Changes in rainfall and relative humidity in river basins in northwest and central India

Seasonal and annual trends of changes in rainfall, rainy days, heaviest rain and relative humidity have been studied over the last century for nine different river basins in northwest and central India. The majority of river basins have shown increasing trends both in annual rainfall and relative humidity. The magnitude of increased rainfall for considered river basins varied from 2–19% of mean per 100 years. The maximum increase in rainfall is observed in the Indus (lower) followed by the Tapi river basin. Seasonal analysis shows maximum increase in rainfall in the post‐monsoon season followed by the pre‐monsoon season. There were least variations in the monsoon rainfall during the last century and winter rainfall has shown a decreasing trend. Most of the river basins have experienced decreasing trends in annual rainy days with a maximum decrease in the Mahanadi basin. The heaviest rain of the year has increased from 9–27 mm per 100 years over different river basins with a maximum of 27 mm for the Brahamani and Subaranrekha river basins. A combination of increase in heaviest rainfall and reduction in the number of rainy days suggest the possibility of increasing severity of floods. Such information is useful in the planning, development and management of water resources in the study area. Further, the majority of river basins have also experienced an increasing trend in relative humidity both on seasonal and annual scales. An increase in annual mean relative humidity for six river basins has been found in the range of 1–18% of mean per 100 years, while a decrease for three river basins from ? 1 to ? 13% of mean per 100 years was observed, providing a net increase in the study area by 2·4% of mean per 100 years. It is understood that an increase in areal extent of vegetation cover as well as rainfall over the last century has increased the moisture in the atmosphere through enhanced evapotranspiration, which in turn has increased the relative humidity. Copyright © 2007 John Wiley & Sons, Ltd.     

Phosphorus dynamics in water and sediments in urbanized and non-urbanized rivers in Southern Brazil

Phosphorus flux models show that the removal tends to be a common feature in polluted estuarine systems whereas the release of P to the adjacent coastal area occurs in pristine environments. This study analyzes the distribution of P in water and sediments along six rivers in the south coast of Brazil. Three rivers located inside protected areas were considered non-polluted and used as a control of urbanization. The other three, situated within urbanized areas, were considered as having highly elevated concentrations of P. Results showed a different behavior of P in water and sediments located in urbanized and non-urbanized areas. The concentrations of dissolved organic (P-org) and inorganic (P-inorg) phosphorus in water, and the total phosphorus (P-tot) and polyphosphate (P-poly) in sediments where higher in the urbanized rivers compared to the non-urbanized ones. Both P of punctual origin and of diffuse origin contributed to the maintenance of elevated concentrations and disturbed the natural fluxes along the polluted rivers. The minimum and maximum concentrations in urbanized areas varied from 0.39 to 12.45 (microM) for P-org and 0.00 to 5.92 (microM) for P-inorg in water, and in sediments from 89.90 to 808.16 (microM g(-1)) for P-tot and 0.00 to 76.51 (microM g(-1)) for P-poly. In non-urbanized areas concentrations in water varied from 0.22 to 1.20 (microM) for P-inorg and 4.43 to 5.56 (microM) for P-org, and in sediments from 45.91 to 652.26 (microM g(-1)) for P-tot and 0.00 to 8.61 (microM g(-1)) for P-poly. Using a hierarchical sampling design and a simple model of variation of P (K(d) model) it was possible to demonstrate that urbanized and non-urbanized estuaries may act as sinks or sources of P. The variation of P analysis in different points along each of the six rivers showed that release and removal areas may occur within a same river independently of its urbanization.     

Spatial and temporal variations in rainfall characteristics in mountainous and lowland areas in Taiwan

Although changes in rainfall characteristics have been noted across the world, few studies have reported those in mountainous areas. This study was undertaken to clarify spatial and temporal variations in rainfall characteristics such as annual rainfall amount (Pr), mean daily rainfall intensity (η), and ratio of rain days (λ) in mountainous and lowland areas in Taiwan. To this aim, we examined spatial and year‐to‐year variations and marginal long‐term trends in Pr, η, and λ, based on rainfall data from 120 stations during the period 1978–2008. The period mean rainfall () at the lowland stations had strong relationships with the period mean daily rainfall intensity () and the period mean ratio of rain days () during those 31 years. Meanwhile, was only strongly related to at mountainous stations, indicating that influences on spatial variations in were different between lowland and mountainous stations. Year‐to‐year variations in Pr at each station were primarily determined from the variation in η at most stations for both lowland and mountainous stations. Long‐term trend analysis showed that Pr and η increased significantly at 10% and 31% of the total 120 stations, respectively, and λ decreased significantly at 6% of the total. The increases in Pr were mostly accompanied by increases in η. Although stations with significant η increases were slightly biased toward the western lowland area, increases or decreases in Pr and λ were not common. These results contribute to understanding the impacts of possible climate changes on terrestrial hydrological cycles. Copyright © 2012 John Wiley & Sons, Ltd.     

Organic Matter and Its Transformation Rates in Spawning and Fattening Lakes in Kamchatka

The concentration of dissolved and particulate organic matter (OM) in Lakes Kuril'skoe and Azabach'e is shown to depend on the rate of its production by phytoplankton (and by macrophytes in Lake Azabach'e) and on the amount of allochthonous OM delivered by rivers. The rate of OM transformation in the production–destruction cycle and the regeneration of phosphates were evaluated based on the activities of redox enzymes of the electron-transport system and the hydrolytic enzymes of alkaline phosphatase and protease. The intense assimilation of allochthonous OM in lake ecosystems was found to take place due to active hydrolytic disintegration of the arriving OM.     

New developments in process understanding and modelling in geomorphology: introduction and overview

This Special Issue of Earth Surface Processes and Landforms develops from the ‘Geomorphology: a 2020 Vision’ Annual Conference of the British Society for Geomorphology, organised at the University of Birmingham, UK, in July 2007. Entitled ‘New Developments in Process Understanding and Modelling in Geomorphology’, the Issue comprises a vibrant selection of 10 ‘process’ papers from leading researchers in geomorphological processes who presented at Birmingham. It aims to provide a readily accessible source of new and emerging ideas in understanding different landform processes across a range of space and time scales, based on innovations in geomorphological modelling and monitoring. The last few years have seen significant and exciting changes in geomorphology, especially in conceptual developments, numerical simulations, monitoring methodologies, data‐acquisition strategies and dating techniques. The resultant empirical datasets, theory development and modelling results have generated substantial advances in the understanding of geomorphological processes, form‐process feedbacks, scale impacts, long‐term landform evolution, the effects of climate and environmental change, and human impacts and management strategies. The Special Issue attempts to address the following key challenges: (a) to build on our Conference theme ‘Geomorphology: a 2020 Vision’, by identifying fundamental areas where doors need to be opened, for example in theory development, conceptual understanding, model evaluation, integration of the chemistry, physics, biology and mathematics of geomorphological processes, experimental validation, data needs and monitoring requirements; (b) to look forward to the next decade and beyond, and critically examine some of the approaches we will need for the questions ahead; and (c) to stimulate new research in the geomorphological sciences by highlighting both research gaps and promising developments, including emerging process modelling approaches, monitoring technologies and robust datasets. Copyright © 2010 John Wiley & Sons, Ltd.     

Jurassic and Lower Cretaceous radiolarian zonation in Japan and in the western Pacific

Abstract A radiolarian zonal scheme for the entire Jurassic and Lower Cretaceous using biostratigraphic data from both Japanese Island sections and the western Pacific seafloor is documented. The zonation is applicable to low and middle paleolatitude portions of the Paleo-Pacific ocean. Radiolarian bio-events such as the evolutionary first appearance biohorizon, first occurrence biohorizon, and last occurrence biohorizon were used to define zones. The 11 zones proposed are, in ascending order, Parahsuum simplum, Trillus elkhornensis, Laxtorum(?) jurassicum, Tricolocapsa plicarum, Tricolocapsa conexa, Stylocapsa(?) spiralis, Hsuum maxwelli, Pseudodictyomitra primitiva, Pseudodictyomitra carpatica, Cecrops sep-temporatus, and Acanthocircus carinatus zones. Preliminary age assignments for these zones are presented.     

Variations in the loadings and riverine transport of nitrate and nitrite in Latvia

The intra-annual and long-term variations in the nitrate and nitrite concentrations and transport are considered for the years 1948–1990. The nutrient loading on the Latvian rivers is subject to considerable intra-annual variations. Weak direct relationships with the fresh water inputs were observed for nitrite, while inverse ones were characteristic for nitrate. The nitrate and nitrite concentrations have been increasing since the late 1950s followed by an increase of the year-to-year variability. Non-point sources of anthropogenic impact (fertilizers leaching from agriculture and the reclamation) increase riverine concentrations of nitrogen compounds, and in particular of nitrate from 300–500 to 1300–1500%.     

我国油气资源勘探开发中存在的主要问题及对策

本文对中国石油、天然气资源作了重点的介绍.强调了这些资源对我国国民经济和国防建设的重要性.目前,我国油气资源短缺的现象日益严重.作者指明了在前第三纪海相残留盆地中勘探这些资源,会带来光明的前景.     

Geoinformatics and Systems Analysis in Geophysics and Geodynamics

Izvestiya, Physics of the Solid Earth - The application of geoinformatics and systems analysis methods for processing and interpreting geospatial data in geophysics and geodynamics is considered....     

Soil pipes and their role in runoff generation and chemical denudation in a humid tropical catchment in dominica

Numerous soil pipes are reported from a small catchment in an area of kandoid (kaolin-rich) soils and 2375 mm annual rainfall in the humid tropical volcanic island of Dominica, West Indies. Two spot surveys in August 1982 at baseflow during the wet season indicated that pipes contributed at least 14–16 per cent of streamflow. Sampled pipeflow was of similar chemical composition to the baseflow-dominated streamwater. Specific conductance (249–420 μS cm^?1) and silica (75 mg l^?1) levels of pipeflow were high and suggested that the pipes tapped solute-rich water close to the soil-rock interface. The principal pipes flow perennially and showed little response to daily rainfalls of up to 43 mm during the monitoring period.     

Effect of Moon phases in riometer absorption and in the ionospheric and geomagnetic parameters

Variations in the frequency of occurrence of riometer absorption, minimum frequency of reflection of the ionospheric F layer, minimum height, and height of maximum electron density of the ionospheric F layer near the solar minimum have been studied. Application of the superposed epoch technique has detected the Moon phase effect on these ionospheric parameters. This effect was: three events per day in the occurrence of riometer absorption, 0.056 MHz in the minimum frequency of reflection of the F layer, and 2.6 and 6.7 km, in the change of the minimum height of reflection and height of reflection from the region with maximum electron density of the ionospheric F layer, respectively. The lunar tide action changes the ionospheric conductivity and, thus, influences the current systems of the magnetosphere. Through changes of magnetospheric currents, the Moon phase effect is exhibited in the Ap and Dst indices and is 4.3 and 4.25 nT, respectively.     

Carbon isotopes in eclogite and apatite separate from Huangzhen and Shima in SE Dabie

The carbon isotope compositions of high- and ultrahigh-pressure eclogite and apatite separate from Huangzhen and Shima in SE Dabie Mountains were analyzed by EA-MS online technique. The δ13C values of the eclogites cover a wide range of -30.7‰ - +1.5‰, whereas those of apatites only have a small range of -28.1‰--21.0‰. Some of the eclogites with the high δ13C values suffered retrogressive alteration by CO2-bearing fluids. The low δ13C values of the apatites indicate that the eclogites contain surficial carbon of organic origin. It is concluded that protoliths of the eclogites were exposed to the surface of the Earth, and that the carbon-bearing fluid was depleted in 13C during the eclogite-facies metamorphism.     

Fractals in geology and geophysics

The definition of a fractal distribution is that the number of objectsN with a characteristic size greater thanr scales with the relationNr ^–D. The frequency-size distributions for islands, earthquakes, fragments, ore deposits, and oil fields often satisfy this relation. Fractals were originally introduced by Mandelbrot to relate the length of a coastline to the length of the measuring stick. This application illustrates a fundamental aspect of fractal distributions, scale invariance. The requirement of an object to define a scale in photographs of many geological features is one indication of the wide applicability of scale invariance to geological problems, scale invariance can lead to fractal clustering. Geophysical spectra can also be related to fractals; these are self-affine fractals rather than self-similar fractals. Examples include the earth's topography and geoid.     

Zirconium and hafnium in meteorites

The abundances of zirconium and hafnium have been determined in nine stony meteorites by a new, precise neutron-activation technique. The Zr/Hf abundance ratios for the chondrites vary in a rather narrow range, consistent with previously published observations from our group. Replicate analyses of new, carefully selected clean interior samples of the C1 chondrite Orgueil yield mean zirconium and hafnium abundances of 5.2 and 0.10 ppm, respectively. These abundances are lower than we reported earlier for two C1 chondrite samples which we now suspect may have suffered contamination. The new C1 zirconium and hafnium abundances are in closer agreement with predictions based on theories of nucleosynthesis than the earlier data.     

Differences in oxygen-18 content of throughfall and rainfall in hardwood and coniferous forests

The differences between δ¹⁸O in throughfall and open rainfall were studied for 16 selected spring and summer storms in deciduous, pine and spruce forests in central Pennsylvania, USA. Throughfall δ¹⁸O averaged 0.17, 0.32 and 0.24%_o greater than δ¹⁸O of open rainfall for all storms at the deciduous, pine and spruce sites, respectively. Throughfall ¹⁸O enrichment was greater in low intensity spring rainfall events than higher intensity growing season storms and greater in the coniferous stands than the deciduous hardwood stand. Maximum throughfall ¹⁸O enrichment of l.61%_o occurred in the spruce forest during one spring event. The differences between rainfall and throughfall ¹⁸O observed in this study for individual storm events may have important implications for isotope flow separation studies.