An optimized baseflow separation method for assessment of seasonal and spatial variability of baseflow and the driving factors     

SUN Jiaqi  WANG Xiaojun  Shamsuddin SHAHID  LI Hongyan 《地理学报(英文版)》2021,31(12):1873-1894

Baseflow is an important component of river or streamflow. It plays a vital role in water utilization and management. An improved Eckhardt recursive digital filter(IERDF) is proposed in this study. The key filter parameter and maximum baseflow index(BFImax) were estimated using the minimum smoothing method to improve baseflow estimation accuracy. The generally considered BFImax of 0.80, 0.50 and 0.25 according to the drainage basin's predominant geological characteristics often leads to significant errors in the regions that have complex subsurface and hydrologic conditions. The IERDF improved baseflow estimation accuracy by avoiding arbitrary parameter values. The proposed method was applied for baseflow separation in the upstream of Yitong River, a tributary of the Second Songhua River, and its performance was evaluated by comparing the results obtained using isotope-tracer data. The performance of IERDF was also compared with nine baseflow separation techniques belonging to filter, BFI and HYSEP methods. The IERDF was also applied for baseflow separation and calculation of rainfall infiltration recharge coefficient at different locations along the Second Songhua River's mainstream for the period 2000–2016. The results showed that the minimum smoothing method significantly improved BFImax estimation accuracy. The baseflow process line obtained using IEDRF method was consistent with that obtained using isotope 18 O. The IERDF estimated baseflow also showed stability and reliability when applied in the mainstream of the Second Songhua River. The BFI alone in the river showed an increase from the upstream to the downstream. The proportion of baseflow to total flow showed a decrease with time. The intra-annual variability of BFI was different at different locations of the river due to varying climatic conditions and subsurface characteristics. The highest BFI was observed at the middle reaches of the river in summer due to a water surplus from power generation. The research provided valuable information on baseflow characteristics and runoff mode determination, which can be used for water resources assessment and optimization of economic activity distribution in the region.  相似文献   

A Closed Loop Wastewater Biorefinery Based on the Recently Introduced SHEFROL Reactor and Two Freely Available Macrophytes     

Tabassum-Abbasi  Pratiksha Patnaik  Shahid Abbas Abbasi 《洁净——土壤、空气、水》2023,51(3):2100287

With an objective to develop a closed loop wastewater biorefinery, the performance of two free floating aquatic weeds water hyacinth (Eichhornia crassipes, Mart, Solms) and salvinia (Salvinia molesta, Mitchell) is explored when either is used as the main bioagent for treating sewage in “sheet flow root level” (SHEFROL) bioreactors. Both the macrophytes prove to be easy to propagate and maintain while they are able to help in achieving significant primary, secondary, and tertiary treatment steps of greywater in a single step. Water hyacinth is able to remove suspended solids, chemical oxygen demand (COD), biological oxygen demand (BOD), total Kjeldahl nitrogen, soluble phosphorous, zinc, copper, nickel, and manganese to the average extents of 81%, 79%, 43%, 41%, 40%, 36%, 34%, and 29%, respectively. The reduction in COD and BOD levels achieved by salvinia is marginally lesser than by water hyacinth but in terms of the removal of other pollutants, the performance of salvinia is comparable to that of water hyacinth. It is possible to convert the dead or harvested plants to organic fertilizer thus making it a closed-loop system with no waste of its own.  相似文献   

Microseismic events enhancement and detection in sensor arrays using autocorrelation‐based filtering          下载免费PDF全文

Entao Liu  Lijun Zhu  Anupama Govinda Raj  James H. McClellan  Abdullatif Al‐Shuhail  SanLinn I. Kaka  Naveed Iqbal 《Geophysical Prospecting》2017,65(6):1496-1509

Passive microseismic data are commonly buried in noise, which presents a significant challenge for signal detection and recovery. For recordings from a surface sensor array where each trace contains a time‐delayed arrival from the event, we propose an autocorrelation‐based stacking method that designs a denoising filter from all the traces, as well as a multi‐channel detection scheme. This approach circumvents the issue of time aligning the traces prior to stacking because every trace's autocorrelation is centred at zero in the lag domain. The effect of white noise is concentrated near zero lag; thus, the filter design requires a predictable adjustment of the zero‐lag value. Truncation of the autocorrelation is employed to smooth the impulse response of the denoising filter. In order to extend the applicability of the algorithm, we also propose a noise prewhitening scheme that addresses cases with coloured noise. The simplicity and robustness of this method are validated with synthetic and real seismic traces.  相似文献   

Evaluation of the real-time TRMM-based multi-satellite precipitation analysis for an operational flood prediction system in Nzoia Basin,Lake Victoria,Africa   总被引：3，自引：0，他引：3  

Li Li  Yang Hong  Jiahu Wang  Robert F. Adler  Frederick S. Policelli  Shahid Habib  Daniel Irwn  Tesfaye Korme  Lawrence Okello 《Natural Hazards》2009,50(1):109-123

Many researchers seek to take advantage of the recently available and virtually uninterrupted supply of satellite-based rainfall information as an alternative and supplement to the ground-based observations in order to implement a cost-effective flood prediction in many under-gauged regions around the world. Recently, NASA Applied Science Program has partnered with USAID and African-RCMRD to implement an operational water-hazard warning system, SERVIR-Africa. The ultimate goal of the project is to build up disaster management capacity in East Africa by providing local governmental officials and international aid organizations a practical decision-support tool in order to better assess emerging flood impacts and to quantify spatial extent of flood risk, as well as to respond to such flood emergencies more expediently. The objective of this article is to evaluate the applicability of integrating NASA’s standard satellite precipitation product with a flood prediction model for disaster management in Nzoia, sub-basin of Lake Victoria, Africa. This research first evaluated the TMPA real-time rainfall data against gauged rainfall data from the year 2002 through 2006. Then, the gridded Xinanjiang Model was calibrated to Nzoia basin for period of 1985–2006. Benchmark streamflow simulations were produced with the calibrated hydrological model using the rain gauge and observed streamflow data. Afterward, continuous discharge predictions forced by TMPA 3B42RT real-time data from 2002 through 2006 were simulated, and acceptable results were obtained in comparison with the benchmark performance according to the designated statistic indices such as bias ratio (20%) and NSCE (0.67). Moreover, it is identified that the flood prediction results were improved with systematically bias-corrected TMPA rainfall data with less bias (3.6%) and higher NSCE (0.71). Although the results justify to suggest to us that TMPA real-time data can be acceptably used to drive hydrological models for flood prediction purpose in Nzoia basin, continuous progress in space-borne rainfall estimation technology toward higher accuracy and higher spatial resolution is highly appreciated. Finally, it is also highly recommended that to increase flood forecasting lead time, more reliable and more accurate short- or medium-range quantitative precipitation forecasts is a must.  相似文献   

Petrogenesis of Volcanic Rocks in the Khabr-Marvast Tectonized Ophiolite:Evidence for Subduction Processes in the South-Western Margin of Central Iranian Microcontinent   总被引：1，自引：1，他引：0  

Azam SOLTANMOHAMMADI  Mohammad RAHGOSHAY  Morteza KHALATBARI-JAFARI 《《地质学报》英文版》2009,83(5):884-892

Abstract: The Late Cretaceous Khabr–Marvast tectonized ophiolite is located in the middle part of the Nain–Baft ophiolite belt, at the south-western edge of the central Iranian microcontinent. Although all the volcanic rocks in the study area indicate subduction-related magmatism (e.g. high LILE (large ion lithophile elements) / HFSE (high field strenght elements) ratios and negative anomalies in Nb and Ta), geological and geochemical data clearly distinguish two distinct groups of volcanic rocks in the tectonized association: (1) group 1 is comprised of hyaloclastic breccias, basaltic pillow lavas, and andesite sheet flows. These rocks represent the Nain–Baft oceanic crust; and (2) group 2 is alkaline lavas from the top section of the ophiolite suite. These lavas show shoshonite affinity, but do not support the propensity of ophiolite.  相似文献   

巴基斯坦达尔巴丁(Dalbandin）地震前观测到的电离层foF2异常变化     

穆罕默德?伊尔凡  阿夫塔?阿拉姆  默罕默德?朱奈德  默罕默德?埃亚茨?阿明  达拉?伊克巴尔  黄辅琼 《中国地震研究》2015,29(4):567-575

电离层foF2变化对地震反应非常敏感,与地震有关的电离层扰动变化结果似乎非常有望用于地震短期预测。格林威治时间2011年1月18日20:23分,一次7.2级的大地震发生在巴基斯坦的达尔巴丁(28.73oＮ, 63.92oＥ）。本文研究中,我们必须利用架设在巴基斯坦的伊斯兰堡（33.78oN, 73.06oE）、玛尔坦（32.26oN,71.51oE）和卡拉奇（24.89oN,67.02oE）三个垂直探测台站获得的白天（08:00 a.m. - 05:00 p.m.）小时值数据找出地震前的foF2异常变化特征。结果显示,在达尔巴丁地震前几天,foF2出现了显著变化;并且距离震中最近的台站观测到的频率与幅度异常变化大于较远的位于孕震区边缘的台站。尽管地震异常特征显著,但增加其它电离层参数可以提高foF2异常的高置信度水平。  相似文献   

Dewatering Behaviour of a Uranium Ore Slurry Containing Clays     

Maki Ito  Shahid Azam 《Geotechnical and Geological Engineering》2017,35(6):2549-2569

The main objective of this paper was to investigate the dewatering behaviour of a clayey uranium ore slurry. The slurry (containing 28% clay size) exhibited moderate water adsorption (w _l  = 83% and w _p  = 30%). Primarily composed of muscovite (46%) and quartz (30%), the clay minerals included illite (8%), chlorite (5%) and kaolinite (2%) alongside a CEC of 41 (cmol(+)/kg) with Ca²⁺ and Mg²⁺ as the dominant cations. Likewise, the high EC (17,600 μS/cm) and ionic strength (1.15 mol/L) indicated a flocculated microstructure due to the presence of SO₄ ^2? (22,600 mg/L) and Mg²⁺ (1340 mg/L) in the slurry water. Settling included sedimentation and consolidation at low initial solids condition (25–35%) whereas only consolidation was observed at high initial solids contents (40–50%). The average k reduced from 1.2 × 10^?6 m/s (initial s = 25%) to 5.3 × 10^?8 m/s (initial s = 50%) along with a void ratio reduction from 7.4 to 2.6. Due to thixotropic strength, volume compressibility during consolidation showed apparent pre-consolidation at low effective stress (0.3–2 kPa) with a reduction in void ratio from 2.6 to 2.5. The e _s was found to be 2.46 at σ′ = 2 kPa and was followed by a steeper slope with the void ratio reducing to 2.1 at σ′ = 31 kPa. Likewise, the hydraulic conductivity during consolidation decreased from 2.6 × 10^?9 m/s (at e = 2.6) to 2.0 × 10^?10 m/s (at e = 2.1).  相似文献   

Effects of convective available potential energy,temperature and humidity on the variability of thunderstorm frequency over Bangladesh     

Wahiduzzaman  Md  Ali  Md. Arfan  Luo  Jing-Jia  Wang  Yu  Uddin  Md. Jalal  Shahid  Shamsuddin  Islam  A. R. M. Towfiqul  Mondal  Sanjit Kumar  Siddiki  Ubaydur Rahaman  Bilal  Muhammad  Qiu  Zhongfeng  Dambul  Ramzah  Eibek  Kutubuddin  Haque  Md. Emdadul 《Theoretical and Applied Climatology》2022,147(1-2):325-346

Theoretical and Applied Climatology - The present study examines the effects of convective available potential energy (CAPE), temperature and humidity on the spatiotemporal variation of...  相似文献   

Analysis and farmers’ perception of climate change in the Kashmir Valley,India     

Mahdi  S. Sheraz  Dhekale  B. S.  Jan  Rukhsana  Bhat  M. Anwar  Hussain  Ashaq  Jehangir  Intikhab Aalum  Sofi  Najeebul Rehman  Ahmed  Latief  Qureshi  Asif M. Iqbal  Aezum  Aziz Mujtaba  Bangroo  Shabir A.  Wani  Owais Ali  Bahar  F. A.  Mishra  S. K. 《Theoretical and Applied Climatology》2022,149(1-2):727-741

Theoretical and Applied Climatology - Analysis of climatic variables is important for the detection and attribution of climate change trends and has received considerable attention from researchers...  相似文献   

Bias correction method of high-resolution satellite-based precipitation product for Peninsular Malaysia     

Iqbal  Zafar  Shahid  Shamsuddin  Ahmed  Kamal  Wang  Xiaojun  Ismail  Tarmizi  Gabriel  Hamza Farooq 《Theoretical and Applied Climatology》2022,148(3-4):1429-1446

Theoretical and Applied Climatology - Satellite-based precipitation (SBP) is emerging as a reliable source for high-resolution rainfall estimates over the globe. However, uncertainty in SBP is...  相似文献