Derivation of indices using remote sensing data to evaluate cropping systems

This paper presents the work done in Bathinda District of Punjab state of India for evaluating the cropping system efficiency using multi-date, multi-year and multi-sensor satellite based remote sensing data along with various spatial and non-spatial collateral data. Three efficiency indices, such as Multiple Cropping Index (MCI), Area Diversity Index (DI), Cultivated Land Utilization Index (CLUI), have been worked out to characterize the cropping systems. The salient findings point out that, the MCI has, increased remarkably. A further increase is possible by only taking a third crop. The ADI has increased in kharif (rainy) season, due to introduction of rice in the cotton belt, however in rabi (winter) season the ADI has reduced nearly to one, showing it to be a mono-cropped situation. The CLUI is low (> 0.5) in many blocks, showing there is a great scope to improve it. Since in summer the land is remaining unutilized, a summer crop can very well be taken up to improve it.     

Ionic conductivity in gem-quality single-crystal alkali feldspar from the Eifel: temperature,orientation and composition dependence

We measured the ion conductivity of single-crystal alkali feldspar originating from two different locations in the Eifel/Germany, named Volkesfeld and Rockeskyller sanidine and having potassium site fractions \(C_\mathrm{K}\) of 0.83 and 0.71, respectively. The dc conductivities resulting from electrochemical impedance spectroscopy over the temperature range of 300–900 \(^{\circ }\hbox {C}\) show a weak composition dependence but pronounced differences between the b-direction [\(\perp (010)\)] and \(c^{*}\)-direction [\(\perp (001)\)] of the monoclinic feldspar structure. Conductivity activation energies obtained from the observed linear Arrhenius plots are close to 1.2 eV in all cases, which is closely similar to the activation energies of the \(^{22}\mathrm{Na}\) tracer diffusivity in the same crystals. Taking into account literature data on K tracer diffusion and diffusion correlation effects, the present results point to a predominance of the interstitialcy mechanism over the vacancy mechanism in mass and charge transport on the alkali sublattice in potassium-rich alkali feldspar.     

Holocene tectono-geomorphic evolution of Haryana plains,Western Ganga plain,India

Haryana plain is the drainage divide between the Ganga plain in the east and the Indus plain in the west. Being a part of the Himalayan foreland, its geomorphology, sedimentation processes, and tectonism are broadly controlled by the Himalayan tectonics. Soil and geomorphological mapping in Haryana plain bring out geomorphic features such as paleochannels, various active drainage patterns, and landforms such as old fluvial plains, floodplains, piedmonts, pediments, terminal fans, and eolian plains. Based on the degree of soil development, and Optical stimulated luminescence (OSL) ages, the soil-geomorphic units were grouped into six members (QIMS-I to VI) (Quaternary Indus Morphostratigraphic Sequence) of a morphostratigraphic sequence: QIMS-VI 9.86–5.38 Ka, QIMS-V 5.38–4.45 Ka, QIMS-IV 4.45–3.60 Ka, QIMS-III 3.60–2.91 Ka, QIMS-II <?2.91–1.52 Ka, and QIMS-I <?1.52 Ka. OSL chronology of different geomorphic features suggests six episodes of tectono-geomorphic evolution in the region since 10 Ka. Neotectonic features such as nine faults, two lineaments, and five fault-bounded tectonic blocks have been identified. Independent tilting and sagging of the blocks in response to neotectonics have resulted in modification of landforms, depositional processes, and hydro-geomorphology of the region. Major rivers like the Yamuna, the Ghaggar, and the Sutlej show different episodes of shifting of their courses. Lineament controlled few extinct channels have been recorded between 20 and 25 m depth below the surface in the ground-penetrating radar (GPR) profiles. These buried channels are aligned along the paleo-course of the Lost Saraswati River interpreted from the existing literature and hence are considered as the course of the lost river. Seven terminal fans have been formed on the downthrown blocks of the associated faults. The Markanda Terminal Fan, the first of such features described, is indeed a splay terminal fan and was formed by a splay distributary system of the Markanda River. Association of three terminal fans of different ages with the Karnal fault indicates the segment-wise development of the fault from west to east. Also, comparison with other such studies in the Ganga plain to further east suggests that the terminal fans formed by streams with distributary drainage pattern occur only in semiarid regions as in the present area and thus are indicators of semiarid climate/paleoclimate. Though the whole region is tectonically active, the region between the Rohtak fault and Hisar fault is most active at present signified by the concentration of earthquake epicenters.     

Calibration of AGRS System Using Transportable Pads in India: An Application to AGRS Data of Aravalli Basin,Banswada Block,South Rajasthan

Calibration of airborne gamma ray spectrometric system (AGRS) over standard radioactive sources of known elemental abundances is essential before carrying out airborne surveys. In India, fixed calibration pads were constructed in 1985. Since then calibration of AGRS system was carried out over the fixed pads. However the fixed pads are expensive to build and maintain. Also the large pads are subject to variations in radiation output due to variable moisture content and radon loss. Alternate approach is to construct transportable calibration pads which are discussed in this paper.Atomic Minerals Directorate for Exploration & Research (AMD) under Department of Atomic Energy has recently constructed five transportable calibration pads. Three pads i.e. K, U and Th have been spiked with the respective radioelements while keeping the minor radioelements to the least in order to obtain pure spectra. A composite pad has been constructed which contains all the three radioelements. This helps in cross verifying the obtained calibration results. A background pad has also been constructed which is helpful to obtain the background values during calibration.Analysis of the data acquired over the transportable pads with airborne gamma ray spectrometer (16.8 ltr) has been carried out and presented in this paper. A comparison with the data acquired over the fixed calibration pads is also included. There is a good agreement of results which suggests the use of transportable pads in future.     

Rootless calc-silicate folds in granite: An implication towards syn- to post-plutonic emplacement

Deformation of the Champaner Group of rocks that form a part of Southern Aravalli Mountain Belt, western India, occurred during the Grenville orogeny (ca. 1400–935 Ma). Two phases of deformation are recorded: \(\hbox {D}_{1}\), persistent throughout the group and characterised by westerly plunging tight isoclinal folds and \(\hbox {D}_{2}\), a localized phase of deformation associated with shortening of the earlier folds from the eastern margin. Both the phases of deformation are in association with the syn-tectonically emplaced Godhra granite. The present work records rootless calc-silicate folds in granite belonging to the older formation, located at the eastern fringe of the Champaner Group. Field evidences suggest superimposition of Type 2 interference pattern trending NE–SW over rootless Type 0 of varying trends from NW–SE to N–S. The superposed pattern obtained from the field study differs in terms of structural trends with the neighbouring Precambrian stratigraphic units. These stratigraphic units include the Champaner Group to which the study area belongs, the Kadana Formation of the Lunavada Group and Pre-Chamapaner Gneissic Complex. Rootless character of folds found within the study area imply syn-post plutonic emplacement of Godhra granite.     

Estimation of drag coefficient over the western desert sector of the Indian summer monsoon trough

In the estimation of momentum fluxes over land surfaces by the bulk aerodynamic method, no unique value of the drag coefficient (C _D) is found in the literature. The drag coefficient is generally estimated from special observations at different parts of the world. In this study an attempt is made to estimate drag coefficient over the western desert sector of India using data sets of Monsoon Trough Boundary Layer Experiment (MONTBLEX) during the summer monsoon season of 1990. For this purpose, the fast and slow response data sets obtained simultaneously from a 30 m high micro-meteorological tower at Jodhpur are used. All the observations used in this study are confined to a wind speed regime of 2.5–9.0 ms⁻¹. A comparison of momentum fluxes computed by eddy correlation (direct estimation) with profile and bulk aerodynamic (C _D = 3.9 × 10⁻³, Garratt, 1977) methods revealed that though the nature of variation of the fluxes by all these methods is almost similar, both the indirect methods give an under-estimated value of the fluxes. The drag coefficient is estimated as a function of wind speed and surface stability by a multiple regression approach. An average value of the estimated drag coefficient is found to be of the order of 5.43 × 10⁻³. The estimated value ofC _D is validated with a set of independent observations and found to be quite satisfactory. The recomputed momentum fluxes by bulk aerodynamic method using the estimated drag coefficient are in close agreement with the directly estimated fluxes.     

Diverse mode of phosphatic rocks in the environs of Proterozoic Bijawar and Sonrai basins and its relevance to uranium mineralisation — A case study from central India

The Bundelkhand massif comprising a variety of Archean-Paleoproterozoic granitoids along with low grade and high-grade metamorphites and located in the centre of the Indian Plate, underwent extension during Paleoproterozoic period, resulting in the formation of homotaxial intracratonic Bijawar and Sonrai basins in the south and Gwalior basin in the northern margin. The Bijawar and Sonrai basins are typified by their characteristic sediments and basic volcanic rocks. A feature common to both the basins, is the overwhelming occurrence of phosphatic rocks across stratigraphy and lithotype in the Bijawar basin and its confinement to the basal part of the sedimentary column in Sonrai basin. Most of these rocks are primarily of marine origin, and later subjected to periods of repeated phosphatic redistribution. Multiple episodes of such phosphatisation culminates in the proliferation and enrichment of phosphate in the upper Bijawar rocks of Bijawar basin (phosphatic breccia of Hirapur-Mardeora) and lower Bijawar rocks of Sonrai basin (phosphatic breccia of Lalitpur). Apart from these established phosphatic rocks in both the basins, quartz reefs occurring in the basement as well as the lower Bijawar Malhera Chert Breccia Formation in Bijawar basin at places are endowed with anomalously high phosphate content. The phosphatic component in all the lithotypes is in the form of apatite varying in form from microcrystalline to well formed coarser crystal aggregate comprising cement, veins and botroidal encrustations. Irrespective of its spatial, temporal and paragenetic position, it invariably registers weak to moderate radioactivity, due to the presence of uranium within it, as is evident from microprobe data. Although intra-grain and inter-grain distribution of uranium is found to be random and erratic, in general, it is observed that uranium tends to be enriched in the later generation phosphates, due to secondary process of dissolution and reprecipitation. The present paper, with fresh inputs from petrological, geochemical, minerochemical and isotope data pertaining to apatite from all these diverse units, not only explores the already established association of uranium and phosphate in these basins but also provides new insight to the phosphatic quartz reef within the basement and the phosphatised arenaceous sediments of the lower Bijawar Formation.     

Radiation and energy balance dynamics over young chir pine (Pinus roxburghii) system in Doon of western Himalayas

The regional impacts of future climate changes are principally driven by changes in energy fluxes. In this study, measurements on micrometeorological and biophysical variables along with surface energy exchange were made over a coniferous subtropical chir pine (Pinus roxburghii) plantation ecosystem at Forest Research Institute, Doon valley, India. The energy balance components were analyzed for two years to understand the variability of surface energy fluxes, their drivers, and closure pattern. The period covered two growth cycles of pine in the years 2010 and 2011 without and with understory growth. Net short wave and long wave radiative fluxes substantially varied with cloud dynamics, season, rainfall induced surface wetness, and green growth. The study clearly brought out the intimate link of albedo dynamics in chir pine system with dynamics of leaf area index (LAI), soil moisture, and changes in understory background. Rainfall was found to have tight linear coupling with latent heat fluxes. Latent heat flux during monsoon period was found to be higher in higher rainfall year (2010) than in lower rainfall year (2011). Higher or lower pre-monsoon sensible heat fluxes were succeeded by noticeably higher or lower monsoon rainfall respectively. Proportion of latent heat flux to net radiation typically followed the growth curve of green vegetation fraction, but with time lag. The analysis of energy balance closure (EBC) showed that the residual energy varied largely within ±30% of net available energy and the non-closure periods were marked by higher rainspells or forced clearance of understory growths.     

Comparison of Vegetation Indices from Two Ground Based Sensors

The best and commonly used ground-based sensor to monitor crop growth, ASD FieldSpecPro Spectroradiometer (Analytical Spectral Devices, Boulder, CO, USA) is a passive sensor, which can be used under adequate light condition. However, now-a-days active sensors such as GreenSeeker? (GS) handheld crop response (Trimble Agriculture division, USA) are used for monitoring crop growth and are flexible in terms of timeliness and illumination conditions besides being cheaper than the ASD. Before its wide use, the suitability and accuracy of GS should be assessed by comparing the NDVI measured by this instrument with that by ASD, under diverse wheat growing conditions of India. Keeping this in view, the present experiment was undertaken with the following objectives: (1) to find out the temporal variation of NDVI measured both by ASD and GS treatments, (2) to find out relationship between the NDVI measured through ASD and GS and, (3) to evaluate the suitability of GS for NDVI measurements. It was observed that the numerical value of NDVI as measured by GS was always significantly (P < 0.05) lower than that measured by ASD for all the experiments under study. The NDVI-ASD and NDVI-GS were significantly positively correlated (P < 0.01) with the correlation coefficients being +0.94, +0.88 and +0.87 for irrigation and nitrogen experiment, irrigation and cultivars experiment, and tillage, residue and nitrogen experiments, respectively. Further, the regression equation developed between the NDVI-ASD and NDVI-GS: [NDVI-GS = 1.070 × (NDVI-ASD ? 0.292] can be successfully used to compute the NDVI of ASD from that computed by GS.     

Development of a Lunar Scintillometer as part of the national large optical telescope site survey

Ground layer turbulence is a very important site characterization parameter used to assess the quality of an astronomical site. The Lunar Scintillometer is a simple and effective site-testing device for measuring the ground layer turbulence. It consists of a linear array of photodiodes which are sensitive to the slight variations in the moon’s brightness due to scintillation by the lower layers of the Earth’s atmosphere. The covariance of intensity values between the non-redundant photodiode baselines can be used to measure the turbulence profile from the ground up to a height determined by the furthest pair of detectors. The six channel lunar scintillometer that has been developed at the Indian Institute of Astrophysics is based closely on an instrument built by the team led by Andrei Tokovinin of Cerro Tololo Inter-American Observatory (CTIO), Chile (Tokovinin et al., Mon. Not. R. Astron. Soc. 404(3), 1186–1196 2010). We have fabricated the instrument based on the existing electronic design, and have worked on the noise analysis, an EMI (Electromagnetic Induction) resistant PCB design and the software pipeline for analyzing the data from the same. The results from the instrument’s multi-year campaign at Mount Saraswati, Hanle is also presented.