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In this study, the amount of cyanide in gold mine tailings is modeled as conceptual, statistical, and mathematical to determine environmental risk level and also to estimate the fate and transport of cyanide in tailings. Therefore, 116 points were selected for sampling from three levels of gold mine tailings and analyzed by colorimetric method. As a matter of fact, new hybrid modeling methods such as AdaBoost, Support Vector Machine, Linear Discriminant Analysis, and Random Forest were used in estimation. In current study, The AdaBoost method was qualified as the best one by minimum estimation error (less than 10%). The model derived from the AdaBoost method shows an average variation of 581 g/day in the volume of cyanide tailings. Thus, the important results of this paper are the presentation of 3D numerical and especially conceptual models according to the 3D cyanide variation in the sulfide gold mine tailings and governing physic/chemical parameters. These qualitative and quantitative results can be used for the management of tailings dam and prevention of the contaminant extension. 相似文献
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Maryam Moridnejad Stewart Cameron Asaad Y. Shamseldin Floris Verhagen Catherine Moore Bruce W. Melville Nick Dudley Ward 《Ground water》2020,58(4):661-673
The Ngongotaha Stream was used as a case study to assess the applicability of fiber optic distributed temperature sensing (FODTS) to identify the location of springs and quantify their discharge. Thirteen springs were identified, mostly located within a 115 m reach, five discharged from the right bank and eight from the left bank. To quantify groundwater discharge, a new approach was developed in which the one-dimensional transient heat transport model was fitted to the FODTS measurements, where the main calibration parameters of interest were the unknown spring discharges. The spatial disposition of the groundwater discharge estimation problem was constrained by two sources of information; first, the stream gains ∼500 L/s as determined by streamflow gauging. Second, the temperature profiles of the left and right banks provide the spatial disposition of springs and their relative discharges. FODTS was used to measure stream temperature near the left and right banks, which created two temperature datasets. A weighted average of the two datasets was then calculated, where the weights reflected the degree of mixing between the right and left banks downstream of a spring. The new approach in this study marks a departure from previous studies, in which the general approach was to use the steady-state thermal mixing model (Selker et al. 2006a; Westhoff et al. 2007; Briggs et al. 2012) to infer groundwater discharge, which is then used as an input into a transient model of the general form of equation to simulate stream temperature (Westhoff et al. 2007). 相似文献
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Shari L. Gallop Ana Vila-Concejo Thomas E. Fellowes Mitchell D. Harley Maryam Rahbani John L. Largier 《地球表面变化过程与地形》2020,45(15):3854-3868
Many estuaries contain sandy beaches that provide habitats and offer protective buffers for wetlands and infrastructure, alongside cultural and recreational resources. Research underpinning coastal management tends to focus on tide- and swell-dominated sandy beaches, but little attention is given to beaches in estuaries and bays (BEBs) that exist along a continuum of wind/swell wave, tide and riverine influence. BEBs are subject to less wave energy than open coast locations because of the generally narrow window of directions for which ocean waves can propagate through the entrance. However, when storm wave direction coincides with the orientation of the estuary or bay entrance, waves can penetrate several kilometres inside. Here we focus on eight BEBs in two major bays/estuaries in Sydney, Australia and present observations from before and after a major extratropical storm with waves from an atypical direction in June 2016. We quantify magnitudes of beach erosion and recovery rates for 3 years post-storm. We show that when high-energy storm waves penetrate bays and estuaries, BEBs can undergo up to 100% of subaerial beach erosion. Three years after the storm, only 5 of the 29 (17%) eroded subaerial beach profiles had recovered to their pre-storm volume. This is likely due to the lack of low-frequency, beach-building waves at BEBs under modal weather conditions in between storms, in contrast to open coast beaches. We also show that the recovery of BEBs may be limited by the absence of adjacent sediment reservoirs due to the dominance of tidal processes mid-channel. Our study highlights the unique behaviour of BEBs relative to beaches on the open coast, and that shifting wave direction needs to be considered in long-term beach resilience under climate change. © 2020 John Wiley & Sons, Ltd. 相似文献
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Ocean Dynamics - The surface enthalpy fluxes (latent and sensible heat fluxes) provide the necessary energy to intensify tropical cyclones (TCs). The surface momentum fluxes modify the intensity of... 相似文献
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Textile wastewater contains huge quantities of nitrogen (N)‐containing azo‐dyes. Irrigation of crops with such wastewater adds toxic dyes into our healthy soils. One of the ways to prevent their entry to soils could be these waters after the dyes' biodegradation. Therefore, the present study was conducted to evaluate the impact of textile dyes on wheat growth, dye degradation efficiency of bacteria‐fungi consortium, and alleviation of dye toxicity in wheat by treatment with microbial consortium. Among dyes, Red‐S3B (3.19% N) was found to be the most toxic to germination and growth of seven‐day‐old wheat seedlings. Shewanella sp. NIAB‐BM15 and Aspergillus terreus NIAB‐FM10 were found to be efficient degraders of Red‐S3B. Their consortium completely decolorized 500 mg L?1 Red‐S3B within 4 h. Irrigation with Red‐S3B‐contaminated water after treatment with developed consortium increased root length, shoot length, root biomass, and shoot biomass of 30‐day‐old wheat seedlings by 47, 18, 6, and 25%, respectively, than untreated water. Moreover, irrigation after microbial treatment of dye‐contaminated water resulted in 20 and 51% increase in shoot N content and N uptake, respectively, than untreated water. Thus, co‐inoculation of bacteria and fungi could be a useful bioremediation strategy for the treatment of azo‐dye‐polluted water. 相似文献
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Natural Resources Research - The uniaxial compressive strength and static Young’s modulus are among the key design parameters typically used in geotechnical engineering projects. In this... 相似文献
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Maryam Dehghani Mohammad Javad Valadan Zoej Sassan Saatchi Juliet Biggs Barry Parsons Tim Wright 《Journal of the Indian Society of Remote Sensing》2009,37(1):147-156
A large agricultural area located in 20 km north of the city of Mashhad in the north-east of Iran is subject to land subsidence.
The subsidence rate was achieved in a couple of sparse points by precise leveling between 1995 and 2005, and continuous GPS
measurements obtained from 2005 to 2006. In order to study the temporal behavior of the deformation in high spatial resolution,
the small baseline subset (SBAS) algorithm was used to generate the interferometric SAR time series analysis. Time series
analysis was performed using 19 interferograms calculated from 12 ENVISAT ASAR data spanning between 2003 and 2006. The time
series results exhibited that the area is subsiding continuously without a significant seasonal effect. Mean LOS deformation
velocity map obtained from time series analysis demonstrated a considerable subsidence rate up to 24 (cm/yr). In order to
evaluate the time series analysis results, continuous GPS measurements as a geodetic approach were applied. The comparisons
showed a great agreement between interferometry results and geodetic technique. Moreover, the information of various piezometric
wells distributed in the area corresponding to 1995 to 2005 showed a significant decline in water table up to 20 meters. The
correlation between the piezometric information and the surface deformation at well’s locations showed that the subsidence
occurrence in Mashhad is due to the excess groundwater withdrawal. 相似文献
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The Kooh-Shah region located in a Tertiary volcanic-plutonic belt of the Lut Block in eastern Iran comprises several subvolcanic intermediate to acidic intrusive rocks, diorite to syenite in composition, which have intruded into volcanic rocks. The Kooh-Shah granitoid rocks are characterized by enrichment in large ion-lithophile elements (LILE: e.g. Sr, Ba, Rb) and depletion in high field-strength elements (HFSE: e.g. Nb, Ta, Ti). The chondrite-normalized REE patterns are characterized by moderate LREE enrichment (La/Yb)N=6.01-10.01, medium-heavy REE enrichment, and absence of Eu anomalies. The Kooh-Shah intrusive rocks are metaluminous, shoshonitic with calc-alkaline affinity and high values of magnetic susceptibility, and classified as the magnetite-series of oxidant I-type granitoids. The age of Kooh-Shah granitoid rocks based on zircon U-Pb age dating is 39.7±0.7 Ma (=Middle Eocene) and the ranges of their initial 87Sr/86Sr and 143Nd/144Nd ratios are from 0.704812 to 0.704920 and 0.512579 to 0.512644, respectively, when recalculated to an age of 39 Ma. The initial ?Nd isotope values for the Kooh-Shah intrusive rocks range from -0.18 to 1.09. This geochemical data indicates that the Kooh-Shah granitoid rocks formed from depleted mantle in an island arc setting. The geochemical signature of the studied granitoid rocks represents a characteristic guide for future exploration of copper-gold porphyry-type deposits in the Lut block. 相似文献
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Journal of Seismology - Earthquake is always known as a natural phenomenon with complex and unpredictable characteristics. One of the parameters which affects the ground motion properties is soil.... 相似文献