Добірка наукової літератури з теми "Drainage Victoria"

The dairy industry is a major user of water in northern Victoria and southern New South Wales. Water is typically applied to pasture using the border-check irrigation system. The border-check system is largely gravity driven and thus energy efficient. However, deep drainage can potentially be high because the system allows only limited control over the depth of water applied in each irrigation event. For this reason, heavy soils are regarded as the most suitable for border-check irrigation. This study quantified net deep drainage (deep drainage less capillary rise) under border-check irrigated pasture on a Goulburn clay loam soil. Additionally, the study investigated the extent to which irrigation frequency and watertable conditions influence water use, dry matter production and deep drainage. The water balance and dry matter production were monitored over 2.5 years in a lysimeter facility in northern Victoria. The Goulburn clay loam is representative of the heavier textured soils used for border-check irrigation of pasture in northern Victoria. The average measured net deep drainage was 4 mm/year. This indicates that relatively small levels of net deep drainage can be achieved under well-managed border-check irrigation on a Goulburn clay loam soil. Net deep drainage losses were greatest following winter, when rainfall exceeded pasture water use for an extended period. Increasing the interval between irrigation events resulted in reduced plant water use, infiltration of irrigation water, rainfall runoff and pasture production. However, increasing the interval did not impact on net deep drainage or water use efficiency. Depth of watertable had a relatively minor impact on the water balance.

Waterlogging is a major problem of dryland agriculture in many areas of Australia. Yellow duplex soils, especially those with bleached A2 horizons, are the soils most commonly associated with waterlogging. The problem is principally the development of perched watertables in the A horizons after rain, due to the restricted downward drainage of water caused by the low hydraulic conductivity of heavy clay subsoils. Pipe and mole drainage techniques are briefly reviewed, and experience with subsoil drainage in yellow duplex soils in Victoria is outlined.

The Lake Victoria drainage basin (LVD) in Kenya is home to ten nominal species of small barbs (Enteromius) and one of large barbs (Labeobarbus altianalis). A recent molecular study genetically characterized small barbs in this region and found evidence of introgression between certain species, complicating the taxonomy and species identification of these fishes. This study aimed to extend our understanding on the evolution of these fishes by: (1) determining whether putatively pure individuals of Enteromius cercops are found in the Kenyan LVD, as the previous study only found hybrid individuals of this species in this region; (2) testing the sister relationship between Enteromius profundus, endemic to Lake Victoria, and Enteromius radiatus, also found in Lake Victoria, which had been previously synonymized; (3) examining the phylogenetic relationships of small barbs of the Kenyan LVD with those reported from other ichthyological provinces of Africa; and (4) examining the phylogenetic relationships of Labeobarbus altianalis with other Labeobarbus species. To this end, we obtained mitochondrial Cytochrome b and nuclear Growth Hormone (GH) intron 2 gene sequences of nine Enteromius species from the LVD in Kenya, as well as cytochrome b sequences for L. altianalis. We conducted Maximum likelihood and Bayesian phylogenetic analyses to establish their evolutionary relationships in relation to many other barbs specimens from Africa. Phylogenetic analyses did not reveal instances of hybridization/introgression among the individuals sequenced by us. A sister relationship between E. profundus and E. radiatus was not found. This latter species shows instead a sister relationship with a lineage comprised of two species from West Africa. Other sister relationships between taxa from the East coast and other ecoregions from Africa are observed, suggesting that past drainage connections and vicariant events contributed to the diversification of Enteromius. Finally, only a single haplotype was recovered among the L. altianalis individuals examined, which is most similar to a specimen from Lake Edward in Uganda.

The environment, duplex soil types and trends in crop production in South Australia, southern New South Wales, north-eastern and north-central Victoria, the southern Wimmera and the Victorian Western District are reviewed. In the latter 2 regions, pastoral industries dominate and crop production is curtailed by regular and severe soil waterlogging, except for limited areas of lower rainfall. Subsurface drainage can eliminate waterlogging, but is feasible only for the Western District where subsoils are sufficiently stable. The other regions all have a long history of soil degradation due to cropping practices, but these effects can now be minimised with the use of direct drilling and stubble retention cropping methods. A vigorous pasture ley phase is still considered necessary to maintain nitrogen levels and to restore soil structure to adequate levels for sustainable farming. Future productivity improvements will require increased root growth in the subsoils. Deep ripping, 'slotting' of gypsum, and crop species capable of opening up subsoils are techniques which may hold promise in this regard. The inclusion of lucerne, a perennial species, in annual pastures and intercropping at intervals is a technique being pioneered in north-central and western Victoria and may provide the best opportunity to crop duplex soils successfully without associated land degradation.

Excess water in duplex soils can be removed by drains. In soils in which drainage is impractical, some success has been obtained by deep ripping and by gypsum amendment. These practices can increase profile storage or drainage. Interceptor drains are suitable for duplex soils with slopes of more than about 1.5%. On more gentle slopes, relief drains are used to remove excess water. Subsurface tube and mole drains have been used successfully to drain cereal crops in Victoria, but in Western Australia open drains are preferred because they can carry storm runoff as well as seepage waters. The greatest cost of open drains is the land removed from production. Over 35% of the rain falling during the growing season has been removed by drains in Victoria and Western Australia in wet years. Drainage was almost entirely downslope of monitored interceptor drains in Western Australia, which is not predicted from the theory. Simulation of water levels between drains and of drain flows using the DRAINMOD model indicated significant, preferred pathways for water flow to drains. The pathways explain the predominantly downslope effect of interceptor drains and the wide drain spacings which can be used. Deep ripping and the incorporation of gypsum can reduce waterlogging in some soils, but has had no effect in several others. The effect of deep ripping on recharge is unclear. Drains may decrease groundwater recharge, water and wind erosion, and soil structure decline. Their effect on phosphate export from catchments is unclear.

Litter is generated in shopping areas and is washed or blown into stormwater drainage systems. These convey the litter to open water bodies leading to the accumulation of non-biodegradable litter on the banks and beaches of urban waterways and bay foreshores. The increasing public awareness of the problem prompted the State Government of Victoria to provide funding to develop an innovative patented litter trap known as the In-line Litter Separator (ILLS). The ILLS is retrofitted to the drainage system downstream of shopping areas and removes litter and other pollutants from the passing stormwater. In a two-year development program, ten prototypes were installed and tested in the Melbourne and metropolitan area. The results were so successful that the ILLS is now manufactured in Australia and overseas under license from Swinburne University. This paper presents the performance criteria, the design concepts, the outcomes of laboratory and hydrologic modelling and the analyses of prototype test results that led to the commercial production of the ILLS.

Wheat, triticale, and rapeseed growth and yield were studied under various tillage (conventional, deep ripping, direct drilling) and stubble-handling (burnt, retained) regimes with and without drainage at Hamilton in south-western Victoria from 1985 to 1987. Grain yield was increased from about 2 to >4 t/ha by drainage in both years; however, effects of other treatments, although significant, were much less. Soil structure (as measured by fractional air-filled porosity at -5 J/kg) deteriorated during winter and recovered during spring and summer. A laboratory experiment showed that this variation in soil structure resulted from saturation per se and redrying. In the field, the decline in porosity was most pronounced with cultivation and the absence of drainage, but overall, the effects of stubble retention and tillage treatments were small. There was a significant positive relationship between yield and porosity on undrained areas, but not where drains were present. Drainage reduced soil structural decline during winter, while stubble retention reduced the decline in porosity in the cultivated-undrained treatment in 1987.

Crop production in south-western Victoria has historically been constrained by waterlogging. As a result raised beds have recently become a popular tillage method on soils prone to waterlogging. Soil water properties, air-filled porosity, plant dry matter, and grain yield were compared for raised beds and conventional cultivation treatments during 2003 and 2004. Although rainfall was less than the long-term average, over the whole period the raised beds had consistently lower water content and drained faster than the conventional cultivation. Air-filled porosity was greater and above the critical value of 10% for longer in the raised beds (e.g. in 2004 air-filled porosity was >10% for 69 days longer in the raised beds). Benefits on the raised bed soil (such as greater soil aeration) were probably due to the increased depth to the B horizon and the soil surface topography created by regular furrows. No waterlogging was observed in 2003 and the crop on the conventional cultivation produced significantly more dry matter. Although visible waterlogging of the crop on the conventional cultivation was observed in 2004, the crop on the raised beds was not affected. Despite the different response in growth for each treatment, there was no significant difference in grain yield in either year. Nevertheless, it is predicted that raised beds should provide a well-drained and aerated soil that maintains crop productivity under average or greater rainfall in south-western Victoria.

Objectives: To compare the recurrence rate between incision drainage andmultiple needle aspiration for breast abscess treatment. Study Design: Randomized ControlledTrial. Setting: Department of General Surgery, Bahawal Victoria Hospital, Bahawalpur. StudyDuration: 29th September 2015 to 29th June 2016. Materials & Methods: A total of 60 femalepatients with breast abscess of <2 cm in size and of duration <2 weeks between 20 to 40 yearsof age were included. Patients with multiple breast abscesses, recurrent breast abscesses andcomplicated abscesses were excluded. The patients were randomized into Group A (incisionand drainage) & Group B (needle aspiration), by using lottery method. Follow up was done forup to 7 days and recurrence was noted. Results: The mean age of patients in group A was30.83 ± 5.67 years and in group B was 31.53 ± 5.73 years. Mean duration of disease was 7.58± 2.83 days. Mean size of abscess was 0.86 ± 0.43 cm. Recurrence was found in 07 (23.33%)patients in group A (incision drainage) while in 21 (70.0%) patients in group B (multiple needleaspiration) with p-value of 0.000 which is statistically significant. Conclusion: The recurrencerate is less after incision & drainage as compared to multiple needle aspirations for treatingbreast abscess.

Abstract. A spatially distributed hydrologic model (WetSpa) is used to estimate daily river water discharge in the Simiyu river a tributary of Lake Victoria, Tanzania. The model combines topography, landuse and soil maps, and observed daily meteorological time series to predict discharge hydrographs and the spatial distribution of hydrological parameters in the catchment. The elevations in the catchment range from 2000 to 1100 m at the outlet, with average slope of 1.4%. The dominant landuse types are, wasteland, grassland, bushland, cultivated land, and a very small area is covered by surface water. The dominant soil types are sandy loam, followed by sandy clay loam, clay loam, clay, loam and sandy clay. There are two distinctive seasons in the Simiyu catchment. Short rains mainly in November, December and January, and long rains in March to May, resulting in a total average annual precipitation of 700 to 1000 mm. The annual potential evapotranspiration is about 1300 mm, and the river discharge at the catchment outlet ranges from 0 to about 200 m3/s. Global parameters of the model are calibrated using three years of daily observed discharge values measured at the mouth of the river at Lake Victoria. The estimated average travel time of the runoff to the outlet of the catchment is about 2.4 d and maximum 8 d for the most remote areas. The model results also show that the surface runoff and interflow provide respectively 38.6% and 61.4% of the total runoff, while the contribution of groundwater drainage is nil. The absence of groundwater drainage is probably due to the high evaporation demand of the atmosphere, which accounts for about 90% of the total precipitation being lost by evapotranspiration. The annual water balance estimated with the model reveals that the total outflow to Lake Victoria is about 500×106 m3 per year, which occurs mainly in the wet seasons, i.e. from March to May and from November to January. The volume of runoff produced by agricultural land amounts to about 9% of the total runoff annually.

The location of the site where the pioneers settled permanently was determined by the availability of water in the immediate environment. The Highveld contains fertile soils, a fine climate, and an abundance of water. The area has always been extensively used for crop and stock farming, but in general, mixed farming was practiced. The farmers depended on the availability of water, therefore their experiences, observations, weather forecasts, and conclusions, developed into a popular folk meteorology. Furthermore, environmental factors such as local topography, micro climate, hydrography, ground fertility, and the appearance of natural vegetation determined whether or not an area was suitable for permanent residence. The farmstead may be divided into three functional zones (the core-, extended-, and outer farmyard) that are joined by a canal network, used for irrigation and drinking water. The farmhouse and buildings, erected a stones throw away from the water source, served as a focal point for the activities of the farmer. The manipulation of the water source by obstruction of streams and the construction of water canals, weirs and water furrows, assisted the farmer in planning his activities and in using the water to his advantage. The settlement and development of the residence on the rural parts of the Highveld may be divided into three distinct phases. Firstly, the temporary trekboer phase, secondly the pioneer phase and thirdly the permanent settlement phase. The permanence of residence had a direct influence in the layout of the house, the method of construction, and the use of the available water supply. At first, the trekkers were content to reside in roof dwellings (their wagons and tents and a grass screen as their kitchen and a hut near a spring). The first houses were hartbieshuise and kapsteilhuise. The more permanent homesteads of the earlier settlers were a simple rectangular structure (pioneer house) with a saddle grass roof. With the introduction of galvanised iron sheeting, the house was expanded and developed into the veranda-, stoeproom- and a flat roofed rectangular house. This development resulted into a typical rural Highveld homestead. After the discovery of gold in the vicinity of the Witwatersrand, the first gold rush took place resulting in the proclamation of Johannesburg in 1886. Prospectors, mostly foreigners, descended upon the Witwatersrand. Housing took on a more planned structure resembling the late Victorian period of housing in England. The water supply and drainage systems were planned and improved, making it possible to provide running water to kitchens and bathrooms. This impacted firstly on the upper riches of society in the cities, later on the lower middle classes and lastly on the rural areas. European technology regarding the supply of hot pipe water and drainage systems changed the layout of the house. The cooking activity moved from outside behind a screen to a seperate room inside the house. Inevitable changes regarding collecting, storage, purpose, saving and drainage of household water took place. Between 1840 and 1910, evolutionary changes took place regarding sanitation, water supply and personal hygiene. Being part of a particular social class made certain facilities available to certain individuals. A rural Highveld dwelling rarely included sanitary facilities, instead dwellers had a more primitive wash basin in each room in which they washed daily. On a Saturday, a weekly bath was taken in a bathtub in the kitchen or bedroom. Trekkers simply relieved themselves outside. A revolution in sanitary habits and facilities became inevitable. The Victorian dwelling on the Highveld was built according to a standard plan, including a flush water system already in place. This was the ultimate manifestation of sophistication and civilization. The aim of this investigation is to identify the similarities and differences between the use of water by the pioneer, the poor people and the wealthy in their rural dwellings. Furthermore, information has been obtained regarding water usage and sanitation in the bathroom and kitchen in the rural dwelling to be useful in the area of historic architecture and the heritage of our water history.
Thesis (M.A. (History))--North-West University, Vaal Triangle Campus, 2008.

The intense concentration of human activity in urban areas leads to changes in both the quantity and quality of runoff that eventually reaches our streams, lakes, wetlands, estuaries and coasts. The increasing use of impervious surfaces designed to provide smooth and direct pathways for stormwater run-off, has led to greater runoff volumes and flow velocities in urban waterways. Unmanaged, these changes in the quantity and quality of stormwater can result in considerable damage to the environment. Improved environmental performance is needed to ensure that the environmental values and beneficial uses of receiving waters are sustained or enhanced. Urban Stormwater - Best-Practice Environmental Management Guidelines resulted from a collaboration between State government agencies, local government and leading research institutions. The guidelines have been designed to meet the needs of people involved in the planning, design or management of urban land uses or stormwater drainage systems. They provide guidance in ten key areas: Environmental performance objectives; Stormwater management planning; Land use planning; Water sensitive urban design; Construction site management; Business surveys; Education and awareness; Enforcement; Structural treatment measures; and Flow management. Engineers and planners within local government, along with consultants to the development industry, should find the guidelines especially useful. Government agencies should also find them helpful in assessing the performance of stormwater managers. While developed specifically for application in Victoria, Australia, the information will be of value to stormwater managers everywhere.

Accurate information on the state of water resources in the Lake Victoria watershed is crucial for planning and sustainable development in the East African region. This region largely depends on its natural resource-base for economic development, and therefore comprehensive information on its resources dynamics is key in implementing poverty alleviation strategies, improving human condition and preserving the biological systems upon which the region‘s population depends. This chapter focuses on key issues, which have emerged as a result of population growth and development in the region. The research on which this chapter is based aims to address the concerns on land use and settlement trends in the study sites, vulnerability of the communities to water stress and sustainability of the livelihood systems in the watersheds of Nzoia River Basin (Kenya), Nakivubo Wetland (Uganda) and Simiyu River Basin (Tanzania). These communities engage in unique land use practices that have intensified environmental degradation in recent times. The research adopts a multi-disciplinary approach in bringing to the fore the various processes affecting watershed resources use and management in the selected wetlands of the Lake Victoria Drainage Basin (LVDB). The data presented covers trends in vegetation cover loss, pesticide pollution and general water quality parameters. Geographic information systems (GIS) and remote sensing techniques were employed to unveil land use patterns that have resulted in the degradation of the watershed. Wetland degradation levels have been characterized using secondary data generated by analytical techniques. New emerging challenges of environmental degradation caused by industrial, domestic and agricultural activities are presented and discussed. The potential of the new science of hydroinformatics in integrated watershed management through mathematical modeling, geographic information systems analysis and water supply management is highlighted.

At the Pine Ridge winery in Napa Valley, California, a sign lists six essential steps in wine production. The first step reads . . . Determine the site—prepare the land, terrace the slopes for erosion control, provide drainage and manage soil biodiversity. . . . Determining the site means gathering comprehensive data on the local cli­mate, topography, and geology, as well as the main soil types and their distribu­tion. Traditionally, site determination was done using the knowledge and experi­ence of individuals. Now it is possible to combine an expert’s knowledge with digital data on climate, parent material, topography, and soils in a GIS format to assess the biophysical suitability of land for wine grapes. Viticultural and soil ex­perts together identify the key properties and assign weightings to these proper­ties. An example of an Analytical Hierarchy Process is shown in figure 8.1. In this approach, both objective and subjective data were pooled and evaluated to decide the suitability of land for viticulture in West Gippsland, Victoria. In this region with a relatively uniform, mild climate, soil was given a 70% weighting, and the important soil properties were identified as depth, drainage, sodicity, texture, and pH. But in other areas, with another group of experts, a different set of key prop­erties and weightings may well be identified. For example, a similar approach used in Virginia, in the United States, gave only a 25% weighting to soil and 30% to elevation (which affected temperature, a critical factor governing growth rate and ripening) (Boyer and Wolf 2000). This kind of approach can be refined to indicate site suitability for a partic­ular variety within a region of given macroclimate. For example, Barbeau et al. (1998) assessed the suitability of sites in the Loire Valley, France, for the cultivar Cabernet Franc, using an index of “precocity.” Such an index is related to the ability of the fruit to accumulate sugar and anthocyanins and to attain a favorable acidity.