Reconstruction and Fractal Dimension Analysis of Extreme Drought Events that occurred in eastern Northwest China from 1470 to 1912

Bi Shuoben*, Jiang Tingting, Qian Yujun, Ling Dequan and Lu Ying

Historical data on drought disasters including drought intensity, duration and range, from 1470 to 1912 in eastern Northwest China were collected. We define the heavy drought event, build the factor model of extreme drought, reconstruct the extreme events of eastern Northwest China for 443 years and mine the time series fractal dimension characteristics of extreme drought events according to the fractal theory of time.

The results obtained from the model have significant similarity with records. The temporal fractal dimension of drought disasters of the whole series decreases with the increase in extreme drought intensity which proves the inverse correlation with extreme drought period. Different types of extreme drought events have their own recapitulation law in the time domain. The drought degree is lower, the scale-free area is wider, the fractal dimension is higher and the short period is rather obvious.

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The Temporal Variation of Drought Indices in times of Climate Change in Tien Giang Province

Tran Van Thuong*, Phan Van Phu and Dao Ngoc Hung

Climate change has been a hotspot of scientific research in the world for decades which caused serious effects on humanity. In recent year, the frequency of drought has been significantly increasing in Tien Giang province and Mekong River Delta more broadly. In this study, the  Reconnaissance Drought Index (RDI) was applied for calculating monthly and yearly drought on periods of 1978 – 2015, 2016 – 2035 and the multiple regression model was also used for demonstrating among drought indices, temperature and precipitation. The line graph showed the temporal change in classifications of drought established for predicting it under climate change context.

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Quantification of recent seismicity and a back propagation Neural Network for forecasting of earthquake magnitude in Northeast Region of India

Zarola Amit and Sil Arjun*

This study presents the spatial variation of seismicity parameters and artificial neural network model for earthquake magnitude prediction in the northeast region of India considering updated earthquake catalog of magnitude Mw ≥ 4.0 that occurred from year 1731 to 2015 in the study area. The study area has been divided into 17 seismic source zones keeping in view the spatial variation in earthquake occurrences, distribution pattern of events and orientation of seismic sources. Seismicity parameters were estimated for each source zone as well as for the whole study area. The estimated ‘b’ value in this study varies from 0.50 to 0.84 in different seismic source zones and for the whole study area it is found as 0.77.

However, the proposed artificial neural network (ANN) technique to predict the possible magnitude of earthquakes in the identified seismic source zones is based on feed forward back propagation neural network model (FFBPNNM) with single hidden layer. Total five input parameters namely, longitude, latitude, elapsed time between two events, cumulative magnitude probability and seismic energy and one output parameter namely, magnitude of earthquakes were used in ANN. The ‘b’ value estimated in this study was used as an input unit in ANN in calculating the cumulative magnitude probability for different zones. The performance of ANN was evaluated by estimating the mean absolute error (MAE), sum of squared error (SSE) and mean squared error (MSE). However, the results obtained in this study show that the ANN model yields good prediction accuracy for earthquake magnitude in NE India.

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Preliminary Research on Law of Migration of Carbon Dioxide for Geological Storage of Carbon Dioxide in Underground

Han Fengshan*, Wu Xinli and Song Li

The CO2 emission in atmosphere results in global climates warm, reduction of CO2 emission is concern of many countries. The geological storage of CO2 is effective method to reduce CO2 emission and to protect the atmospheric environment and to prevent a larger number of other serious natural disasters. It is necessary to research on law of migration of carbon dioxide for geological storage of carbon dioxide in underground.

In this paper law of migration and distribution of carbon dioxide for geological storage of carbon dioxide are researched. According to the diffusion effect and the convection effect, with view to the adsorption effect, the general differential equation of migration and distribution of CO2 are derived, both in a half Infinite Homogeneous Porous media and in multilayer homogeneous porous media in underground for geological storage of CO2. Solutions of general differential equation of migration and distribution of CO2 are obtained. The research results provide theoretical significance for geological storage of carbon dioxide in underground.

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Fundamentals of Direct Displacement Based Design Procedure - A Brief Introduction

Titiksh Abhyuday

Although structures are designed to yield during the event of an earthquake, only the elastic part of the response is often analyzed due to the complexities in evaluating the inelastic part. In order to meet the non-collapse criterion, appropriate capacity design rules and reinforcement detailing are needed. This leads to a safe albeit a rather conservative design. Also, the real deformation of the structure (displacements) tends to be underestimated.

In this study, the importance of structural displacement during the design of structural and non-structural elements is evaluated and a fundamental description of the Direct Displacement Based Design (DDBD) procedure (as proposed by Priestley, 2007) is presented along with its advantages and limitations over the traditional Force Based Design (FBD) approach. The various performance levels are studied and accordingly a methodological explanation of the method is given for calculating the value of base shear.

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