Drought and water policy in Australia: Challenges for the future illustrated by the issues associated with water trading and climate change adaptation in the Murray–Darling Basin     

Anthony S. Kiem 《Global Environmental Change》2013,23(6):1615-1626

This paper reviews historical and existing drought and water policy in Australia in order to gain a sense of the strengths and weaknesses in enabling effective adaptation to climate change. In particular, (a) the social, economic, and environmental costs and benefits of water trading and (b) the limitations of using ‘market-based’ instruments (MBIs), like water trading, for adapting to drought and water security related climate change impacts are investigated. It was found that water trading has potential as a climate change adaptation strategy with many benefits experienced in previous and current versions of water trading. However, there are also limitations and those negatively impacted by water trading are hit hard. These social impacts of water trading have not been thoroughly investigated and are not well understood. Significant uncertainty also exists around the impacts of water trading on the environment (e.g. changed hydrological regimes, underestimation of sustainable environmental flows etc.). Proper quantification of these impacts is needed, however, it is a complex task given Australia's large hydroclimatic variability and the current lack of understanding as to how to optimise water needs of the environment, humans, agriculture and other industries. It appears that ‘cap and trade’ quantity-based MBIs such as water trading will eventually do what they are designed to do (i.e. reallocate a resource to ‘high value’ users). However, given that the ‘low value’ users in this case are agriculture and town/urban water supply (not including drinking water) and the ‘high value’ users are mining, manufacturing, and electricity production (i.e. high greenhouse gas emissions), do we really want the water trading MBI to achieve its objective? And, what would the social and environmental ramifications of such a shift in water use within Australia be? These questions, along with the limitations and potential implications of using water trading (and MBIs in general) as a climate change adaptation tool, must be carefully considered if past Australian drought and water policy failures are not to be repeated.  相似文献   

Inverse vibration technique for structural health monitoring of offshore jacket platforms     

《Applied Ocean Research》2017

In this paper a new approach is introduced for structural health monitoring of offshore jacket platforms. The procedure uses the measured ambient vibration responses and the corresponding readable natural frequencies and mode shapes of the structural system. Since offshore platforms are composed of heavy topsides supported by jacket structures, participation of the first mode is dominant in each direction in the response of the structure under field excitations. Moreover, ambient vibrations such as wave loads and boat impacts only excite the first modes of the structure. Therefore, it is difficult to find higher modes and the pertinent frequencies by use of accelerometers data. The introduced innovative method in this research uses the first few fundamental frequencies and mode shapes of the structure. The algorithm employs the inverse vibration technique to develop a simple two and three dimensional reference model for monitoring health of the structure. To show the efficiency of the proposed procedure, a case study is carried out on the models of a jacket-type platform in the Persian Gulf, namely SPD2. Finally, an uncertainty analysis is performed, due to the existence of noises and uncertainties in input data collected by accelerometers. Results indicate that the proposed method has the ability to detect the induced damages by a high level of accuracy considering probable sources of error.  相似文献   

Sedimentary evolution of overlapped sand bodies in terrestrial faulted lacustrine basin: Insights from 3D stratigraphic forward modeling     

《Marine and Petroleum Geology》2017

Terrestrial faulted lacustrine basins usually have large variabilities in structural subsidence and multiple river sources. The facies in such basins are thus characterised by frequently changed facies and complex relationship of overlapped sand bodies (e.g. Liaoxi Depression of Liaodong Bay, Bohai Sea, China). Therefore, it's a great challenge to quantitatively describe evolution of sand bodies and their overlap relationship. In this study a three-dimensional stratigraphic forward model is used to solve this problem, which is corrected according to well log data. After the parameter optimization was verified against borehole strata thickness and lithology, this model had a thickness error within 8%, and the lithology distribution agreed with the well data as a whole.Four evolution phases of the Shahejie 3 Formation were recognised through the modeling. In the first phase, the lake level rose, and the eastern fan delta sand developed. In the second phase, the fan delta sand scaled up, and the braided river delta front sand developed at a small scale. In the third phase, the lake level shifted from falling to rising, the fan delta sand further expanded the scale, and the braided river delta developed at a large scale. Sands on both sides overlapped at a large scale. In the fourth phase, the lake level rose, the lake basin expanded, and lake shale was the main lithology in the study area. From the sedimentary evolution of Es3 formation, sand overlapped in the third stage. In 39.75 Ma, two parts of the sand body began to overlap and reached largest scale in 39.6 Ma, which was approximately 10 km². Both then retrograded to a separation in 39 Ma when the overlap ended.Coupling stratigraphic forward simulation with uncertainty quantification allowed us to estimate the influence of each stratigraphic parameter on sand overlap. Fluvial discharge appears to be the most influential parameter while the initial bathymetry and lake level variations exert a minor to moderate impact.  相似文献   

砂卵(砾)石动剪切模量比与阻尼比的试验研究     

王晓军  赵凤新  尤红兵  聂大巍 《震灾防御技术》2018,13(1):1-12

砂卵(砾)石的动剪切模量比和阻尼比是河谷地貌场地地震反应分析的重要参数,对设计地震动参数的确定有重要影响。本文利用商洛市地震小区划项目砂卵石的动三轴试验结果,结合其他砂卵(砾)石动三轴试验结果,分组统计得到了稍密、中密、密实砂卵(砾)动三轴试验的推荐结果。建立了典型场地模型,研究了其动剪切模量比和阻尼比的不确定性对场地地震反应的影响。研究表明:动剪切模量比、阻尼比平均值±1倍标准差的不确定性对砂卵石场地峰值加速度的影响较小,说明了分组及统计结果的合理性;不同概率水平下,动剪模量比、阻尼比的变化导致高频部分反应谱有明显差异,0.04-0.1s的反应谱变化范围在20%左右,但对大于1.0s的长周期反应谱影响很小。针对砂卵(砾)石动剪切模量比和阻尼比的研究对提高工程场地设计地震动参数的可靠性具有重要意义。  相似文献   

Perceptual models of uncertainty for socio-hydrological systems: a flood risk change example   总被引：2，自引：2，他引：0  

Ida K. Westerberg  Keith J. Beven  Gemma Coxon  Tobias Krueger 《水文科学杂志》2017,62(11):1705-1713

Characterizing, understanding and better estimating uncertainties are key concerns for drawing robust conclusions when analyzing changing socio-hydrological systems. Here we suggest developing a perceptual model of uncertainty that is complementary to the perceptual model of the socio-hydrological system and we provide an example application to flood risk change analysis. Such a perceptual model aims to make all relevant uncertainty sources – and different perceptions thereof – explicit in a structured way. It is a first step to assessing uncertainty in system outcomes that can help to prioritize research efforts and to structure dialogue and communication about uncertainty in interdisciplinary work.  相似文献   

Dynamical analysis and robust control for dive plane of supercavitating vehicles     

《Applied Ocean Research》2019

The high-speed supercavitating vehicle (HSSV) utilizes advanced technology that enables an underwater vehicle to reach its unprecedented high speed. The vertical motion control of the HSSV is challenging problem because of its complex dynamics with nonlinear planing force, parametric uncertainties, external disturbances, actuator saturation, and sensor noises. This paper deals with dynamical analysis and a robust H∞ loop-shaping synthesis with modified PID (proportional-integral-derivative) algorithm to control the dive plane maneuver of the HSSV. Typically, the control scheme has the low order structure and provides robustness against dynamic uncertainties, which can be implemented using the bilinear matrix inequality (BMI) optimization of an equivalent Schur formula. Simulation results show that the controlled vehicle system provides good performance and high robustness against uncertainties, ensuring no-overshoot and fast in time-domain responses. In addition, the control algorithm can decouple the dynamic interactions in the multi-input multi-output (MIMO) system, overcoming parametric uncertainty, planing force, and actuator saturation while minimizing the effect of the strong external disturbances and measurement noises.  相似文献   

断层圈闭形成机制及时空配置有效性评价——以歧口凹陷歧南斜坡为例     

汪顺宇  孙晓军  王海学  李静  姜文亚  曹晓峰  毕晨阳  种健 《地质科学》2020,(1):93-108

断层的分段生长和连接控制着断层圈闭的形成,为了研究断层形成过程对圈闭形成的控制作用,应用位移/离距法和位移梯度比法判别断层相互作用阶段,落实断层圈闭的空间匹配有效性。针对空间匹配的断层圈闭,应用最大断距相减法开展断层圈闭形成时期的研究,在成藏关键时期前形成的断层圈闭是油气有利聚集的部位。本文以歧口凹陷歧南斜坡的南大港同向断层与扣村反向断层为例,开展断层圈闭时空配置有效性评价,研究结果表明油气多分布在同时具备空间和时间匹配有效的断层圈闭内,仅具备空间或时间匹配有效性的断层圈闭中未见油气聚集。因此,通过对未钻探断层圈闭开展时空匹配有效性评价,能够有效地降低勘探开发的风险。  相似文献   

Uncertainty in the analysis of speed and powering trials     

M. Insel   《Ocean Engineering》2008,35(11-12):1183-1193

Full-scale speed trials of a ship have been questioned for the uncertainty of speed and power measurements especially when the sea conditions differ from the ideal calm water conditions. Such uncertainty has been investigated by utilizing ITTC standard speed/powering trial analysis procedure through Monte Carlo simulations. A case study was conducted for a set of sea trials with 12 sister ships for which sea trial data were available for a range of displacement, water depth, water temperature, wind speed and wave height values. Precision errors were observed as the most influential error source for the whole speed range, even though their effects were more substantial at low speeds. Beaufort scale was observed as the most important elementary error source indicating the need for the best weather conditions for the most reliable sea trail predictions.  相似文献   

时空数据质量与模型     

童小华 《地理信息世界》2009,7(2)

时空数据不确定性与数据质量是地理信息科学的基础理论之一,也是GIS应用发展的重要问题.本文作为ISPRS2008大会专题"时空数据质量与模型"导读,从空间实体的位置不确定性、数字高程模型的位置不确定性、遥感数据的不确定性、属性数据的不确定性与质量控制、空间分析与操作的不确定性传播和空间数据采集的不确定性与处理等方面,分析了时空数据不确定性与数据质量的最近发展.  相似文献   

遥感反演中参数的不确定性与敏感性矩阵   总被引：26，自引：6，他引：20  

李小文  高峰  王锦地  朱启疆 《遥感学报》1997,1(1):5-14

多角度遥感中二向性反射（ＢＲＤＦ）物理模型的反演,是当前国际遥感界学术研究的热点之一,反演中先验知识的表达和利用,参数敏感性的判别和处理,已提出了若干年,但只是到最近,才有了将参数的先验概率引入拟合误差平方加权,及定义参数对观测值敏感性的尝试,该文简述了这些最新进展,并首次建议了反演中参数的“不确定性与敏感性矩阵”的定义,并以作者最近的反演实例,说明这样定义的矩阵,如何直接用于反演的多阶段目标决策  相似文献