Frontiers in Environmental Engineering
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Open Access journal
ISSN (Print) 2326-5779 - ISSN (Online) 2326-5787
Published by Science and Eng Pub Co. [48 journals]
- Automatic Change Detection from Remote Sensing Stereo Image for Large
Surface Coal Mining Area
Abstract: Automatic Change Detection from Remote Sensing Stereo Image for Large Surface Coal Mining Area
Author Feifei zhaoNisha BaoBaoying YeSizhuo WangXiaocui LiuJianyan Ga
Surface mining activities may cause the significant change of the topography and stability of landscape, which may lead to a series of environmental issues, such as water runoff, soil erosion and vegetation degradation. Thus, the characteristic of artificial landscapes should be concerned for reconstruction of mining ecosystems. Remote sensing imagery, particularly stereo image with the advantage of generating digital elevation model (DEM) efficiently can provide information of topography from the surface mining area. The purpose of this study is to monitor topographic change using remote sensing stereo image in large surface coal mine. In this study the ASTER stereo imageries collected in 2002 and 2006 were used to generate DEM. Quantitative methods such as the RMSE and topography profile were conducted to evaluate the accuracy of the ASTER DEM based on the reference 1:50000 topography map. Furthermore, the change of topographic which can be detected were developed based on the image difference by setting a threshold value and watershed transform method. The results indicated that: root-mean-square errors (RMSEs) in elevation are 25m for ASTER DEM in 2002, and 26m for ASTER DEM in 2006. The topographic change from open pit at 2002 and dump at 2006 was automatically and accurately detected, which provided quantitative information for exploiting-peeling-deserting unification of mining. Such piece of information would be very useful in mining rehabilitation and ecology restoration.
- Influence of Climate And Grazing on NDVI in a Typical Steppe Region in
Inner Mongolia, China
Abstract: Influence of Climate And Grazing on NDVI in a Typical Steppe Region in Inner Mongolia, China
Author Haimei WangZhenghai LiGuodong Ha
Based on temperature and precipitation data from 15 meteorological stations and data on livestock populations, we digitized spatial data related to climate aridity and livestock density in Xilingol Leauge, a typical steppe region of northern China, and analyzed the relationships among vegetation cover change (as measured by NDVI), aridity and grazing activity. The results show that: (1) the spatial pattern of the relationship between NDVI and the de Martonne aridity index (IdM) was positive in most parts of Xilingol League; (2) livestock density increased from northwest to southeast, with 53.2% of the study area having livestock density of 40-80 standard sheep units/km2; (3) there was a binomial regression relationship between NDVI and livestock density, with higher livestock density that was concentrated in areas where the NDVI value ranged from 0.46 to 0.62; (4) there was complex linear correlation among NDVI, IdM, and livestock density; (5) partial correlation analysis revealed a significant negative correlation between livestock density and NDVI, and a positive correlation between IdM and NDVI, and the influence of aridity on NDVI was considerably greater than that of livestock density.
- Climate Change Impact of the Caspian Sea Level Changes in the Quaternary
Abstract: Climate Change Impact of the Caspian Sea Level Changes in the Quaternary Sediment
Author Alireza GhodratiPayam Alemi SafavalMir Ahmad Lashteh Neshae
In recent years, the coastline of Caspian Sea in Guilan province, especially the estuary of big rivers such as Sefidroud delta has changed increasingly due to the environmental, continental and marine factors. The changes in the position of these coastlines have led to some damages. The changes of water level that come from the land, the differences in the land sediment levels and the situation of erosion in the coastline's sediments such as continental factors and the changes of sea level and the patterns of current and Caspian Sea waves are the some changes that occur in Caspian Sea's coastlines. The purpose of this study is to investigate the causes of these factors in different regions of Guilan's coastlines. Using aerial photos in the two periods of years in 1967 and 1994 with the scale of 1/20000 and software's such as ILWIS, Photoshop sediment levels are estimated. Some geographic and topographic mapswith the scales of 1/20000, 1/50000, and space measurements are used in order to complete the information in this research. The sedimentary units used in this study in geography are called Quaternary unit. These units in the sedimentary environment are Qt1, Qt2 and QM, which are related to land environment. Qts, Qsp units belong to land and Qt1, Qt2, Qt3 are related to river environment and finally the Q2be, Q2b, and Qbm units are related to middle and under coastline. The Guilan's coastline progress under the sea erosion was estimated in Astaneh-Ashrafiye 84.08 ha, Talesh 49.52 ha, Anzali 45.87 ha, Lasko-kelaye 1430.69 ha and Roudsar 678.5 ha. Retrograde under the coastline's sediment was estimated in Astaneh-Ashrafiye 276.99, Talesh 48.31, Anzali has no retrograde, Lasko-kelaye 2.04 and Roudsar 5.46 ha.
- Comparison on Different Evaluation Methods of Heavy Metal Pollution----- A
Case for K1 Columnar Samples of Yalu River Estuary Watercourse
Abstract: Comparison on Different Evaluation Methods of Heavy Metal Pollution----- A Case for K1 Columnar Samples of Yalu River Estuary Watercourse
Author H.J. LiY. ChengJ.X. WangR.X. LiY.J. M
Heavy metals were determined in columnar sediment samples of the Yalu River estuary watercourse. The environmental status was assessed by using the pollution load index, geologic cumulative index, potential ecological harm index and Nemerow index. It is shown that the geologic cumulative index and Nemerow index show a low level of heavy metal pollution indicating that the pollution of K1 columnar samples is not serious. The results of the ecological risk index and the pollution load index are consistent by indicating a medium pollution degree of columnar sediments of the Yalu River estuary watercourse.
- A Revised Correlation on Downstream Temperature Distribution of
Fire-Induced Flow with Mechanical Longitudinal Ventilation
Abstract: A Revised Correlation on Downstream Temperature Distribution of Fire-Induced Flow with Mechanical Longitudinal Ventilation
Author S.C. LiY.H. ZhaoW. Wan
To evaluate the stability of smoke stratification and fire evacuation effectively, the temperature distribution downstream the fire beneath the ceiling of tunnels with mechanical longitudinal ventilation needs to be estimated. Based on Li model, a revised correlation is proposed by concerning the effects of the mechanical longitudinal ventilation velocity and the width of the tunnel. Ten full-scale field test data in three real tunnels from Hu et al. are employed to correlate the revised correlation. The applicability of the new revised model is validated by comparing with the field test data and previous models. Results indicate that the new model can agree with the field test data well. The Mean Absolute Percentage Error (MAPE) of the revised model is found to be 19.99%. Great improvement of the prediction accuracy is achieved as compared with the previous models.
- A Model Describing Filter Removal Efficiency at Different Inlet
Abstract: A Model Describing Filter Removal Efficiency at Different Inlet Concentrations
Author Chi-Wen KuoTzu-Sou ChuangLuh-Maan Chan
The goal of this study is to model the behavior of removal efficiency from the filtration experiments of former research. Filters have been used widely for industrial manufacturing and personnel air conditioning to protect from airborne molecular contaminations (AMC). Extensive testing has been performed in order to get a clear picture of filtration mechanisms. However, only few researches have been done to find critical parameters regarding to the filter removal efficiency at different concentration. This paper presents a mathematical model based on former researches of the Wheeler-Jonas equation, with a numerical technique of finite element method (FEM) for finding the filter removal efficiency. Hence, the proposed model divided the whole filtration domain into simpler and smaller parts to extrapolate experiment which results in different inlet concentration situations making it promising for filter efficiency prediction and can further help to optimize the design and maintenance of the air filtration systems.
- Research on the Relation between Investment in Industrial Pollution
Control and Economic Growth in Xinjiang
Abstract: Research on the Relation between Investment in Industrial Pollution Control and Economic Growth in Xinjiang
Author Gao Yan
This paper analyzes the investment efficiency of the industrial pollution control of Xinjiang (2001-2013) by using DEA models. The results show that the efficiency of the whole industrial pollution control investment in Xinjiang is relatively low, and the investment DEA is not effective for industrial pollution and environment governance. Industrial pollution control investment efficiency level is low. This is mainly caused by the non-effectiveness of the pure technical efficiency prior to 2010 and the non-effectiveness of post-2010 scale efficiency. It means that the industrial pollution control investment and output structure prior to 2010 is irrational and the post-2010 scale efficiency is decreasing. Finally, aiming at the investment efficiency level of the industrial pollution control in Xinjiang, the paper puts forward to some countermeasures and suggestions.
- Influence of Different Corrosive Mediums on Q235 Carbon Steel
Abstract: Influence of Different Corrosive Mediums on Q235 Carbon Steel
Author C.Y. JiangG.X. LeiX.L. TianW.Y. Li
The corrosion behavior and mechanical properties of Q235 low carbon steel were determined in different corrosive mediums by analyzing the corrosion rate, tensile strength, and microstructure. Various techniques, such as scanning electron microscopy (SEM), and electronic universal tensile testing were used for characterizing the samples. The results revealed that among the various mediums, aerobic bacteria produce the highest degree of corrosion with a large number of corrosion pits on the sample surface and a corrosion rate of 41.36 g/(m2.h) over 10 days. The weight and theoretical tensile strength (σb) were clearly reduced with the σb decreasing by 22.4%. The anaerobic bacteria medium, however, produced a less pronounced effect and the sample surface exhibited only slight pitting. The effect of diluted sulfate was even weaker and the surface of the Q235 specimen remained flat without any obvious changes in the mass or size of the sample after 10 days. In the case of diluted sulfate, the mechanical properties were also not significantly affected with σb reducing by only 2.8%. Neither microbial nor diluted sulfate-induced corrosion reduced the elongation of Q235 carbon steel and the fracture surfaces of the tensile samples analyzed by SEM showed characteristics typical of ductile fracture. Similarly, none of the corrosive mediums tested produced hydrogen embrittlement.
- Studies of Leaching Characteristics of Arsenic and Antimony for Jinya Gold
Abstract: Studies of Leaching Characteristics of Arsenic and Antimony for Jinya Gold Mine
Author Han WeiTang ZhongqinHe QianChen Jianhu
Jinya gold mine is a typical Carlin type gold deposit in Fengshan, China and the main gold-bearing minerals are arsenopyrite and As-bearing pyrite. The mine drainage mainly contains arsenic and antimony, which can cause pollution to the environment. In the present study, the simulated rain water was used to leach the arsenic and antimony in solid waste obtained from the mine in order to investigate the leaching characteristics of arsenic and antimony. The results indicated that a large number of arsenic and antimony dissoluted from the waste rock and tailings.
- Research on Rapid Determination of Total Chlorine and Chlorine Dioxide by
DPD Method in Drinking Water
Abstract: Research on Rapid Determination of Total Chlorine and Chlorine Dioxide by DPD Method in Drinking Water
Author Nan Nan LuWu Chang SongRui Bao JiaShao Hua SunFu Min ChuYan X
Chlorine and chlorine dioxide are widely used for water disinfection nowadays. To establish standard technical process for total chlorine and chlorine dioxide determination, the factors affected total chlorine and chlorine dioxide determination by DPA method were researched in this paper. Temperature should be balanced at 20℃ in determination and pH value should be controlled between 5 and 9. The reaction time should be controlled within 5 minutes for the best results. The interference of metal ions can be eliminated by adding glycine or potassium iodide solution in determination of chlorine dioxide. The results using this method showed no significant difference with using the method GB/T 5749-2006. The research provides support on establishing the standard technical process for rapid determination of total chlorine and chlorine dioxide in drinking water.