Riverine flood assessment in Jhang district in connection with ENSO and summer monsoon rainfall over Upper Indus Basin for 2010     

Bushra Khalid  Débora Souza Alvim  Shumaila Javeed  Junaid Aziz Khan  Muhammad Asif Javed  Azmat Hayat Khan 《Natural Hazards》2018,92(2):971-993

Pakistan has experienced severe floods over the past decades due to climate variability. Among all the floods, the flood of 2010 was the worst in history. This study focuses on the assessment of (1) riverine flooding in the district Jhang (where Jhelum and Chenab rivers join, and the district was severely flood affected) and (2) south Asiatic summer monsoon rainfall patterns and anomalies considering the case of 2010 flood in Pakistan. The land use/cover change has been analyzed by using Landsat TM 30 m resolution satellite imageries for supervised classification, and three instances have been compared, i.e., pre-flooding, flooding, and post-flooding. The water flow accumulation, drainage density and pattern, and river catchment areas have been calculated by using Shutter Radar Topography Mission digital elevation model 90 m resolution. The standard deviation of south Asiatic summer monsoon rainfall patterns, anomalies and normal (1979–2008) has been calculated for July, August, and September by using rainfall data set of Era interim (0.75° × 0.75° resolution). El Niño Southern Oscillation has also been considered for its role in prevailing rainfall anomalies during the year 2010 over Upper Indus Basin region. Results show the considerable changing of land cover during the three instances in the Jhang district and water content in the rivers. Abnormal rainfall patterns over Upper Indus Basin region prevailed during summer monsoon months in the year 2010 and 2011. The El Niño (2009–2010) and its rapid phase transition to La Niña (2011–2012) may be the cause of severity and disturbances in rainfall patterns during the year 2010. The Geographical Information System techniques and model based simulated climate data sets have been used in this study which can be helpful in developing a monitoring tool for flood management.  相似文献   

Seismicity assessment of Fukushima region,fault kinematics and calculation of PGA value for Idosawa fault in Hamadori area,Japan     

Ahmed  Naseer  Ghazi  Shahid  Sami  Javed 《Natural Hazards》2018,92(2):1065-1079

Natural Hazards - In depth assessment of seismicity distribution for a particular region like Fukushima, prefecture is key towards reliable seismic hazard analysis for the area. Assessment of...  相似文献   

Landslide susceptibility mapping using an integrated model of information value method and logistic regression in the Bailongjiang watershed,Gansu Province,China   总被引：4，自引：2，他引：2  

Guo-liang Du  Yong-shuang Zhang  Javed Iqbal  Zhi-hua Yang  Xin Yao 《山地科学学报》2017,14(2):249-268

Bailongjiang watershed in southern Gansu province, China, is one of the most landslide-prone regions in China, characterized by very high frequency of landslide occurrence. In order to predict the landslide occurrence, a comprehensive map of landslide susceptibility is required which may be significantly helpful in reducing loss of property and human life. In this study, an integrated model of information value method and logistic regression is proposed by using their merits at maximum and overcoming their weaknesses, which may enhance precision and accuracy of landslide susceptibility assessment. A detailed and reliable landslide inventory with 1587 landslides was prepared and randomly divided into two groups, (i) training dataset and (ii) testing dataset. Eight distinct landslide conditioning factors including lithology, slope gradient, aspect, elevation, distance to drainages, distance to faults, distance to roads and vegetation coverage were selected for landslide susceptibility mapping. The produced landslide susceptibility maps were validated by the success rate and prediction rate curves. The validation results show that the success rate and the prediction rate of the integrated model are 81.7 % and 84.6 %, respectively, which indicate that the proposed integrated method is reliable to produce an accurate landslide susceptibility map and the results may be used for landslides management and mitigation.  相似文献   

Mechanisms involved in triggering debris flows within a cohesive gravel soil mass on a slope: a case in SW China   总被引：1，自引：1，他引：0  

Ning-sheng Chen  Yun-hua Zhu  Qi Huang  Javed Iqbal  Ming-feng Deng  Na He 《山地科学学报》2017,14(4):611-620

The triggering mechanisms of debris flows were explored in the field using artificial rainfall experiments in two gullies, Dawazi Gully and Aizi Gully, in Yunnan and Sichuan Provinces, China, respectively. The soils at both sites are bare, loose and cohesive gravel-dominated. The results of a direct shear test, rheological test and back-analysis using soil mass stability calculations indicate that the mechanisms responsible for triggering debris flows involved the decreases in static and dynamic resistance of the soil. The triggering processes can be divided into 7 stages: rainfall infiltration, generation of excess runoff, high pore water pressure, surface erosion, soil creep, soil slipping, debris flow triggering and debris flow increment. In addition, two critical steps are evident: (i) During the process of the soil mass changing from a static to a mobile state, its cohesion decreased sharply (e.g., the cohesion of the soil mass in Dawazi Gully decreased from 0.520 to 0.090 kPa, a decrease of 83%). This would have reduced the soil strength and the kinetic energy during slipping, eventually triggered the debris flow. (ii) When the soil mass began to slip, the velocity and the volume increment of the debris flow fluctuated as a result of the interaction of soil resistance and the sliding force. The displaced soil mass from the source area of the slope resulted in the deposition of a volume of soil more than 7 - 8 times greater than that in the source area.  相似文献   

Phase and amplitude error indices for error quantification in pseudodynamic testing     

Reza Mirza Hessabi  Oya Mercan 《地震工程与结构动力学》2012,41(10):1347-1364

Real-time pseudodynamic (PSD) and hybrid PSD testing methods are displacement controlled experimental techniques that are used to investigate the dynamic behaviour of complex and load rate-dependent structures. Because the imposed command displacements are not predefined but generated during the test based on measured feedback, these methods are inherently prone to error propagation, which can affect the accuracy and even the stability of the entire experiment. As a result, to have these experimental methods as reliable tools, the accuracy of the test results needs to be assessed by carefully monitoring, and if possible, quantifying the errors involved. In this paper, phase and amplitude error indices (PAEI) are introduced to identify the experimental errors through uncoupled closed-form equations. Unlike the indicators that have been previously introduced in the literature for error identification purposes, PAEI do not use test setup specific parameters in their formulation, and can quantify the errors independent of the amplitude of the command displacements. As such, PAEI can be used as standard tools for assessing the quality of the experiments performed in different laboratories or under different conditions. Additionally, because they can quantify the error, when implemented online, PAEI have the potential to be incorporated in the control law and thereby improve the actuator control during the tests. The formulation and implementation of PAEI are provided in this paper. The enhanced performance of the proposed indices is demonstrated by processing several different measured and command signals using PAEI and comparing the results with those revealed by the previous indicators. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Chemical Characterization and Source Apportionment of Atmospheric Particles Across Multiple Sampling Locations in Faisalabad,Pakistan   总被引：1，自引：0，他引：1       下载免费PDF全文

Wasim Javed  Anthony S. Wexler  Ghulam Murtaza  Muhammad Mazhar Iqbal  Yongjing Zhao  Tayyaba Naz 《洁净——土壤、空气、水》2016,44(7):753-765

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Employing Response Surface Methodology for Optimization of Mercury Bioremediation by Vibrio parahaemolyticus PG02 in Coastal Sediments of Bushehr,Iran          下载免费PDF全文

Seyed Ali Jafari  Sama Cheraghi  Maryam Mirbakhsh  Roozbeh Mirza  Ammar Maryamabadi 《洁净——土壤、空气、水》2015,43(1):118-126

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Linear and non-linear approaches to predict the Darcy-Weisbach friction factor of overland flow using the extreme learning machine approach     

Kiyoumars Roushangar  Saba Mirza Alipour  Dominique Mouaze 《国际泥沙研究》2018,33(4):415-432

In modeling of overland flow and erosion, the overland flow friction factor (f), is a crucial factor. Due to the importance of a good understanding of f and its variability, the current study aimed to investigate the capability of non-linear approaches to estimate the Darcy-Weisbach friction factor of overland flow and its components (sediment transport, wave, form, and grain friction factors) through the Extreme Learning Machine (ELM) approach. Four datasets were used herein which were obtained from flume experiments done by different researchers. In order to investigate the effects of different parameters on the friction factor, numerous models consisting of various parameters were utilized to predict the friction factor using the ELM approach. The modeling procedure was established in two stages; the first stage aimed to model the overland flow friction factor and investigate the effect of the different parameters on the friction factor using non-linear separation via the ELM approach. In the second stage, the friction factor was linearly separated into different types of friction factors and then the separate components were estimated. Sensitivity analysis results confirmed the key role of Froude number (Fr) values for most of the models. On the other hand, the results obtained for estimated values of the friction factor were acceptable and outperformed available empirical approaches.  相似文献   

Prediction of rainfall‐induced shallow landslides in the Loess Plateau,Yan'an,China, using the TRIGRS model          下载免费PDF全文

Jianqi Zhuang  Jianbing Peng  Gonghui Wang  Javed Iqbal  Ying Wang  Wei Li  Qiang Xu  Xinghua Zhu 《地球表面变化过程与地形》2017,42(6):915-927

In this work, a transient rainfall infiltration and grid‐based regional slope‐stability model (TRIGRS) was implemented in a case study of Yan'an City, Northwest China. In this area, widespread shallow landslides were triggered by the 12 July 2013 exceptional rainstorm event. A high‐resolution DEM, soil parameters from in‐situ and laboratory measurements, water table depths, the maximum depth of precipitation infiltration and rain‐gauge‐corrected precipitation of the event, were used as inputs in the TRIGRS model. Shallow landslides triggered on the same day were used to evaluate the modeling results. The summarized results are as follows: (i) The characteristics and distribution of thirty‐five shallow landslides triggered by the 12 July 2013 rainfall event were identified in the study area and all were classified as shallow landslides with the maximum depth, area and volume less than 3 m, 200 m² and 1000 m³, respectively, (ii) Four intermediate factor of safety (F_S) maps were generated using the TRIGRS model to represent the scenarios 6, 12, 18 and 24 hours after the storm event. The area with F_S < 1 increased with the rainfall duration. The percentage of the area with F_S < 1 was 0.2%, 3.3%, 3.8% and 5.1% for the four stages, respectively. Twenty‐four hours after the rainstorm, TRIGRS predicted that 1255 grid cells failed, which is consistent with the field data. (iii) TRIGRS generated more satisfactory results at a given precipitation threshold than SINMAP, which is ideal for landslide hazard zoning for land‐use planning at the regional scale. Comparison results showed that TRIGRS is more useful for landslide prediction for a certain precipitation threshold, also in the regional scale. (iv) Analysis of the responses of loess slope prone to slope failure after different precipitation scenarios revealed that loess slopes are particularly sensitive to extended periods of heavy precipitation. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Addition of Phosphorus and Nitrogen Support the Invasiveness of Alternanthera Philoxeroides Under Water Stress     

Jianfan Sun  Qaiser Javed  Ahmad Azeem  Muhammad Saif Ullah  Ghulam Rasool  Daolin Du 《洁净——土壤、空气、水》2020,48(9)

Coordination of plant functional traits with changes in the environment is helpful to understand the mechanisms underlying both invasiveness and adaptation of plants. Thus, to investigate the performance and functional traits in invasive Alternanthera philoxeroides (Mart.), an experiment of water stress is conducted with different nutrient concentrations. Alternanthera philoxeroides plants are grown under natural and nutrient soils and subjected to three levels of nitrogen (N) and phosphorus (P) solution: ambient P and N concentration (P?N?), P addition with an ambient N concentration (P+N?), and P addition with high N concentration (P+N+) in combination with three different irrigation water levels as 1) 100% irrigation, 2) 50% irrigation, and 3) 25% deficit irrigation. Based on results, A. philoxeroides produces significantly higher biomass in both soils under 100% irrigation with P+N? treatment and exhibits higher values of leaf area and root length. However, 25% irrigation with P?N? treatment in both soils exerts a significant negative effect on relative growth rate and root/shoot ratio of A. philoxeroides plants. Under 50% irrigation in soils with both P+N? and P+N+ treatments, high values of leaf nitrogen are recorded. Moreover, nutrient soil is more supportive to A. philoxeroides than natural soil.  相似文献