Prediction in a socio-hydrological world     

V. Srinivasan  M. Sanderson  M. Garcia  M. Konar  G. Blöschl  M. Sivapalan 《水文科学杂志》2020,65(Z2):338-345

ABSTRACT

Water resource management involves public investments with long-ranging impacts that traditional prediction approaches cannot address. These are increasingly being critiqued because (1) there is an absence of feedbacks between water and society; (2) the models are created by domain experts who hand them to decision makers to implement; and (3) they fail to account for global forces on local water resources. Socio-hydrological models that explicitly account for feedbacks between water and society at multiple scales and facilitate stakeholder participation can address these concerns. However, they require a fundamental change in how we think about prediction. We suggest that, in the context of long-range predictions, the goal is not scenarios that present a snapshot of the world at some future date, but rather projection of alternative, plausible and co-evolving trajectories of the socio-hydrological system. This will both yield insights into cause–effect relationships and help stakeholders identify safe or desirable operating space.  相似文献   

Moving socio-hydrologic modelling forward: unpacking hidden assumptions,values and model structure by engaging with stakeholders: reply to “What is the role of the model in socio-hydrology?”*     

V. Srinivasan  M. Sanderson  M. Garcia  M. Konar  G. Blöschl  M. Sivapalan 《水文科学杂志》2020,65(Z2):1444-1446

ABSTRACT

The arguments presented in Melsen et al. advance ideas in the “Panta Rhei” decade (2013–2022) of the International Association of Hydrological Sciences, which focuses on change in hydrology and society. While we reiterate that, despite acknowledged shortcomings, the enterprise of integrating societal feedbacks into hydrological models is beneficial in prediction and adaptive management, we also agree with the sentiments of the authors. In response, we offer concrete steps the socio-hydrologic community can take to educate modellers to become aware about unconscious biases embedded in model structure and clearly communicate assumptions. We stress the need for “knowledge brokers” that can help modellers work with stakeholders, instead of doing everything themselves. We also caution, however, against the danger of over-reaching. Young scholars already pay a big price by having to master both the natural and social sciences. As coupled human–water problems increase in societal importance, along with calls for more holistic thinking, we also need to promote an academic culture that rewards reaching across the aisle.  相似文献   

Morphostructural provinces and neotectonics in the Amazonian lowlands of Peru     

J.F. Dumont  E. Deza  F. Garcia   《Journal of South American Earth Sciences》1991,4(4)

The Amazonian lowlands of Peru are composed of the Subandean Zone (foreland), the Marañón Basin (foredeep) and the Iquitos Geanticline (Brazilian Craton). The Subandean Zone includes the Subandean Thrust and Fold Belt (STFB) to the west, which crops out mostly in the foothills, and the Subandean Tilted Block Zone (STBZ) to the east, which is principally exposed in the Amazonian lowlands of central Peru. The main trends of river belts are related to structural style. Main rivers in the STFB are antecedent, and secondary drainage is subsequent. In the STBZ, river basins are channelized, parallel to structural grain. The special asymmetric pattern of the Subandean drainage network depends on these two juxtaposed structural regions. As a result, fluvial migration in Peruvian lowlands is more controlled and limited by neotectonics than previously supposed.  相似文献   

Chemistry and palynology of carbon seams and associated rocks from the Witwatersrand goldfields, South Africa     

L.B. Ebert  E.I. Robbins  K.D. Rose  R.V. Kastrup  J.C. Scanlon  L.A. Gebhard  A.R. Garcia 《Ore Geology Reviews》1990,5(5-6)

Carbon seams in the Witwatersrand System of South Africa host some of the richest gold concentrations in the world. A study of the microscopic characteristics in thin sections and acid residues, and of the chemical and physical nature of the carbon-bearing phases, was undertaken to gain some understanding of the biological precursors and thermal changes that have occurred since the seams were buried.The HCl---HF acid-resistant organic tissues in this Early Proterozoic coal are filamentous and spherical, which are typical morphologies for microorganisms. The tissues are carbonized black as would be expected for metamorphic rocks, so usual palynological techniques were of limited use. Therefore, the chemical and physical nature of the organic remains was studied by ratios, X-ray diffraction (XRD), ¹³C nuclear magnetic resonance (NMR), reductive chemistry, crosspolarization/magic angle spinning NMR (CP/MAS), and electron spin resonance (ESR).The ratios of the samples examined are similar to those of semi-anthracite and petroleum cokes from delayed cokers. XRD shows graphite is not present and that the gold is in elemental form, not chemically bound or intercalated between carbon planes. NMR shows that both aromatic and paraffinic carbons are present. Integration of the carbon NMR spectra suggests that 80% of the carbon is sp²-hybridized and 20% is sp³-hybridized. Reductive chemistry shows that the benzenoid entities are larger than common polynuclear aromatic hydrocarbons such as perylene and decacyclene. Dipolar dephasing CP/MAS NMR suggests the presence of two types of paraffinic carbons, a rigid methylene group and a rotating methyl group. The narrowing of the ESR linewidth between room temperature and 300°C shows that the materials examined have not previously been subjected to temperatures as high as 300°C.  相似文献   

Nature and cause of compositional variation among the alkalic cap lavas of Mauna Kea Volcano,Hawaii     

H. B. West  M. O. Garcia  F. A. Frey  A. Kennedy 《Contributions to Mineralogy and Petrology》1988,100(3):383-397

Most Hawaiian basaltic shield volcanoes are capped by moderately to strongly evolved alkalic lavas (MgO<4.5 wt.%). On Mauna Kea Volcano the cap is dominantly composed of hawaiite with minor mugearite. Although these lavas contain dunite and gabbroic xenoliths, they are nearly aphyric with rare olivine and plagioclase phenocrysts and xenocrysts. The hawaiites are nearly homogeneous in radiogenic isotope ratios (Sr, Nd, Pb) and they define coherent major and trace element abundance trends. These compositional trends are consistent with segregation of a plagioclase-rich cumulate containing significant clinopyroxene and Fe-Ti oxides plus minor olivine. Elements which are usually highly incompatible, e.g., Rb, Ba, Nb, are only moderately incompatible within the hawaiite suite because these elements are incorporated into feldspar (Rb, Ba) and oxides (Nb). However, in the most evolved lavas abundances of the most incompatible elements (P, La, Ce, Th) exceed (by 5–10%) the maximum enrichments expected from models based on major elements. Apparently, the crystal fractionation process was more complex than simple, closed system fractionation. The large amounts of clinopyroxene in the fractionating assemblage and the presence of dense dunite xenoliths with CO₂ inclusions formed at minimum pressures of 2 kb are consistent with fractionation occurring at moderate depths. Crystal segregation along conduit or magma chamber walls is a possible mechanism for explaining compositional variations within these alkalic cap lavas.  相似文献   

Contrasting fluid evolution of granulite-facies marbles: implications for a high-T intermediate-P terrain in the Famatinian Range, San-Juan, Argentina     

Florian Gallien  Aberra Mogessie  Ernesto Bjerg  Sergio Delpino  Brigida Castro de Machuca 《Mineralogy and Petrology》2009,95(1-2):135-157

High-temperature, intermediate-pressure calc-silicate marbles occur in the granulite-facies terrain of the La Huerta Range in the Province of San Juan, NW-Argentina, in three bulk-compositional varieties: Type (1) dolomite-absent scapolite-wollastonite-grandite-clinopyroxene-quartz—calcite marbles; Type (2) diopside-forsterite-spinel-corundum—calcite marbles with dolomite exolution lamellae in calcite; Type (3) serpentinized forsterite-spinel-dolomite marbles. An isobaric cooling path from peak-metamorphic conditions of 860°C to 750°C at 6.5 kbar is inferred from scapolite-wollastonite-grandite reaction textures in Type (1) and is consistent with cooling after an advective heat input from related gabbroic and tonalitic intrusive bodies. Stable carbon and oxygen isotope geochemistry was used to decipher the fluid/rock evolution of the three marble types. An interpreted four-stage temperature-time-fluid flow path comprises: (1) infiltration of pre-peak-metamorphic fluids, depleted in δ¹⁸O, that caused a shift of primary sedimentary δ¹⁸O ratios to lower values (19.6–20.0); (2) syn-metamorphic fluid liberation from Type (1) marbles with evidence for processes close to batch devolatilization that caused a weak coupled ¹³C and ¹⁸O depletion during prograde metamorphism. A different devolatilization behaviour, close to Rayleigh fractionation, texturally associated with fold settings indicates that granulite-facies fluid flow was focused rather than pervasive; (3) H₂O-absent conditions were dominant when coronal grandite formed during incipient high-temperature isobaric cooling at the expense of scapolite and wollastonite in the Type (1) marbles; (4) intense post-peak- hydration of Type (2) and Type (3) marbles is the last recognizable metasomatic event. In combination, the three marble types record fluid infiltration both before and after the metamorphic peak.  相似文献   

Relics of eclogite facies assemblages in the Ceará Central Domain, NW Borborema Province, NE Brazil: Implications for the assembly of West Gondwana   总被引：1，自引：0，他引：1  

Ticiano J. Saraiva dos Santos  Maria da Glria M. Garcia  Wagner Silva Amaral  Renauld Caby  Eberhard Wernick  Michel H. Arthaud  Elton L. Dantas  M. Santosh 《Gondwana Research》2009,15(3-4):454-470

The Borborema Province, in the NE of Brazil, is a rather complex piece in the Brazil–Africa puzzle as it represents the junction of the Dahomeyide/Pharusian, Central African, Araçuai and Brasilia fold belts located between the West-African/São Luis, Congo/São Francisco and Amazonas craton. The correlation between the Dahomeyides from W-Africa (Ghana, Benin, Togo, and Mali) and the Borborema Province involves the Médio Coreaú and Central Ceará domains. The inferred continuation of the main oceanic suture zone exposed in the Dahomeyides of W Africa is buried beneath the Phanerozoic Parnaíba Basin in Brazil (northwest of the Médio Coreaú domain) where some high density gravity anomalies may represent hidden remnants of an oceanic suture. In addition to this major suture a narrow, nearly continuous strip composed of mainly mafic pods containing relics of eclogite-facies assemblages associated with partially migmatized granulite-facies metapelitic gneisses has been found further east in the NW Borborema Province. These high pressure mafic rocks, interpreted as retrograded eclogites, are located between the Transbrasiliano Lineament and the Santa Quitéria continental arc and comprise primitive to evolved arc-related rocks with either arc- or MORB-type imprints that can indicate either deep subduction of oceanic lithosphere or roots of continental and oceanic magmatic arcs. Average peak P–T conditions under eclogite-facies metamorphism (T = 770 °C and P = 17.3 kbar) were estimated using garnet–clinopyroxene thermometry and Jd content in clinopyroxene. Transition to granulite-facies conditions, as well as later widespread re-equilibration under amphibolite facies, were registered both in the basic and the metapelitic rocks and suggest a clockwise P–T path characterized by an increase in temperature followed by strong decompression. A phenomenon possibly related to the exhumation of a highly thickened crust associated with the suturing of the Médio Coreaú and Central Ceará domains, two distinct crustal blocks separated by the Transbrasiliano Lineament.  相似文献   

Recent deformation at the junction between the North Luzon block and the Central Philippines from ERS-1 Images   总被引：2，自引：0，他引：2  

M. Pubellier  F. Garcia  A. Loevenbruck and  J. Chorowicz 《Island Arc》2000,9(4):598-610

Abstract The transfer of the major part of the motion between the Philippine Sea Plate and the Sunda block is accommodated along a north-west shear wide zone partly on the Philippine Fault and partly on the Sibuyan Verde Passage Fault (SVPF) as indicated by global positioning satellite and geological data. Given the limited motion along the SVPF and the important motion along the Philippine Fault, as well as the necessity of a connection between these faults and the southern Manila Trench, a transtensional motion along the northeast-southwest Macolod Corridor (MC) may be predicted. We used synthetic aperture radar European remote sensing (SAR ERS-1) images to analyze the volcano– tectonic features of this area, because these images are sensitive to minute textural or topographic contrasts resulting from small effects of recent deformation. In addition, they allow us to determine accurately the shape of the base of volcanic edifices and to detect linear clusters of very small adjacent cones. The results presented herein allow us to extend the features recognized earlier to a larger MC. Large faults actually connect the Philippine Fault to the Sibuyan Verde Passage Fault all across the Taal Volcanic Field. In addition to extension along north-east faults, we identify an important component of left-lateral strike–slip underlined by fault scarps, dykes, alignments of volcanoes and pull-apart basins, accompanied by extension along north-south faults. A relative chronology of the fractures and volcanic edifices is proposed. When compared to the existing ages of the volcanics, an evolution scheme of the area may be proposed, according to which extension shifted from a nearly north-south opening between 5 and 2 million years to a direction close to east-west at Present. The early north-south extension existed in the Marinduque Basin and may have migrated northward and rotated to the present MC.  相似文献   

Internal structure of Tenerife (Canary Islands) based on gravity, aeromagnetic and volcanological data     

V. Araa  A. G. Camacho  A. Garcia  F. G. Montesinos  I. Blanco  R. Vieira  A. Felpeto 《Journal of Volcanology and Geothermal Research》2000,103(1-4)

Gravity and magnetic methods have been applied to the Tenerife Island, to provide new information about its internal structure. For this study, 365 gravity stations covering the central part of the island have been selected. The anomalous density maps at different depths were obtained by means of an inversion global adjustment, on fixed density contrast, to describe the three-dimensional (3D) geometry of the anomalous bodies. On the other hand, several analysis techniques, such as reduction to the pole, spectral analysis, low-pass filtering, terrain correction and forward modelling, were applied to process the high-resolution data obtained in an aeromagnetic survey, completed with marine and terrestrial data.The joint analysis of gravity and magnetic anomalies has shown tectonic and volcanic features that define some fundamental aspects of the structural framework and volcanic evolution of the island. A strong gravity anomaly produced by a large and deep source has been associated with an uplifted block of the basement beneath the southern part of Tenerife. The sources of the observed gravity highs from 8 km b.s.l. may be associated with the growth of the submarine shield stage that was clearly controlled by regional tectonic.The long-wavelength magnetic anomalies reveal highly magnetic sources, interpreted as gabbro-ultramafic cumulates associated with the root zone of a large dyke swarm. This intrusive body could be topped by the emplacement zone of magma chambers that correlate with a magnetic horizon at 5.7±0.8 km depth. Rooted in this highly magnetic zone, two dike–like structures can be associated with the magmatic feeding system of large recent basaltic volcanoes. A shallow magnetic horizon (1.4 km a.s.l.) can be correlated with the bottom phonolites of the Las Cañadas Edifice.In the central part of the island the coincidence of some gravity and magnetic lows is consistent with the presence of low-density and low-magnetic materials, that infill a collapsed caldera system. The structures close to the surface are characterised by low-density areas connected with the recent volcanism, in particular the minimum over the Teide volcano. Hydrothermal alteration is assumed to be the cause of a short-wavelength magnetic low over the Teide volcano.  相似文献   

Preface     

Sebastian Wolf  Paulo J.V. Garcia   《New Astronomy Reviews》2008,52(2-5):19

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