Correction to: Spatiotemporal variability of vegetation due to drought dynamics (2012–2017): a case study of the Upper Paraíba River basin,Brazil

Natural Hazards - This correction stands to support the updating of the original article for changing the name Glauciene Justino Ferreira to Glauciene Justino Ferreira da Silva. The author group...     

Seasonal variation of particulate heavy metals in the Lower Paraíba do Sul River, R.J., Brazil

 Temporal and spatial variability of particulate metal concentrations (Cu, Cr, Zn, Mn and Fe) were investigated in the lower drainage basin of the Paraíba do Sul River. The results showed that the spatial variability was not important for all the studied metals, however, temporal variations seems to be considerable. In general, two distinct behaviors were observed for particulate heavy metals: (1) metal concentration increase together with water flow (Fe and Cu) and (2) concentration decrease with increasing water flux (Zn, Cr and Mn). The Fe and Cu behavior is probably due to the strong association of these metals with surface runoff, although their sources seem to be distinct. Iron probably originates from the regional soils rich in iron oxides, and Cu is possibly associated to the large-scale use of copper fungicides in the sugar cane plantations. The opposite trend observed for Zn, Cr and Mn probably reflects the importance of the industrial and urban effluents as a secondary source of these elements for the system. Their behavior is probably associated with the dilution effect caused by the input of a suspended matter poor in these metals originated from the surface runoff during the rainy season. Received: 4 March 1998 · Accepted: 30 June 1998     

High-Pressure Metamorphosed Fe-Ti Ore-Hosting Island-Arc Tholeiites at Itatuba (Paraíba) as an Indication of a Proterozoic Suture in the Pajeú-Paraíba Fold Belt,Borborema Province,Northeastern Brazil

Petrological investigations on metamafic rocks and three associated Ti-Fe occurrences from Itatuba in the state of Paraíba are reported. The rocks analyzed here are part of a Proterozoic gneissic-migmatitic complex that includes some marble intercalations.

Microtextural relations support a complex metamorphic evolution of three stages. A first stage, reflecting eclogitic conditions, is indicated by the lack of primary plagioclase in relics of garnet pyroxenite, with symplectitic intergrowths of pyroxenes and/or amphibole and secondary piagioclase replacing garnets and primary pyroxene, ostensibly omphacite. A second event at granulitic conditions is represented by the paragenesis of garnet-clinopyroxene-plagioclase. Equilibrium textures between hornblende-plagioclase are typical for the third stage under amphibolite-facies conditions. Mineral chemistry of the clinopyroxene-garnet pairs suggests equilibrium conditions in the range of 726° to 1185°C and 4.8 to 8.2 kb, established during the granulitic and amphibolitic stages of the metamorphic evolution. The chemical composition of the metamafic rocks reveals a tholeiitic basaltic composition.

Discriminant diagrams and spiderdiagrams based on rare-earth and trace elements (K, Rb, Ba, Sr, Ti, Zr, U, Th, Ta, V, Co, and Ni) suggest an island-arc tholeiitic character. The differentiation and fractionation of this tholeiitic melt generated the mafic protoliths, culminating with the formation of the Fe-Ti ore. This magma supposedly was generated from mantle below a subduction zone.     

Geostatistical analysis of spatiotemporal variability of groundwater level fluctuations in Amman–Zarqa basin,Jordan: a case study

The main objective of this study was to assess the spatial and temporal variability of groundwater level fluctuations in the Amman–Zarqa basin, during the period 2001–2005. In the year 2003, as a consequence of war, there was a sudden increase in the population in this basin. Knowing that the basin is already heavily populated and witnesses most of the human and industrial activities in Jordan, this study was prompted to help make wise water resources management decisions to cope with the new situation. Data from 31 fairly distributed wells in the upper aquifer of the basin were subjected to geostatistical treatment. Kriging interpolation techniques have indicated that the groundwater flow directions remained almost constant over the years. The two main directions are SW–NE and E–W. Kriging mapped fluctuations have also showed that drop and rise events are localized in the basin. Forecasting possibilities for management purposes were tackled using autocorrelation analysis. The constructed autocorrelograms indicated, in general, the temporal dependence of seasonal water level fluctuations, and that forecasting can be carried out within a period of 3–21 months. Several suggestions were made to mitigate the drop and rise hazards in the detected sites.     

The 2012–2013 earthquake swarm in the eastern Guadalquivir basin (South Spain): A case of heterogeneous faulting due to oroclinal bending

From October 2012 to October 2013, a seismic swarm released more than 7000 microearthquakes beneath the eastern Guadalquivir foreland basin. From double-difference relocations of 501 events (m_d > 1.5), we can image the active structures associated with this swarm. Most of the events occurred along two ~ N–S trending lineaments separated ~ 1 km. Relocation places most events at 4–6.5 km depth in the Iberian-massif basement below the basin. Moment tensor inversion yields strike-slip mechanisms consistent with the hypocenter alignments, attributing left-lateral motion to the N–S structures and right-lateral motion to the ESE–WNW ones, in compliance with the ~ NNW direction of the main compressive stress field in the central Betics. These structures respond to a vertical-axis bend in the mountain front associated with the protrusion of Sierra Cazorla east of the epicentral area. This bend is mimicked by concordant, gentle bends in the foreland units, which are evident from the surface geology as well as through structural elements like strike-slip faults, crisscrossing joints. In this context, the right-lateral shear zone responsible for the Torreperogil sequence is taking up deformation in the western limb of the foreland bend.     

Stratigraphy and ecostratigraphic distribution of foraminiferal morphogroups from the Upper Jurassic of the Makar’yev section (Unzha River,Volga River basin)

Investigation of the Upper Callovian to Lower Kimmeridgian microfossils from the Makar’yev reference section (Unzha River, East European Platform) has been carried out. The section is characterized by ammonite debris and abundant associations of benthic and planktic foraminifers. It is a perfect object for stratigraphic and paleoecological researches. The biostratigraphic distribution of foraminifers from the Makar’yev section allows one to identify standard foraminifera zones of the East European Platform, as well as to upgrade some of them. The analysis of vertical and lateral ammonites and foraminiferal distribution, completed with litho stratigraphy, has precised the stratigraphic volume and position of boundaries of several lithological units.An improved stratigraphic scheme for the Kostroma area of the Moscow Depression is proposed. Analysis of the composition, structure, and dynamic changes of the foraminiferal assemblages has been performed. The morphofunctional analysis of foraminiferal genera has for the first time identified how foraminiferal morphogroups differing in their life style and feeding strategy varied with short-term paleoenvironmental changes. These morphogroup changes allow establishing four ecostratigraphic levels. These paleoecological data have been calibrated along with geochemical factors. They have shown a crisis of foraminiferal association during the Late Oxfordian and Early Kimmeridgian. A similar crisis has also been discovered in the north of Siberia, which may be an argument for its global distribution. The analysis of the taxonomic composition and the density of foraminiferal associations, in parallel with the structure of the association, has revealed a succession of transgressive and regressive events during the Late Callovian-Early Kimmeridgian. It allows the typification of each assemblage in relation with each event and underlines the occurrence of second-order sea-level fluctuations (middle part of the Middle Oxfordian and the earliest Kimmeridgian).     

Social perception and response to the drought process: a case study of the drought during 2009–2010 in the Qianxi’nan Prefecture of Guizhou Province

Studies carried out on the drought process, which can be classed as a gradual disaster, can help us to understand the disaster mechanism and offer strategies for disaster prevention. This paper uses the example of the drought in the Qianxi??nan Prefecture of Guizhou Province from July 2009 to May 2010. Data have been collected from government gazetteers, meteorological monitoring data, and field surveys to build up a sequence of meteorological drought indices. The categorization of the victims?? perception of drought impact, and the stages of drought responses of different subjects (government, social organizations, and the public), has also been examined by the same way. By contrasting the differences between the metrological drought indices, and victims?? perception of drought impact, researchers explored the drought cognition features of victims, social response features, and dynamic relationships between drought development and social responses. The results were as follows: The drought evolution process could be divided into 6 phases, and victims?? perception of drought impact could be divided into 7 phases. They were consistent in time period, and the victims?? perception of drought was subjective and based on their direct experiences. Their response has the characteristics of long term and concentration on a time. The responses of government and social organizations obviously fell behind those of victims, but they were effective and intensive in both timescale and effort. As the drought developed, responses shifted from individual to social responses and from practical to economic, political, and technological responses. On the basis of the results, the author has suggested methods of preparing stakeholders against possible drought risks.     

Correction to: Spatial distribution and estimation of rainfall trends and erosivity in the Epitácio Pessoa reservoir catchment,Paraíba,Brazil

Natural Hazards - The article “Spatial distribution and estimation of rainfall trends and erosivity in the Epitácio Pessoa reservoir catchment, Paraíba, Brazil”, written by da...     

New petrified forest in Maranhão,Permian (Cisuralian) of the Parnaíba Basin,Brazil

This work presents a new fossil plant-bearing area located in the municipalities of Duque Bacelar and Coelho Neto, Maranhão State, Brazil, recovered from lower Permian (Cisuralian) strata of the Pedra de Fogo Formation, northeastern portion of the Parnaíba Basin. The area comprises more than five exposures with assemblages formed mostly of large gymnosperm woods, a number of them in life-position (reaching up to ∼2.30 m in height and 1.15 m in diameter) and, in lesser degree, of horizontal tree-fern stems (up to 5 m in length), some of them being referable to Psaronius sp. The fossils are recorded in sedimentary beds of continental origin that accumulated in shallow, nearshore areas of large lakes, which eventually were affected by rapid burial episodes generated by non-channelized, high energy fluvial systems. The new fossil assemblages are included within lacustrine rocks placed at the base of the Pedra de Fogo Formation, i.e., Sílex Basal Member, near the contact with the underlying Piauí Formation (Pennsylvanian). This observation contrasts with previous studies at the southwestern portion of the basin, where the stratigraphic position of plant fossils is referred to the upper Pedra de Fogo Formation (Trisidela Member) or even to the overlying Motuca Formation. The new sites currently suffer damage from human activities and require urgent actions in order to protect them. Based on the current laws, some measures of protection for these sites are discussed and proposed herein.     

Spatial distribution and estimation of rainfall trends and erosivity in the Epitácio Pessoa reservoir catchment,Paraíba,Brazil

Natural Hazards - The main goals of this study are to better understand the spatial and temporal variabilities in rainfall and to identify rainfall trends and erosivity for the period from 1963 to...     

Open carbonate ramp facies,microfacies and paleoenvironments of the Gramame Formation (Maastrichtian), Pernambuco–Paraı́ba Basin,Northeastern Brazil

The monotonous carbonates of the Maastrichtian Gramame Formation can be divided into 11 microfacies, but these do not correspond with the five major facies distinguished in the field. The microfacies were grouped into six composite microfacies which were used to construct a depositional model. In this model, tectonic disturbances of a relatively steeply sloping carbonate ramp caused apparently random occurrences of coarser and sandier bioclastics and influx of clastic material into generally mid-outer-ramp environments. Only the central section of the carbonate ramp is exposed in a strike section. Shallower and deeper facies must be inferred from the transgressive nature of the sequence. Dolomitization is ubiquitous but apparently random. The closest modern analogy of the Gramame Formation is the relatively steep West Florida ramp. However this does not have fault-bounded shallows, for which analogies can be found on the shelf of the Arabian Gulf. Combining features from both of these allows a plausible reconstruction to be made of Gramame Formation environments. We envisage a steeply sloping ramp cut by horsts and grabens related to the opening of the south Atlantic ocean.     

Impact assessment of projected climate change on the hydrological regime in the SE Alps, Upper Soča River basin, Slovenia

According to climate change projections, the Alps will be one of the most affected regions in Europe. A basis for adaptation measures to climate changes is the quantification of the impact. This study investigates the impact of projected climate change on the hydrological cycle in the Upper So?a River basin. It is based on the use of climate model data as input for hydrological modelling. The climatic input data used were generated by a global climate model (IPCC A1B emission scenario) and downscaled for local use. Hydrological modelling was performed using the distributed hydrological model MIKE SHE. The simulated impact was quantified by comparing results of the hydrological modelling for the control period (1971–2000) and different scenario periods (2011–2040, 2041–2070, 2071–2100). The climate projections show an increase in the average temperature (+0.9, +2.3, +3.8°C) and negligible changes in average precipitation amounts in the scenario periods. More distinctive are changes in the temporal pattern of mean monthly values (up to +5.2°C and ±45% for precipitation), which result in warmer and wetter winters and hotter and drier summers in the scenario periods. The projected rise in temperature is reflected in the increased actual evapotranspiration, the reduction of snow amount and summer groundwater recharge. Changes of monthly and period average discharges follow the trends of the meteorological variables. Changes in precipitation patterns have a major influence on the projected hydrological cycle and are the most important source of uncertainty. Estimated extreme flows indicated increased hazards related to floods, especially in the near-future scenario period, while in the far future scenario period, distinctive drought conditions are projected.     

Pseudo- and real-inverted metamorphism caused by the superposition and extrusion of a stack of nappes: a case study of the Southern Brasília Orogen,Brazil

International Journal of Earth Sciences - The Southern Brasília Orogen is a Neoproterozoic belt that occurs along the southernmost border of the São Francisco Craton where the...     

Development of a drought vulnerability index using MCDM and GIS: study case in São Paulo and Ceará, Brazil

Natural Hazards - Although climate change vulnerability research in general has increased over the last decade, Latin American countries have more directed more limited efforts toward vulnerability...     

Combining textural and geochemical investigations to explore the dynamics of magma ascent during Plinian eruptions: a Somma–Vesuvius volcano (Italy) case study

Trigger mechanisms and syn-eruptive processes of Plinian eruptions are poorly understood especially in the case of mafic powerful events. In the last decades, the combined geochemical and textural studies on volcanic rocks have proven to be fundamental tools for exploring the dynamics of magma ascent in volcanic conduits and for improving our ability to interpret volcano-monitoring signals and assess hazard. In this case study, we quantitatively investigate 2D and 3D micro-textural, geochemical, and isotopic features of pyroclastic rocks erupted during the Pomici di Base Plinian eruption (22 ka), the generally acknowledged first and most powerful event of the Somma–Vesuvius volcano. A peculiar aspect of this eruption is its high intensity that remained stable during the entire Plinian phase despite the strong magma compositional variation towards mafic terms. We infer that the transfer of magma towards the surface was intensified by the occurrence of rapid vesiculation pulses driven by limestone assimilation (skarn recycling) during magma ascent through the carbonatic bedrock. We conclude that limestone assimilation can hence be a syn-eruptive process, able to trigger further gas nucleation with deep impact on the eruption intensity, particularly crucial in the case of mafic/intermediate magma compositions.     

Biostratigraphy of the Bajocian–Bathonian boundary beds in the basin of the Bolshoi Zelenchuk River (Northern Caucasus)

The study of ammonites from the upper part of the upper Bajocian and lower part of the lower Bathonian in the sections of the basin of the Bolshoi Zelenchuk (Karachay-Cherkessia) allowed the recognition of Beds with Parkinsonia djanelidzei (approximate equivalent of the middle part of the Parkinsonia parkinsoni Chronozone) and Beds with Oraniceras scythicum (lower part of the Zigzagiceras zigzag Chronozone). The taxonomic composition and distribution of foraminifers, ostracodes, dinoflagellate cysts, and miospores were studied in the samples from these deposits (upper part of the upper member of Djangura Formation). The recognized characteristic assemblages of microfauna and palynomorphs allowed ostracode and dinocyst subdivisions to be proposed for the Bajocian–Bathonian boundary beds of the Northern Caucasus for the first time. The most important taxa, including ammonites, foraminifers, ostracodes, and dinocysts, are illustrated.     

Hydrological impacts of land use–land cover change and detention basins on urban flood hazard: a case study of Poisar River basin,Mumbai, India

Flooding in urban area is a major natural hazard causing loss of life and damage to property and infrastructure. The major causes of urban floods include increase in precipitation due to climate change effect, drastic change in land use–land cover (LULC) and related hydrological impacts. In this study, the change in LULC between the years 1966 and 2009 is estimated from the toposheets and satellite images for the catchment of Poisar River in Mumbai, India. The delineated catchment area of the Poisar River is 20.19 km². For the study area, there is an increase in built-up area from 16.64 to 44.08% and reduction in open space from 43.09 to 7.38% with reference to total catchment area between the years 1966 and 2009. For the flood assessment, an integrated approach of Hydrological Engineering Centre-Hydrological Modeling System (HEC-HMS), HEC-GeoHMS and HEC-River analysis system (HEC-RAS) with HEC-GeoRAS has been used. These models are integrated with geographic information system (GIS) and remote sensing data to develop a regional model for the estimation of flood plain extent and flood hazard analysis. The impact of LULC change and effects of detention ponds on surface runoff as well as flood plain extent for different return periods have been analyzed, and flood plain maps are developed. From the analysis, it is observed that there is an increase in peak discharge from 2.6 to 20.9% for LULC change between the years 1966 and 2009 for the return periods of 200, 100, 50, 25, 10 and 2 years. For the LULC of year 2009, there is a decrease in peak discharge from 10.7% for 2-year return period to 34.5% for 200-year return period due to provision of detention ponds. There is also an increase in flood plain extent from 14.22 to 42.5% for return periods of 10, 25, 50 and 100 years for LULC change between the year 1966 and year 2009. There is decrease in flood extent from 4.5% for 25-year return period to 7.7% for 100-year return period and decrease in total flood hazard area by 14.9% due to provisions of detention pond for LULC of year 2009. The results indicate that for low return period rainfall events, the hydrological impacts are higher due to geographic characteristics of the region. The provision of detention ponds reduces the peak discharge as well as the extent of the flooded area, flood depth and flood hazard considerably. The flood plain maps and flood hazard maps generated in this study can be used by the Municipal Corporation for flood disaster and mitigation planning. The integration of available software models with GIS and remote sensing proves to be very effective for flood disaster and mitigation management planning and measures.     

Debris control on glacier thinning—a case study of the Batal glacier,Chandra basin,Western Himalaya

Complex factors such as climate, glacial geometry, topographical features and debris covers have significant influence on the dynamics of the Himalayan glaciers. Presence of debris covers on the surface of glaciers can significantly alter the surface energy balance and influence the climatic response of glaciers. In this study, the influence of debris covers and its impact on the ablation processes were analyzed from the in situ data collected over the surface of the Batal glacier in Chandra Basin, Western Himalaya. Almost 90 % of the ablation zone of the Batal glacier is covered by debris, 35 % of which is thick debris (>10 cm). Fourteen stakes (depth ～10 m) with increasing altitude and with varying debris thicknesses were installed to cover the whole ablation zone. Among them, four stakes represent thin debris (<2 cm), two stakes represent 2–5 cm debris thickness, two stakes represent 5–25 cm debris thickness, three stakes represent 25–50 cm debris thickness and three stakes represent >50 cm debris thickness. Our study has revealed high surface melting (?2.0 cm. w.e.d^?1) in the debris free glacier while low surface melting observed in thick debris covered ice (?0.6 cm. w.e.d^?1). Although limited to one season, this observation revealed a significant difference in the rate of surface melting as per the increasing debris thickness. Contrasting to normal ablation pattern over glaciers, Batal has experienced inverse retreat rate of ablation along with increasing altitude. A high degree of negative correlation (r = ?0.82, p < 0.05) between ablation rate and debris thickness in Batal suggest a significant control of debris thickness over ablation rate.