A unique value function for an optimal control problem of irrigation water intake from a reservoir harvesting flash floods     

Koichi?UnamiEmail authorView author&#;s OrcID profile  Osama?Mohawesh 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(11):3169-3182

Operation of reservoirs is a fundamental issue in water resource management. We herein investigate well-posedness of an optimal control problem for irrigation water intake from a reservoir in an irrigation scheme, the water dynamics of which is modeled with stochastic differential equations. A prototype irrigation scheme is being developed in an arid region to harvest flash floods as a source of water. The Hamilton–Jacobi–Bellman (HJB) equation governing the value function is analyzed in the framework of viscosity solutions. The uniqueness of the value function, which is a viscosity solution to the HJB equation, is demonstrated with a mathematical proof of a comparison theorem. It is also shown that there exists such a viscosity solution. Then, an approximate value function is obtained as a numerical solution to the HJB equation. The optimal control strategy derived from the approximate value function is summarized in terms of rule curves to be presented to the operator of the irrigation scheme.  相似文献   

Directional wave spectra at the regional scale with the KuROS airborne radar: comparisons with models     

Le Merle  Eva  Hauser  Danièle  Tison  Céline 《Ocean Dynamics》2019,69(6):679-699

Ocean Dynamics - In situ observations, satellite observations, and regional observations from airborne remote sensing are very useful to characterize sea state evolution and related physical...  相似文献   

Geomorphic controls on floodplain sediment and soil organic carbon storage in a Scottish mountain river     

Ward Swinnen  Teun Daniëls  Eline Maurer  Nils Broothaerts  Gert Verstraeten 《地球表面变化过程与地形》2020,45(1):207-223

River floodplains constitute an important element in the terrestrial sediment and organic carbon cycle and store variable amounts of carbon and sediment depending on a complex interplay of internal and external driving forces. Quantifying the storage in floodplains is crucial to understand their role in the sediment and carbon cascades. Unfortunately, quantitative data on floodplain storage are limited, especially at larger spatial scales. Rivers in the Scottish Highlands can provide a special case to study alluvial sediment and carbon dynamics because of the dominance of peatlands throughout the landscape, but the alluvial history of the region remains poorly understood. In this study, the floodplain sediment and soil organic carbon storage is quantified for the mountainous headwaters of the River Dee in eastern Scotland (663 km²), based on a coring dataset of 78 floodplain cross-sections. Whereas the mineral sediment storage is dominated by wandering gravel-bed river sections, most of the soil organic carbon storage can be found in anastomosing and meandering sections. The total storage for the Upper Dee catchment can be estimated at 5.2 Mt or 2306.5 Mg ha^-1 of mineral sediment and 0.7 Mt or 323.3 Mg C ha^-1 of soil organic carbon, which is in line with other studies on temperate river systems. Statistical analysis indicates that the storage is mostly related to the floodplain slope and the geomorphic floodplain type, which incorporates the characteristic stream power, channel morphology and the deposit type. Mapping of the geomorphic floodplain type using a simple classification scheme shows to be a powerful tool in studying the total storage and local variability of mineral sediment and soil organic carbon in floodplains. © 2019 John Wiley & Sons, Ltd.  相似文献   

Late stage differential exhumation of crustal blocks in the central Eastern Alps: evidence from fission track and (U–Th)/He thermochronology     

Andreas Wölfler  Christian Dekant  Martin Danišík  Walter Kurz  István Dunkl  Marián Putiš  Wolfgang Frisch 《地学学报》2008,20(5):378-384

Thermal history modelling based on zircon‐ and apatite fission track and apatite (U–Th)/He data constrain and refine the near‐surface exhumation of the south‐eastern Tauern Window (Penninic units) and neighbouring Austroalpine basement units in the Eastern Alps. Fast exhumation on both sides of the Penninic/Austroalpine boundary coincides with a period of lateral extrusion and tectonic denudation of the Penninic units in Miocene time (22–12 Ma). The jump to older ages occurs within the Austroalpine unit along the Polinik fault, which therefore defines the boundary between the tectonically denuded units and the hangingwall at that time. According to the different (U–Th)/He ages between the Penninic Hochalm‐ and Sonnblick Domes we demonstrate a differential cooling history of these two domes in the latest Miocene and early Pliocene.  相似文献   

Foreword     

Marc Van Meirvenne  Patrick Bogaert  Dimitri D��Or 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(8):1029-1029

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Comparative study of polycyclic aromatic hydrocarbons (PAHs) in plasma of Eastern Atlantic juvenile and adult nesting loggerhead sea turtles (Caretta caretta)     

Camacho M  Boada LD  Orós J  Calabuig P  Zumbado M  Luzardo OP 《Marine pollution bulletin》2012,64(9):1974-1980

Polycyclic aromatic hydrocarbons (PAHs) were measured in plasma samples of 162 juvenile loggerhead sea turtles (Caretta caretta) from Canary Islands, and 205 adult nesting loggerheads from Cape Verde. All the 367 samples showed detectable values of some type of PAH. Phenanthrene was the PAH most frequently detected and at the highest concentration in both populations. Median concentrations of ∑PAHs in the plasma of loggerheads from the Canary Islands and Cape Verde were similar (5.5 and 4.6ng/ml, respectively). Di- and tri-cyclic PAHs were predominant in both populations suggesting petrogenic origin rather than urban sources of PAHs. In the group of turtles from Canary Islands, there was evident an increasing level of contamination over the last few years. The present study represents the first data of contamination by PAHs in sea turtles from the studied areas.  相似文献   

Predation and competition effects on the size diversity of aquatic communities     

Xavier D. Quintana  Matías Arim  Anna Badosa  José María Blanco  Dani Boix  Sandra Brucet  Jordi Compte  Juan J. Egozcue  Elvira de Eyto  Ursula Gaedke  Stéphanie Gascón  Luis Gil de Solá  Kenneth Irvine  Erik Jeppesen  Torben L. Lauridsen  Rocío López-Flores  Thomas Mehner  Susana Romo  Martin Søndergaard 《Aquatic Sciences - Research Across Boundaries》2015,77(1):45-57

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When will it end? Long-lived intracontinental reactivation in central Australia     

Raphael Quentin de Gromard  Christopher L.Kirkland  Heather M.Howard  Michael T.D.Wingate  Fred Jourdan  Brent I.A.Mc Innes  Martin Daniík  Noreen J.Evans  Bradley J.McDonald  R.Hugh Smithies 《地学前缘(英文版)》2019,10(1):149-164

The post-Mesoproterozoic tectonometamorphic history of the Musgrave Province, central Australia, has previously been solely attributed to intracontinental compressional deformation during the 580 -520 Ma Petermann Orogeny. However, our new structurally controlled multi-mineral geochronology results,from two north-trending transects, indicate protracted reactivation of the Australian continental interior over ca. 715 million years. The earliest events are identified in the hinterland of the orogen along the western transect. The first tectonothermal event, at ca. 715 Ma, is indicated by40 Ar/39 Ar muscovite and U e Pb titanite ages. Another previously unrecognised tectonometamorphic event is dated at ca. 630 Ma by Ue Pb analyses of metamorphic zircon rims. This event was followed by continuous cooling and exhumation of the hinterland and core of the orogen along numerous faults, including the Woodroffe Thrust,from ca. 625 Ma to 565 Ma as indicated by muscovite, biotite, and hornblende40 Ar/39 Ar cooling ages. We therefore propose that the Petermann Orogeny commenced as early as ca. 630 Ma. Along the eastern transect,40 Ar/39 Ar muscovite and zircon(Ue Th)/He data indicate exhumation of the foreland fold and thrust system to shallow crustal levels between ca. 550 Ma and 520 Ma, while the core of the orogen was undergoing exhumation to mid-crustal levels and cooling below 600-660℃. Subsequent cooling to 150 -220℃ of the core of the orogen occurred between ca. 480 Ma and 400 Ma(zircon [Ue Th]/He data)during reactivation of the Woodroffe Thrust, coincident with the 450 -300 Ma Alice Springs Orogeny.Exhumation of the footwall of the Woodroffe Thrust to shallow depths occurred at ca. 200 Ma. More recent tectonic activity is also evident as on the 21 May, 2016(Sydney date), a magnitude 6.1 earthquake occurred, and the resolved focal mechanism indicates that compressive stress and exhumation along the Woodroffe Thrust is continuing to the present day. Overall, these results demonstrate repeated amagmatic reactivation of the continental interior of Australia for ca. 715 million years, including at least 600 million years of reactivation along the Woodroffe Thrust alone. Estimated cooling rates agree with previously reported rates and suggest slow cooling of 0.9 -7.0℃/Ma in the core of the Petermann Orogen between ca. 570 Ma and 400 Ma. The long-lived, amagmatic, intracontinental reactivation of central Australia is a remarkable example of stress transmission, strain localization and cratonization-hindering processes that highlights the complexity of Continental Tectonics with regards to the rigid-plate paradigm of Plate Tectonics.  相似文献   

森林水文服务市场的开发与经济激励机制――思考和启示     

Danièle Perrot-Maitre 《湿地科学与管理》2002,(3)

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Dévitrification et altération supergène d'une rhyolite (bassin du Paraná, Brésil) : mécanismes et bilans géochimiques     

Marjorie Bernard  Patrick Dudoignon  Norberto Dani 《Comptes Rendus Geoscience》2004,336(9):789-798

The weathering of a rhyolitic lava flow of the Paraná Basin (Brazil) developed, on few centimeters only, simplified petrographic features. The initial meteoric fluid pass-way is marked by celadonite-to-nontronite transformation. The second step is the complete dissolution of plagioclases, and the last one is the massive precipitation of halloysite. The geochemical mass balances according to the alteration features demonstrate the progressive leaching of major and trace elements fractionated by plagioclases, glass and opaques, and the sorption of Cu>As>Sb in the halloysite matrix. To cite this article: M. Bernard et al., C. R. Geoscience 336 (2004).  相似文献