Regionalization of hydrologic parameters of Nash mode

hydrologic models are important tools to estimate runoff from a catchment. Identification of broad based parameters of a hydrologic model for development of direct runoff hydrograph is a key issue for the modelers. Optimization and regionalization of hydrologic parameters for application of Nash’s model is investigated in this paper. Six catchments dominated by hill torrent flows were selected for this purpose. Fifty seven rainfall events were used for regionalization of parameters and about 55 events were used for validation of the results. The hydrologic parameters of the Nash Model, number of linear cascades (N) and storage coefficient (k) were determined using optimization based upon Downhill Simplex method. The data was collected by field measurements and from Water and Power Development Authority (WAPDA) Pakistan. The physical parameters of the catchments were derived from the satellite images of the watersheds with the help of ERDAS software. The performance of the model was assessed by the model efficiency. It is concluded that the conceptual Nash model can simulate direct runoff hydrograph using regional hydrologic parameters with model efficiency of 67%.     

First report of eudialyte occurrence from the Sushina hill region,Purulia district,West Bengal

Eudialyte is a group of hydrated silicate minerals essentially consisting of Na and Zr with a very complex crystal structure, and generally associated with alkaline rocks. The complexity of the eudialyte structure can be understood from the fact that Na alone exist in five distinct sites and extensive solid solubility can occur in almost all cation sites, sometimes one element occupying multiple sites to the extent of exclusion of other elements. Structurally, eudialyte can be represented as Na₁₅[M ₁ ]₆[M 2]₃Zr₃[M ₃ ](Si₂₅O₇₃)(O,OH,H₂O)₃X₂ (Johnsen and Grice, 1999), where M ₁ and M ₂ sites are occupied by Ca, Mn and Fe, M ₃ by Nb and X by OH, Cl and F. In addition, cations like Al, Hf, W, Ta, Sr, Ba and various REEs get incorporated into the eudialyte structure by substitution, and additional site vacancies even may develop in order to maintain electrical neutrality. Eudialyte, approximately of the composition Na₉Ca₈Mn₃Nb(Zr,Ce)₃Si₂₅O₇₃(OH)₂, has hydrothermally replaced albite in the nepheline syenite gneiss exposed south of the Sushina hill of Purulia district, West Bengal. The eudialyte contains ≈2.25 atom% Zr and 0.75 atom% Nb. In addition to eudialyte in nepheline syenite, an unknown Na-Zr silicate (NZS) has also replaced the albite crystals. The NZS contains ≈ 7 atom% Zr with a possible empirical formula of Na₁₂Zr₁₁Si₃₆O₉₅(OH)₁₀. Surface exposures of these rocks are limited at Sushina hill, yet a detailed and systematic investigation on this enigmatic rock is warranted for they may turn out to be a resource for Zr.     

Atmospheric NO2 concentration measurements using differential absorption lidar technique

Using the Differential Absorption Lidar (DIAL) technique, two types of approaches, namely, reflection from retroreflector/topographic target and backscatter from atmosphere, are available for studying remotely the atmos-pheric NO2 concentration. The Argon ion lidar system at the Indian Institute of Tropical Meteorology (IITM), Pune, India has been used for the measurements by following both the path-averaged and range-resolved ap-proaches. For the former, a topographic target (hill) is used for determining path-averaged surface concentration. In the latter, spectral properties of atmospheric attenuation is used for making range-resolved measurements in the sur-face layer. The results of the observations collected by following both approaches are presented. The average surface NO2 concentration was found to vary between 0.01 and 0.105 ppm and the range-resolved measurements exhibited higher values suggesting treatment of the lidar data for scattering and extinction effects due to atmospheric aerosols and air molecules, and atmospheric turbulence. Certain modifications that arc suggested to the experimental set-up, data acquisition and analysis to improve the measurements are briefly described.     

Deformation of an elastic layer coupling in different ways to a base due to a very long vertical strike-slip dislocation

The closed-form analytic expressions for the displacement and stresses at any point of an elastic layer lying over a base due to a very long vertical strike-slip dislocation are obtained. The interface between the layer and the base is assumed to be either ‘smooth-rigid’ or ‘rough-rigid’ or ‘welded’. The variations of displacement and stresses with the horizontal distance from the fault for different types of coupling of the layer with the base have been studied. It is found that the displacement for ‘welded interface’ lies between the displacements due to ‘smooth rigid’ and ‘rough-rigid’ interfaces for different positions of the observer and different values of the ratio of rigidities of the layer and half-space.     

SEASONAL VARIATION OF LIDAR-DERIVED AEROSOL CONTENT IN THE LOWER LAYERS OF THE ATMOSPHERE

Results of the study of seasonal variation of total column content of aerosols in the 50—1100 m heightregion are presented,The columnar content of aerosols is computed by integrating the height profiles ofnighttime aerosol number density estimated from the Argon ion lidar observations collected at the ⅡTM,Pune for the one year period from October 1986 to September 1987.The results of the study indicated thatthe aerosol content was higher during winter than during monsoon months by over 78% with an annualmean columnar aerosol content of 1.66×10~8 cm~(-2).The observed seasonal variaticn of aerosol content wasfound to be associated with that of surface wind,temperature,relative humidity(R.H.)and rainfall datarecorded for the above one year period at the station.     

Composition and Regeneration of Trees in the Community Forests of Lamjung District,Nepal

The community forest program in Nepal is one of the successful conservation initiatives. Tree species in a forest ecosystem have a fundamental role in maintaining the vegetation structure, complexity, and heterogeneity. This study analyzes the composition and regeneration of tree species in five community forests (CFs) of the sub-tropical region, Lamjung district, Nepal for preparing baseline data for long-term research projects and helps the community to manage their CFs scientifically. Tree species data were generated by stratified random sampling using 35 quadrate plots (size: 20 m x 20 m). The density of adult trees in the forests ranged from 575 Ind ha ^-1 (Tilahar CF) to 1196 Ind/ha (Deurali Thadopakha CF). The sapling ranged from 2533 Ind ha ^-1 (Tilahar CF) to 4000 Ind ha ^-1 (Thuliban CF) and seedling from 19583 Ind ha ^-1 (Tilahar CF) to 37500 Ind ha ^-1 (Thuliban CF). Similarly, the adult tree basal area varied from 28.34 m ² ha ^-1 (Tilahar CF) to 49 m ²ha ^-1 (Deurali CF). The adult tree diversity index (Shannon-Weiner’s H) also ranged from 1.08 (Thuliban CF) to 1.88 (Tilahar CF). The tree species such as Sapium insigne, Ficus benghalensis, Lagerstroemia parviflore, Albizia sp. and Pinus roxburghii were weak regeneration. In general, the forests have good regeneration status except for Tilahar Community Forest, but based on the DBH size class distribution diagram, there is no sustainable regeneration. Among the five community forests the DBH size of adults was significantly different, and the DBH of Deurali Thadopakha was the lowest. But only few species have good regeneration and most of the species have weak, poor to no regeneration. The dominancy of fewer species like Shorea robusta, Castanopsis indica, and Schima wallichii accordingly maintain the overall regeneration of tree of CFs, so further plantation needs to be done inside the CF by triage accordingly those species whose regeneration has poor.     

Earthquake-induced built-up damage identification using IRS-P6 data: a comparative study using fuzzy-based classifiers

The 8 October 2005 earthquake caused widespread destruction in both the state of Jammu and Kashmir of India and Northern Pakistan. Due to poor accessibility in the hazardous and difficult mountainous terrain, a proper and comprehensive ground-based survey was not possible. However, with the help of remote sensing data and its analysis techniques, it is feasible to undertake both earthquake-related damage identification and assessment. This study attempts to document and identify built-up damaged (BD) areas using spectral indices taking temporal multispectral images from IRS-P6 LISS-IV. Five spectral indices have been used to identify BD areas using supervised possibilistic c-means (PCM) and noise cluster (NC) classifiers, to analyse the satellite data. The result indicates that Class Based Sensor Independent (CBSI) based Transformed Normalized Difference Vegetation Index (TNDVI) temporal indices provide the best results for identifying BD areas, while Simple Ratio (SR) index gives the best results for built-up undamaged area identification. Further, it observed that PCM classifier performed better in comparison to NC classifier.     

Migratory Patterns and Settlement Experiences of African Australians of Refugee Background in Murray Bridge,South Australia

In the past decade Australian immigration policy has emphasised settlement of refugees/humanitarian entrants in rural and regional locations, in preference to metropolitan areas. The settlement outcomes of a case study of African humanitarian entrants of South Sudanese background in Murray Bridge, a regional centre in South Australia, are examined. These participants were self-settled secondary movers from metropolitan Adelaide. The factors which attracted them were centred on employment. Settlement outcomes for Murray Bridge respondents were better than their urban counterparts, in terms of both housing and employment outcomes. However, some later left Murray Bridge because of a lack of opportunities for tertiary education. The results highlight issues of sustainability of settlement and retention, in regional centres in Australia, and of the fluidity of attraction and retention factors and therefore settlement in regional centres.     

Bianchi Type I Magnetized String Cosmological Model in General Relativity

Bianchi Type I magnetized string cosmological model following the techniques used by Letelier and Stachel, is investigated. To get a determinate model, we assume a condition ∊ = λ (geometric string) where ∊ is the rest energy density, λ the string tension density and expansion (θ) is proportional to eigen value σ₁ ¹ of shear tensor (σ _j ⁱ ), which leads to A = ℓ (BC) ⁿ where A, B, C are metric potentials and ℓ and n are constants. The behaviour of the model in presence and absence of magnetic field is discussed. The physical and geometrical aspects of the model are also discussed.