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21.
Nainwal Harish Chandra Shankar R. Mishra Aditya Mishra Sumit Pandey Ankit Shah Sunil Singh Chauhan Gambhir Singh Kumar Deepak 《Natural Hazards》2022,113(1):157-184
Natural Hazards - Drought severity is increasing in Southern Africa which is affecting rain-fed agriculture, the main source of livelihood in most countries in this region. The study assessed the... 相似文献
22.
Bharat Lohani Nishant Bhatnagar Aditya Roshan 《Journal of the Indian Society of Remote Sensing》2008,36(1):1-11
ISRO is launching a LiDAR instrument (LLRI) onboard Chandrayan-I. The LLRI will collect topographic data of lunar surface.
Flying at an altitude of 100km the LLRI will have a footprint of 100m on the moon surface. Time of travel measurement, which
is fundamental for topographic coordinate computation, depends upon the shape of the return pulse. This shape in turn is a
function of the characteristics of footprint, i. e. its geometry, reflectance and roughness. This paper uses a mathematical
model to simulate the return waveform at the receiver for different conditions of said characteristics within the footprint.
Mathematical equations are employed to generate footprints that vary in their characteristics in terms of reflectance, geometry
and roughness. A footprint is divided into small bins so that each bin has uniform property. Energy distribution in transmitted
pulse is considered Gaussian. Energy irradiated over footprint is approximated using the assumed distribution. For each bin
the energy incident is computed and accordingly the quantum and distribution of reflected energy is determined. The final
waveform is generated by integrating the energy returned from all the bins according to their time of arrival and spread.
Some results are presented to show the performance of the developed system. 相似文献
23.
Kenji Satake Yuichi Nishimura Purna Sulastya Putra Aditya Riadi Gusman Haris Sunendar Yushiro Fujii Yuichiro Tanioka Hamzah Latief Eko Yulianto 《Pure and Applied Geophysics》2013,170(9-10):1567-1582
The 2010 Mentawai earthquake (magnitude 7.7) generated a destructive tsunami that caused more than 500 casualties in the Mentawai Islands, west of Sumatra, Indonesia. Seismological analyses indicate that this earthquake was an unusual “tsunami earthquake,” which produces much larger tsunamis than expected from the seismic magnitude. We carried out a field survey to measure tsunami heights and inundation distances, an inversion of tsunami waveforms to estimate the slip distribution on the fault, and inundation modeling to compare the measured and simulated tsunami heights. The measured tsunami heights at eight locations on the west coasts of North and South Pagai Island ranged from 2.5 to 9.3 m, but were mostly in the 4–7 m range. At three villages, the tsunami inundation extended more than 300 m. Interviews of local residents indicated that the earthquake ground shaking was less intense than during previous large earthquakes and did not cause any damage. Inversion of tsunami waveforms recorded at nine coastal tide gauges, a nearby GPS buoy, and a DART station indicated a large slip (maximum 6.1 m) on a shallower part of the fault near the trench axis, a distribution similar to other tsunami earthquakes. The total seismic moment estimated from tsunami waveform inversion was 1.0 × 1021 Nm, which corresponded to Mw 7.9. Computed coastal tsunami heights from this tsunami source model using linear equations are similar to the measured tsunami heights. The inundation heights computed by using detailed bathymetry and topography data and nonlinear equations including inundation were smaller than the measured ones. This may have been partly due to the limited resolution and accuracy of publically available bathymetry and topography data. One-dimensional run-up computations using our surveyed topography profiles showed that the computed heights were roughly similar to the measured ones. 相似文献
24.
Aditya Saputra Christopher Gomez Ioannis Delikostidis Peyman Zawar-Reza Danang Sri Hadmoko Junun Sartohadi 《地球空间信息科学学报》2021,24(2):256-278
Yogyakarta is one of the large cities in Central Java, located on Java Island, Indonesia. The city, and the Pleret sub-district, where the study has taken place, is prone to earthquake hazards, because it is close to several seismically active zones, such as the Sunda Megathrust and the active fault known as the Opak Fault. Since a devastating earthquake of 2006, the population of the Pleret sub-district has increased significantly. Thus, the housing demand has increased, and so is the pace of low-cost housing that does not meet earthquake-safety requirements, and furthermore are often located on unstable slopes. The local alluvial material covering a jigsaw of unstable blocks and complex slope is conditions that can amplify the negative impacts of earthquakes. Within this context, this study is aiming to assess the multi-hazards and risks of earthquakes and related secondary hazards such as ground liquefaction, and coseismic landslides. To achieve this, we used geographic information systems and remote sensing methods supplemented with outcrop study and existing seismic data to derive shear-strain parameters. The results have revealed the presence of numerous uncharted active faults with movements visible from imagery and outcrops. show that the middle part of the study area has a complex geological structure, indicated by many unchartered faults in the outcrops. Using this newly mapped blocks combined with shear strain data, we reassessed the collapse probability of buildings that reach level >0.75 near the Opak River, in central Pleret sub-district. Classifying the buildings and from population distribution, we could determine that the highest risk was during nighttime as the buildings susceptible to fall are predominantly housing buildings. The secondary hazards follow a slightly different distribution with a concentration of risks in the West. 相似文献
25.
26.
Estimating the uncertainty of land-cover extrapolations while constructing a raster map from tabular data 总被引：2，自引：0，他引：2
Robert Gilmore?Pontius Jr.Email author Aditya?Agrawal Diana?Huffaker 《Journal of Geographical Systems》2003,5(3):253-273
This paper presents novel techniques to estimate the uncertainty in extrapolations of spatially-explicit land-change simulation models. We illustrate the concept by mapping a historic landscape based on: 1) tabular data concerning the quantity in each land cover category at a distant point in time at the stratum level, 2) empirical maps from more recent points in time at the grid cell level, and 3) a simulation model that extrapolates land-cover change at the grid cell level. This paper focuses on the method to show uncertainty explicitly in the map of the simulated landscape at the distant point in time. The method requires that validation of the land-cover change model be quantified at the grid-cell level by Kappa for location (Klocation). The validation statistic is used to estimate the certainty in the extrapolation to a point in time where an empirical map does not exist. As an example, we reconstruct the 1951 landscape of the Ipswich River Watershed in Massachusetts, USA. The technique creates a map of 1951 simulated forest with an overall estimated accuracy of 0.91, with an estimated users accuracy ranging from 0.95 to 0.84. We anticipate that this method will become popular, because tabular information concerning land cover at coarse stratum-level scales is abundant, while digital maps of the specific location of land cover are needed at a finer spatial resolution. The method is a key to link non-spatial models with spatially-explicit models. 相似文献
27.
Pichelli Emanuela Coppola Erika Sobolowski Stefan Ban Nikolina Giorgi Filippo Stocchi Paolo Alias Antoinette Belu&#;i&#; Danijel Berthou Segolene Caillaud Cecile Cardoso Rita M. Chan Steven Christensen Ole B&#;ssing Dobler Andreas de Vries Hylke Goergen Klaus Kendon Elizabeth J. Keuler Klaus Lenderink Geert Lorenz Torge Mishra Aditya N. Panitz Hans-Juergen Sch&#;r Christoph Soares Pedro M. M. Truhetz Heimo Vergara-Temprado Jesus 《Climate Dynamics》2021,56(11):3581-3602
This paper presents the first multi-model ensemble of 10-year, “convection-permitting” kilometer-scale regional climate model (RCM) scenario simulations downscaled from selected CMIP5 GCM projections for historical and end of century time slices. The technique is to first downscale the CMIP5 GCM projections to an intermediate 12–15 km resolution grid using RCMs, and then use these fields to downscale further to the kilometer scale. The aim of the paper is to provide an overview of the representation of the precipitation characteristics and their projected changes over the greater Alpine domain within a Coordinated Regional Climate Downscaling Experiment Flagship Pilot Study and the European Climate Prediction system project, tasked with investigating convective processes at the kilometer scale. An ensemble of 12 simulations performed by different research groups around Europe is analyzed. The simulations are evaluated through comparison with high resolution observations while the complementary ensemble of 12 km resolution driving models is used as a benchmark to evaluate the added value of the convection-permitting ensemble. The results show that the kilometer-scale ensemble is able to improve the representation of fine scale details of mean daily, wet-day/hour frequency, wet-day/hour intensity and heavy precipitation on a seasonal scale, reducing uncertainty over some regions. It also improves the representation of the summer diurnal cycle, showing more realistic onset and peak of convection. The kilometer-scale ensemble refines and enhances the projected patterns of change from the coarser resolution simulations and even modifies the sign of the precipitation intensity change and heavy precipitation over some regions. The convection permitting simulations also show larger changes for all indices over the diurnal cycle, also suggesting a change in the duration of convection over some regions. A larger positive change of frequency of heavy to severe precipitation is found. The results are encouraging towards the use of convection-permitting model ensembles to produce robust assessments of the local impacts of future climate change.
相似文献28.
Climates of urbanization: local experiences of water security,conflict and cooperation in peri-urban South-Asia 总被引：1，自引：0，他引：1
Dik Roth Muhammad Shah Alam Khan Israt Jahan Rezaur Rahman Vishal Narain Aditya Kumar Singh 《Climate Policy》2019,19(6):S78-S93
ABSTRACTThis article explores changing water (in)securities in a context of urbanization and climate change in the peri-urban spaces of four South-Asian cities: Khulna (Bangladesh), Gurugram and Hyderabad (India), and Kathmandu (Nepal). As awareness of water challenges like intensifying use, deteriorating quality and climate change is growing, water security gets more scientific and policy attention. However, in peri-urban areas, the dynamic zones between the urban and the rural, it remains under-researched, despite the specific characteristics of these spaces: intensifying flows of goods, resources, people, and technologies; diversifying uses of, and growing pressures on land and water; and complex and often contradictory governance and jurisdictional institutions. This article analyses local experiences of water (in-)security, conflict and cooperation in relation to existing policies. It uses insights from the analysis of the case studies as a point of departure for a critical reflection on whether a ‘community resilience’ discourse contributes to better understanding these cases of water insecurity and conflict, and to better policy solutions. The authors argue that a community resilience focus risks neglecting important insights about how peri-urban water insecurity problems are experienced by peri-urban populations and produced or reproduced in specific socio-economic, political and policy contexts. Unless supported by in-depth hydro-social research, such a focus may depoliticize basically political questions of water (re) allocation, prioritization, and access for marginalized groups. Therefore, the authors plead for more critical awareness among researchers and policy-makers of the consequences of using a ‘community resilience’ discourse for making sense of peri-urban water (in-)security.Key policy insights
There is an urgent need for more (critical) policy and scientific attention to peri-urban water insecurity, conflict, and climate change.
Although a changing climate will likely play a role, more attention is needed to how water insecurities and vulnerabilities in South Asia are socially produced.
Researchers and policy-makers should avoid using depoliticized (community) resilience approaches for basically socio-political problems.
29.
Gunawat Anshuman Sharma Devesh Sharma Aditya Dubey Swatantra Kumar 《Natural Hazards》2022,111(2):2077-2096
Natural Hazards - Crop simulation models are essential tools to facilitate the evaluation and application of crop production practices under different climate scenarios. The present study analyzed... 相似文献
30.
Vijay Sharma Pitambar Pati M. L. Dora Narendra K. Patel Chinmay Dash Parvej Alam Aditya K. Verma Ankit Gupta 《Journal of the Geological Society of India》2018,91(2):201-208
Paleogene sediments of the inner fold belt, Naga hills, have very well preserved ichnofossils. 16 ichnospecies have been documented among 13 ichnogenera such as Arenicolites isp., Chondrites targionii, Cylindrichnus isp., Diplocraterion parallelum, Gyrochorte isp., Ophiomorpha annulata, O. irregulaire, O. nodosa, O. rudis, Palaeophycus tubularis, Planolites beverleyensis, Scolicia palaeobullia, Skolithos linearis, Trypinites weisei, Thalassinoides horizontalis and Zoophycos isp. The ichnofossil assemblages comprise mostly domichnia and fodinichnia benthos of the Skolithos and Cruziana ichnofacies. A shallow marine nearshore to offshore marine environment with fluctuating energy condition has been envisaged. 相似文献