Integrated management and conservation of Dutch coastal areas: Premises, practice and solutions

Both the basic principles and some practical examples of the integrated environmental management of coastal areas in The Netherlands (land as well as water systems) are explored. It is shown that the developments in ideas about nature conservation and nature management during the last few decades may be recognized in the recent decisions of the Dutch government with respect to the coastal dune areas and to the marine environment. The present practical management of the coastal dunes is given, together with the present policy in the Netherlands for the preservation and development of the dune areas. In this policy, the multipurpose use of Dutch dunes within the main aim of nature conservation is a starting point for current and future management and preservation. For the shallow Wadden Sea in the north of The Netherlands, the policy is for the integral preservation of natural values by a (revised) physical planning key decision (PKD) of the Dutch government. A specific case of nature protection in relation to (mussel and cockle) fishery in the Wadden Sea and water pollution is considered.     

Quantitative failure metric for gravity dams

Quantitative failure monitoring is a critical tool for safety assessment of concrete dams. This includes damage occurrence, intensity, location, number, size, and propagation pattern. Such an assessment is essential for a quantifiable prioritization of repair and will thus reduce overall cost and improve safety. This paper will address this timely topic through the nonlinear transient analysis of a dam and failure will be ascertained through a multi‐scale damage index. A damage‐plastic model for mass concrete is used, Drucker‐Prager elasto‐plastic one for the foundation, and infinite elements are used for far‐field boundaries. Water‐dam interaction is accounted for through fluid finite elements. It is determined that the proposed damage indices can indeed provide a quantitative metric for the degree of failure in gravity dams in terms of the input dynamic motion. Copyright © 2014 John Wiley & Sons, Ltd.     

Amplification of flood discharge caused by the cascading failure of landslide dams

The cascading failure of multiple landslide dams can trigger a larger peak flood discharge than that caused by a single dam failure.Therefore,for an accurate numerical simulation,it is essential to elucidate the primary factors affecting the peak discharge of the flood caused by a cascading failure,which is the purpose of the current study.First,flume experiments were done on the cascading failure of two landslide dams under different upstream dam heights,downstream dam heights,and initial downstream reservoir water volumes.Then,the experimental results were reproduced using a numerical simulation model representing landslide dam erosion resulting from overtopping flow.Finally,the factors influencing the peak flood discharge caused by the cascading failure were analyzed using the numerical simulation model.Experimental results indicated that the inflow discharge into the downstream dam at the time when the downstream dam height began to rapidly erode was the main factor responsible for a cascading failure generating a larger peak flood discharge than that generated by a single dam failure.Furthermore,the results of a sensitivity analysis suggested that the upstream and downstream dam heights,initial water volume in the reservoir of the downstream dam,upstream and downstream dam crest lengths,and distance between two dams were among the most important factors in predicting the flood discharge caused by the cascading failure of multiple landslide dams.     

Effects of “Grain for Green” reforestation program on rural sustainability in China: an AHP approach to peasant consensus of public land use policies

Climate change will affect the regional ability to achieve the poverty reduction and sustainable development (SD) objectives. Thus, any action plans to achieve these objectives should make climate change policies an integral part of the development planning process. The best practices and measures of climate change policies should be implemented to ensure regional or community sustainability. In this paper, a case study that promotes the integration of carbon sequestration into sustainable forest management and rural development plan with multi-stakeholders participation is introduced. To achieve SD goals, appropriate tools and methods are required to address impacts of alternative forest land uses on carbon sequestration and rural sustainability, and to prioritise land use options. A range of forest land use scenarios that address various aspects of the forest carbon sequestration rate and rural sustainability are evaluated against a SD indicator system. Planting vegetation is one of the practical approaches in mitigating global warming by sequestrating carbon from the atmosphere to plant matter and soil. In order to protect environment, reduce excessive soil erosion, and decrease the propensity and frequency of flooding and other natural disasters, China has initiated nationwide pivotal projects such as “Grain for Green” to mitigate exacerbated environmental deterioration and degradation. Such ecological programs may affect the socio-economic livelihoods of peasants and the economic activities of the whole region. The impact and economic uncertainty associated with such projects urge policy makers to include all stakeholders in the decision making process so that an agreeable solution towards sustainable rural development can be identified. This study uses Liping County in Guizhou province as a case study to identify a consensus among peasants regarding planting selected tree-species. Analytic hierarchy process (AHP) is used as a multicriteria decision making tool to rank sustainability criteria and determine the priority of options. The method helps policy makers to understand what the peasants want to achieve by participating in a Grain for Green program and what their priorities are with respect to particular types of vegetation. The case study finds that economic and financial concerns are the most important drivers of the decision of which trees to plant among the peasants who took part in the implementation of the Grain for Green program. As a result of this, Gingko, redpine, and Chinese chestnut were the predominant trees planted under the program. The integrated assessment based on the AHP method provides an effective tool to help understand how economic, social and environmental factors are related to each other in affecting the nature of rural sustainability.     

Modeling urban land use conversion of Daqing City,China: a comparative analysis of “top-down” and “bottom-up” approaches

During the past decades, Daqing City, China has experienced unprecedented urban expansion due to the rapid development of petroleum industry. With rapid urbanization and lack of strategic planning, Daqing is facing many socio-economic and environmental problems, and it is essential to examine the process of urbanization, and to develop policy recommendations for sustainable development. To address this problem, this paper examined the urbanization process of Daqing City through developing two multi-level models: an integrated system dynamic (SD) and CLUE-S model (SD-CLUES), and an integrated SD and stochastic cellular automata model (SD-CA). Analysis of results suggests that these two models generate significantly different results. With the SD-CLUES model, new urban developments are clustered in the downtown area or along major transportation networks, indicating exogenous driving forces playing an important role in shaping urban spatial dynamics. With the SD-CA model, on the contrary, the resultant new urban cells are spread over the entire study area, and associated with existing urban areas. Further, visual comparisons and validations indicate that the SD-CA model is a better alternative in explaining the urbanization mechanism of Daqing City. In addition, analysis of results suggests that the stochastic factor in the CA model has significant impact on the modeling accuracy.     

The common agricultural policy and the general environmental policies concerned with agriculture in the European Community and their implications for fertilizer consumption

This paper traces the major developments in the European Common Agricultural Policy (CAP) and related environmental policy and examines their impact on the use of crop nutrients. The objectives of the CAP were set out in the Treaty of Rome in 1957 and have not been explicitly revised. The Community has, however, progressed from being a significant importer to a major exporter of food. Various changes in the policy measures/reforms, have been implemented, each to control the continuing increase in farm output. The latest of these in May 1992 reduced commodity prices towards world market levels, introduced 15% set aise for arable land, as well as agreeing a number of agri-environmental measures. Further changes are anticipated following the Uruguay Round of the General Agreement on Tariffs and Trade (GATT) and as new trade agreements are reached with the countries of the former Eastern Bloc. Inevitably, existing farm systems will be subject to careful reappraisal. The Community's environmental objectives were added to the Treaty in 1987 with the passing of the European Single Act. The interaction between agriculture and the environment has been a prominent concern. The Directive 91/676, which seeks to protect water against pollution caused by nitrate from agricultural sources, is the first Directive to have a major direct impact on farm practive. The Fifth Environmental Action Plan for 1993–2000 ‘Towards Sustainability’ selects agriculture as one of five industries for specific attention. The plan seeks an extensification of agriculture and a reduction in the use of chemicals. Changes in the amount of plant nutrients from both farmyard manure and mineral fertilizers used in agriculture are quantified. Methods of determining the efficiency with which they are utilized are assessed. New advisory techniques which will improve the efficiency of nutrient use on the farm are considered, as are the implications for the future demand for nutrients from mineral fertilizers. This paper is the view of the European Fertilizer Manufacturers Association.     

Probabilistic eruption forecasting at short and long time scales

Any effective volcanic risk mitigation strategy requires a scientific assessment of the future evolution of a volcanic system and its eruptive behavior. Some consider the onus should be on volcanologists to provide simple but emphatic deterministic forecasts. This traditional way of thinking, however, does not deal with the implications of inherent uncertainties, both aleatoric and epistemic, that are inevitably present in observations, monitoring data, and interpretation of any natural system. In contrast to deterministic predictions, probabilistic eruption forecasting attempts to quantify these inherent uncertainties utilizing all available information to the extent that it can be relied upon and is informative. As with many other natural hazards, probabilistic eruption forecasting is becoming established as the primary scientific basis for planning rational risk mitigation actions: at short-term (hours to weeks or months), it allows decision-makers to prioritize actions in a crisis; and at long-term (years to decades), it is the basic component for land use and emergency planning. Probabilistic eruption forecasting consists of estimating the probability of an eruption event and where it sits in a complex multidimensional time–space–magnitude framework. In this review, we discuss the key developments and features of models that have been used to address the problem.     

Nonlinear seismic response of tall concrete-faced rockfill dams in narrow canyons

The seismic behavior of tall concrete face rockfill dams in narrow canyons is investigated, based on numerical simulation of the staged construction, creep settlements, reservoir impoundment and seismic shaking of the dam. The study takes into account the flexibility of the canyon rock, the hydrodynamic effects and potential dynamic rockfill settlements. The static analysis uses a hyperbolic model for the rockfill, whereas the dynamic analysis uses a nonlinear hysteretic model, which accounts for the initial dynamic stiffness and produces hysteresis loops in agreement with the experimental data regarding the shear modulus and damping ratio. A damage plasticity model is used for the reinforced concrete, whereas frictional contact behavior is considered at the base and vertical walls of the concrete slab panels. An existing 150-m-high dam is used to investigate some key issues on the seismic behavior of such dams subjected to upstream−downstream and vertical excitation. Emphasis is placed on the evaluation of the tensile stresses within the slab panels, the compressive stresses at the slab-to-slab vertical interfaces and the opening of the joints. Moreover, the effect of potential dynamic settlements on both the slab stresses and joint openings is investigated. Recommendations for increasing the dam safety and reducing the water leakage through the dam body are given.     

Adjustments in channel morphology due to land‐use changes and check dam installation in mountain torrents of Calabria (southern Italy)

In Mediterranean semi‐arid conditions, the availability of studies monitoring channel adjustments as a response to reforestation and check dams over representative observation periods, could help develop new management strategies. This investigation is an integrated approach assessing the adjustments of channel morphology in a typical torrent of southern Italy after land‐use changes and check dam construction across a period of about 60 years. A statistical analysis of historical rainfall records, an analysis of land‐use changes in the catchment area and a geomorphological mapping of channel adjustments were carried out and combined with field surveys of bed surface grain‐size over a 5‐km reach including 14 check dams. The analysis of the historical rainfall records showed a slight decrease in the amount and erosivity of precipitation. Mapping of land‐use changes highlighted a general increase of vegetal coverage on the slopes adjacent to the monitored reaches. Together with the check dam network installation, this increase could have induced a reduction in water and sediment supply. The different erosional and depositional forms and adjustments showed a general narrowing between consecutive check dams together with local modifications detected upstream (bed aggradation and cross‐section expansion together with low‐flow realignments) and downstream (local incision) of the installed check dams. Changes in the torrent bends were also detected as a response to erosional and depositional processes with different intensities. The study highlighted: the efficiency of check dams against the disrupting power of intense floods by stabilizing the active channel and the influence of reforestation in increasing hillslope protection from erosion and disconnectivity of water and sediment flows towards the active channel. Only slight management interventions (for instance, the conversion of the existing check dams into open structures) are suggested, in order to mobilize the residual sediment avoiding further generalized incision of the active channel and coast line erosion. Copyright © 2017 John Wiley & Sons, Ltd.     

Seismic failure modeling of concrete dams considering heterogeneity of concrete

Study on the failure process of high concrete dams subjected to strong earthquakes is crucial to reasonable evaluation of their seismic safety. Numerical simulation in this aspect involves dynamic failure analysis of big bulk concrete dam subjected to cyclic loading. The Rock Failure Process Analysis (RFPA) proposed by C.A. Tang, with successful applications to failure modeling of rock and concrete specimens mainly subjected to static loading, is extended for this purpose. For using the proposed model, no knowledge on the cracking route needs to be known beforehand, and no remeshing is required. Simulation of the whole process of elastic deformation, initiation and propagation of microcracks, severe damage and ultimate failure of concrete dams in earthquakes with a unified model is enabled. The model is verified through a shaking table test of an arch dam. Finally a practical gravity dam is employed as a numerical example. Considering the uncertainty in ground motion input and concrete material, typical failure process and failure modes of gravity dam are presented. Several small cracks may occur due to tension particularly at dam neck, dam faces and dam heel, and a few of them evolve into dominant ones. Relatively smaller earthquake may cause damage to the dam neck while a bigger one may bring on cracks at lower parts of the dams. Cracking at the dam bottom may incline to a direction almost perpendicular to the downstream face after propagating horizontally for a certain distance when the shaking is strong enough.     

Seismic failure modeling of concrete dams considering heterogeneity of concrete

Study on the failure process of high concrete dams subjected to strong earthquakes is crucial to reasonable evaluation of their seismic safety. Numerical simulation in this aspect involves dynamic failure analysis of big bulk concrete dam subjected to cyclic loading. The Rock Failure Process Analysis (RFPA) proposed by C.A. Tang, with successful applications to failure modeling of rock and concrete specimens mainly subjected to static loading, is extended for this purpose. For using the proposed model, no knowledge on the cracking route needs to be known beforehand, and no remeshing is required. Simulation of the whole process of elastic deformation, initiation and propagation of microcracks, severe damage and ultimate failure of concrete dams in earthquakes with a unified model is enabled. The model is verified through a shaking table test of an arch dam. Finally a practical gravity dam is employed as a numerical example. Considering the uncertainty in ground motion input and concrete material, typical failure process and failure modes of gravity dam are presented. Several small cracks may occur due to tension particularly at dam neck, dam faces and dam heel, and a few of them evolve into dominant ones. Relatively smaller earthquake may cause damage to the dam neck while a bigger one may bring on cracks at lower parts of the dams. Cracking at the dam bottom may incline to a direction almost perpendicular to the downstream face after propagating horizontally for a certain distance when the shaking is strong enough.     

Hybrid method to update the design flood shape for spillway operation in a dam: case study of the Huites Dam,Mexico

To design and review the operation of spillways, it is necessary to estimate design hydrographs, considering their peak flow, shape and volume. A hybrid method is proposed that combines the shape of the design hydrograph obtained with the UNAM Institute of Engineering Method (UNAMIIM) with the peak flow and volume calculated from a bivariate method. This hybrid method is applied to historical data of the Huites Dam, Sinaloa, Mexico. The goal is to estimate return periods for the maximum discharge flows (that account for the damage caused downstream) and the maximum levels reached in the dam (measure of the hydrological dam safety) corresponding to a given spillway and its management policy. Therefore, to validate the method, the results obtained by the flood routing of the 50-year hydrograph are compared with those obtained by the flood routing of the three largest historical floods. Both maximum flow and elevation were in the range of values observed within 37.5–75 years corresponding to the length of the historical record.     

Blunt extension of discrete universal multifractal cascades: development and application to downscaling

ABSTRACT

Scale issues are ubiquitous in geosciences. Because of their simplicity and intuitiveness, and despite strong limitations, notably its non-stationarity features, discrete random multiplicative cascade processes are very often used to address these scale issues. A novel approach based on the parsimonious framework of Universal Multifractals (UM) is introduced to tackle this issue while preserving the simple structure of discrete cascades. It basically consists in smoothing at each cascade step the random multiplicative increments with the help of a geometric interpolation over a moving window. The window size enables to introduce non-conservativeness in the simulated fields. It is established theoretically,] and numerically confirmed, that the simulated fields also exhibit a multifractal behaviour with expected features. It is shown that such an approach remains valid over a limited range of UM parameters. Finally, we test downscaling of rainfall fields with the help of this blunt discrete cascade process, and we discuss challenges for future developments.     

An integrated model to simulate sown area changes for major crops at a global scale

Dynamics of land use systems have attracted much attention from scientists around the world due to their ecological and socio-economic implications. An integrated model to dynamically simulate future changes in sown areas of four major crops (rice, maize, wheat and soybean) on a global scale is pre- sented. To do so, a crop choice model was developed on the basis of Multinomial Logit (Logit) model to model land users' decisions on crop choices among a set of available alternatives with using a crop utility function. A GIS-based Environmental Policy Integrated Climate (EPIC) model was adopted to simulate the crop yields under a given geophysical environment and farming management conditions, while the International Food Policy and Agricultural Simulation (IFPSIM) model was utilized to estimate crop price in the international market. The crop choice model was linked with the GIS-based EPIC model and the IFPSIM model through data exchange. This integrated model was then validated against the FAO statistical data in 2001-2003 and the Moderate Resolution Imaging Spectroradiometer (MODIS) global land cover product in 2001. Both validation approaches indicated reliability of the model for ad- dressing the dynamics in agricultural land use and its capability for long-term scenario analysis. Finally, the model application was designed to run over a time period of 30 a, taking the year 2000 as baseline. The model outcomes can help understand and explain the causes, locations and consequences of land use changes, and provide support for land use planning and policy making.     

地震波斜入射输入体系下坝后式厂房易损性分析

为了考虑地震波斜入射对坝后式厂房易损性的影响,通过斜入射SV波和P波波场叠加,在地表得到与实测地震动一致的设计地震动分量。同时为了考虑坝后式厂房的动力损伤,在程序中嵌入混凝土动力损伤本构,编写了可以考虑地震波斜入射体系的结构易损性分析程序。最后从太平洋地震工程研究中心（PEER）数据库中选取26条近场地震动数据,根据峰值地面加速度（PGA）对每条地震波进行调幅,以我国西南地区某坝后式厂房为工程实例,用增量动力学分析法计算了其上下游墙体在不同强度斜入射体系地震动作用下的易损性曲线。与传统垂直入射模式下的地震易损性曲线对比发现,传统垂直入射下的破坏概率较高,两种入射模式破坏概率最大相差26%。其中,坝后式厂房下游墙的破坏概率比上游墙大,最大相差可19%。因此坝后式厂房的抗震设计需考虑地震波斜入射的影响,并重点考虑下游墙部位的抗震安全性。     

Investigation of the elevation of saltwater wedge due to subsurface dams

Subsurface dams are rather effective and used for the prevention of saltwater intrusion in coastal regions around the world. We carried out the laboratory experiments to investigate the elevation of saltwater wedge after the construction of subsurface dams. The elevation of saltwater wedge refers to the upward movement of the downstream saltwater wedge because the subsurface dams obstruct the regional groundwater flow and reduce the freshwater discharge. Consequently, the saltwater wedge cannot further extend in the longitudinal direction but rises in the vertical profile resulting in significant downstream aquifer salinization. In order to quantitatively address this issue, field-scale numerical simulations were conducted to explore the influence of various dam heights, distances, and hydraulic gradients on the elevation of saltwater wedge. Our investigation shows that the upward movement of the saltwater wedge and its areal extension in the vertical domain of the downstream aquifer become more severe with a higher dam and performed a great dependence on the freshwater discharge. Furthermore, the increase of the hydraulic gradient and the dam distance from the sea boundary leads to a more pronounced wedge elevation. This phenomenon comes from the variation of the freshwater discharge due to the modification of dam height, location, and hydraulic gradient. Large freshwater discharge can generate greater repulsive force to restrain the elevation of saltwater wedge. These conclusions provide theoretical references for the behaviour of the freshwater–seawater interface after the construction of subsurface dams and help optimize the design strategy to better utilize the coastal groundwater resources.     

Regime shifts in the marine environment: the scientific basis and political context

Regime shifts in the marine environment have recently received much attention. To date, however, few large-scale meta-analyses have been carried out due to insufficient data coverage and integration between sustained observational datasets because of diverse methodologies used in data collection, recording and archival. Here we review the available data on regime shifts globally, followed by a review of current and planned policies with relevance to regime shifts.We then focus on the North and Baltic Seas, providing examples of existing efforts for data integration in the MarBEF Network of Excellence. Existing gaps in data coverage are identified, and the added value from meta-analyses of multiple datasets demonstrated using examples from the MarBEF integrated data project LargeNet. We discuss whether these efforts are addressing current policy needs and close with recommendations for future integrated data networks to increase our ability to understand, identify and predict recent and future regime shifts.     

Analysis of seismic disaster failure mechanism and dam-break simulation of high arch dam

Based on a Chinese national high arch dam located in a meizoseismal region, a nonlinear numerical analysis model of the damage and failure process of a dam-foundation system is established by employing a 3-D deformable distinct element code(3DEC) and its re-development functions. The proposed analysis model considers the dam-foundation-reservoir coupling effect, infl uence of nonlinear contact in the opening and closing of the dam seam surface and abutment rock joints during strong earthquakes, and radiation damping of far fi eld energy dissipation according to the actual workability state of an arch dam. A safety assessment method and safety evaluation criteria is developed to better understand the arch dam system disaster process from local damage to ultimate failure. The dynamic characteristics, disaster mechanism, limit bearing capacity and the entire failure process of a high arch dam under a strong earthquake are then analyzed. Further, the seismic safety of the arch dam is evaluated according to the proposed evaluation criteria and safety assessment method. As a result, some useful conclusions are obtained for some aspects of the disaster mechanism and failure process of an arch dam. The analysis method and conclusions may be useful in engineering practice.     

Prediction of the behaviour of landslide dams using a geomorphological dimensionless index

Landslide dams are a common phenomenon. They form when a landslide reaches the bottom of a river valley causing a blockage. The first effect of such a dam is the infilling of a lake that inundates the areas upstream, while the possibility of a sudden dam collapse, with a rapid release of the impounded waters, poses a higher flood risk to the downstream areas. The results of the main inventories carried out to date on landslide dams, have been examined to determine criteria for forecasting landslide dam evolution with particular emphasis on the assessment of dam stability. Not all landslides result in the blockage of a river channel. This only occurs with ones that can move a large amount of material with moderate or high‐velocities. In most cases, these landslides are triggered by rainfall events or high magnitude earthquakes. A relationship also exists between the volume of the displaced material and the landslide dam stability. Several authors have proposed that landslide dam behaviour can be forecast by defining various geomorphological indexes, that result from the combination of variables identifying both the dam and the dammed river channel. Further developments of this geomorphological approach are presented in this paper by the definition of a dimensionless blockage index. Starting with an analysis of 84 episodes selected worldwide, it proved to be a useful tool for making accurate predictions concerning the fate of a landslide dam. Copyright © 2002 John Wiley & Sons, Ltd.     

长白山天池火山溃湖洪水最大流量的初步估算及影响分析

长白山天池火山是目前最具潜在喷发危险的活火山。依据长白山天池火山的最新监测研究成果,结合地形地貌、水文流域特点及天池火山历史喷发类型,重点分析了长白山天池火山未来喷发时发生溃湖洪水的危险性。利用相关的水动力学公式,建立了溃口规模和洪水湿周、流量和流速的内在关系。详细分析溃湖洪峰在下游二道白河镇、白山水电站、红石水电站等关键位置的最大流量及流速。结果表明,若天池火山湖水溃泄一半即10亿m3时,距火山口50km处的二道白河镇瞬时洪水流速达84 904m3/s,该镇将全部被淹没。下游的白山水库、丰满水库将分别受到流量23 560m3/s和1 505m3/s洪水的冲击,水库安全受到严重威胁。