1. Kumar, T. V. L., K. K. Rao, H. A. Barbosa and E. P. Jothi: Studies on spatial pattern of NDVI over India and its relationship with rainfall, air temperature, soil moisture adequacy and ENSO.
The changes in spatial distribution of Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) are studied for different seasons in India for the period 1982 to 2000. The inter-annual variability of All India NDVI (AINDVI) has been studied and related to rainfall, air temperature, soil moisture adequacy, Southern Oscillation Index (SOI) and Nino 3 Sea Surface Temperature (Niño 3 SST) to understand the influence of these variables on vegetal cover. The results show that the NDVI is high during the south-west (June to September) monsoon and retreat (October and November) seasons where in major crop seasons Kharif and Rabi take place over India. The trend of AINDVI is increasing and displayed higher values during La Niña and lower in El Niño episodes. The correlation between rainfall and NDVI of All India is not significant on monthly basis (+0.13) but it is more prominent when the cumulative annual amounts of rainfall are involved (+0.61). NDVI responded very well to the variations of soil moisture adequacy (SAD) which enumerates the strongest correlation (+0.73) of crop performance with NDVI. This significant strong correlation inferred that SAD can be taken as the indicator for the NDVI variations rather rainfall. The linear regression analysis of AINDVI and the ENSO indices revealed the strong impact of sea surface temperatures than SOI on vegetation pattern over India
Keywords: NDVI, inter-annual variability, rainfall, air temperature, soil moisture adequacy, ENSO
2. Shaltout M., A. El Gindy and A. Omstedt: Recent climate trends and future scenarios along the Egyptian Mediterranean coast.
This paper analyses the present
Egyptian Mediterranean coast (EMC) climate and the response of its climate
variables to global changes. First, the accuracy of the ERA-Interim dataset
(1979–2010) for the studied region is examined by comparing these data with
available independent observations. Second, the qualities of six global climate
models (GCMs), together with the ensemble mean of multiple model realisations of
the A1B scenario, are examined by comparing these with the ERA-Interim dataset.
Finally, GCM simulations are used to describe the uncertainties in future
climate change along the EMC.
The results indicate that the observations are in good agreement with the ERA-Interim data. The data for the EMC, 1979–2000, display a significant positive trend for 2-m air temperature together with significant negative trends for total precipitation and sea level pressure. The climate model that best describes the present EMC climate is the CGCM 3.1 model, which is used to describe the future climate of the study area. The CGCM 3.1 model indicates that the EMC area will experience significant warming, substantial droughts, and a weak decrease in sea level pressure in the end of the current century.
Keywords: Mediterranean Sea, Egypt, air temperature, precipitation, sea level pressure, climate, trend analysis, climatic models
3. Samadianfard, S., R. Delirhasannia, O. Kiši and E. Agirre-Basurko: Comparative analysis of ozone level prediction models using gene expression programming and multiple linear regression.
Ground-level ozone (O3) has been a serious air pollution problem for several decades and in many metropolitan areas, due to its adverse impact on the human respiratory system. Therefore, to reduce the risks of O3 related damages, developing, maintaining and improving short term ozone forecasting models is needed. This paper presents the results of two prognostic models including gene expression programming (GEP), which is a variant of genetic programming (GP), and multiple linear regression (MLR) to forecast ozone levels in real-time up to 6 hours ahead at four stations in Bilbao, Spain. The inputs to the GEP were meteorological conditions (wind speed and direction, temperature, relative humidity, pressure, solar radiation and thermal gradient), hourly ozone levels and traffic parameters (number of vehicles, occupation percentage and velocity), which were measured in the years of 1993-94. The performances of developed models were compared with observed values and were evaluated using specific performance measurements for the air quality models established in the Model Validation Kit and recommended by the US Environmental Protection Agency. It was found that the GEP in most cases gives superior predictions. Finally it can be concluded on the basis of the results of this study that gene expression programming appears to be a promising technique for the prediction of pollutant concentrations.
Keywords: air quality modelling, gene expression programming, multiple linear regression, ozone level forecasting, Bilbao area, Spain
4. Kumar, V. and J. P. Narayan: Study of combined effects of sediment rheology and anticlinal basement topography on ground motion characteristics.
A very peculiar damage patterns have been reported during Northridge earthquake of 1994 and Nisqually earthquake of 2001 caused by basement focusing. Similarly, basement de-focusing may cause lesser damage than the expectations but such inferences have not been reported. Further, as far as we know, no theoretical study related to de-focusing effects of anticlinal basement topography (ABT) is available in the literature. In order to fulfill this gap, this article presents the combined effects of sediment rheology and ABT on the SH- and SV-waves characteristics. The simulated results revealed an increase of de-amplification factors with distance travelled in basin above the ABT. The computed snapshots also confirmed amplitude de-amplification, diffraction and mode conversion of SV-wave. Elastic response revealed that the de-amplification factors caused by ABT were not frequency dependent. The average spectral de-amplification factors were more or less same for both the waves even after strong mode conversion of SV-wave at the lower part of ABT. Based on simulated results, it was inferred that the incorporation of effects of ABT in seismic hazard assessment is equally important as that of synclinal basement topography (SBT) effects for cost effective earthquake engineering.
Keywords: simulation of viscoelastic seismic response, finite difference method, mode conversion, basement topography effects and local site effects