Assessment of Spatial Variation of Groundwater Quality and Its Relationship With Land Use in Perth Metropolitan

To determine the effects of land use on groundwater quality in Western Australia, a quantitative analysis is carried out using groundwater quality data supplied by the Department of Water from over 500 groundwater wells across the Perth metropolitan area. We analyzed four main groundwater quality indicators; nutrients, physical parameters, inorganic non metals and trace metals. We found that groundwater beneath agricultural land was found to be particularly susceptible to nutrient loading due to the application of fertilizers. Nutrient levels were found to be rising over time due to increasing agriculture and urban development. Industrial areas were also found to have numerous contamination plumes that continue to migrate with the groundwater flow. According to Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines and the Australian Drinking Water Guidelines (ADWG), several areas including rural areas like Carabooda lake, Gnangara and Jandakot Mounds, Cockburn Sound, Forrestdale, Joondalup, and Ellenbrook and high density urban areas like Balcatta and Neerabup, industrial areas like North Fremantle, Welshpool and Kwinana are indentified as the vulnerable areas for groundwater quality

Characteristics of Stormwater Runoff in Different Land Use Areas

Research covered in this paper has outlined the basis for a detailed study into the specific effects of land use onstorm water runoff and drainage. It can be seen that the runoff is highly variable although still follows some basic trends with one of these being heavily based on land use. This study used different land use areas including residential, commercial, industrial and agricultural areas. Results show the temporal change of rainfall versus overland flow for each land use type. In addition the results concluded the rainfall – runoff relationship for each land use areas. It is obvious from the research carried out here that there are also a lot more factors that affect the runoff quantity and characteristics

Comparing Hydrology and Hydraulics Surface Routing Approaches in Modeling an Urban Catchment

Urban hydrological environment is difficult to assess with its complex verity of components by using simple hydrological models which are not fully capable enough to represents the exact urban catchment’s features. The urban catchments comprising with various infrastructures having low permeability and low roughness coefficients have increased their runoff volume, while decreasing the time of concentration. This has been caused urban flooding threatening the urban environments in many aspects. This study uses two of numerical modeling approaches to represent the urban catchment, and assess the flood risk of an urban catchment; hydrological surface routing approach and hydraulic 2D surface routing approach. Both approaches were combined with 1D hydraulic stormwater drainage network. XPSWMM was used as the modeling tool. Comparison of results of two approaches shows that the both approaches are suitable to represent urban catchment’s hydrological behavior, but the results of hydrological surface routing are more close to observation data. When representing the flood inundation areas, it is better to use the hydraulic approach since it calculates the flood depth by using surface runoff and excess water from pipe network at the same time

Geotechnical Assessment of Soil Permeability in Land Development Areas

Infiltration is identified as one of the best operational and sustainable methods to handle urban storm water. Until recently, in stormwater management designs and selection of best stormwater management strategies, permeability value of different soils were not been considered as major factor. Due to the increasing housing density local land development authorities requires storm water runoff from developing lots to be retained/detained within the property. Due to lack of information on local soil properties, specifically permeability rates within the soil predominant in land development areas, it is difficult to assess storm water retention/detention requirement. This case study was carried out within the new development areas in Gosnells in Western Australia mainly focusing on identification of different soil types with respect to their infiltration capacities in selection of best stormwater management strategies. The Guelph Permeameter have been used to investigate the saturated permeability of different soil types. Based on the above tests, the results have been categorized in to four main types of permeability groups; Very Rapid (> 1.56 m/day), Rapid (0.48<1.56 m/day), Moderate (0.12<0.48 m/day) and Slow (<0.12 m/day). Finally, with the help of the existing soil map, the point represent permeability data were been generalized logically. These results have been used to develop permeability maps representing the areal average. The soil types and their observed permeability values compared with the literature; soil classification data of Department Agriculture. The comparison shows that field test data has a higher agreement with literature based soil classification. These field tests will be extended to identify the best stormwater management practices for the selected land development areas. The result will be useful for land developers as well as authorities, decision makers and policy makers to come up with sustainable land development strategies

Development of storm water quality improvement strategy plan for local city councils in Western Australia

The aim of this study was to develop a storm water quality improvement strategy plan (WQISP) which assists managers and decision makers of local city councils in enhancing their activities to improve regional water quality. City of Gosnells in Western Australia has been considered as a case study. The procedure on developing the WQISP consists of reviewing existing water quality data, identifying water quality issues in the study areas and developing a decision making tool for the officers, managers and decision makers. It was found that land use type is the main factor affecting the water quality. Therefore, activities, sources and pollutants related to different land use types including residential, industrial, agricultural and commercial are given high importance during the study. Semi-structured interviews were carried out with coordinators of different management sections of the regional councils in order to understand the associated management framework and issues. The issues identified from these interviews were used in preparing the decision making tool. Variables associated with the defined "value versus threat" decision making tool are obtained from the intensive literature review. The main recommendations provided for improvement of water quality in local city councils, include non-structural, structural and management controls and potential impacts of climate change

Assessment of Urban Stormwater Quality in Western Australia

The main aim of this study was to understand the impacts of land use on stormwater quality. Stormwater samples have been collected from three main land use areas; residential, commercial and industrial lands around the Town of Victoria Park in Western Australia. Each sample was tested to measure water quality parameters such as total organic carbon (TOC), suspended solids (SS), total nitrogen (TN), Nitrate Nitrogen (NO3-), Nitrite Nitrogen (NO2−), Ammonia Nitrogen (NH3-N) and total phosphorus (TP). Time variation of stormwater flow, rainfall intensity and stormwater quality clearly showed that the highest concentration of pollutants in stormwater occurs during the first flush event. Further analysis shows that the commercial stormwater demonstrated the cleanest appearing stormwater with lowest amounts of suspended solids whereas the industrial stormwater had the dirtiest appearing stormwater quality. Nutrients in the residential stormwater have the lowest nitrate, ammonia and phosphate concentrations. Overall, the industrial land use site recorded the worst stormwater quality. These results of the preliminary study are only a snapshot of the quality of Western Australia's stormwater runoff, but they emphasize the value of further detailed investigations

Urban Flood Control and Management - An Integrated Approach

Flood management is one of the important fields in urban storm water management. Floods are influenced by the increase of huge storm event, or improper planning of the area. This study mainly provides the flood protection in four stages; planning, flood event, responses and evaluation. However it is most effective then flood protection is considered in planning/design and evaluation stages since both stages represent the land development of the area. Structural adjustments are often more reliable than nonstructural adjustments in providing flood protection, however structural adjustments are constrained by numerous factors such as political constraints and cost. Therefore it is important to balance both adjustments with the situation. The technical decisions provided will have to be approved by the higher-ups who have the power to decide on the final solution. Costs however, are the biggest factor in determining the final decision. Therefore this study recommends flood protection system should have been integrated and enforces more in the early stages (planning and design) as part of the storm water management plan. Factors influencing the technical decisions provided should be reduced as low as possible to avoid a reduction in the expected performance of the proposed adjustments

Urban Flood Control and Management - An Integrated Approach

Introduction to a Symposium on Peirce's theory of the "Economy of Research

Assessment of snowmelt triggered landslide hazard and risk in Japan

This study is pertaining to an evaluation of landslide occurrence on natural terrain due to snowmelt in Japan, using a probabilistic model based on multiple logistic regression analysis. The evaluation concerns several physical parameters such as hydraulic parameters, geographical parameters and geological parameters which are considered to be influential in the occurrence of landslides. A Snow Water Equivalent model (SWE) is utilized to estimate snowmelt and associated infiltration in light, heavy and normal snow years. Using the constructed spatial data-sets, we apply a multiple logistic regression model to produce landslide susceptibility maps showing the spatial–temporal distribution of landslide hazard probabilities throughout Japan using 1 km × 1 km resolution grid cells. The results have revealed that, over 95% landslide hazard probability exists in the mountain ranges on the western side of Japan (the Japan Sea side). In particular, this study is dealing with the Aizu region of Fukushima prefecture in order to verifying the landslide hazard probability. Verification proved that, the areas identified as high risk areas (having over 90% landslide hazard probability in numerical modeling) show 87% agreement with observed landslides in the Aizu region. Also we evaluated the relationship between landslides and snow melting process giving special concern to change of temperature in the spring