Flood-hazard assessment and risk-based zoning of a tropical flood plain: case study of the Yom River,Thailand     

Tawatchai Tingsanchali  Fazlul Karim 《水文科学杂志》2013,58(2):145-161

Abstract

This study contributes to the comprehensive assessment of flood hazard and risk for the Phrae flood plain of the Yom River basin in northern Thailand. The study was carried out using a hydrologic–hydrodynamic model in conjunction with a geographic information system (GIS). The model was calibrated and verified using the observed rainfall and river flood data during flood seasons in 1994 and 2001, respectively. Flooding scenarios were evaluated in terms of flooding depth for events of 25-, 50-, 100- and 200-year return periods. An impact-based hazard estimation technique was applied to assess the degree of hazard across the flood plain. The results showed that 78% of the Phrae flood-plain area of 476 km² in the upper Yom River basin lies in the hazard zone of the 100-year return-period flood. Risk analyses were performed by incorporating flood hazard and the vulnerability of elements at risk. Based on relative magnitude of risk, flood-prone areas were divided into low-, moderate-, high- and severe-risk zones. For the 100-year return-period flood, the risk-free area was found to be 22% of the total flood plain, while areas under low, medium, high and severe risk were 33, 11, 28 and 6%, respectively. The outcomes are consistent with overall property damage recorded in the past. The study identifies risk areas for priority-based flood management, which is crucial when there is a limited budget to protect the entire risk zone simultaneously.

Citation Tingsanchali, T. & Karim, F. (2010) Flood-hazard assessment and risk-based zoning of a tropical flood plain: case study of the Yom River, Thailand. Hydrol. Sci. J. 55(2), 145–161.  相似文献   

Assessment of the Relative Adequacy of Landfills as a Means of Solid Waste Disposal in Malaysia     

Zubaidah Ismail  Siti Zaleha Abdullah  Siti Zulaikha Othman  Sharif M. Shirazi  Ramlee Karim 《洁净——土壤、空气、水》2013,41(11):1122-1128

This study examined the relative adequacy of active landfills between states in Malaysia. The percentages of closed landfills were determined. The accessibility and loading of the landfills were examined. The characteristics of each landfill studied were noted. The study involved the compilation and analyses of data on groundwater, stream water and current land use surrounding landfills. Results of the study showed that the number of active landfills was not adequate to handle solid waste disposal. The potential of alternative approaches was examined and discussed.  相似文献   

Modelling hydrological connectivity of tropical floodplain wetlands via a combined natural and artificial stream network          下载免费PDF全文

Fazlul Karim  Anne Kinsey‐Henderson  Jim Wallace  Paul Godfrey  Angela H. Arthington  Richard G. Pearson 《水文研究》2014,28(23):5696-5710

The ecological condition and biodiversity values of floodplain wetlands are highly dependent on the hydrological connectivity of wetlands to adjacent rivers. This paper describes a method for quantifying connectivity between floodplain wetlands and the main rivers in a wet tropical catchment of northern Australia. We used a one‐dimensional hydrodynamic model to simulate time‐varying water depths across the stream network (i.e. rivers, streams and man‐made drains). The timing and duration of connectivity of seven wetlands (four natural and three artificial) with the two main rivers in the catchment were then calculated for different hydrological conditions. Location and areal extent of the wetlands and the stream network were identified using high‐resolution laser altimetry, and these data formed key inputs to the hydrodynamic model. The model was calibrated using measured water depths and discharges across the floodplain. An algorithm was developed to identify contiguous water bodies at daily time steps, and this gave the temporal history of connection and disconnection between wetlands and the rivers. Simulation results show that connectivity of individual wetlands to both rivers varies from 26 to 365 days during an average hydrological condition. Location, especially proximity to a main river, and wetland type (natural stream or artificial drain) were identified as key factors influencing these levels of connectivity. Some natural wetlands maintain connection with the river for most or all of the year, whereas the connectivity of some artificial wetlands varies from 26 to 36 days according to their patterns of network connection to adjacent rivers – a result that has important implications for the accessibility of these types of wetland to aquatic biota. Using readily available river gauge data, we also show how connectivity modelling can be used to identify periods when connectivity has fallen below critical thresholds for fish movement. These connectivity patterns within the floodplain network are central to the setting of river flows that will meet environmental requirements for biota that use floodplain wetlands during their life history. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

A new pan-sharpening method using multiobjective particle swarm optimization and the shiftable contourlet transform     

Jamal Saeedi  Karim Faez   《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(3):365-381

In this paper, a novel approach based on multiobjective particle swarm optimization (MOPSO) is presented for panchromatic (Pan) sharpening of a multispectral (MS) image. This new method could transfer spatial details of the pan image into a high-resolution version of the MS image, while color information from the low-resolution MS image is well preserved. The pan and MS images are locally different because of different resolutions, and therefore we cannot directly combine them in the spatial domain. For this reason, we generate two initial results, which are more appropriate for a weighted combination. First, the pan and the MS images are histogram matched. Then we use the shiftable contourlet transform (SCT) to decompose the histogram-matched pan and MS images. The SCT is a new shiftable and modified version of the contourlet transform. In this step, an algorithm based on the SCT is used to generate two initial results of the high-resolution MS images. Our objective is to produce two modified high-resolution MS images, in which one has high spatial similarity to the pan image and the other one has high radiometric quality in each band. Therefore, we have used two different fusion rules to integrate the high-frequency contourlet coefficients of the pan and MS images to generate two initial results of high-resolution MS image or the pan-sharpened (PS) image. Finally, we can find the optimal PS image by applying the MOPSO algorithm and using the two initial PS results. Specifically, the PS image is obtained via a weighted combination of the two initial results, in which the weights are locally estimated via a multiobjective particle swarm optimization algorithm to generate a PS image with high spatial and radiometric qualities. Based on experimental results obtained, the produced pan-sharpened image also has good spectral quality. The efficiency of the proposed method is tested by performing pan-sharpening of high-resolution (Quickbird and Wordview2) and medium-resolution (Landsat-7 ETM +) datasets. Extensive comparisons with the state-of-the-art pan-sharpening algorithms indicate that our new method provides improved subjective and objective results.  相似文献   

Incorporating climate change into water resources planning for the town of Polokwane,South Africa   总被引：2，自引：0，他引：2  

James Cullis  Ken Strzepek  Mark Tadross  Karim Sami  Beyers Havenga  Burgert Gildenhuys  Joel Smith 《Climatic change》2011,108(3):437-456

Incorporating climate change into water resource planning is crucial to ensuring sustainable growth and development. The aim of this study was to investigate how the proposed steps to incorporating climate change into project planning developed by USAID could be applied in practice using the town of Polokwane in northeastern South Africa as a case study. Two Regional Circulation Models (RCMs) and statistical downscaling from a range of General Circulation Models (GCMs) were used to produce a set of monthly climate scenarios for 2025 and 2050. These scenarios were used to estimate the impact on surface water runoff in the Olifants River catchment and the Letaba River catchment, and groundwater recharge in the Sand River Aquifer. The impact on the potential yields from the existing Flag Bashielo Dam and other proposed dams in the Olifants River catchment were determined using the Water Resources Yield Model (WRYM). The results of the analysis were discussed at a regional stakeholders workshop. The workshop participants concluded that the higher priority for now should be on water conservation and demand management (WCDM) and to consider a phased approach to developing additional storage capacity. The results of this study show that the six-stage process for incorporating climate change into resource planning can be applied in practice and that the potential threat of climate change can give emphasis to existing win–win approaches such as WCDM and phased implementation that should form part of any sustainable water resource planning approach.  相似文献   

Ocean acoustic noise and passive coherent array processing     

Philippe Roux  W.A. Kuperman  Karim G. Sabra 《Comptes Rendus Geoscience》2011,343(8-9):533-547

Broadband correlation processing for extracting time-domain Green's functions and coherent wavefronts from random ocean noise has been demonstrated recently using experiments and numerical simulations that are consistent with theoretical predictions. Ocean acoustic noise processing presents additional challenges over its seismological counterpart. Mainly, the ocean environment is temporally non-stationary and it is spatially heterogeneous. Further, in the lower underwater acoustic frequency regime of about 20 to 500 Hz, space-time episodic shipping is the dominant noise source. The data from different publications and research groups are gathered here, with the goal being to review recent underwater acoustic research that demonstrates the viability and potential applications of passive coherent array processing in the ocean.  相似文献   

Review of constitutive models for describing the time dependent behaviour of soft clays     

Md. Rajibul Karim  C. T. Gnanendran 《Geomechanics and Geoengineering》2014,9(1):36-51

Different classes of constitutive models have been proposed to capture the time-dependent behaviour of soft soil (creep, stress relaxation, rate dependency). This paper critically reviews many of the models developed based on understanding of the time dependent stress-strain-stress rate-strain rate behaviour of soils and viscoplasticity in terms of their strengths and weaknesses. Some discussion is also made on the numerical implementation aspects of these models. Typical findings from numerical analyses of geotechnical structures constructed on soft soils are also discussed. The general elastic viscoplastic (EVP) models can roughly be divided into two categories: models based on the concept of overstress and models based on non-stationary flow surface theory. Although general in structure, both categories have their own strengths and shortcomings. This review indicates that EVP analysis is yet to be vastly used by the geotechnical engineers, apparently due to the mathematical complication involved in the formulation of the constitutive models, unconvincing benefit in terms of the accuracy of performance prediction, requirement of additional soil parameter(s), difficulties in determining them, and the necessity of excessive computing resources and time.  相似文献   

Comparison of the antioxidant defense system in Crassostrea rhizophorae and Crassostrea gigas exposed to domestic sewage discharges     

Zanette J  Nunes FF  Medeiros ID  Siebert MN  Mattos JJ  Lüchmann KH  Rodrigues de Melo CM  Bainy AC 《Marine environmental research》2008,66(1):196-198

Oysters Crassostrea rhizophorae and Crassostrea gigas were kept for fourteen days at four sites in S?o José, SC, Brazil, chosen according to a sewage discharge contamination gradient. Enzymatic activities of CAT, GST, G6PDH and GR were evaluated in gills and digestive glands. Higher CAT activity was observed in tissues of C. rhizophorae in response to sewage contamination possibly indicating peroxisome proliferation induction. C. gigas showed elevated G6PDH activity in digestive gland, and GR in gills, after domestic sewage exposure. In conclusion, C. rhizophorae and C. gigas showed different biochemical responses after in situ exposure to domestic sewage. However, C. rhizophorae showed more significant changes in CAT suggesting that this organism could be a better monitor to this kind of effluent.  相似文献