First discovery of fossil winged seeds of <Emphasis Type="BoldItalic">Pinus</Emphasis> L. (family Pinaceae) from the Indian Cenozoic and its palaeobiogeographic significance

The occurrences of Pinus L. (family Pinaceae) megafossils (cones and leaf remains) have been abundantly documented from the Cenozoic sediments of eastern Asia (Japan and China), but none has been confirmed from the Indian Cenozoic till date. Here, we describe Pinus arunachalensis Khan and Bera, sp. nov. on the basis of seed remains from the middle to late Miocene Siwalik sediments of the Dafla Formation exposed around West Kameng district in Arunachal Pradesh, eastern Himalaya. Seeds are winged, broadly oblong to oval in outline, 1.3–1.5 cm long and 0.4–0.6 cm broad (in the middle part), located basipetally and symmetrically to wing, cellular pattern of wing is seemingly undulatory and parallel with the long axis of the wing. So far, this report provides the first ever fossil record of Pinus winged seeds from India. This record suggests that Pinus was an important component of tropical-subtropical evergreen forest in the area during the Miocene and this group subsequently declined from the local vegetation probably because of the gradual intensification of MSI (monsoon index) from the Miocene to the present. We also review the historical phytogeography and highlight the phytogeographic implication of this genus.     

A direct analysis of flood interval probability using approximately 100-year streamflow datasets

ABSTRACT

Series of observed flood intervals, defined as the time intervals between successive flood peaks over a threshold, were extracted directly from 11 approximately 100-year streamflow datasets from Queensland, Australia. A range of discharge thresholds were analysed that correspond to return periods of approximately 3.7 months to 6.3 years. Flood interval histograms at South East Queensland gauges were consistently unimodal whereas those of the North and Central Queensland sites were often multimodal. The exponential probability distribution (pd) is often used to describe interval exceedence probabilities, but fitting utilizing the Anderson-Darling statistic found little evidence that it is the most suitable. The fatigue life pd dominated sub-year return periods (<1 year), often transitioning to a log Pearson 3 pd at above-year return periods. Fatigue life pd is used in analysis of the lifetime to structural failure when a threshold is exceeded, and this paper demonstrates its relevance also to the elapsed time between above-threshold floods. At most sites, the interval medians were substantially less than the means for sub-year return periods. Statistically the median is a better measure of the central tendency of skewed distributions but the mean is generally used in practice to describe the classical concept of flood return period.

Editor Z.W. Kundzewicz; Associate editor I. Nalbantis     

BIBLIOGRAPHY—BIBLIOGRAPHIE

Abstract

The Coupled Routing and Excess STorage model (CREST, jointly developed by the University of Oklahoma and NASA SERVIR) is a distributed hydrological model developed to simulate the spatial and temporal variation of land surface, and subsurface water fluxes and storages by cell-to-cell simulation. CREST's distinguishing characteristics include: (1) distributed rainfall–runoff generation and cell-to-cell routing; (2) coupled runoff generation and routing via three feedback mechanisms; and (3) representation of sub-grid cell variability of soil moisture storage capacity and sub-grid cell routing (via linear reservoirs). The coupling between the runoff generation and routing mechanisms allows detailed and realistic treatment of hydrological variables such as soil moisture. Furthermore, the representation of soil moisture variability and routing processes at the sub-grid scale enables the CREST model to be readily scalable to multi-scale modelling research. This paper presents the model development and demonstrates its applicability for a case study in the Nzoia basin located in Lake Victoria, Africa.

Citation Wang, J., Yang, H., Li, L., Gourley, J. J., Sadiq, I. K., Yilmaz, K. K., Adler, R. F., Policelli, F. S., Habib, S., Irwn, D., Limaye, A. S., Korme, T. &; Okello, L. (2011) The coupled routing and excess storage (CREST) distributed hydrological model. Hydrol. Sci. J. 56(1), 84–98.     

Occurrence of scheelite-powellite in the rocks of Mahakoshal Group, Wyndhamganj area, Sonbhadra district, Uttar Pradesh

Scheelite and Powellite occur as dissemination and fractures filling in the hornfels and tourmaline-garnet granite in the Palaeoproterozoic rocks of Mahakoshal Group, at about 2.5 km north of Wyndhamganj, Sonbhadra district, Uttar Pradesh. This new find opens new vistas for the search of tungsten mineralization along the contact zones of Mahakoshal Group and the younger granite.     

Annual and seasonal trends of cooling, heating, and industrial degree-days in coastal regions of Saudi Arabia

In this study, we systematically analyze the changing properties of reference evapotranspiration (ETref) across China using Penman?CMonteith (P-M) method, exploring the major sensitive meteorological variables for ETref, and investigating influences of human activities, mainly urbanization in this study, on ETref changes in both space and time. We obtain some important conclusions: (1) decreasing annual and seasonal ETref is observed in the east, south and northwest China. However, a long strip lying between these regions is identified to be characterized by increasing ETref; (2) in the regions east to 100°E, the net total solar radiation is the main cause behind the decreasing ETref. In northwest China, however, relative humidity is recognized as the most sensitive variable for the ETref; (3) in the east and south China, urbanization greatly influences the ETref by directly decreasing net solar radiation. The increased air pollution and aerosols in the highly urbanized regions are the main driving factors causing decreasing net radiation; and (4) this study reveals accelerating hydrological cycle from south to north China. Besides, increasing ETref in the source regions of large rivers in China may pose new challenges for the basin-scale water resource management. The results of this study highlight the integrated effects of climate changes and human activities on ETref changes in different regions of China, which will be of great scientific and practical merits in in-depth understanding of hydrological cycle alterations under the changing environment in China.     

GIS-based impact assessment of land-use changes on groundwater quality: study from a rapidly urbanizing region of South India

This study attempts to assess the influence of changing land-use patterns on the groundwater quality of the hard rock aquifer system in the Maheshwaram watershed, near Hyderabad, India. The study area is a rapidly urbanizing region with land development progressing at a fast pace. To study the impact of this rapid urbanization and overall land-use transition, a groundwater quality index (GQI) was prepared within a geographical information system (GIS). The GQI integrates the different water quality parameters to give a final index value that can be used for spatio-temporal comparisons. The land-use transitions were closely monitored from 2003 to 2008 using multispectral satellite images. The land-use pattern has changed drastically with an increase in the built-up area at the expense of other land uses. The analysis reveals a rapid deterioration of groundwater quality related mainly to the increase in built-up land with unsewered sanitation and poultry farms. Seasonal variability of the groundwater quality was also assessed. Mean GQI decreased from 84.16 to 83.26 over a period of 5 years from 2003 to 2008, while seasonal variability of water quality increased. GQI and Seasonal Variability of water quality were integrated in GIS to yield a groundwater sustainability map, in terms of water quality. Zones of sustainable and unsustainable groundwater use were demarcated for better decision making related to municipal land allotment in this rapidly urbanizing region.     

Lee yang theory for cosmological many body problem

We study the phase transition in a gravitating system by analyzing grand canonical partition function as a function of complex fugacity. We extend the Yang-Lee theory to study phase transitions in the gravitational galaxy clustering of galaxies having a variety of masses. This generalizes our previous work based on the same theory for the single-component system to a multicomponent system. We find that galaxy clustering is sensitive to masses and number densities of individual galaxies at early stages while at later stages collective behavior of the particles is more pronounced. This validates our earlier work obtained from different considerations.     

Paleoclimatic evolution of central Sudan during the Late Miocene to Pleistocene

In this paper, information derived from X-ray diffraction and heavy and light fractions analyses were discussed with the aim to trace the paleoclimatic changes of central Sudan during the Late Miocene to Pleistocene. Based on lithological and mineralogical characters noted in the Sayal and Umm Ruwaba Formations, four phases of distinct paleoclimatic changes were recognized. The first phase commenced in the Late Miocene during the deposition of the Sayal formation. The area was slightly uplifted and of gentle slope, a feature deduced from the deposition of clayey and fine-grained sandy materials with subordinate gravely component. A hot and humid climate, depicted from the development of kaolinite and iron oxide, is proposed during the deposition of the Sayal formation. The second phase is characterized by development of depressions in which alluvial streams and possibly small lacustrine basins occurred. This is inferred from the presence of sandy and silty materials, a characteristic of the lower and middle parts of the Umm Ruwaba Formation. The climate remained hot and humid during the deposition of the lower part of the Umm Ruwaba Formation in the early Pliocene. A shift to dry conditions with possible periodic humid seasons is, however, thought to be established during the deposition of the middle part of the Umm Ruwaba Formation deduced from the observed increase in salinity and decrease in iron oxide content. During the third phase, throughout the deposition of the upper part of the Umm Ruwaba Formation, the kinetic energy of streams increased as can be inferred from the presence of gravely intercalations. Deposition under arid climate is suggested for the lowermost part due to the increased amount of feldspars and the absence of iron oxide. However, evidence of cool condition is again noted at the topmost part of the formation inferred from the relatively high content of iron oxide in the deposits.     

A Parametric Study on Stability of Open Excavations in Alluvial Soils of Lahore District, Pakistan

Rapid urbanization and expansion of metropolitans in the developing world is pressing the need of tall structures with multiple basements. In several such projects, open land is available around excavation site and unsupported deep excavations by maintaining appropriate side slopes offer economical solution. In this research, subsoil stratigraphy of Lahore district was established to be comprising of a top clay stratum 1.5–8 m thick, followed by a sand layer. Considering subsoil data from several geotechnical investigation reports, the effect of four key parameters viz., cohesion of clay layer, friction angle of sand layer, thickness of clay layer at the top and slope inclination of underlying sand layer on safety factor of open excavations was studied. Six hundred twenty-five slope stability analyses were conducted by considering different geometries and soil properties. Based on the results of these analyses, a regression model was suggested to estimate safety factor of open excavations in similar stratigraphy which would be useful in feasibility studies and preliminary design of deep excavations. It was established that the clay layer cohesion was the most dominant contributor to safety factor.