Heavy metals accumulation and ecophysiological effect on <Emphasis Type="Italic">Typha angustifolia</Emphasis> L. and <Emphasis Type="Italic">Cyperus esculentus</Emphasis> L. growing in distillery and tannery effluent polluted natural wetland site,Unnao, India

Distillery and tanneries are major source of heavy metals pollution in natural wetland sites in India. Present study deals with the heavy metals accumulation potential of Typha angustifolia and Cyperus esculentus growing in distillery and tannery effluent polluted wetland sites. The metal accumulation pattern in both macrophytes showed direct correlation with the metal content in sediments. Both macrophytes were observed root accumulator for Fe, Cr, Pb, Cu, and Cd. The metal accumulation in T. angustifolia was found higher than C. esculentus, and accumulation pattern was Fe > Mn > Cr > Zn > Pb > Cu > Ni > Cd. Simultaneously, chlorophyll, protein, cysteine, and ascorbic acid were also induced in T. angustifolia than C. esculentus. In addition, formation of multinucleolus in shoot of T. angustifolia was found an evidence of extra protein synthesis for tolerance under stress conditions. Hence, C. esculentus was observed potential but less tolerance for metals than T. angustifolia. Therefore, these wetland plants could be used for phytoremediation of heavy metals from wastewater.     

A laboratory model of thermal convection under a central force field

Abstract

A laboratory model of thermal convection under a central force field has been constructed using a strong, alternating electric field gradient in a dielectric liquid. Both the electric field gradient and a temperature gradient are maintained between concentric vertical cylinders. The onset of thermal convection is detected by heat transfer and temperature measurements. It is governed by an electrical Rayleigh number, in which the electric force replaces gravity. Marginal stability analysis gives a critical electrical Rayleigh number in agreement with the experimentally determined value.     

Impact Assessment of GIS Based Land Resource Inventory Towards Optimizing Agricultural Land Use Plan in Dandakaranya and Easternghats Physiographic Confluence of India

GIS based land resource inventory (LRI) with fine resolution imagery is considered as most authentic tool for soil resource mapping. Soil resource mapping using the concept of soil series in a smaller scale limits its wide application and also its impact assessment for crop suitability is controversial. In this study, we attempted to develop LRI at large scale (1:10,000 scale) at block level land use planning (LUP) in Dandakaranya and Easternghats physiographic confluence of India. The concept of land management unit was introduced in this endeavour. The impact assessment of LRI based LUP was exercised to develop efficient crop planning with best possible management practices. The study area comprised six landforms with slope gradient ranging from very gentle (1–3%) to steep slopes (15–25%). The very gently sloping young alluvial plains occupied maximum areas (19.95% of TGA). The single cropped (paddy) land appears to dominate the land use systems (40.0% of TGA). Thirty three landscape ecological units were resulted by GIS-overlay. Eighteen soils mapping units were generated. The area was broadly under two soil orders (Inceptisols and Alfisols); three great group (Haplaquepts, Rhodustalfs and Endoaquepts) and ten soil series. Crop suitability based impact assessment of LRI based LUP revealed that average yield of different crops increased by 39.2 and 14.5% in Kharif (rainy season) and Rabi (winter) seasons respectively and annual net returns by 83.4% for the cropping system, compared to traditional practices. Productivity and net returns can be increased several folds if customized recommended practices are adopted by the farmers. Informations generated from the study emphasized the potentiality of LRI towards optimizing LUP and exhibited an ample scope to use the methodology as a tool to assess in other physiographic regions in India and abroad.     

Back-thrusting in Lesser Himalaya: Evidences from magnetic fabric studies in parts of Almora crystalline zone,Kumaun Lesser Himalaya

The present study aims to understand evolution of the Lesser Himalaya, which consists of (meta) sedimentary and crystalline rocks. Field studies, microscopic and rock magnetic investigations have been carried out on the rocks near the South Almora Thrust (SAT) and the North Almora Thrust (NAT), which separates the Almora Crystalline Zone (ACZ) from the Lesser Himalayan sequences (LHS). The results show that along the South Almora Thrust, the deformation is persistent; however, near the NAT deformation pattern is complex and implies overprinting of original shear sense by a younger deformational event. We attribute this overprinting to late stage back-thrusting along NAT, active after the emplacement of ACZ. During this late stage back-thrusting, rocks of the ACZ and LHS were coupled. Back-thrusts originated below the Lesser Himalayan rocks, probably from the Main Boundary Thrust, and propagated across the sedimentary and crystalline rocks. This study provides new results from multiple investigations, and enhances our understanding of the evolution of the ACZ.     

Crustal accretion and metamorphism of Mesoarchean granulites in Palghat-Cauvery Shear Zone,Southern India

This work provides unequivocal evidence of the existence of Mesoarchean granulite facies metamorphic event in the Palghat-Cauvery Shear Zone (PCSZ) of South India. Charnockite samples from two prominent hills at Kollaimalai (KM) and Pachchaimalai (PM) as well as from two quarries within the Bhavani Shear Zone (BSZ) have been analyzed for their Sm-Nd and Rb-Sr ages to investigate the existence or otherwise of the Archean granulite facies events within the PCSZ. The Rb-Sr whole-rock isochron ages for massive charnockites from both the hills appear to be contemporaneous at 2.9 Ga with the initial Sr isotopic ratios of 0.7012 and 0.7014, respectively. However, the Rb-Sr data for whole-rock samples of basic granulites from one of the quarries within the BSZ indicate open system behavior, while the charnockites from the other quarry have insufficient spread in ⁸⁷Rb/⁸⁶Sr ratios and do not yield any isochron. The Sm-Nd data, on the other hand, do not distinguish between the massive charnockite and the lowland charnockite and yield Depleted Mantle model ages in the range 2.98±0.3 Ga for all of them. The ɛ^T _CHUR for all of these rocks are highly positive. Both the Sr isotopic ratios and positive ɛ^T _CHUR values for these rocks strongly suggest a mantle source for all of them. An upper age limit of ∼3.28 Ga may be assigned to the crustal accretion of the protolith of all these rocks on the basis of their Nd model ages. The Rb-Sr isochron ages of 2.9 Ga for the two massifs could be the age of granulite facies metamorphism. Thus, the metamorphism in the KM and PM Hills took place within ∼100 Ma of crustal accretion of these rocks and probably was part of the same geological event of crust formation and metamorphism. The open system behavior with respect to Rb-Sr isotopes in the basic granulite from Bhavani is possibly due to the migration of Sr isotopes, triggered during the later shearing of these rocks.     

Impact of forest degradation on streamflow regime and runoff response to rainfall in the Garhwal Himalaya,Northwest India

Baseflows have declined for decades in the Lesser Himalaya but the causes are still debated. This paper compares variations in streamflow response over three years for two similar headwater catchments in northwest India with largely undisturbed (Arnigad) and highly degraded (Bansigad) oak forest. Hydrograph analysis suggested no catchment leakage, thereby allowing meaningful comparisons. The mean annual runoff coefficient for Arnigad was 54% (range 44–61%) against 62% (53–69%) at Bansigad. Despite greater total runoff Q_t (by 250 mm year^–1), baseflow at Bansigad ceased by March, but was perennial at Arnigad (making up 90% of Q_t vs. 51% at Bansigad). Arnigad storm flows, Q_s, were modest (8–11% of Q_t) and occurred mostly during monsoons (78–98%), while Q_s at Bansigad was 49% of Q_t and occurred also during post-monsoon seasons. Our results underscore the importance of maintaining soil water retention capacity after forest removal to maintain baseflow levels.

EDITOR D. Koutsoyiannis; ASSOCIATE EDITOR D. Gerten     

Collisional excitation of interstellar molecules

An effective straight-line trajectory (EST) approach has been proposed for computation of collision-induced rotational line widths (half widths at half maximum) and excitation rates in case of atom-molecule system under the frame work of Smithet. al. (1976) formalism and molecule-molecule systems under the framework of a normalized semi-classical perturbative approach. An arbitrary multiplication factor RX with its optimum value can be used as a measure of significance of the curved trajectories of the colliding particles. The EST approach has been tested for HCL-Ar system and further applied to CO-He, CO-H₂, and OCS-H₂ systems of interstellar interest. The line width computations in case of HCl–Ar system are in accordance with the trend of the experimental values. The results obtained by the present approach are in good agreement with the theoretical computations using semi-perturbative approach. The present approach provides significant information about the lower and upper bound of the collision-induced rates even for the perturbers in rotationally excited states. The EST approach is not expensive in nature. It can be generalized for vibrational-electronic excitations.     

Temporal divergence in cropping pattern and its implications on geospatial drought assessment

Time series data on cropping pattern at disaggregated level were analysed and its implications on geospatial drought assessment were demonstrated. An index of Cropping Pattern Dissimilarity (CP-DI) between a pair of years, developed in this study, proved that the cropping pattern of a year has a higher degree of similarity with that of recent past years only and tends to be dissimilar with longer time difference. The temporal divergence in cropping pattern has direct implications on geospatial approach of drought assessment, in which, time series NDVI data are compared for drought interpretation. It was found that, seasonal NDVI profiles of drought year and normal year did not show any anomaly when the cropping patterns were dissimilar and two normal years having dissimilar cropping pattern showed different NDVI profiles. Therefore, it is suggested that such temporal comparisons of NDVI are better restricted to recent past years to achieve more objective interpretation.