Hamid Mirfenderesk

Comparison of Fuzzy-AHP and AHP in a spatial multi-criteria decision making model for urban land-use planning

Modern planning theories encourage approaches that consider all stakeholders with a variety of discourse values to avoid political and manipulative decisions. In the last decade, application of quantitative approaches such as multi-criteria decision making techniques in land suitability procedures has increased, which allows handling heterogeneous data. The majority of these applications mainly used decision-making techniques to rank the priority of predefined management options or planning scenarios. The presented study, however, shows how spatial decision-making can be used not only to rank the priority of options and performing scenario analysis, but also to provide insight into the spatial extent of the alternatives. This is particularly helpful in situation where political transitions in regard to urban planning policies leave local decision-makers with considerable room for discretion. To achieve this, the study compares the results of two quantitative techniques (analytical hierarchy procedure (AHP) and Fuzzy AHP) in defining the extent of land-use zones at a large scale urban planning scenario. The presented approach also adds a new dimension to the comparative analysis of applying these techniques in urban planning by considering the scale and purpose of the decision-making. The result demonstrates that in the early stage of the planning process, when identifying development options as a focal point is required, simplified methods can be sufficient. In this situation, selecting more sophisticated techniques will not necessarily generate different outcomes. However, when planning requires identifying the spatial extent of the preferred development area, considering the intersection area suggested by both methods will be ideal.

Uncertainty analysis in the application of multi-criteria decision-making methods in Australian strategic environmental decisions

Multi-criteria decision-making techniques have become increasingly widespread in strategic environmental decision making. In Australia, these techniques are used to integrate both conservation and development aspects of natural resource use. MCDM can also evaluate the effects of uncertainties at each stage of the decision-making process and examine the sensitivity of results to the inputs. This paper reviews the potential uncertainties in environmental management decision-making procedures and explores how uncertainty analysis in the framework of MCDM can address some of these uncertainties. It then examines the application of MCDM in 16 Australian case studies to determine how uncertainty has been addressed in practice. Results demonstrate that appropriate use of MCDM can address uncertainties associated with decision-makers’ preferences and from using different techniques (epistemic uncertainty). Results also highlighted the need for incorporating visualising techniques, such as GIS and simulation algorithms (e.g. Monte Carlo simulations), to examine the effects of uncertainty on the spatial pattern of the outcomes. This approach also presents promising ways to gain an understanding of the effects of some dimensions of stochastic uncertainty, and assists in increasing the transparency of the decision-making process.

The need for adaptive strategic planning

Purpose – The purpose of this paper is to explore the feasibility of developing an adaptive strategy to address the impact of climate change in the context of flooding.Design/methodology/approach – The paper analyses flood risk and highlights the need for an adaptive strategic plan for flood risk management under the impact of climate change. It introduces a framework for the development of an adaptive strategic plan. The paper identifies organizational issues (at the local government scale) associated with having an adaptive strategic plan and developing a methodology to address these issues. It also identifies the need for a strategic decision support system (SDSS) and conceptualizing the system in order to support adaptive planning principle.Findings – This study identifies lack of adaptability as a gap in traditional strategic planning for addressing flood risk associated with climate change. An adaptive strategic plan has adequate flexibility, promptness and responsiveness to adapt itself to new real...

Observation and Analysis of Hydrodynamic Parameters in Tidal Inlets in a Predominantly Semidiurnal Regime

Abstract Gold Coast Seaway and Jumpinpin Bar are two tidal inlets that connect the Pacific Ocean to the extensive Gold Coast estuarine system. While the Gold Coast Seaway has been stabilized in the mid-1980s by two rock walls, Jumpinpin Bar has remained a highly dynamic tidal inlet. A detailed study of these two tidal inlets is overdue and has been hindered for a long time by the lack of comprehensive field data. This study provides an extensive hydrodynamic data set, which on one side provides an insight into the hydrodynamic behavior of these two tidal inlets and on another side provides a base for their further study. The measured data show relatively high flow velocities at both locations exceeding 2 m/s. It also shows a strong spatial asymmetry in flow velocity distribution across the Gold Coast Seaway during the ebb tide, which accounts for some of the morphological changes at the study area. A five-month water-level measurement indicates a mixed, predominantly semidiurnal tidal regime at these tidal inlets. Examination of tidal variation shows minor temporal tidal asymmetry at both inlets with potential impact on the sediment transport regime at the inlets. In terms of stability, investigation into the tidal prism and cross-sectional area relationship for both inlets can be described using existing relationships obtained from regression analysis of tidal inlets on Pacific and Atlantic coasts. In regards to stability analysis based on tidal prism–littoral drift relationship, the Gold Coast Seaway seems to be approaching stability while Jumpinpin Bar seems to be more of a dynamic inlet.

Interaction between Coastal Development and Inland Estuarine Waterways at the Short–Medium Timescale

Abstract This article highlights the impact of tidal inlet modification on the evolution of inland estuarine waterways at the short–medium timescale. The study area is the Nerang River estuarine system located on the east coast of Australia. This estuary has been affected by a range of developments, including stabilization of its tidal entrance. This study is mainly focused on quantifying the tidal regime change and potential morphological and ecological implications resulting from these changes. To this end, the study started with field data collection and numerical modelling of the study area. The results of harmonic analysis showed that the Nerang Estuary responds nonlinearly to tidal forcing and is dominated by frictional forces. Analysis of water level and current time histories showed a mixed, predominantly semidiurnal, and flood-dominant tidal regime within the estuary. It also showed strong asymmetry of tide along the estuary. At the second stage of the study, historical data of the study area were analyzed and compared with the recently collected data. The purpose of this stage of the study was to understand the evolution of the estuary as a result of the changes at its entrance over the past 20 years. Variations in the ratio of amplitudes from M4 to M2 demonstrate that the Nerang Estuary nonlinear response to tidal forcing has reduced over the past 20 years. Analysis of historical data also suggests that the estuary has become less flood-dominant over the past 20 years, and as a result, the balance between tide-influenced sediment infilling and sediment flushing of the estuary during freshwater flooding events may have shifted toward transporting more sand out of the estuary.

Development of a Three Dimensional Model to Understand Modified Tidal Entrance Processes

This paper presents results from a three-dimensional numerical simulation of flow, mixing and transport processes at the Gold Coast Seaway tidal entrance. To simulate the flow field in a realistic situation, a three-dimensional model (MIKE3) for the study area is setup. An extensive observational data set including water level variations, current, salinity, temperature, wind and atmospheric pressure measurements has been used for calibration of the model. To compare the effectiveness of a two-dimensional simulation of advection-dispersion within the Seaway against the more realistic three dimensional simulation and to better understand the benefits of the three-dimensional approach, a vertically averaged two dimensional model (MIKE 21) of the study area has also have been developed and its results been compared with the three dimensional model. The two models are run under various environmental forces to examine the relative importance of the environmental forces on the mixing and transport processes within the study area.

Estuarine flood modelling using artificial neural networks

Prediction of water levels at estuaries poses a significant challenge for modelling of floods due to the influence of tidal effects. In this study, a two-stage forecasting system is proposed. In the first stage, the tidal portion of the available records is used to develop a tidal prediction system. The predictions of the first stage are used for flood modelling in the second. Experimental results suggest that the proposed flood modelling approach is advantageous for forecasting flood levels with more than 1 hour lead times.

Spatial uncertainty analysis in coastal land use planning: a case study at Gold Coast, Australia

ABSTRACT Mosadeghi, R., Warnken, J., Mirfenderesk, H., Tomlinson, R., 2013. Spatial uncertainty analysis in coastal land use planning: a case study at Gold Coast, Australia. Vulnerability of coastal areas to the global environmental changes and uncertainties in climate change predictions, particularly at local scales has presented a challenge to land-use planning in coastal cities. To make more accurate decisions, the uncertainty due to imperfect knowledge (epistemic uncertainty) is required to be considered in tandem with the inherent uncertainty or randomness of nature, and socio-economic dynamics (stochastic uncertainty). This paper examines the application of spatial Multi-criteria Decision Making (MCDM) tools to evaluate the effects of uncertainties at each stage of the decision- making process. The north east Gold Coast, Queensland (Australia) was considered as a case study to evaluate the sensitivity of the land-use planning decisions to input uncertainties. Uncertainty analysis in the framework of MCDM has been performed to address epistemic uncertainty. To examine the effects of uncertainty in a spatial context, conventional uncertainty analysis was combined with the visualisation capability of GIS and Monte Carlo simulation algorithm. The analysis results graphically display the sensitivity of output to the uncertainties in inputs and present a promising way to assist more transparency in the decision-making process.

Towards robust flood forecasts using neural networks

In this paper, design of a neural network for a domain-specific problem is described. The problem of concern is forecasting flood events where data is contaminated heavily by noise, training examples have different importance levels and noisy data coincides with the most important ones. To this end, two ideas are explored namely, changing the loss function and integrating a coefficient that reflects on the relative importance of training examples. To this end, backpropagation is re-derived considering implication of having a more general objective function. Independently, inclusion of scores associated with each training examples and its implication of overall loss function and the way weights are optimized is explored. The derived model is implemented in MATLAB and flood data from Talebudgera, Australia is considered for investigations. Compared to the base case being backpropagation, the results suggest that inclusion of scored for training examples corresponds to visible improvement when predicting peaks.

Water Circulation in the Coomera River Estuary

Abstract This paper describes development of a numerical tidal model and a data collection program for the Coomera River estuary on the Gold Coast. The primary objective of this project was to provide a detailed picture of the tidal characteristics within the study area; to investigate the degree and importance of tidal asymmetry at the Coomera River; to calculate the tidal prism; and also to enable the simulation of water circulation within the study area. A comprehensive data set was collected as part of this study to understand the local dynamics, and to calibrate and validate the model. The collected data include current, water level and meteorological forces in the study area. Calibration and validation were achieved through: comparison of computed tidal harmonics against those derived from harmonic analyses of the measured water level variations; and comparison between the measured discharges across four cross-sections at critical locations within the study area with the discharges predicted through modelling. As part of this study, harmonic analyses of the collected data were conducted to identify the major tidal constituents of the tidal signal within the study area. Calculations show that tide becomes mixed, and is mainly semi-diurnal in the estuary.