Rice-acreage estimation for Orrisa using remotely sensed data

Rice is one of the most important foodgrains grown in India. Attempts have been made to estimate kharif rice acreage of Orissa state since 1986 using digital remote sensing data from Landsat MSS/TM and/or IRS-1A. Accuracies of the estimates obtained have been evaluated against BES (Bureau of Economics and Statistics) estimate. This paper describes the methodology adopted for rice acreage estimation of Orissa state, the results obtained for three years, i.e. 1986–87, 1988–89 and 1989–90, and their accuracy.     

Multi temporal ERS-1 SAR data for identification of rice crop

Microwave sensors having all-weather capabilities provide an opportunity to monitor rice grown in monsoon season. An attempt has been made to identify rice crop using multitemporal ERS-1 SAR data in C-band (5.3 GHz). Data acquired on August 15 (D1), September 19 (D2), October 24 (D3) and November 28 (D4) 1993 were taken. Combinations of data acquired on different dates were used for identification of rice crop. Single-date IRS-1B LISS II data in visible and NIR bands acquired on October 23, 1993 was also used for comparison of estimated rice area. Analysis of the results has shown that a combination of SAR data acquired at the tillering (August), booting (September) and heading (October) stages of rice crop enabled identification and area estimation of rice crop grown under lowland conditions. Single-date SAR data acquired in the month of October was found to be better for identification of rice compared to other dates.     

Procedures for computation of saturation radiances: A case study for proposed sensors onboard Indian remote sensing satellite-1C

Saturation radiance (SR) is one of the important parameters required while designing a sensor and it depends on application requirements as well as sensor requirements. This study describes the procedures for computation of SR values using theoretical calculations of earthatmosphere radiances as well as radiances observed by existing satellites such as IRS-1A/1B LISS-I, Landsat TM and SPOT sensors. A possible set of saturation radiances for IRS-1C LISS-III, WIFS and PAN sensors has been suggested.     

Crop classification accuracy as influenced by training strategy,data transformation and spatial resolution of data

The possibility of improving classification accuracies using different training strategies and data transformations within the framework of a supervised maximum likelihood classification scheme was explored in this study. The effect of spatial resolution of data on the accuracy of classification was also studied Single-pixel training strategy resulted in improved classification accuracy over the block-training method. Data transformations gave no significant improvements in accuracy over untransformed data. There was a reduction in classification accuracy as resolution of data improved from 72 m (LISS I) to 36 m (LISS II) while other sensor characteristics remained same.     

Development of a wheat yield model for Punjab using remotely sensed data and historical yield trends

Spectral yield models for Punjab were updated by incorporating the latest data set on district-wise Normalised Difference Vegetation Index (NDVI) and wheat yields. In order to improve the model, historical yield trend for the past ten years was used to derive a linear regression relation for each district. Yield predicted by these linear trend relations was evaluated for validation of the approach. Finally a multiple regression relation incorporating both NDVI and trend-predicted yield was developed. This model shows better prediction capability as seen from yield forecasts of 1991–92 season.     

Sedimentology of a Late Quaternary lacustrine record from the south-eastern Carpathian Basin

The Upper Pleistocene geoarchives in the south-eastern Carpathian Basin are represented predominantly by loess–palaeosol records. In 2015, a 10 m sediment core composed of clay-rich lacustrine sediments was recovered by vibracoring a dry lake basin located between the Vršac Mountains (Serbia) and the Banat Sands in the south-eastern Carpathian Basin; a location relevant for placing regional archaeological results in a palaeoenvironmental context. Here, we present results from geoelectrical prospection and a lithostratigraphic interpretation of this sequence supported by a detailed granulometric study supplemented by ostracod analysis. An age model based on luminescence dating is discussed against sedimentological proxy data and its implication for palaeoenvironmental change. The cores show a stratigraphy of lighter ochre-coloured and darker greyish sediment, related to the deposition of clay and silt trapped in an aquatic environment. Geophysical measurements show ~20 m thick lacustrine sediments. The grain-size distributions including the variability in fine clay are indicative of a lacustrine environment. Fine particles were brought into the depositional environments by aquatic input and settled from suspension; also, direct dust input is constrained by grain-size results. Riverine input and aeolian dust input interplayed at the locality.     

A non-invasive anaesthetic method for accessing the brood chamber of the Chilean flat oyster (Ostrea chilensis)

A cost effective method to discern brooding from non-brooding specimens of the Chilean flat oyster (Ostrea chilensis Phillipi, 1844) is needed to optimise current hatchery practices for this species. Accordingly, we investigated the efficacy of two treatments, AQUI-S® and MgCl₂, in anaesthetising individuals of this species and then mapped any subsequent mortality of anaesthetised oysters. Oysters immersed for 3 h in solutions of 20, 40, 80 and 100 µL L^?1 of AQUI-S® exhibited no signs of anaesthesia and also recorded low levels of mortality (i.e. 8% or less). Conversely, oysters immersed in 30, 40 and 50 g L^?1 MgCl₂ showed between 96%–100% anaesthesia after 3 h whereas only 70% of oysters immersed in 60 g L^?1 MgCl₂ were anaesthetised over this time period. Time taken for 50% of oyster shells to open (SO₅₀) was compared among MgCl₂ treatments with oysters immersed in 60 g L^?1 taking significantly longer than (103 min) those immersed in 30–50 g L^?1 (SO₅₀ values of 43, 54 and 37 min respectively). Furthermore, treating oysters with MgCl₂ resulted in low levels of mortality (i.e. 13% or less) and was not related to MgCl₂ concentration. Thus, our results show that immersing O. chilensis in MgCl₂ to be an efficient and cost effective method to access the brood chamber of this species. We recommend the use of 30 g L^?1 for routine anaesthesia and recommend that future work investigates the efficacy of cheaper MgCl₂ sources and what effects MgCl₂ anaesthetisation has on developing larvae.     

Pleistocene glaciation chronology of Spitsbergen

Troitsky, Leonid, Punning, Jaan-Mati, HÜtt, Galina & Rajamäe, Raivo 1979 12 01: Pleistocene glaciation chronology of Spitsbergen. Boreas , Vol. 8, pp. 401–407. Oslo. ISSN 0300–9483.
Geomorphological and geochronological studies of Pleistocene deposits were carried out in sections along Billefjorden and Bellsund as well as on Bröggerhalvöya and Prins Karls Forland. For purposes of correlation and development of a time scale, radiocarbon (¹⁴C) and thermoluminescent (TL) dating methods were used. The dates obtained indicate the presence of older Pleistocene deposits on Spitsbergen and also provide information on the distribution of Middle Pleistocene glacial deposits. A correlation scheme of Pleistocene deposits of Spitsbergen with stratigraphic units of the Alps and northwestern Europe is presented.     

Thermoluminescence dating of the Eemian-Early Weichselian sequence at Fjøsanger, western Norway

Thermoluminescence (TL) dating of shallow marine sediments from the well studied interglacial-carly glacial sequence at Fjtfsangcr, western Norway has yielded ages that with few exceptions become progressively older with depth. For Ecmian samples the TL method yielded a mean of 111,000 ± 23,000 years, close to the often postulated age of 125,000 years. For the Early Weichselian the TL dates were younger than suggested by the amino-acid method.     

Mapping Cropping Practices Using MODIS Time Series: Harnessing the Data Explosion

The MODIS (Moderate Resolution Imaging Spectroradiometer) 250m EVI dataset provides a valuable ongoing means of characterising and monitoring changes in land use and resource condition. However the multiple factors that influence a time series of greenness data make the data difficult to analyse and interpret. Without prior knowledge, underlying models for time series in a given remote sensing image are often heterogeneous. So while conventional time series analysis methods such as wavelet transform and Fourier analysis may work well for part of the image, these models are either invalid or must be substantially re-parameterised for other parts of the image. To overcome these challenges we propose a new approach to distil information from earth observation time series data. The characteristics of a remote sensing time series are represented by a set of statistics (which we call coefficients) selected to correspond to the dynamics of a natural system. To ensure the coefficients are robust and generic, statistics are calculated independently by applying statistical models with less complexity on shorter segments within the time series. An International Standards Organization (ISO) Land Cover classification (Jansen 2000) was generated for cropping regions in the Gwydir and Namoi catchments, in Australia. Areas identified in the classification as irrigated and rain fed cropping were analysed using a tailored time series analysis tool. The crop analysis tool identifies time series features such as the number and duration of fallow periods, crop timing, presence/absence of a crop during a year for a specific growing season. This information is combined with paddock boundaries derived from Landsat imagery to provide detailed year-by-year insight into cropping practices in the Gwydir and Namoi catchments.