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31.
Coastal vulnerability assessment of the future sea level rise in Udupi coastal zone of Karnataka state, west coast of India 总被引：1，自引：0，他引：1
G.S. Dwarakish S.A. Vinay Usha Natesan Toshiyuki Asano Taro Kakinuma Katta Venkataramana B. Jagadeesha Pai M.K. Babita 《Ocean & Coastal Management》2009,52(9):467-478
Udupi coast in Karnataka state, along the west coast of India, selected as a study area, is well known for sandy beaches, aquaculture ponds, lush greenery, temples and major and minor industries. It lies between 13°00′00″–13°45′00″ north latitudes and 74°47′30″–74°30′00″ east longitudes, the length of the coastline is 95 km, and is oriented along the NNW–SSE direction. It is vulnerable to accelerated sea level rise (SLR) due to its low topography and its high ecological and touristy value. The present study has been carried out with a view to calculate the coastal vulnerability index (CVI) to know the high and low vulnerable areas and area of inundation due to future SLR, and land loss due to coastal erosion. Both conventional and remotely sensed data were used and analysed through the modelling technique and by using ERDAS Imagine and geographical information system software. The rate of erosion was 0.6018 km2/yr during 2000–2006 and around 46 km of the total 95 km stretch is under critical erosion. Out of the 95 km stretch coastline, 59% is at very high risk, 7% high, 4% moderate and 30% in the low vulnerable category, due to SLR. Results of the inundation analysis indicate that 42.19 km2 and 372.08 km2 of the land area will be submerged by flooding at 1 m and 10 m inundation levels. The most severely affected sectors are expected to be the residential and recreational areas, agricultural land, and the natural ecosystem. As this coast is planned for future coastal developmental activities, measures such as building regulation, urban growth planning, development of an integrated coastal zone management, strict enforcement of the Coastal Regulation Zone (CRZ) Act 1991, monitoring of impacts and further research in this regard are recommended for the study area. 相似文献
32.
Summer monsoon onset over Kerala: New definition and prediction 总被引：3，自引：0，他引：3
The summer monsoon onset over Kerala (MOK) marks the beginning of the rainy season for the country. Associated with the MOK,
significant transitions of large scale atmospheric and oceanic circulation patterns are observed over the Asia-Pacific region.
In this study, a new method for the objective identification of MOK, based on large scale circulation features and rainfall
over Kerala, is discussed. Further, a set of empirical models based on the principal component regression (PCR) technique
was developed for the prediction of the date of MOK by keeping in mind the IMD’s operational forecasting service requirements.
Predictors for the models were derived using correlation analysis from the thermal, convective and circulation patterns. Only
five predictors pertaining to the second half of April were used in the first model (Model-1) so that the prediction of MOK
can be prepared by the end of April itself. The second model (Model-2) used four additional predictors pertaining up to the
first half of May along with two predictors used in the Model-1 for update prediction at the end of the first half of May.
To develop each of the PCR models, Principal Components Analysis (PCA) of the respective predictor data was carried out followed
by regression analysis of first two principal components (PCs) with the date of MOK. Both these models showed good skill in
predicting the date of MOK during the independent test period of 1997–2007. The root mean square error (RMSE) of the predictions
from both the models during the independent test period was about four days which was nearly half the RMSE of the predictions
based on climatology. 相似文献
33.
To minimize potential loss of life and property caused by rainfall during typhoon seasons, precise rainfall forecasts have been one of the key subjects in hydrological research. However, rainfall forecast is made difficult by some very complicated and unforeseen physical factors associated with rainfall. Recently, support vector regression (SVR) models and recurrent SVR (RSVR) models have been successfully employed to solve time‐series problems in some fields. Nevertheless, the use of RSVR models in rainfall forecasting has not been investigated widely. This study attempts to improve the forecasting accuracy of rainfall by taking advantage of the unique strength of the SVR model, genetic algorithms, and the recurrent network architecture. The performance of genetic algorithms with different mutation rates and crossover rates in SVR parameter selection is examined. Simulation results identify the RSVR with genetic algorithms model as being an effective means of forecasting rainfall amount. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
34.
GPS求得的高程是地面点在WGS84坐标系中的大地高,而我国采用正常高系统的高程,是通过该点的大地高减去该点的高程异常获得。高程异常的获取,惯用的做法是曲面拟合法,这种方法在水准点稀少的测区（特别是山区）实施起来比较困难。EGM2008模型是迄今为止分辨率最高、精度最好、阶次最多的全球重力场模型。首先利用EGM20081′×1′的大地水准面模型计算各点的高程异常,再通过联测一个一等水准点,获取EGM2008模型所表示的全球似大地水准面与我国高程基准面之间的差异,即可将GPS大地高转换为1985国家高程基准的正常高。兴城测区实例表明,EGM2008模型高程转换法在山区仅用一个水准点即可实现GPS大地高到正常高的转换,且高效率、高精度。 相似文献
35.
Ankush Bhaskar Avadhut Purohit M. Hemalatha Chintamani Pai Anil Raghav Chetan Gurada S. Radha Virendra Yadav Vishal Desai Abhishek Chitnis Padmanabh Sarpotdar Anirudha Patankar 《Astroparticle Physics》2011,35(5):223-229
The gamma ray flux was measured during the annular solar eclipse on January 15, 2010 at Rameswaram, India using NaI (Tl) scintillator detectors and the variation in charged particles and gamma rays was monitored using Geiger Mu¨ller (GM) counters. The gamma ray flux variation was studied in energy range of 0.1–3.5 MeV. Weather parameters (temperature and humidity) were continuously recorded throughout the duration of the eclipse at the site and correlation between gamma ray flux and weather parameters was examined. Analysis of the secondary cosmic ray flux using Fast Fourier Transform (FFT) was carried out to study the impact of the eclipse on the flux modulation. An overall decrease in flux was observed by both GM counters and scintillator detectors. A relative enhancement observed for short time during the eclipse which could be associated with the presence of counter electrojet observed at Rameswaram. This is suggestive of an increase in secondary cosmic ray flux at the geomagnetic equator during every counter electrojet due to decrease in geomagnetic rigidity. 相似文献
36.
37.
After the 1999 Chi-Chi earthquake, the Taiwanese government immediately issued new guidelines prohibiting the construction
of structures for human occupancy within the Chelungpu fault zone. However, these guidelines were not based upon an in-depth
hazard analysis of the near-fault regions. The positions of more than 80% of the 2,492 victims of the Chi-Chi earthquake were
found by our research team. A Victim Attribute Database has been compiled that includes the GPS coordinates of the positioned
victims as well as other attribute data associated with the victims. The human-fatality rates in the near-fault regions have
been analyzed with regard to distances from the Chelungpu fault, the hanging-wall and footwall areas, as well as building
type. The severity at the human-fatality rates in the near-fault regions is inversely proportional to distances from the causative
fault, i.e., the closer the distance, the higher the human-fatality rate observed. The human-fatality rate for victims who
lived in closer proximity to the hanging-wall areas is also significantly higher than those who lived in closer proximity
to the footwall areas, especially in areas on either side of the fault and within 1,000 m of the fault surface trace. In terms
of different building types, factors that include the capacity of the buildings to resistant strong shaking and the level
of strong ground-motion greatly affected the human-fatality rates in the hanging-wall and footwall areas. Therefore simply
prohibiting the construction of buildings within the active fault zone would be an insufficient method of reducing the number
of potential victims; a nationwide effort should be undertaken to upgrade the capacity of buildings to resist strong shaking. 相似文献
38.
YAO Pai LIANG Zuo-Ping LI Hai-yan ZHAO Fu-you .Geophysical Prospecting Company of Coal Geology of Jilin Province Changchun China .No. Prospecting Company of Coal Geology of Jilin Province Yanji Jilin China 《吉林大学学报(地球科学版)》2006,(Z2)
通过实例论述了用RTK放样三维地震测线的作业流程,并从三个方面分析了RTK放样点所达到的精度完全满足规范的要求,指出RTK测量具有广阔的发展前景。 相似文献
39.
A. K. Sahai S. Sharmila R. Chattopadhyay S. Abhilash S. Joseph N. Borah B. N. Goswami D. S. Pai A. K. Srivastava 《Natural Hazards》2017,88(2):853-865
The duration and extreme fluctuations of prolonged wet or dry spells associated with intraseasonal variability during extreme monsoon have devastating impacts on agrarian-based economy over Indian subcontinent. This study examines the potential predictability limit of intraseasonal transitions between rainy to non-rainy phases (i.e., active to break phases) or vice versa over central Indian region during extreme monsoon using very high-resolution (0.25° × 0.25°) daily rainfall datasets. The present study reveals that the transitions from both active to break and break to active conditions are more predictable by ~8 days during the weak monsoon (WM) years compared to the strong monsoon (SM) years. Such asymmetric behavior in the limit of predictability could be linked to the distinct differences in the large-scale seasonal mean background instability during SM and WM years. The achievability of such predictability is further evaluated in a state-of-the-art climate model, the climate forecast system (CFSv2). It is demonstrated that the observed asymmetry in predictability limit could be reproducible in the CFSv2 model, irrespective of its spatial resolution. This study provides impetus for useful dynamical prediction of wet/dry spells at extended range during the extreme monsoon years. 相似文献
40.
Su-Cheng Pai Sen Jan Tung-Yuan Ho Jin-Yuan Liu Ken-Sheng Chu Wen-Huei Lee Cheng-Yun Wang Ping-Yi Huang Hung-Yu Hsu Yiing-Jang Yang 《Journal of Oceanography》2017,73(6):711-723
Significant variations of phosphate and silicate concentrations have been observed in seawater from selected industrial pipelines at intake depths between 400 and 710 m off the Hualien coast, eastern Taiwan, revealing a strong vertical movement of water mass in this intermediate layer. An intensive monitoring experiment was carried out, in which pipeline seawater from three land-based pumping stations and seawater collected by a research vessel were obtained and analyzed in parallel during a 2-day observation period. The results showed clearly that the changes of nutrient concentrations in both pipeline and shipboard samples followed a semidiurnal cycle. The maximum vertical displacement occurred in the 300–800 m layer with a scale as surprisingly large as 100 m, when compared with that observed in other areas. The tidal cycles for different layers may not synchronize with surface tide or each other. Empirical equations have been implemented between nutrient concentrations and temperature for the Hualien off-shore area. The equation can be used to check temperature variation of the intermediate water by measuring either phosphate or silicate in pipeline seawater. 相似文献