39 research outputs found
Species-level classification of mangrove forest using AVIRIS-NG hyperspectral imagery
No full textSpecies-level classification of mangroves provides important inputs for conservation, rehabilitation and understanding of ecosystem functions. The hyperspectral sensor, Airborne Visible InfraRed Imaging Spectrometer-New Generation (AVIRIS-NG), holds promises for species-level discrimination by virtue of its coverage across a wider spectrum at very high spatial resolution. Using the continuum removal (CR) technique and absorption band depth (ABD), this study applied Random Forest (RF) model to classify the distribution of three species (Heritiera fomes, Excoecaria agallocha and Avicennia officinalis) and two of their combinations (Heritiera fomes-Excoecaria agallocha and Avicennia officinalis-Excoecaria agallocha). The classified map demonstrated good accuracy (overall accuracy = 88%; kappa coefficient = 0.84) using ABD as an independent variable. The important wavelengths (972, 1172, 1177 nm) identified for mangrove species discrimination correspond to water absorption bands. This characteristic may be replicated for species-level classification of other mangrove forests with similar species
Leaf chlorophyll concentration estimation using absorption spectroscopy of AVIRIS-NG for a mangrove forest in India
No full textChlorophyll concentration is one of the important biochemical properties of vegetation as it relates to photosynthetic activity and health. The amount of chlorophyll in a vegetation canopy indicates the physiological status or the health condition. Compared to other terrestrial ecosystems, mangroves are highly productive, so there is a need for a better understanding of the dynamics of carbon sequestration by monitoring their health and nutrition status for ecological conservation and restoration processes. In spite of many ecosystem services, limited research has been conducted concerning mangrove chlorophyll assessment due to the challenges of field sampling. The majority of the chlorophyll assessments in mangroves are being executed with the help of remote sensing data-derived vegetation indices (VIs). However, they are site or species-specific, which prohibits a universal adaptation. Our study quantifies leaf chlorophyll concentration (LCC) distribution using the Airborne Visible InfraRed Imaging Spectrometer—Next Generation (AVIRIS-NG) hyperspectral imagery and field observed dataset for the Bhitarkanika National Park (BNP), a mangrove ecosystem of India. This study aims to predict the LCC utilizing absorption features such as absorption band depth (ABD) as a predictor variable. This was calculated using continuum removal techniques and further predicted using machine learning (Random Forest, RF). This study identifies the red-edge region (676–722 nm) as the prominent part of the electromagnetic spectrum that is useful for predicting LCC. Our model achieved an acceptable accuracy (R2 = 0.82, RMSE = 0.34) and comparable validation statistics (R2 = 0.44, RMSE = 0.38), despite on-field logistic constraints in LCC measurements. This study demonstrated a protocol for a rapid estimate of biochemical variables using (AVIRIS-NG) hyperspectral imagery
Journal of Natural Rubber Research 1987-1996: A ten-year bibliometric study
No full textThe Journal of Natural Rubber Research, published by the Rubber Research Institute of Malaysia since 1929, has played a key role in the dissemination of natural rubber information all over the world. This paper analyses the authorship pattern, the range and frequency of references cited, the extent of acknowledgement and appendix or appendices being included in research articles of natural rubber, the types of collaborative research in natural rubber and the international collaboration scenario as portrayed in the Journal. Results indicated that the trend is towards multi-authorship and a high degree of collaboration between natural rubber researchers
Studies in Logic: A Dialogue Between the East and the West. Homage to Bimal Krishna Matilal
No full textTen essays of this book, two of which are written in Sanskrit, range from modern logic to classical Indian theories of inference. Classical Indian philosophy comprising Pracina and Navya- Nyaya, Sankhya, Buddhist and Jaina logical and philosophical standpoints are discussed in most modern technical terms of western philosophy, often with the aid of terminologies of modern logic. Similarly, western ideas propounded by the ancient Greek philosophers like Aristotle as well as contemporary philosophers such as Frege, Russell, Srawson, Kripke and many others are placed against the backdrop of classical Indian philosophy. The book will be immensely useful to those interested in stimulating meaningful dialogues between philosophical thinkings of India and the West. The book will also be of interest to those who aim at broadening the horizon of logic and philosoph
A baseline estimate of regional agricultural water demand from GEO-LEO satellite observations
No full textAgricultural water demand (AWD) and irrigation water demand (IWD) were assessed (2009–2018) over India using geostationary and polar orbiting satellites. A novel concept of satellite based composite crop-coefficient was introduced to address bulk AWD from mixed agricultural landscape. Significant spatio-temporal variation of AWD was observed over India. The decadal mean of annual AWD was found to be 1521 km3 contributing around 52% (789 km3) and 48% (732 km3) in kharif and rabi seasons, respectively. The decadal average IWD over India was found to be 360 km3. At annual scale, around 75% of AWD was found fulfilled by effective rainfall and the rest 25% is the IWD. The decadal trend of AWD and IWD showed significant increasing trend over Indian region. The study provides a baseline reference for regional agricultural water management policy over diverse agro-climatic regions of India with an opportunity to optimize AWD and IWD at different locations
Assessing the accuracy of multi-model approaches for downscaling land surface temperature across diverse agroclimatic zones
No full textLand surface temperature (LST) is a critical parameter for land surface and atmospheric interactions. However, the applicability of current LST estimates for field-level hydrological, agricultural, and ecological operations is challenging due to their coarse spatiotemporal resolution. In the current article, we compared three different models, namely 1) Thermal Sharpening (TsHARP), 2) Thin Plate Spline (TPS), and 3) Random Forest (RF) for downscaling LST from 100 to 10 m by using high-resolution Sentinel-1,2 optical-microwave data. TsHARP, TPS, and RF are commonly used methods for improving the spatial resolution of large-scale environmental or climate data to finer scales for field-level applications. The analysis was performed at agricultural farms in the semi-arid, arid, and per-humid regions of India during the winter and summer seasons of 2020–21 and 2021–22. The calibration accuracy of the RF model was in better agreement with the coefficient of determination (R2), root mean square error (RMSE), and normalized RMSE (nRMSE) values ranging between 0.961–0.997, 0.103–0.439 K, and 0.034–0.143%, respectively, and lower values of standard errors for all three locations. Though the validation accuracy of models varied between the regions, RF and TPS consistently outperformed the TsHARP model. Further the impact of individual features on LST downscaling was analyzed using Accumulated Local Effects (ALE) plot. The study concluded that RF is an effective and adaptable strategy that can be used in various agroclimatic zones and land cover types, suggesting its broader applicability in agricultural and ecological operations. Finer resolution LST data with enhanced precision can support tailored field-level decision-making and interventions in agriculture and environmental monitoring
Modelling monthly diffuse solar radiation fraction and its validity over the Indian sub-tropics
No full text
A Short Biography of Dr Radhabinod Pal, 1886-1967
No full textDr. Radhabinod Pal is an Indian jurist remembered by modern historians for his dissentient judgment at the International Military Tribunal for the Far East convened in Tokyo from 1946 to 1948, in which he held all of the accused not guilty of each and all of the charges brought against them. This paper attempts to bring his biographical data from various sources together and put them in order for the use of Japanese researchers. The main part is a translation of the short biography of Dr. Pal from Bengali into Japanese. It was contained in a booklet handed out by the family of the deceased to the people who attended the funeral service (sraddha) observed in Calcutta in 1967. The text is fully annotated by the author with a body of factual information taken from, first, a series of interviews conducted in Calcutta in September 2008 with Mr. Prasanta Kumar Pal, Mr. Bimal Ray and Mr. Samar Dutt; second, archival material preserved in the National Archives of India, the National Library of Australia and the India Office Library; and third, periodicals and books published in India and Japan. It is unfortunate that grossly distorted stories about Dr. Pal’s life and opinions have been in circulation in Japan for no less than half a century since the Tokyo trial. It is the author’s hope that the present paper will help set them right and lay foundations for assessing Dr. Pal’s dissentient judgment in proper historical perspective
