basin. There is only a marginal increase in annual mean discharge over the last 21 years. The 2-, 5- and 10-year peak discharges, for the entire study period showed that more years since the mid 1990's have had high peak discharges despite having relatively less annual rain. The study also presents the hydrologic model calibration and validation results over the Nzoia Basin. The spatiotemporal variability of the water cycle components were quantified using a physically-based, distributed hydrologic model, with in-situ and multi-satellite remote sensing datasets. Moreover, the hydrologic capability of remote sensing data such as TRMM-3B42V6 was tested in terms of reconstruction of the water cycle components. The spatial distribution and time series of modeling results for precipitation (P), evapotranspiration (ET), and change in storage (dS/dt) showed considerable agreement with the monthly model runoff estimates and gauge observations. Runoff values responded to precipitation events that occurred across the catchment during the wet season from March to early June. The hydrologic model captured the spatial variability of the soil moisture storage. The spatially distributed model inputs, states, and outputs, were found to be useful for understanding the hydrologic behavior at the catchment scale. Relatively high flows were experienced near the basin outlet from previous rainfall, with a new flood peak responding to the rainfall in the upper part of the basin. The monthly peak runoff was observed in the months of April, May and November. The analysis revealed a linear relationship between rainfall and runoff for both wet and dry seasons. The model was found to be useful in poorly gauged catchments using satellite forcing data and showed the potential to be used not only for the investigation of the catchment scale water balance but also for addressing issues pertaining to sustainability of the resources within the catchment.
10
Armstrong, D. P., K. A. Tarrant, C. K. M. Ho, L. R. Malcolm, and W. J. Wales. "Evaluating development options for a rain-fed dairy farm in Gippsland." Animal Production Science 50, no. 6 (2010): 363. http://dx.doi.org/10.1071/an10009.
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A case study and modelling approach was used to examine options for a dairy farm in the high rainfall area of Gippsland (southern Victoria) that would enable it to maintain or increase profit in the future (next 5–10 years) in the face of a continuing ‘cost-price squeeze’. The economic performance of the business under a range of development options, identified by an ‘expert panel’, was analysed for a planning period of 10 years. The options analysed were: (i) increased herd size without purchasing more land, (ii) increased milking area and (iii) purchasing non-milking area for production of conserved fodder. Expanding the milking area by purchasing more land without significantly increasing herd size (reducing stocking rate from 2.5 to 2.1 cows/ha) increased annual operating profit without increasing variability in profit between years compared with the base farm. The increased profit resulted from a reduction in the amount of purchased feed. The purchase of an additional outblock for fodder production reduced risk compared with the base farm system, but did not improve the profitability of the farm system. Other options significantly reduced profit while increasing risk. The most appropriate changes to dairy farm businesses in response to changes in the operating environment will vary from farm to farm. The analysis suggested that there may be an alternate path to the historical trends of larger and more intensive operations. It has also highlighted the importance of home-grown feed and efficient supplement use to increase or maintain profitability in the medium term.
11
Whisson, Desley A., Freya McKinnon, Matthew Lefoe, and Anthony R. Rendall. "Passive acoustic monitoring for detecting the Yellow-bellied Glider, a highly vocal arboreal marsupial." PLOS ONE 16, no. 5 (May 25, 2021): e0252092. http://dx.doi.org/10.1371/journal.pone.0252092.
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Passive acoustic monitoring (PAM) is increasingly being used for the survey of vocalising wildlife species that are otherwise cryptic and difficult to survey. Our study aimed to develop PAM guidelines for detecting the Yellow-bellied Glider, a highly vocal arboreal marsupial that occurs in native Eucalyptus forests in eastern and south-eastern Australia. To achieve this, we considered the influence of background noise, weather conditions, lunar illumination, time since sunset and season on the probability of detecting vocalisations. We deployed Autonomous Recording Units (ARUs) at 43 sites in the Central Highlands of Victoria during two periods: spring/summer (October 2018 to January 2019), and autumn/winter (May to August 2019). ARUs were programmed to record for 11 hours from sunset for 14 consecutive days during each period. Background noise resulted from inclement weather (wind and rain) and masked vocalisations in spectrograms of the recordings, thus having the greatest influence on detection probability. Vocalisations were most common in the four hours after sunset. Rainfall negatively influenced detection probability, especially during the autumn/winter sampling period. Detection of Yellow-bellied Gliders with PAM requires deploying ARUs programmed to record for four hours after sunset, for a minimum of six nights with minimal inclement weather (light or no wind or rain). The survey period should be extended to 12 nights when rain or wind are forecast. Because PAM is less labour intensive than active surveys (i.e., spotlighting and call playbacks with multiple observers and several nights’ survey per site), its use will facilitate broad-scale surveys for Yellow-bellied Gliders.
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Vines, R. G. "Australian rainfall patterns and the southern oscillation. 2. A regional perspective in relation to Luni-solar (Mn) and Solar-cycle (Sc) signals." Rangeland Journal 30, no. 3 (2008): 349. http://dx.doi.org/10.1071/rj07025.
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This investigation is an extension of earlier work on rainfall patterns in eastern Australia. Using district averages rather than rainfall data for individual cities or towns, further evidence is provided for cyclic variations in precipitation with periods of 18–19, 10–11 and 6–7 years. Results from various regional areas in western Queensland and western New South Wales differ from those found further south in Victoria, and connections are suggested between El Niño/southern oscillation events and the incidence of drought in these two separate areas. Such findings are consistent with ecological aspects of the quasi-periodic occurrence of bushfire seasons as observed in both Victorian eucalypt forests after prolonged drought, or after intermittent widespread rains in the semi-arid Mallee rangelands of western New South Wales. The ~19-year cycles may be at least partly a reflection of solar and lunar tidal components and the ~11-year cycles (connected with the Sunspot cycle) could be the result of absorption of short wavelength solar emissions in the stratosphere and resultant photochemical events magnified to produce sea surface temperature changes. The ~19-year cycles are apparently associated with either increased or decreased rainfall, and such connections appear to reverse in parts of Australia about every 100 years. These reversals have been associated with major droughts at the end of the 19th and 20th centuries.
13
Khan, S. I., P. Adhikari, Y. Hong, H. Vergara, R. F Adler, F. Policelli, D. Irwin, T. Korme, and L. Okello. "Hydroclimatology of Lake Victoria region using hydrologic model and satellite remote sensing data." Hydrology and Earth System Sciences 15, no. 1 (January 14, 2011): 107–17. http://dx.doi.org/10.5194/hess-15-107-2011.
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Abstract. Study of hydro-climatology at a range of temporal scales is important in understanding and ultimately mitigating the potential severe impacts of hydrological extreme events such as floods and droughts. Using daily in-situ data over the last two decades combined with the recently available multiple-years satellite remote sensing data, we analyzed and simulated, with a distributed hydrologic model, the hydro-climatology in Nzoia, one of the major contributing sub-basins of Lake Victoria in the East African highlands. The basin, with a semi arid climate, has no sustained base flow contribution to Lake Victoria. The short spell of high discharge showed that rain is the prime cause of floods in the basin. There is only a marginal increase in annual mean discharge over the last 21 years. The 2-, 5- and 10- year peak discharges, for the entire study period showed that more years since the mid 1990's have had high peak discharges despite having relatively less annual rain. The study also presents the hydrologic model calibration and validation results over the Nzoia basin. The spatiotemporal variability of the water cycle components were quantified using a hydrologic model, with in-situ and multi-satellite remote sensing datasets. The model is calibrated using daily observed discharge data for the period between 1985 and 1999, for which model performance is estimated with a Nash Sutcliffe Efficiency (NSCE) of 0.87 and 0.23% bias. The model validation showed an error metrics with NSCE of 0.65 and 1.04% bias. Moreover, the hydrologic capability of satellite precipitation (TRMM-3B42 V6) is evaluated. In terms of reconstruction of the water cycle components the spatial distribution and time series of modeling results for precipitation and runoff showed considerable agreement with the monthly model runoff estimates and gauge observations. Runoff values responded to precipitation events that occurred across the catchment during the wet season from March to early June. The spatially distributed model inputs, states, and outputs, were found to be useful for understanding the hydrologic behavior at the catchment scale. The monthly peak runoff is observed in the months of April, May and November. The analysis revealed a linear relationship between rainfall and runoff for both wet and dry seasons. Satellite precipitation forcing data showed the potential to be used not only for the investigation of water balance but also for addressing issues pertaining to sustainability of the resources at the catchment scale.
14
Gudoshava, Masilin, and Fredrick H. M. Semazzi. "Customization and Validation of a Regional Climate Model Using Satellite Data Over East Africa." Atmosphere 10, no. 6 (June 10, 2019): 317. http://dx.doi.org/10.3390/atmos10060317.
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This study focused on the customization of the fourth generation International Center for Theoretical Physics Regional Climate Model version 4.4 and its ability to reproduce the mean climate and most dominant modes of variability over East Africa. The simulations were performed at a spatial resolution of 25 km for the period 1998–2013. The model was driven by ERA-Interim reanalysis. The customization focus was on cumulus and microphysics schemes during the Short Rains for the year 2000. The best physics combinations were then utilized for the validation studies. The East Africa region and Lake Victoria Basin region are adapted to carry out empirical orthogonal function analysis, during the Short and Long Rains. Tropical Rainfall Measuring Mission data was utilized in the validation of the model. The first mode of variability from the model and observational data during the Short Rains was associated with the warming of the Pacific Ocean and the sea surface temperature gradients over the Indian Ocean. During the Long rains, the inter-annual rainfall variability over the Lake Victoria region was associated with the sea surface temperature anomaly over the Indian Ocean and for the East Africa region the associations were weak. The drivers during the Long Rains over East Africa region were then further investigated by splitting the season to the March–April and May periods. The March–April period was positively correlated to the West Pacific and Indian Ocean dipole index, while May was associated with the Quasi-Biennial Oscillation. In conclusion, although the model can reproduce the dominant modes of variability as in the observational data sets during the Short Rains, skill was lower during the Long Rains.
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Young, Kathy L., W. Robert Bolton, Ånund Killingtveit, and Daqing Yang. "Assessment of precipitation and snowcover in northern research basins*." Hydrology Research 37, no. 4-5 (August 1, 2006): 377–91. http://dx.doi.org/10.2166/nh.2006.021.
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In 2004, a workshop was held to collect and synthesize the water balance data from 39 northern research basins (NRB) in Victoria, BC, Canada. One of the recommendations from the meeting was a need to review systematically each component of the water balance for these northern basins in order to identify spatial and temporal trends and to address significant knowledge gaps. Here, we assess the methodologies for measuring snow and rain in these northern basins; examine the temporal and spatial patterns of snow accumulation both during and at the end-of-the winter; consider ablation patterns and comment on the occurrence of extreme events. Our evaluation indicates that northern hydrologists still employ a variety of gauges and approaches to both measure and correct precipitation. For the NRB, rainfall contributions dominate in lower latitudes while snowfall gains importance with higher latitudes and altitude. Occurrence of large water bodies, topography (i.e. aspect, slope) and vegetation influence precipitation amount and its distribution across the landscape. Only two NRB studies showed a declining trend in snowcover (SWE). Snow is still considered the most important input of water in these northern basins, but extreme summer precipitation events (both rain and snow) have triggered higher magnitude floods than seasonal snowmelt runoff. Glacierized basins are sensitive to summer snowfalls and low winter snow storage. Both have the potential to dampen or enhance melting despite warmer or cooler air temperatures. Standardized gauges, approaches and continued monitoring of the NRB is encouraged.
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Nuttall, J. G., G. J. O'Leary, N. Khimashia, S. Asseng, G. Fitzgerald, and R. Norton. "‘Haying-off' in wheat is predicted to increase under a future climate in south-eastern Australia." Crop and Pasture Science 63, no. 7 (2012): 593. http://dx.doi.org/10.1071/cp12062.
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Under a future climate for south-eastern Australia there is the likelihood that the net effect of elevated CO2, (eCO2) lower growing-season rainfall and high temperature will increase haying-off thus limit production of rain-fed wheat crops. We used a modelling approach to assess the impact of an expected future climate on wheat growth across four cropping regions in Victoria. A wheat model, APSIM-Nwheat, was performance tested against three datasets: (i) a field experiment at Wagga Wagga, NSW; (ii) the Australian Grains Free Air Carbon dioxide Enrichment (AGFACE) experiment at Horsham, Victoria; and (iii) a broad-acre wheat crop survey in western Victoria. For down-scaled climate predictions for 2050, average rainfall during October, which coincides with crop flowering, decreased by 32, 29, 26, and 18% for the semiarid regions of the northern Mallee, the southern Mallee, Wimmera, and higher rainfall zone, (HRZ) in the Western District, respectively. Mean annual minimum and maximum temperature over the four regions increased by 1.9 and 2.2°C, respectively. A pair-wise comparison of the yield/anthesis biomass ratio across climate scenarios, used for assessing haying-off response, revealed that there was a 39, 49 and 47% increase in frequency of haying-off for the northern Mallee, southern Mallee and Wimmera, respectively, when crops were sown near the historically optimal time (1 June). This translated to a reduction in yield from 1.6 to 1.4 t/ha (northern Mallee), 2.5 to 2.2 t/ha (southern Mallee) and 3.7 to 3.6 t/ha (Wimmera) under a future climate. Sowing earlier (1 May) reduced the impact of a future climate on haying-off where decreases in yield/anthesis biomass ratio were 24, 28 and 23% for the respective regions. Heavy textured soils exacerbated the impact of a future climate on haying-off within the Wimmera. Within the HRZ of the Western District crops were not water limited during grain filling, so no evidence of haying-off existed where average crop yields increased by 5% under a future climate (6.4–6.7 t/ha). The simulated effect of eCO2 alone (FACE conditions) increased average yields from 18 to 38% for the semiarid regions but not in the HRZ and there was no evidence of haying-off. For a future climate, sowing earlier limited the impact of hotter, drier conditions by reducing pre-anthesis plant growth, grain set and resource depletion and shifted the grain-filling phase earlier, which reduced the impact of future drier conditions in spring. Overall, earlier sowing in a Mediterranean-type environment appears to be an important management strategy for maintaining wheat production in semiarid cropping regions into the future, although this has to be balanced with other agronomic considerations such as frost risk and weed control.
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Hunt, J. R., C. Browne, T. M. McBeath, K. Verburg, S. Craig, and A. M. Whitbread. "Summer fallow weed control and residue management impacts on winter crop yield though soil water and N accumulation in a winter-dominant, low rainfall region of southern Australia." Crop and Pasture Science 64, no. 9 (2013): 922. http://dx.doi.org/10.1071/cp13237.
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The majority of rain used by winter grain crops in the Mallee region of Victoria, Australia, falls during the cooler months of the year (April–October). However, rain falling during the summer fallow period (November–March) and stored as soil moisture contributes to grain yield. Strategies to better capture and store summer fallow rain include (i) retention of crop residues on the soil surface to improve water infiltration and evaporation; and (ii) chemical or mechanical control of summer fallow weeds to reduce transpiration. Despite the widespread adoption of no-till farming systems in the region, few published studies have considered the benefits of residue management during the summer fallow relative to weed control, and none quantify the impacts or identify the mechanisms by which summer fallow weeds influence subsequent crop yield. Over 3 years (2009–11), identical experiments on adjacent sand and clay soil types at Hopetoun in the southern Mallee were conducted to quantify the effect of residue management (standing, removed, or slashed) and summer fallow weed control (± chemical control) compared with cultivation on soil water and nitrogen (N) accumulation and subsequent crop yield. The presence of residue (2.4–5.8 t/ha) had no effect on soil water accumulation and a small negative effect on grain yield on the clay soil in 2011. Controlling summer weeds (Heliotropium europaeum and volunteer crop species) increased soil water accumulation (mean 45 mm) and mineral N (mean 45 kg/ha) before sowing on both soil types in 2 years of the experiment with significant amounts of summer fallow rain (2010 and 2011). Control of summer weeds increased grain yield of canola by 0.6 t/ha in 2010 and wheat by 1.4 t/ha in 2011. Using the data from these experiments to parameterise the APSIM model, simulation of selected treatments using historical climate data (1958–2011) showed that an extra 40 mm of stored soil water resulted in an average additional 0.4 t/ha yield, most of which was achieved in dry growing seasons. An additional 40 kg/ha N increased yield only in wetter growing seasons (mean 0.4 t/ha on both soil types). The combination of extra water and N that was found experimentally to result from control of summer fallow weeds increased subsequent crop yield in all season types (mean 0.7 t/ha on sand, 0.9 t/ha on clay). The co-limitation of yield by water and N in the Mallee environment means that yield increases due to summer weed control (and thus returns on investment) are very reliable.
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Tomkins, IB, JD Kellas, KG Tolhurst, and DA Oswin. "Effects of fire intensity on soil chemistry in a eucalypt forest." Soil Research 29, no. 1 (1991): 25. http://dx.doi.org/10.1071/sr9910025.
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Soil samples taken in the Wombat State Forest in Victoria, at depths of 0-2, 2-5, and 5-10 cm before and after burning fuel loads of 0 (unburnt control), 15, 50, 150, and 300 t ha-1 were analysed for pH, exchangeable cations and cation exchange capacity, available and total P, organic carbon and soil moisture, over a 2-year, 2000 mm rainfall period. Short term responses (up to 6 months) occurred in levels of exchangeable NH4+, K+, and Mg2+, and long term changes (2 years or longer) over the period of the study were observed for pH, available and total P and exchangeable ca2+ at the 0-2 cm soil depth for the burnt treatments. Following burning (and 108 mm of rain), changes in soil chemical parameters were strongly correlated with fuel load and the quantity of fuel burnt. Changes through the 0-10 cm profile for the various chemical parameters are described, together with seasonal variations. For similar yellow podzolic soils, measurement of soil pH may be a useful criterion for monitoring soil chemical changes following slash and fuel reduction burning, provided that accurate estimates of fuel loads, composition and amount burnt can be established.
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Mcdonald, G., TR New, and RA Farrow. "Geographical and Temporal Distribution of the Common Armyworm, Mythimna Convecta (Lepidoptera: Noctuidae), in Eastern Australia: Larval Habitats and Outbreaks." Australian Journal of Zoology 43, no. 6 (1995): 601. http://dx.doi.org/10.1071/zo9950601.
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Surveys for juvenile Mythimna convecta throughout the agricultural and arid regions of eastern Australia were conducted from 1986 to 1989. Armyworm populations north of 33 degrees S were generally dominated by M. convecta, and further south by Persectania ewingii. M. convecta was most widely distributed in spring. Incidence during autumn and winter ranged from very low in Victoria to high in northern New South Wales and southern Queensland. Summer infestations were found mostly on the south-east coast where favourable habitats were abundant. Colonised habitats included extremely arid regions, where small numbers of larvae were associated with grasses in temporary watercourses, and the higher-rainfall, eastern regions. The largest infestations occurred in south-east Queensland and north central and north-east New South Wales, particularly after heavy autumn rains. There appeared to be two generations of M. convecta over the autumn/winter period: the first a synchronised event starting on the autumn rains and the second commencing in June/July and comprising a wide spread in age distribution. The progeny of the winter generation are probably the source of most economic outbreaks. Mythimna convecta larvae were collected from subtropical and temperate grasses. In the former, most larvae were found in tussocks, particularly of Dichanthium sericeum and Chloris truncata, which provided a dense, fine-leaf crown and canopy. After good autumn rainfall and vegetative growth, the wiry-stemmed tussocks, including Astrebla spp. and C. ciliaris, were also common hosts. The temperate grasses, particularly Avena fatua and Hordeum leporinum, were the main winter hosts although the greatest densities were found only in thick swards of growth, particularly those that contained dried grass. Two of the largest surveys, in autumn 1987 and 1988, followed periods of heavy rain and provided strongly contrasting results. The 1987 survey of central and south-west Queensland located no M. convecta larvae, indicating that densities were below detection thresholds. The paucity of larvae was attributed to lack of suitable atmospheric conditions to assist moth immigrations and absence of adequate populations in potential source areas. The 1988 survey revealed a major outbreak of M. convecta larvae in south-east Queensland and northern New South Wales. The area received record rains during early April of that year, and the outbreak probably arose from moth migrations from the east and south-east coast. An outbreak of similar scale occurred after further heavy autumn rains in 1989.
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Waller, R. A., and P. W. G. Sale. "Persistence and productivity of perennial ryegrass in sheep pastures in south-western Victoria: a review." Australian Journal of Experimental Agriculture 41, no. 1 (2001): 117. http://dx.doi.org/10.1071/ea00049.
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Loss of perennial ryegrass (Lolium perenne L.) from the pasture within several years of sowing is a common problem in the higher rainfall (550–750 mm annual rainfall), summer-dry regions of south-eastern Australia. This pasture grass came to Australia from northern Europe, where it mostly grows from spring to autumn under mild climatic conditions. In contrast, the summers are generally much drier and hotter in this region of south-eastern Australia. This ‘mismatch’ between genotype and environment may be the fundamental reason for the poor persistence. There is hope that the recently released cultivars, Fitzroy and Avalon, selected and developed from naturalised ryegrass pastures in south-eastern Australia for improved winter growth and persistence will improve the performance of perennial ryegrass in the region. Soon-to-be released cultivars, developed from Mediterranean germplasm, may also bridge the climatic gap between where perennial ryegrass originated and where it is grown in south-eastern Australia. Other factors that influence perennial ryegrass persistence and productivity can be managed to some extent by the landholder. Nutrient status of the soil is important since perennial ryegrass performance improves relative to many other pasture species with increasing nitrogen and phosphorus supply. It appears that high soil exchangeable aluminium levels are also reducing ryegrass performance in parts of the region. The use of lime may resolve problems with high aluminium levels. Weeds that compete with perennial ryegrass become prevalent where bare patches occur in the pasture; they have the opportunity to invade pastures at the opening rains each year. Maintaining some herbage cover over summer and autumn should reduce weed establishment. Diseases of ryegrass are best managed by using resistant cultivars. Insect pests may be best managed by understanding and monitoring their biology to ensure timely application of pesticides and by manipulating herbage mass to alter feed sources and habitat. Grazing management has potential to improve perennial ryegrass performance as frequency and intensity of defoliation affect dry matter production and have been linked to ryegrass persistence, particularly under moisture deficit and high temperature stress. There is some disagreement as to the merit of rotational stocking with sheep, since the results of grazing experiments vary markedly depending on the rotational strategy used, climate, timing of the opening rains, stock class and supplementary feeding policy. We conclude that flexibility of grazing management strategies is important. These strategies should be able to be varied during the year depending on climatic conditions, herbage mass, and plant physiology and stock requirements. Two grazing strategies that show potential are a short rest from grazing the pasture at the opening rains until the pasture has gained some leaf area, in years when the opening rains are late. The second strategy is to allow ryegrass to flower late in the season, preventing new vegetative growth, and perhaps allowing for tiller buds to be preserved in a dormant state over the summer. An extension of this strategy would be to delay grazing until after the ryegrass seed heads have matured and seed has shed from the inflorescences. This has the potential to increase ryegrass density in the following growing season from seedling recruitment. A number of research opportunities have been identified from this review for improving ryegrass persistence. One area would be to investigate the potential for using grazing management to allow late development of ryegrass seed heads to preserve tiller buds in a dormant state over the summer. Another option is to investigate the potential, and subsequently develop grazing procedures, to allow seed maturation and recruitment of ryegrass seedlings after the autumn rains.
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Jacobs, J. L., G. N. Ward, A. M. McDowell, and G. Kearney. "Effect of seedbed cultivation techniques, variety, soil type and sowing time, on brassica dry matter yields, water use efficiency and crop nutritive characteristics in western Victoria." Australian Journal of Experimental Agriculture 42, no. 7 (2002): 945. http://dx.doi.org/10.1071/ea01133.
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Effect of cultivation practice and sowing time on soil moisture retention at sowing, growth rates, dry matter yield, water use efficiency and nutritive characteristics (metabolisable energy, crude protein, neutral detergent fibre, water-soluble carbohydrates and starch) of turnip, pasja and rape was determined on 2 soil types (site A and B) over 2 years. Cultivation treatments were: optimum full inversion, an optimum non-inversion cultivation and over cultivated. At each site, cultivation treatments were imposed at 2 different times (early and late).Results showed few differences in soil moisture at sowing between the 3 cultivation systems. Where seedbeds were prepared earlier rather than later, soil moisture at sowing was higher. Given that there was relatively little difference in soil moisture between cultivation treatments within a sowing time, it is likely that rainfall events may have confounded cultivation effects.Apart from year 2 at site A, the water use efficiency of turnip was higher than for pasja and rape. It is proposed that the lower value in year 2 may be due to root development being retarded by low moisture availability, particularly at the later sowing date, thus leading to a lower dry matter yield.Despite no cultivation effects on soil moisture at sowing, there appeared to be clear advantages for the full inversion technique in terms of subsequent weed germination. Generally, weed numbers post germination were lower for this cultivation method compared with both non-inversion techniques. In conclusion, the cultivation techniques used had little effect on soil moisture at sowing and subsequent dry matter yields, provided the resultant seedbed was well-prepared, fine, firm and weed free. Full inversion cultivation techniques in areas where broad-leaved weeds are a problem may substantially reduce subsequent weed burdens. Early sowing where possible may reduce the likelihood of crop failure through the provision of adequate soil moisture at sowing and increase the incidence of rain during the growing period. Timing of sowing will vary according to paddock requirements during early spring (e.g. grazing or forage conservation), soil type, and trafficability for cultivation.
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Callaghan, Jeff. "A comparison of weather systems in 1870 and 1956 leading to extreme floods in the Murray–Darling Basin." Journal of Southern Hemisphere Earth Systems Science 69, no. 1 (2019): 84. http://dx.doi.org/10.1071/es19003.
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This research is the extension of a project studying the impact of 19th century severe weather events in Australia and their relation to similar events during the 20th and 21st century. Two floods with the worst known impacts in the Murray–Darling Basin (MDB) are studied. One of these events which occurred during 1956 is relativelywell known and the Bureau of Meteorology archives contain good rainfall data covering the period. Additionally, information on the weather systems causing this rainfall can be obtained. Rainfall, flood and weather system data for this event are presented here and compared with a devastating event during 1870. Although archived Australian rainfall data is negligible during 1870 and there is no record of weather systems affecting Australia during that year, a realistic history of the floods and weather systems in the MDB during 1870 is created. This follows an extensive search through newspaper archives contained in the National Library of Australia’s web site. Examples are presented showing how the meteorological data in 19th century newspapers can be used to create weather charts. Six such events in 1870 are demonstrated and three of these had a phenomenal effect on the Murray–Darling system. The 1870 floods followed drought type conditions and it is remarkable that it was worse in many ways than the 1956 event which followed flood conditions in the MDB during the previous year. The events in 1870 caused much loss of life from drowning in the MDB in particular froman east coast low (ECL) in April 1870 and two Victorian weather systems in September and October 1870. In 1956, there were also record-breaking events especially during March when all-time record monthly rainfall were reported in New South Wales. Overall the greatest impact from flooding across the whole MDB was associated with the 1870 flooding. Analyses of heavy rainfall areas in the MDB showed a linear trend increase from 1900 to 2018. Analysing the same data using an 8-year moving average highlighted three peaks around the five highest annual rainfall years. The largest peak occurred around 1950 and 1956, the second largest around 1973 and 1974 and the third around 2010. Each of these 5 years occurred during negative phases of the Interdecadal Pacific Oscillation (IPO) and positive phases of the Southern Oscillation Index (SOI). Studies have shown that the SOI is a climate driver in the MDB along with a persistent blocking high-pressure systems south of Australia along longitude 140°E with a low to its north. Three major blocking events with record rainfall and flooding in the MDB occurred in 1983, 1984 and 1990. Thiswas during the period 1977–1990 when blocking was conducive to heavy rain in the MDB and was coincidentwith a positive phase of the IPO, thus helping conflictwith the IPO–MDB heavy rainfall relationship. Persistent and unexplained middle level westerly winds kept subtropical Queensland clear of tropical cyclones during the negative phases of the IPO from 1999 to 2009 and during the 1960s, influencing low rainfall in the MDB during those periods.
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Ridley, A. M., R. E. White, R. J. Simpson, and L. Callinan. "Water use and drainage under phalaris, cocksfoot, and annual ryegrass pastures." Australian Journal of Agricultural Research 48, no. 7 (1997): 1011. http://dx.doi.org/10.1071/a96157.
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The water balance equation was used to calculate plant water use and drainage below a depth of 1·1 m for phalaris, cocksfoot, and annual ryegrass pastures and bare fallow at Rutherglen in north-eastern Victoria. Rainfall from 1990 to 1993 averaged 693 mm/year. Soil water use was greater under perennials over the summer{autumn period and the soil profile was approximately 50 mm drier at the beginning of each drainage season. Following autumn rains, soil water profiles under all treatments converged, usually reaching similar water contents within 4{6 weeks. Over 4 years, soil under phalaris became 33 mm drier, and cocksfoot 24 mm drier (P < 0· 001), than under annual ryegrass or bare fallow. Phalaris had higher actual evapotranspiration (P < 0·05; average, 642 mm/year) than cocksfoot (619 mm/year) and annual ryegrass (606 mm/year), the latter two not differing significantly. Drainage occurred during winter and early spring, ranging from 2 to 12 mm in 1991 (515 mm rainfall) to >100 mm/year in 1990 and 1992 (671 mm and 901 mm rainfall, respectively). The variation between years was greater than the differences between pastures in any one year. Averaged over the 4 years, drainage losses below 1 .1 m decreased in the order bare fallow > annual ryegrass > cocksfoot > phalaris, although differences between the 3 pasture types were not statistically significant. Drainage under phalaris and cocksfoot may have been overestimated relative to annual ryegrass and fallow because of subsurface flow, at the top of the B horizon, between the wetter and drier plots. The drainage under phalaris may also have been overestimated because this pasture extracted water below the depth of soil water measurement. Allowing for these effects, the estimated drainage under phalaris may have been 49-56 mm/year compared with 80-87 mm/year under annual ryegrass, an overall reduction of more than one-third. Although perennial pasture grasses are unlikely to stop all recharge to groundwater in high rainfall areas (>600 mm/year) of south-eastern Australia, they offer a practical way to combine profitable agriculture with reduced land degradation.
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Evans, P. M., and G. A. Kearney. "Melilotus albus (Medik.) is productive and regenerates well on saline soils of neutral to alkaline reaction in the high rainfall zone of south-western Victoria." Australian Journal of Experimental Agriculture 43, no. 4 (2003): 349. http://dx.doi.org/10.1071/ea02079.
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Dryland salinity is a serious problem in Australia. While some introduced perennial grasses such as tall wheat grass (TWG) Thinopyrum ponticum (Podp. Z.W. Liu & R.R.C. Wang) are adapted to saline soils, there are few pasture legumes that are productive and persistent under saline conditions. Melilotus albus (Medik.) has the potential to be 1 such legume in southern Australia. To test the potential of this species, we conducted 2 experiments over a 3-year period on saline soils at Woorndoo and Glenthompson in south-western Victoria. The soil electrical conductivities (1 : 5 water) of the sites, in autumn before sowing, were 1–3 dS/m at Woorndoo and 3–5 dS/m at Glenthompson (0–10 cm depth).At both sites the herbage yields of 2 Melilotus lines were greater than 10 t/ha of dry matter for the whole season between autumn and late summer. The best commercial control species at Woorndoo, white clover cv. Haifa, produced less than 1/6 of the yield of the best Melilotus line during the summer months. At Glenthompson, during the whole second season the herbage yield of the best Melilotus was 40% greater than that of the best commercial control, Persian clover cv. Nitro plus. In the second season, regeneration of Melilotus at both sites was excellent, averaging 3500 seedlings/m2 at Woorndoo, and 1100 and 3400 seedlings/m2 in mixtures with TWG and in monoculture, respectively at Glenthompson. In the third season, however, regeneration averaged only 400 plants/m2 at Woorndoo and 640 plants/m2 at Glenthompson, both with and without grass. It appears that, when there is limited competition, Melilotus albus dominates in the first 2 years. However, as fertility and water use increase, other pasture species, which initially have a low rate of survival and are unproductive, begin to increase their presence in the sward at the expense of M. albus. These annual species germinate after the autumn rains dilute the salt on the surface of the soil and senesce in early summer as soil water deficits and/or evaporation increase the electrical conductivity again. We suggest that Melilotus albus is an excellent pasture legume to revegetate saline soils in southern Australia and represents an opportunity to obtain high levels of out-of-season pasture production from areas that are currently unproductive.
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Kim, Min-Seong, and Byung Kwon. "Rainfall Detection and Rainfall Rate Estimation Using Microwave Attenuation." Atmosphere 9, no. 8 (July 24, 2018): 287. http://dx.doi.org/10.3390/atmos9080287.
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Eight microwave links operating at frequencies ranging from 6 to 8 GHz and with path lengths ranging from 5.7 to 37.4 km traversing the city of Seoul, Korea are used to detect rainfall and estimate path-averaged rainfall rates. Rainfall detection using rain-induced attenuation (dB) was validated by rain detectors installed at automatic weather stations, and the results confirmed that microwave links can be used to detect rainfall with an accuracy ≥80%. The power-law R-k relationships between rain-induced specific attenuation, k (dB km−1), and the rainfall rate, R (mm h−1), were established and cross-validated by estimating the path-averaged rainfall rate. The mean bias of the path-averaged rainfall rate, as compared to the rainfall rate from ground rain gauges, was between −3 and 1 mm h−1. The improved accuracy of rainfall detection led to the improved accuracy of the path-averaged rainfall rate. Hence, it was confirmed that microwave links, used for broadcasting and media communications, can identify rainy or dry periods (rain spells or dry spells) in a way comparable to rain detectors and provide high time-resolution rainfall rates in real time.
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Khansa, Pavita, Evi Siti Sofiyah, and I. Wayan Koko Suryawan. "Determination of Rain Intensity Based on Rain Characteristics Observed from Rain Observation Stations Around South Jakarta." Journal of Advanced Civil and Environmental Engineering 3, no. 2 (October 15, 2020): 94. http://dx.doi.org/10.30659/jacee.3.2.106-115.
Full textAbstract:
South Jakarta has the highest rainfall concentration and the most flood location in Jakarta. Therefore, an urban drainage system is needed to control surface water so flood can be prevented. This research aims to support the urban drainage system planning by determining rainfall intensity based on three methods, those are Van Breen, Bell Tanimoto, and Hasper der Weduwen. The most suitable method will be selected by comparing the value of rainfall intensity with Talbot, Sherman, and Ishiguro approach. This research reveals that the most suitable method is the Van Breen Method with the Talbot equation. The result of the calculation is rainfall intensity for 2, 5, 10, 25, 50, and 100 years rain return period, with each range 27.2 – 182.8 mm/hour, 36.8-197.6 mm/hour, 43.1-206.3 mm/hour, 51.1-216.6 mm/hour, 57-223.9 mm/hour, and 63-230,8 mm/hour.
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Jiang, Haiyan, Jeffrey B. Halverson, Joanne Simpson, and Edward J. Zipser. "Hurricane “Rainfall Potential” Derived from Satellite Observations Aids Overland Rainfall Prediction." Journal of Applied Meteorology and Climatology 47, no. 4 (April 1, 2008): 944–59. http://dx.doi.org/10.1175/2007jamc1619.1.
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Abstract The Tropical Rainfall Measuring Mission–based National Aeronautics and Space Administration Goddard Multisatellite Precipitation Analysis (MPA) product is used to quantify the rainfall distribution in tropical cyclones that made landfall in the United States during 1998–2004. A total of 37 tropical cyclones (TC) are examined, including 2680 three-hourly MPA precipitation observations. Rainfall distributions for overland and overocean observations are compared. It is found that the TC rainfall over ocean bears a strong relationship with the TC maximum wind, whereas the relationship for overland conditions is much weaker. The rainfall potential is defined by using the satellite-derived rain rate, the satellite-derived storm size, and the storm translation speed. This study examines the capability of the overocean rainfall potential to predict a storm’s likelihood of producing heavy rain over land. High correlations between rain potentials before landfall and the maximum storm total rain over land are found using the dataset of the 37 landfalling TCs. Correlations are higher with the average rain potential on the day prior to landfall than with averages over any other time period. A TC overland rainfall index is introduced based on the rainfall potential study. This index can be used to predict the storm peak rainfall accumulation over land. Six landfalling storms during the 2005 Atlantic Ocean hurricane season are examined to verify the capability of using this index to forecast the maximum storm total rain over land in the United States. The range of the maximum storm overland rain forecast error for these six storms is between 2.5% and 24.8%.
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Yu, Zifeng, Yuqing Wang, Haiming Xu, Noel Davidson, Yandie Chen, Yimin Chen, and Hui Yu. "On the Relationship between Intensity and Rainfall Distribution in Tropical Cyclones Making Landfall over China." Journal of Applied Meteorology and Climatology 56, no. 10 (October 2017): 2883–901. http://dx.doi.org/10.1175/jamc-d-16-0334.1.
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AbstractTRMM satellite 3B42 rainfall estimates for 133 landfalling tropical cyclones (TCs) over China during 2001–15 are used to examine the relationship between TC intensity and rainfall distribution. The rain rate of each TC is decomposed into axisymmetric and asymmetric components. The results reveal that, on average, axisymmetric rainfall is closely related to TC intensity. Stronger TCs have higher averaged peak axisymmetric rain rates, more averaged total rain, larger averaged rain areas, higher averaged rain rates, higher averaged amplitudes of the axisymmetric rainfall, and lower amplitudes of wavenumbers 1–4 relative to the total rainfall. Among different TC intensity change categories, rapidly decaying TCs show the most rapid decrease in both the total rainfall and the axisymmetric rainfall relative to the total rain. However, the maximum total rain, maximum rain area, and maximum rain rate are not absolutely dependent on TC intensity, suggesting that stronger TCs do not have systematically higher maximum rain rates than weaker storms. Results also show that the translational speed of TCs has little effect on the asymmetric rainfall distribution in landfalling TCs. The maximum rainfall of both the weaker and stronger TCs is generally located downshear to downshear left. However, when environmental vertical wind shear (VWS) is less than 5 m s−1, the asymmetric rainfall maxima are more frequently located upshear and onshore, suggesting that in weak VWS environments the coastline could have a significant effect on the rainfall asymmetry in landfalling TCs.
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Sinatra, T., A. Awaludin, F. Nauval, and C. Purnomo. "Calibration of Spatial Rain Scanner using Rainfall Depth of Rain Gauges." IOP Conference Series: Earth and Environmental Science 893, no. 1 (November 1, 2021): 012064. http://dx.doi.org/10.1088/1755-1315/893/1/012064.
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Abstract A spatial rain scanner has been developed based on a marine radar to satisfy the demand for spatial rain information for hydrological applications. Since the coverage of the rain scanner is 44 km in radius, it is necessary to expand the coverage by installing it in two sites that intersect each other performing a radar network. For this purpose, the first rain scanner has been installed at the Center for Atmospheric Science and Technology (PSTA) in Bandung and the second one at the Space and Atmospheric Observation Center (BPAA) Tanjungsari in Sumedang. This paper focuses on the calibration of radar observations with rainfall data from 7 rain gauges installed in Bandung area and its surroundings. The calibration method calculates rainfall depth (three parameters) instead of only the intensity of rainfall. The data period used for this research is from March to November 2020. The rain scanners have better rainfall events detection over basin area, such as Dayeuh Kolot and Cidurian, than over highland area, such as Lembang. Two calibration methods are used, and the results show that the calibration by calculating three parameters (accumulated reflectivity, duration, and intensity) in the linear model is able to measure rainfall estimation better than using a linear model with one parameter (accumulated reflectivity) for rainfall depth more than 10 mm. Rainfall estimation calculation using scheme 1 tends to underestimate while scheme 2 tends to overestimate.
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Mapiam, Punpim Puttaraksa, Monton Methaprayun, Thom Bogaard, Gerrit Schoups, and Marie-Claire Ten Veldhuis. "Citizen rain gauges improve hourly radar rainfall bias correction using a two-step Kalman filter." Hydrology and Earth System Sciences 26, no. 3 (February 11, 2022): 775–94. http://dx.doi.org/10.5194/hess-26-775-2022.
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Abstract. The low density of conventional rain gauge networks is often a limiting factor for radar rainfall bias correction. Citizen rain gauges offer a promising opportunity to collect rainfall data at a higher spatial density. In this paper, hourly radar rainfall bias adjustment was applied using two different rain gauge networks: tipping buckets, measured by Thai Meteorological Department (TMD), and daily citizen rain gauges. The radar rainfall bias correction factor was sequentially updated based on TMD and citizen rain gauge data using a two-step Kalman filter to incorporate the two gauge datasets of contrasting quality. Radar reflectivity data from the Sattahip radar station, gauge rainfall data from the TMD, and data from citizen rain gauges located in the Tubma Basin, Thailand, were used in the analysis. Daily data from the citizen rain gauge network were downscaled to an hourly resolution based on temporal distribution patterns obtained from radar rainfall time series and the TMD gauge network. Results show that an improvement in radar rainfall estimates was achieved by including the downscaled citizen observations compared with bias correction based on the conventional rain gauge network alone. These outcomes emphasize the value of citizen rainfall observations for radar bias correction, in particular in regions where conventional rain gauge networks are sparse.
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Minda, Haruya, and Kenji Nakamura. "High Temporal Resolution Path-Average Rain Gauge with 50-GHz Band Microwave." Journal of Atmospheric and Oceanic Technology 22, no. 2 (February 1, 2005): 165–79. http://dx.doi.org/10.1175/jtech-1683.1.
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Abstract Rain radar measures instantaneous spatial-average rainfall, while conventional rain gauges directly measure point rainfall with low temporal resolution. Thus differences in the resolution of the sensors create difficulties for rain radar validation, especially for spaceborne rain radar. Accordingly, rainfall measurement by microwave link has been proposed for several decades, as it estimates instantaneous path-average rainfall. Thus it is expected that the microwave link rain gauge will overcome, at least partly, the problems in the rain radar validation, toward which a 50-GHz band microwave link [the path-averaged rain gauge (PRG)] was developed that has been in operation since September 2000. In this paper, the authors show the potential of the PRG system by a simple model and rainfall comparison with a disdrometer and a tipping-bucket rain gauge. Differences observed by the instruments were within 15% (within 10% in half of the cases) during actual rain events in 2003. This confirmed that the PRG system displayed good performance as a rain gauge. Finally, the possibility of the PRG system being applied for spaceborne rain radar validation is considered.
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Song, Hwan-Jin, Byunghwan Lim, and Sangwon Joo. "Evaluation of Rainfall Forecasts with Heavy Rain Types in the High-Resolution Unified Model over South Korea." Weather and Forecasting 34, no. 5 (September 9, 2019): 1277–93. http://dx.doi.org/10.1175/waf-d-18-0140.1.
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Abstract Heavy rainfall events account for most socioeconomic damages caused by natural disasters in South Korea. However, the microphysical understanding of heavy rain is still lacking, leading to uncertainties in quantitative rainfall prediction. This study is aimed at evaluating rainfall forecasts in the Local Data Assimilation and Prediction System (LDAPS), a high-resolution configuration of the Unified Model over the Korean Peninsula. The rainfall of LDAPS forecasts was evaluated with observations based on two types of heavy rain events classified from K-means clustering for the relationship between surface rainfall intensity and cloud-top height. LDAPS forecasts were characterized by more heavy rain cases with high cloud-top heights (cold-type heavy rain) in contrast to observations showing frequent moderate-intensity rain systems with relatively lower cloud-top heights (warm-type heavy rain) over South Korea. The observed cold-type and warm-type events accounted for 32.7% and 67.3% of total rainfall, whereas LDAPS forecasts accounted for 65.3% and 34.7%, respectively. This indicates severe overestimation and underestimation of total rainfall for the cold-type and warm-type forecast events, respectively. The overestimation of cold-type heavy rainfall was mainly due to its frequent occurrence, whereas the underestimation of warm-type heavy rainfall was affected by both its low occurrence and weak intensity. The rainfall forecast skill for the warm-type events was much lower than for the cold-type events, due to the lower rainfall intensity and smaller rain area of the warm-type. Therefore, cloud parameterizations for warm-type heavy rain should be improved to enhance rainfall forecasts over the Korean Peninsula.
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Hwang, Seokhwan, Narae Kang, and Jung Soo Yoon. "Error Generation Characteristics of the Areal Rainfall Estimation Interpolation Method Using Rainfall Radar Data." Journal of the Korean Society of Hazard Mitigation 22, no. 6 (December 31, 2022): 273–83. http://dx.doi.org/10.9798/kosham.2022.22.6.273.
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This study evaluated the effects of watershed area, rain gauge density, rain gauge distribution, and rainfall movement direction on regional average rainfall estimates by comparing the spatial interpolation results. To this end, the interpolated watershed mean using radar grid data from the Ministry of Environment’s TM rain gauge point was compared with the watershed mean of all radar grids within the watershed. Results showed that eight or more rain gauges are required for accurate area average rainfall estimates in small watersheds of less than 500 km<sup>2</sup>. In addition, the inverse distance weighting method tends to underestimate area average rainfall, whereas the Thiessen method tends to overestimate it. Furthermore, as linearity of rain gauge distribution increased, the number of rainfall events with outliers increased. In particular, when the correlation coefficient exceeded 0.7, outliers appeared to rapidly increase, sharply increasing the possibility of overestimating or underestimating area average rainfall. This study clearly showed that there are limits to area-averaged rainfall estimates when using rain gauge rainfall data in small watersheds.
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Hu, Caihong, Chengshuai Liu, Yichen Yao, Qiang Wu, Bingyan Ma, and Shengqi Jian. "Evaluation of the Impact of Rainfall Inputs on Urban Rainfall Models: A Systematic Review." Water 12, no. 9 (September 5, 2020): 2484. http://dx.doi.org/10.3390/w12092484.
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Over the past several decades, urban flooding and other water-related disasters have become increasingly prominent and serious. Although the urban rain flood model’s benefits for urban flood simulation have been extensively documented, the impact of rainfall input to model simulation accuracy remains unclear. This systematic review aims to provide structured research on how rain inputs impact urban rain flood model’s simulation accuracy. The selected 48 peer-reviewed journal articles published between 2015 and 2019 on the Web of Science™ database were analyzed by key factors, including rainfall input type, calibration times and verification times. The results from meta-analysis reveal that when a traditional rain measurement was used as the rainfall input, model simulation accuracy was higher, i.e., the Nash–Sutcliffe efficiency coefficient (NSE) of traditional technology for rain measurement was higher than the 0.18 for the new technology rain measurement with respect to flow simulation. In addition, the single-field sub-flood calibration model was better than the multi-field sub-flood calibration model. NSE was higher than 0.14. The precision was better for the verification period; NSE of the calibration value showed a 0.07 higher verification value on average in flow simulation. These findings have certain significance for the development of future urban rain flood models and propose the development direction of the future urban rain flood model. Finally, in view of the rainfall input problem of the urban storm flood model, we propose the future development direction of the urban storm flood model.
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Lestari, Sopia, Alain Protat, Valentin Louf, Andrew King, Claire Vincent, and Shuichi Mori. "Subdaily Rain-Rate Properties in Western Java Analyzed Using C-Band Doppler Radar." Journal of Applied Meteorology and Climatology 61, no. 9 (September 2022): 1179–99. http://dx.doi.org/10.1175/jamc-d-21-0041.1.
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Abstract Jakarta, a megacity in Indonesia, experiences recurrent floods associated with heavy rainfall. Characteristics of subdaily rainfall and the local factors influencing rainfall around Jakarta have not been thoroughly investigated, primarily because of data limitations. In this study, we examine the frequency and intensity of hourly and daily rain rate, including spatial characteristics and variations across time scales. We use 6-min C-band Doppler radar and 1-min in situ data during 2009–12 to resolve spatial rain-rate characteristics at higher resolution than previous studies. A reflectivity–rain rate (Z–R) relationship is derived (Z = 102.7R1.75) and applied to estimate hourly rain rate. Our results show that rain rate around Jakarta is spatially inhomogeneous. In the rainy season [December–February (DJF)], rain rate exhibits statistical properties markedly different from other seasons, with much higher frequency of rain, but, on average, less intense rain rate. In all seasons, there is a persistent higher hourly and daily mean rain rate found over mountainous areas, indicating the importance of local orographic effects. In contrast, for hourly rain-rate extremes, peaks are observed mostly over the coastal land and lowland areas. For the diurnal cycle of mean rain rate, a distinct afternoon peak is found developing earlier in DJF and later in the dry season. This study has implications for other analyses of mesoscale rain-rate extremes in areas of complex topography and suggests that coarse-grain products may miss major features of the rain-rate variability identified in our study. Significance Statement For many years, Jakarta and its surrounding regions have been repeatedly inundated by flooding triggered by short-duration heavy rainfall or rainfall accumulated over multiple days. Little is known about the distribution of local rainfall and how it differs between seasons. In this study, we used high-resolution C-band Doppler radar during 2009–12 to understand the characteristics of rainfall over this complex topography. The results demonstrate that the rainfall features vary spatially and seasonally. In the wet season, rainfall is more frequent but, on average, lighter relative to other seasons. In all seasons, the highest hourly and daily mean rain rate persistently occurs over the mountains, indicating the vital role of topography in generating rainfall in the region.
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Oyaro, J., and J. Ben-Edigbe. "The Extent of Capacity Loss Caused by Rainfall at Signalised Intersections." Open Transportation Journal 14, no. 1 (December 21, 2020): 214–21. http://dx.doi.org/10.2174/1874447802014010214.
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Background: Even though their physical characteristics exert a constant influence on capacity and saturation flows, signalized intersections are fixed facilities not affected by rainfall. Whilst traffic conditions with varying effects can be regulated, rainfall conditions cannot be regulated but compensated for by warning drivers to reduce speed. Speed reduction has an impact on signalised intersection capacity, whilst signalised intersection capacity is a function of saturation flow, effective green, and cycle time. In this paper, a capacity loss is the differential percentage between ‘with and without’ rainfall scenario. Aim: The paper investigated the extent of capacity loss caused by rainfall at signalised intersections. Methods: In Durban, South Africa, rainfall data were collected, collated, and correlated with traffic data in a 'with and without' rainfall intensity study. Rainfall intensity was classified according to the rate of precipitation as follows; rainfall intensity(i): light rain (i <2.5mm/h); Moderate rain (2.5mm/h ≤ i < 10mm/h), and heavy rain (10 ≤ i ≤ 50mm/h) as prescribed by the World Meteorological Society. Results: Empirical results show that rainfall intensity has an effect on road capacity at a signalised intersection. Generally, for the vehicles going straight, light rain caused a 4.25% capacity loss; moderate rain 9.18% while heavy rain caused an 11.53% capacity reduction. With right-turning vehicles, light rain caused 7.38% capacity loss; moderate rain caused 14.3%, while heavy rain accounted for 19.15% capacity reduction. Conclusion: The paper concluded that rainfall at signalised intersections would cause an anomalous capacity reduction. Since the database for the study is small, the paper advocates for further studies based on a broader database to include yellow interval time.
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Cecinati, Francesca, Antonio Moreno-Ródenas, Miguel Rico-Ramirez, Marie-claire ten Veldhuis, and Jeroen Langeveld. "Considering Rain Gauge Uncertainty Using Kriging for Uncertain Data." Atmosphere 9, no. 11 (November 14, 2018): 446. http://dx.doi.org/10.3390/atmos9110446.
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In urban hydrological models, rainfall is the main input and one of the main sources of uncertainty. To reach sufficient spatial coverage and resolution, the integration of several rainfall data sources, including rain gauges and weather radars, is often necessary. The uncertainty associated with rain gauge measurements is dependent on rainfall intensity and on the characteristics of the devices. Common spatial interpolation methods do not account for rain gauge uncertainty variability. Kriging for Uncertain Data (KUD) allows the handling of the uncertainty of each rain gauge independently, modelling space- and time-variant errors. The applications of KUD to rain gauge interpolation and radar-gauge rainfall merging are studied and compared. First, the methodology is studied with synthetic experiments, to evaluate its performance varying rain gauge density, accuracy and rainfall field characteristics. Subsequently, the method is applied to a case study in the Dommel catchment, the Netherlands, where high-quality automatic gauges are complemented by lower-quality tipping-bucket gauges and radar composites. The case study and the synthetic experiments show that considering measurement uncertainty in rain gauge interpolation usually improves rainfall estimations, given a sufficient rain gauge density. Considering measurement uncertainty in radar-gauge merging consistently improved the estimates in the tested cases, thanks to the additional spatial information of radar rainfall data but should still be used cautiously for convective events and low-density rain gauge networks.
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Loukas, A., and M. C. Quick. "Rain Distribution in a Mountainous Watershed." Hydrology Research 24, no. 4 (August 1, 1993): 225–42. http://dx.doi.org/10.2166/nh.1993.0005.
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The orographic and temporal gradients of rainfall in a mountainous watershed in southwestern British Columbia have been analyzed and streamflow has been estimated using a watershed model. The study watershed is the Jamieson Creek watershed located approximately 30 km north of Vancouver in the Coastal Mountains. The purpose of the study was to determine whether rainfall follows a definable pattern in this mountainous watershed. Regression analysis has been performed for the total rainfall depth per event and hourly intensity for the period 1972-1975. Data is taken from the rainfall season of June to mid-November in order to avoid complications of combined rain and snow events. In this analysis, the rainfall data from a gauge at the lower elevation was used as the set of independent variables and the data from the other four gauges in the watershed as dependent variables. The results showed that the rainfall depth per event increased up to the mid-elevation of the watershed, and then decreased at the upper elevations. On the other hand, the hourly rainfall intensity was found to decrease with increase of elevation in the watershed, so that longer duration of rainfall events occurs at the middle and upper watershed. The regression equations, developed from the analysis of the distribution of the hourly intensity, were used for the prediction of rainfall events of the years 1976-1977. The agreement between the predicted and the observed rain was statistically good. Also, the simulation of the watershed streamflow using the predicted rainfall gave good results. Consequently, because the rainfall follows a definable distribution as a function of elevation, it is possible to use data from one station located at the lower elevation in combination with the developed predictor equations to accurately describe the rainfall over the watershed.
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Hambali, Roby, Djoko Legono, Rachmad Jayadi, and Satoru Oishi. "Improving Spatial Rainfall Estimates at Mt. Merapi Area Using Radar-Rain Gauge Conditional Merging." Journal of Disaster Research 14, no. 1 (February 1, 2019): 69–79. http://dx.doi.org/10.20965/jdr.2019.p0069.
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Rainfall monitoring is important for providing early warning of lahar flow around Mt. Merapi. The X-band multi-parameter radar developed to support these warning systems provides rainfall information with high spatial and temporal resolution. However, this method underestimates the rainfall compared with rain gauge measurements. Herein, we performed conditional radar-rain gauge merging to obtain the optimal rainfall value distribution. By using the cokriging interpolation method, kriged gauge rainfall, and kriged radar rainfall data were obtained, which were then combined with radar rainfall data to yield the adjusted spatial rainfall. Radar-rain gauge conditional merging with cokriging interpolation provided reasonably well-adjusted spatial rainfall pattern.
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Prakash, Satya, Ashwin Seshadri, J. Srinivasan, and D. S. Pai. "A New Parameter to Assess Impact of Rain Gauge Density on Uncertainty in the Estimate of Monthly Rainfall over India." Journal of Hydrometeorology 20, no. 5 (April 29, 2019): 821–32. http://dx.doi.org/10.1175/jhm-d-18-0161.1.
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Abstract Rain gauges are considered the most accurate method to estimate rainfall and are used as the “ground truth” for a wide variety of applications. The spatial density of rain gauges varies substantially and hence influences the accuracy of gridded gauge-based rainfall products. The temporal changes in rain gauge density over a region introduce considerable biases in the historical trends in mean rainfall and its extremes. An estimate of uncertainty in gauge-based rainfall estimates associated with the nonuniform layout and placement pattern of the rain gauge network is vital for national decisions and policy planning in India, which considers a rather tight threshold of rainfall anomaly. This study examines uncertainty in the estimation of monthly mean monsoon rainfall due to variations in gauge density across India. Since not all rain gauges provide measurements perpetually, we consider the ensemble uncertainty in spatial average estimation owing to randomly leaving out rain gauges from the estimate. A recently developed theoretical model shows that the uncertainty in the spatially averaged rainfall is directly proportional to the spatial standard deviation and inversely proportional to the square root of the total number of available gauges. On this basis, a new parameter called the “averaging error factor” has been proposed that identifies the regions with large ensemble uncertainties. Comparison of the theoretical model with Monte Carlo simulations at a monthly time scale using rain gauge observations shows good agreement with each other at all-India and subregional scales. The uncertainty in monthly mean rainfall estimates due to omission of rain gauges is largest for northeast India (~4% uncertainty for omission of 10% gauges) and smallest for central India. Estimates of spatial average rainfall should always be accompanied by a measure of uncertainty, and this paper provides such a measure for gauge-based monthly rainfall estimates. This study can be further extended to determine the minimum number of rain gauges necessary for any given region to estimate rainfall at a certain level of uncertainty.
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Ciach, Grzegorz J., Witold F. Krajewski, Emmanouil N. Anagnostou, Mary L. Baeck, James A. Smith, Jeffrey R. McCollum, and Anton Kruger. "Radar Rainfall Estimation for Ground Validation Studies of the Tropical Rainfall Measuring Mission." Journal of Applied Meteorology 36, no. 6 (June 1, 1997): 735–47. http://dx.doi.org/10.1175/1520-0450-36.6.735.
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Abstract This study presents a multicomponent rainfall estimation algorithm, based on weather radar and rain gauge network, that can be used as a ground-based reference in the satellite Tropical Rainfall Measuring Mission (TRMM). The essential steps are constructing a radar observable, its nonlinear transformation to rainfall, interpolation to rectangular grid, constructing several timescale accumulations, bias adjustment, and merging of the radar rainfall estimates and rain gauge data. Observations from a C-band radar in Darwin, Australia, and a local network of 54 rain gauges were used to calibrate and test the algorithm. A period of 25 days was selected, and the rain gauges were split into two subsamples to apply cross-validation techniques. A Z–R relationship with continuous range dependence and a temporal interpolation scheme that accounts for the advection effects is applied. An innovative methodology was used to estimate the algorithm controlling parameters. The model was globally optimized by using an objective function on the level of the final products. This is equivalent to comparing hundreds of Z–R relationships using a uniform and representative performance criterion. The algorithm performance is fairly insensitive to the parameter variations around the optimum. This suggests that the accuracy limit of the radar rainfall estimation based on power-law Z–R relationships has been reached. No improvement was achieved by using rain regime classification prior to estimation.
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Widyawati, Ega, Nani Nagu, Muhammad Rizal, K. M. Zulkarnain, and Oki Syafrel. "Rationalization of Rainfall Station In Ternate Island." E3S Web of Conferences 328 (2021): 10016. http://dx.doi.org/10.1051/e3sconf/202132810016.
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Good rainfall data can be obtained from recordings that are maintained and monitored continuously. Thus, the more rain stations there are, the more detailed the rainfall data will be. The rain station network density is expressed as the area of the watershed represented by one rain station. Meanwhile, the pattern of distribution of rain stations states the location of the placement of rain stations in the watershed. Ternate Island with an area of 76 km2 and has stations located in Akehuda Village, Gamayou Village, Tabona Village, Sasa Village, Kastela Village, and Sulamadaha Village. This study aims to rationalize the density of rainfall stations in Ternate Island. Rationalization of rainfall stations using the Kagan-Rodda method. The results obtained for the rationalization of rainfall stations with a total of 5 rain gauge stations spread across the city of Ternate, which are located in the Tabam, Gamayou, Sasa, Dorpedu, and Togafo areas with a grading error of 19.27% with a network density of 4.17 Km2/station.
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Xu, Zhan Wei, and Gui Lin Zheng. "Implementation of a High-Precision Ultrasonic Rain Gauge." Applied Mechanics and Materials 300-301 (February 2013): 382–88. http://dx.doi.org/10.4028/www.scientific.net/amm.300-301.382.
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A novel rain gauge based on acoustic self-calibration principle is proposed in the paper. Acoustic self-calibration principle can eliminate the uncertainty of the velocity of ultrasound and achieve accurate measurement of rainfall. The rain gauge not only overcomes the influence on the rainfall measurement under intensive rainfall conditions, but also improves the precision of rain gauge. Plenty of experiments have been done to validate the design. Both theoretical analysis and experimental results show the effectiveness of the rain gauge. A full description of the rain gauge and implementation are presented.
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Kirsch, Bastian, Marco Clemens, and Felix Ament. "Stratiform and Convective Radar Reflectivity–Rain Rate Relationships and Their Potential to Improve Radar Rainfall Estimates." Journal of Applied Meteorology and Climatology 58, no. 10 (October 2019): 2259–71. http://dx.doi.org/10.1175/jamc-d-19-0077.1.
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AbstractThe variability of the raindrop size distribution (DSD) contributes to large parts of the uncertainty in radar-based quantitative rainfall estimates. The variety of microphysical processes acting on the formation of rainfall generally leads to significantly different relationships between radar reflectivity Z and rain rate R for stratiform and convective rainfall. High-resolution observation data from three Micro Rain Radars in northern Germany are analyzed to quantify the potential of dual Z–R relationships to improve radar rainfall estimates under idealized rainfall type identification and separation. Stratiform and convective rainfall are separated with two methods, establishing thresholds for the rain rate-dependent mean drop size and the α coefficient of the power-law Z–R relationship. The two types of dual Z–R relationships are tested against a standard Marshall–Palmer relationship and a globally adjusted single relationship. The comparison of DSD-based and reflectivity-derived rain rates shows that the use of stratiform and convective Z–R relationships reduces the estimation error of the 6-month accumulated rainfall between 30% and 50% relative to a single Z–R relationship. Consistent results for neighboring locations are obtained at different rainfall intensity classes. The range of estimation errors narrows by between 20% and 40% for 10-s-integrated rain rates, dependent on rainfall intensity and separation method. The presented technique also considerably reduces the occurrence of extreme underestimations of the true rain rate for heavy rainfall, which is particularly relevant for operational applications and flooding predictions.
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Zhuge, Xiao-Yong, Fan Yu, and Cheng-Wei Zhang. "Rainfall Retrieval and Nowcasting Based on Multispectral Satellite Images. Part I: Retrieval Study on Daytime 10-Minute Rain Rate." Journal of Hydrometeorology 12, no. 6 (December 1, 2011): 1255–70. http://dx.doi.org/10.1175/2011jhm1373.1.
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Abstract This study develops a method for both precipitation area and intensity retrievals based on multispectral geostationary satellite images. This method can be applied to continuous observation of large-scale precipitation so as to solve the problem from the measurements of rainfall radar and rain gauge. Satellite observation is instantaneous, whereas the rain gauge records accumulative data during a time interval. For this reason, collocated 10-min rain gauge measurements and infrared (IR) and visible (VIS) data from the FengYun-2C (FY-2C) geostationary satellite are employed to improve the accuracy of satellite rainfall retrieval. First of all, the rainfall probability identification matrix (RPIM) is used to distinguish rainfall clouds from nonrainfall clouds. This RPIM is more efficient in improving the retrieval accuracy of rainfall area than previous threshold combination screening methods. Second, the multispectral segmented curve-fitting rainfall algorithm (MSCFRA) is proposed and tested to estimate the 10-min rain rates. Rainfall samples taken from June to August 2008 are used to assess the performance of the rainfall algorithm. Assessment results show that the MSCFRA improves the accuracy of rainfall estimation for both stratiform cloud rainfall and convective cloud rainfall. These results are practically consistent with rain gauge measurements in both rainfall area division and rainfall intensity grade estimation. Furthermore, this study demonstrates that the temporal resolution of satellite detection is important and necessary in improving the precision of satellite rainfall retrieval.
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Molinié, Gilles, Davide Ceresetti, Sandrine Anquetin, Jean Dominique Creutin, and Brice Boudevillain. "Rainfall Regime of a Mountainous Mediterranean Region: Statistical Analysis at Short Time Steps." Journal of Applied Meteorology and Climatology 51, no. 3 (March 2012): 429–48. http://dx.doi.org/10.1175/2011jamc2691.1.
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AbstractThis paper presents an analysis of the rainfall regime of a Mediterranean mountainous region of southeastern France. The rainfall regime is studied on temporal scales from hourly to yearly using daily and hourly rain gauge data of 43 and 16 years, respectively. The domain is 200 × 200 km2 with spatial resolution of hourly and daily rain gauges of about 8 and 5 km, respectively. On average, yearly rainfall increases from about 0.5 m yr−1 in the large river plain close to the Mediterranean Sea to up to 2 m yr−1 over the surrounding mountain ridges. The seasonal distribution is also uneven: one-third of the cumulative rainfall occurs during the autumn season and one-fourth during the spring. At finer time scales, rainfall is studied in terms of rain–no-rain intermittency and nonzero intensity. The monthly intermittency (proportion of dry days per month) and the daily intermittency (proportion of dry hours per day) is fairly well correlated with the relief. The higher the rain gauges are, the lower the monthly and daily intermittencies are. The hourly and daily rainfall intensities are analyzed in terms of seasonal variability, diurnal cycle, and spatial pattern. The difference between regular and heavy-rainfall event is depicted by using both central parameters and maximum values of intensity distributions. The relationship between rain gauge altitudes and rainfall intensity is grossly inverted relative to intermittency and is also far more complex. The spatial and temporal rainfall patterns depicted from rain gauge data are discussed in the light of known meteorological processes affecting the study region.
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Hudiono, Hudiono, Mochammad Taufik, Ridho Hendra Yoga Perdana, and Amalia Eka Rakhmania. "Telemetering of Rainfall Measurement Results Using 433 MHz Wireless Transmission." JURNAL INFOTEL 13, no. 3 (August 31, 2021): 143–50. http://dx.doi.org/10.20895/infotel.v13i3.603.
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The line of sight (LOS) microwave communication system, especially those operating at frequencies above 10 GHz, is very susceptible to rain attenuation, particularly in tropical countries such as Indonesia. Therefore, it is essential to calculate rain attenuation estimation values as a basis for consideration in designing a line of sight microwave communication system to get stable communication. In this study, telemetering was designed to measure the rainfall intensity from a rain gauge device through a 433 MHz wireless transceiver. Measurement of rainfall intensity values via an Arduino-controlled rain gauge was transmitted directly to the monitoring room, which then processed to be displayed in graphical form in real time and can also be stored as data loggers. The rainfall telemetering device users can measure rainfall remotely and without having to wait for the rain like the rainfall manual measurement.
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Pendergrass, Angeline G., and Dennis L. Hartmann. "Two Modes of Change of the Distribution of Rain*." Journal of Climate 27, no. 22 (November 4, 2014): 8357–71. http://dx.doi.org/10.1175/jcli-d-14-00182.1.
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Abstract The frequency and intensity of rainfall determine its character and may change with climate. A methodology for characterizing the frequency and amount of rainfall as functions of the rain rate is developed. Two modes of response are defined, one in which the distribution of rainfall increases in equal fraction at all rain rates and one in which the rainfall shifts to higher or lower rain rates without a change in mean rainfall. This description of change is applied to the tropical distribution of daily rainfall over ENSO phases in models and observations. The description fits observations and most models well, although some models also have an extreme mode in which the frequency increases at extremely high rain rates. The multimodel mean from phase 5 of the Coupled Model Intercomparison Project (CMIP5) agrees with observations in showing a very large shift of 14%–15% K−1, indicating large increases in the heaviest rain rates associated with El Niño. Models with an extreme mode response to global warming do not agree as well with observations of the rainfall response to El Niño.
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Ebert, Elizabeth E., Michael Turk, Sheldon J. Kusselson, Jianbin Yang, Matthew Seybold, Peter R. Keehn, and Robert J. Kuligowski. "Ensemble Tropical Rainfall Potential (eTRaP) Forecasts." Weather and Forecasting 26, no. 2 (April 1, 2011): 213–24. http://dx.doi.org/10.1175/2010waf2222443.1.
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Abstract Ensemble tropical rainfall potential (eTRaP) has been developed to improve short-range forecasts of heavy rainfall in tropical cyclones. Evolving from the tropical rainfall potential (TRaP), a 24-h rain forecast based on estimated rain rates from microwave sensors aboard polar-orbiting satellites, eTRaP combines all single-pass TRaPs generated within ±3 h of 0000, 0600, 1200, and 1800 UTC to form a simple ensemble. This approach addresses uncertainties in satellite-derived rain rates and spatial rain structures by using estimates from different sensors observing the cyclone at different times. Quantitative precipitation forecasts (QPFs) are produced from the ensemble mean field using a probability matching approach to recalibrate the rain-rate distribution against the ensemble members (e.g., input TRaP forecasts) themselves. ETRaPs also provide probabilistic forecasts of heavy rain, which are potentially of enormous benefit to decision makers. Verification of eTRaP forecasts for 16 Atlantic hurricanes making landfall in the United States between 2004 and 2008 shows that the eTRaP rain amounts are more accurate than single-sensor TRaPs. The probabilistic forecasts have useful skill, but the probabilities should be interpreted within a spatial context. A novel concept of a “radius of uncertainty” compensates for the influence of location error in the probability forecasts. The eTRaPs are produced in near–real time for all named tropical storms and cyclones around the globe. They can be viewed online (http://www.ssd.noaa.gov/PS/TROP/etrap.html) and are available in digital form to users.
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Soehardi, Fitridawati, and Marta Dinata. "Recent Analysis of Maximum Rain Period." International Journal of Engineering & Technology 7, no. 2.3 (March 8, 2018): 63. http://dx.doi.org/10.14419/ijet.v7i2.3.12323.
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Control and Handling of Flood Issues No Regardless of optimum infrastructure availability in flood control efforts such as soil walls, irrigation networks, dams, drainage and others. Planning in the design of water structures for flood control needs to use accurate information and data of the population, such as information on the maximum rainfall data of the area with a certain repetition period, it is necessary to calculate the flood discharge of the plan so that it can calculate the capacity of the dam to be built. This study aims to determine the ratio of maximum rainfall using three calculation methods, namely Iway Kadoya, EJ Gumbel and Log Person III. This research was conducted to get an idea of the maximum rainfall with a return period of 2,5,10,15,20, .... 100 years. The location of this research is conducted in Tualang Subdistrict, the data of the period of maximum rainfall is using the data of rainfall observation station in Tualang Subdistrict. Based on the calculation of rainfall design done can be concluded that the calculation of rainfall design with Iway Kadoya method is greater when compared with Log Pearson Type III and EJ method. Gumbel.