Analysis of one-dimensional rheological consolidation of double-layered soil with fractional derivative Merchant model and non-Darcian flow described by non-Newtonian index

To further investigate the one-dimensional(1D)rheological consolidation mechanism of double-layered soil,the fractional derivative Merchant model(FDMM)and the non-Darcian flow model with the non-Newtonian index are respectively introduced to describe the deformation of viscoelastic soil and the flow of pore water in the process of consolidation.Accordingly,an 1D rheological consolidation equation of double-layered soil is obtained,and its numerical analysis is performed by the implicit finite difference method.In order to verify its validity,the numerical solutions by the present method for some simplified cases are compared with the results in the related literature.Then,the influence of the revelent parameters on the rheological consolidation of double-layered soil are investigated.Numerical results indicate that the parameters of non-Darcian flow and FDMM of the first soil layer greatly influence the consolidation rate of double-layered soil.As the decrease of relative compressibility or the increase of relative permeability between the lower soil and the upper soil,the dissipation rate of excess pore water pressure and the settlement rate of the ground will be accelerated.Increasing the relative thickness of soil layer with high permeability or low compressibility will also accelerate the consolidation rate of double-layered soil.

Development of Risk Index of Uninterrupted Traffic Flow According to the Occurrence of Fog

The driver’s visibility is degraded when weather conditions deteriorate, which affects the traffic flow and induces traffic congestion or accidents. In particular, traffic accidents can be?led to chain reaction collisions, with high rate of fatality, when fog occurs in contrast to other weather factors that may restrict visibility. For the development of a traffic risk index, a deviation of the vehicle’s speed was set for the traffic risk index by referring to previous study results. In addition, factors that affected the deviation in a vehicle’s speed were selected as independent variables based on the traffic flow analysis during occurrences of fog. The visible distance, traffic volume, and speed were selected as the independent variables to estimate the optimal parameters in the regression model. The traffic risk index model during occurrences of fog proposed in this study is an exponential model, with the visible distance and the traffic volume defined as independent variables. According to the study model, traffic risk increased as the visible distance decreased and the traffic volume was lower. Thus, the visible distance that can affect traffic flow during occurrences of fog can be determined in the future based on the results of this study. The study results will be expected to contribute to not only traffic safety improvements, but also the facilitation of traffic flow as drivers and traffic operation managers intuitively recognize the level of risk.

Morphodynamics and sediment connectivity index in an unmanaged,debris-flow prone catchment:a through time perspective

Torrential processes are among the main actors responsible for sediment production and mobility in mountain catchments.For this reason,the understanding of preferential pathways for sediment routing has become a priority in hazard assessment and mitigation.In this context,the sediment Connectivity Index(IC)enables to analyse the existing linkage between sediment sources and the selected target(channel network or catchment outlet).The IC is a grid-based index that allows fast computation of sediment connectivity based on landscape information derived from a single Digital Terrain Model(DTM).The index computation is based on the log-ratio between an upslope and a downslope component,including information about drainage area,slope,terrain roughness,and distance to the analysis target(e.g.outlet).The output is a map that highlights the degree of structural connectivity of sediment pathways over analysed catchments.Until now,these maps are however rarely used to help defining debris-flow hazard maps,notably due to a lack of guidelines to interpret the IC spatial distribution.This paper proposes an exploitation procedure along profiles to extract more information from the analysis of mapped IC values.The methodology relies on the analysis of the IC and its component variables along the main channel profile,integrated with information about sediment budgeting derived from Difference of DEMs(DoD).The study of connectivity was applied in the unmanaged sub-catchment(without torrent control works)of the Rio Soial(Autonomous Province of Trento–NE Italy)to understanding the geomorphic evolution of the area after five debris flows(in ten years)and the related changes of sediment connectivity.Using a recent DTM as validation,we demonstrated how an IC analysis over the older DTM can help predicting geomorphic changes and associated hazards.The results show an IC aptitude to capture geomorphic trajectories,anticipate debris flow deposits in a specific channel location,and depict preferential routing pathways.

THE ASYMPTOTIC SOLUTION OF THE UNSTEADY PLANAR PARALLEL GAS FLOW FOR THE CASE TEAT THE ADIABATIC INDEX NUMBER γ IS BIG

In ref I,under the condition that the components of velocity are only the functions of time and polar angleθ,Drornikov solved eqss.(1.1)(1.3)of the ideal gas unsteady planar parallel potential flow.It was pointed out in ref.[1]that in general cases,the evident solutions could not he obtained.Only for two especial cases,the evident solutions were obtained.In this paper,the author studies the same prohlein as that in ref.[1].In the first section we obtain the evident solution of equations(1.1)-(1.3)under the condition that the sonic velocity is restricted by some complemental conditions.In the second section,we obtain the first-order approximate solutions of the fundamental equation for the case thatγ>>1.

Main flow channel index in porous sand reservoirs and its application

Based on well test interpretation,production performance analysis,overburden permeability and porosity test,gas-water core flooding test and high-pressure mercury injection,a quantitative correlation has been built of in-situ effective permeability with routine permeability and water saturation,and the ranges of Main Flow Channel Index(MFCI)are determined for different permeability levels in porous sand gas reservoirs.A new method to evaluate the in-situ effective permeability of porous sand reservoir and a correlation chart of reserves producing degree and main flow channel index are established.The results reveal that the main flow channel index of porous sand gas reservoirs has close correlation with routine matrix permeability and water saturation.The lower the routine matrix permeability and the higher the water saturation,the lower the MFCI is.If the routine matrix permeability is greater than 5.0×10-3,the MFCI is generally greater than 0.5.When the routine matrix permeability is from 1.0×10-3 to 5.0×10-3,the MFCI is mainly between 0.2 and 0.5.When the routine matrix permeability is less than 1.0×10-3,the MFCI is less than 0.2.The evaluation method of in-situ effective permeability can be used to evaluate newly discovered or not tested porous sand gas reservoirs quickly and identify whether there is tight sand gas.The correlation chart of reserves producing degree and main flow channel index can provide basis for recoverable reserves evaluation and well infilling,and provide technical support for formulation of reasonable technical policy of gas reservoir.

Base Flow Index Evaluation for Yom River,Thailand

The most controversial river in Thailand is the Yom River.It has not been modified by large dam because of several valuable natural resources.Therefore,the river is flooded in rainy season and very low flow in dry season.The low flow causes drought which is much more serious than flooding.The Yom River Basin management is only way to circumvent the low flow problem by studying base flow index(BFI).Base flow analyses for 8 gauging stations along the river were performed by 2 techniques i.e.graphical and modified U.K.Institute of Hydrology(MIH).The mean BFI results from graphical and MIH are 0.37(0.05)and 0.45(0.12).The result from graphical is more reasonable due to its lower standard deviation.BFI values from MIH vary with watershed area which may result from the using of fixing value of N-day at 10.Solution for this problem is ongoing in this study.

Dynamic response of buildings under debris flow impact

This study employs the smoothed particle hydrodynamics–finite element method(SPH–FEM) coupling numerical method to investigate the impact of debris flow on reinforced concrete(RC)-frame buildings. The methodology considers the variables of debris flow depth and velocity and introduces the intensity index IDV(IDV = DV) to evaluate three different levels of debris flow impact intensity. The primary focus of this study is to investigate the dynamic response and failure mechanism of RC-frame buildings under debris flow impact, including structural failure patterns, impact force and column displacement. The results show that under a highintensity impact, a gradual collapse process of the RCframe building can be observed, and the damage mode of the frame column reflects shear failure or plastic hinge failure mechanism. First, the longitudinal infill walls are damaged owing to their low out-of-plane flexural capacity;the critical failure intensity index IDV value is approximately 7.5 m2/s. The structure cannot withstand debris flows with an intensity index IDV greater than 16 m2/s, and it is recommended that the peak impact force should not exceed 2100 k N. The impact damage ability of debris flow on buildings mostly originates from the impact force of the frontal debris flow, with the impact force of the debris flow body being approximately 42% lower than that of the debris flow head. Finally, a five-level classification system for evaluating the damage status of buildings is proposed based on the numerical simulation and investigation results of the disaster site.

HyperFLOW软件非结构网格亚跨声速湍流模拟的验证与确认

计算流体力学(computational fluid dynamics, CFD)数值模拟在航空航天等领域发挥越来越重要的作用,然而CFD数值模拟结果的可信度仍然需要通过不断地验证与确认来提高.本文给出了从制造解精度测试、简单到复杂外形湍流模拟网格收敛性研究等三个方面开展CFD软件验证与确认的方法,并对自主研发的CFD软件平台HyperFLOW在非结构网格上模拟亚跨声速湍流问题的能力进行了验证与确认.首先通过基于Euler方程和标量扩散方程的制造解精度测试,分别验证了HyperFLOW在非结构网格上对Euler方程和黏性项的求解精度,结果表明其能够在任意非结构网格上达到设计的二阶精度.其次,通过NASA Turbulence Modeling Resource中的湍流平板、二维翼型近尾迹流动、二维Bump等几个典型的亚声速湍流算例的网格收敛性研究,量化考察了数值结果的观测精度阶和网格收敛性指数,并与国外知名CFD解算器CFL3D,FUN3D的计算结果进行了对比,验证了HyperFLOW对简单湍流问题的模拟能力,且具有良好的网格收敛性和计算精度(阶).最后,通过NASA Common Research Model标模定升力系数的网格收敛性研究和升阻极曲线预测,验证了软件在复杂外形亚跨声速湍流流动数值模拟中也具有良好的可信度.

Association of arterial stiffness with coronary flow reserve in revascularized coronary artery disease patients

AIM: To investigate the association of arterial wave reflection with coronary flow reserve(CFR) in coronary artery disease(CAD) patients after successful revascularization.METHODS: We assessed 70 patients with angiographically documented CAD who had undergone recent successful revascularization. We measured(1) reactive hyperemia index(RHI) using fingertip peripheral arterial tonometry(RH-PAT Endo-PAT);(2) carotid to femoral pulse wave velocity(PWVc-Complior);(3) augmentation index(AIx), the diastolic area(DAI%) and diastolic reflection area(DRA) of the central aortic pulse wave(Arteriograph);(4) CFR using Doppler echocardiography; and(5) blood levels of lipoprotein-phospholipase A2(LpPLA2).RESULTS: After adjustment for age, sex, blood pressure parameter, lipidemic, diabetic and smoking status, we found that coronary flow reserve was independently related to AIx(b =-0.38, r = 0.009), DAI(b = 0.36, P = 0.014), DRA(b = 0.39, P = 0.005) and RT(b =-0.29,P = 0.026). Additionally, patients with CFR < 2.5 had higher PWVc(11.6 ± 2.3 vs 10.2 ± 1.4 m/s, P = 0.019), SBPc(139.1 ± 17.8 vs 125.2 ± 19.1 mm Hg, P = 0.026), AIx(38.2% ± 14.8% vs 29.4% ± 15.1%, P = 0.011) and lower RHI(1.26 ± 0.28 vs 1.50 ± 0.46, P = 0.012), DAI(44.3% ± 7.9% vs 53.9% ± 6.7%, P = 0.008), DRA(42.2 ± 9.6 vs 51.6 ± 11.4, P = 0.012) and Lp PLA2(268.1 ± 91.9 vs 199.5 ± 78.4 ng/m L, P = 0.002) compared with those with CFR ≥ 2.5. Elevated Lp PLA2 was related with reduced CFR(r =-0.33, P = 0.001), RHI(r =-0.37, P < 0.001) and DRA(r =-0.35, P = 0.001) as well as increased PWVc(r = 0.34, P = 0.012) and AIx(r = 0.34, P = 0.001). CONCLUSION: Abnormal arterial wave reflections are related with impaired coronary flow reserve despite successful revascularization in CAD patients. There is a common inflammatory link between impaired aortic wall properties, endothelial dysfunction and coronary flow impairment in CAD.

Assessment of cerebrovascular reserve impairment using the breath-holding index in patients with leukoaraiosis

Many studies have demonstrated that leukoaraiosis is associated with impaired cerebrovascular reserve function. However, the definitive hemodynamic changes that occur in leukoaraiosis are not clear, and there are many controversies. This study aimed to investigate hemodynamic changes in symptomatic leukoaraiosis using transcranial Doppler ultrasonography and the breath-holding test in a Chinese Han population, from northern China. A total of 203 patients who were diagnosed with ischemic stroke or clinical chronic progressive ischemic symptoms were enrolled in this study, including 97 males and 106 females, with an age range of 43-93 years. The severity of leukoaraiosis was evaluated according to the Fazekas grading scale, and patients were divided into four groups accordingly. Grade 0 was no leukoaraiosis, and grades I, II, and III were mild, moderate, and severe leukoaraiosis, respectively, with 44, 79, 44, and 36 cases in each group. Transcranial Doppler ultrasonography and the breath-holding test were performed. The mean blood flow velocity of the bilateral middle cerebral artery was measured and the breath-holding index was calculated. The breath holding index was correlated with leukoaraiosis severity and cognitive impairment. Patients with a low breath holding index presented poor performance in the Montreal Cognitive Assessment (MoCA) and executive function tests. That is, the lower the breath holding index, the lower the scores for the MoCA and the higher for the trail-making test Parts A and B. These results indicate that the breath-holding index is a useful parameter for the evaluation of cerebrovascular reserve impairment in patients with leukoaraiosis. In addition, the breath-holding index can reflect cognitive dysfunction, providing a new insight into the pathophysiology of leukoaraiosis. This study was approved by the Ethics Committee of the Fifth Peoples Hospital of Shenyang, China (approval No. 20160301) and registered in the Chinese Clinical Trial Registry (registration number: ChiCTR1800014421).

Comparative evaluation of impacts of climate change and droughts on river flow vulnerability in Iran

Rivers in arid and semi-arid regions are threatened by droughts and climate change.This study focused on a comparative evaluation of the impacts of climate change and droughts on the vulnerability of river flows in three basins with diverse climates in Iran.The standardized precipitation-evapotranspiration index(SPEI)and precipitation effectiveness variables(PEVs)extracted from the conjunctive precipitation effectiveness index(CPEI)were used to analyze the drought severity.To investigate hydrological droughts in the basins,the normalized difference water index(NDWI)and the streamflow drought index(SDI)were calculated and compared.The effects of droughts were assessed under various representative concentration pathway(RCP)scenarios.Changes in the number of wet days and precipitation depth restricted hydrological droughts,whereas an increasing number of dry days amplified their severity.The projected increases in dry days and precipitation over short durations throughout a year under future climate scenarios would produce changes in drought and flood periods and ultimately impact the frequency and severity of hydrological droughts.Under RCP 4.5,an increase in the frequencies of moderate and severe meteorological/hydrological droughts would further affect the Central Desert Basin.Under RCPs 2.6 and 8.5,the frequencies of severe and extreme droughts would increase,but the drought area would be smaller than that under RCP 4.5,demonstrating less severe drought conditions.Due to the shallow depths of most rivers,SDI was found to be more feasible than NDWI in detecting hydrological droughts.©2020 Hohai University.Production and hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).

Portal vein pulsatility index is a more important indicator than congestion index in the clinical evaluation of right heart function

AIM： To study the changes of portal blood flow in congestive heart failure. METHODS： We studied the congestion index （CI） and portal vein pulsatility index （PI） in patients with varied degrees of congestive heart failure using ultrasonic Doppler. Ten patients with mean right atrial pressure （RA） 〈10 mmHg were classified as group 1 and the remaining 10 patients with RA〉 10 mmHg as group 2. RESULTS： There were no difference on cardiac index （HI, P= 0.28）, aortic pressure （AO, P= 0.78）, left ventricular end-diastolic pressure （LVED, P=0.06）, maximum portal blood velocity （Vmax, P= 0.17）, mean portal blood velocity （Vmean, P=0.15） and portal blood flow volume （PBF, P= 0.95） between the two groups. Group 2 patients had higher pulmonary wedge pressure （PW, 29.9 ± 9.3 mmHg vs 14.6±7.3 mmHg, P=0.002）, pulmonary arterial pressure （PA, 46.3± 13.2 mmHg vs 25.0±8.2 mmHg, P=0.004）, RA （17.5±5.7 mmHg vs 4.7±2.4 mmHg, P〈 0.001）, right ventricular end-diastolic pressure （RVED, 18.3±5.6 mmHg vs 6.4±2.7 mmHg, P〈0.001）, CI （8.7±2.4 vs 5.8± 1.2, P=0.03）, and PI （87.8±32.3% vs 27.0±7.4%, P〈0.001） than Group 1. CI was correlated with PI （P〈0.001）, PW （P〈0.001）, PA （P〈0.001）, RA （P=0.043）, RVED （P=0.005）, HI （P〈0.001）, AO （P〈0.001）, CO （P〈0.001）, LVED （P〈0.001）, Vmax （P〈0.001）, Vmax （P〈0.001）, cross-sectional area of the main portal vein （P〈0.001） and PBF （P〈0.001）. CI could be as high as 8.3 in patients with RA〈 10 mmHg and as low as 5.9 in those with RA≥10 mmHg.CONCLUSION： Our data show that RI is a more significant indicator than CI in the clinical evaluation of high RA≥ 10 mmHg, whereas CI is better than PI in the assessment of left heart function.

Quantitative criteria for identifying main flow channels in complex porous media

To identify the type of main flow channels of complex porous media in oil and gas reservoirs,the"main flow channel index"is defined as the ratio of comprehensive permeability obtained from well test to matrix permeability obtained from core analysis or well logging.Meanwhile,a mathematical model is established based on equivalent flow assumption,the classification method for main flow channels is put forward,and quantitative characterization of main flow channels is realized.The method has been verified by analysis of typical gas reservoirs.The study results show that the"main flow channel index"can quantitatively classify types of flow channels.If the index is less than 3,the matrix pore is the main flow channel;if the index is between 3 and 20,the fracture is the main flow channel and the matrix pore acts as the supplement one;if the index is more than 20,the fracture is the only seepage channel.The dynamic analysis of typical gas reservoirs shows that the"main flow channel index"can be used to identify the type of flow channel in complex porous media,guiding the classified development of gas reservoirs,and avoiding development risk.

Impacts of environmental and canopy conditions on the nighttime sap flow of larch plantations in the Liupan Mountains,China

Nighttime sap flow(Q_(n))is an important physiological activity under which trees manage drought stress.An in-depth understanding of the characteristics of Q_(n)and its response to environmental and canopy conditions are of significance for arid area forest and water management.This study measured daily sap flow(Q_(s))of a Larix principis-rupprechtii plantation in the Liupan Mountains,northwest China during the 2017-2019 growing seasons,and separated Q_(s)into daytime sap flow(Qd)and Q_(n).Meteorological conditions(reference evapotranspiration,ETref),canopy structure(leaf area index,LAI),and soil moisture(relative soil water content,RSWC)were considered as the main biophysical factors affecting Q_(n).The structural equation model and upper boundary line method determined the effects of compound and single factors on Q_(n)The daily mean Q_(n)values during the growing seasons in 2017,2018,and 2019 were 0.024,0.026,and 0.030 mm d-1,accounting for 6.2,11.2,and 10.1%of Q_(s),respectively.Q_(n)at different canopy development phases(leaf expanding,LG;leaf expanded,LD;and defoliation,DF)over three years was LD>LG>DF.Q_(n)increased with increasing ETref,whereas the ratio of Q_(n)to Q_(s)decreased.Q_(n)did not show regular variation in the three-year growing seasons under different soil moisture conditions.ETrefand LAI mainly controlled Q_(n)by affecting Qd,whereas RSWC had no significant effect on Q_(n).Q_(n)had a positive and linear relationship with LAI and a quadratic relationship with ETref.Both explained 40%of variation in Q_(n)Meteorological and canopy conditions are important factors affecting Q_(n)on the semi-humid study site.The application of the Q_(n)model coupled with the impact of ETrefand LAI furthers understanding of the impacts of climate and forest structure change on Q_(n).

Study on relationship between perifollicular blood flow and in vitro fertilization-embryo transfer

Objective：To study the relationship between perifollicular blood flow and follicule development, oocyte maturing rate, fertilizing rate, cleaving rate, embryo quality and the outcomes of embryo transfer. Methods： The samples were selected from 66 suffers who underwent in vitro fertilization（IVF）or intracytoplasmic sperm injection（ICSl）. Eeach patients＇ perifollicular blood flow（diameter ≥ 12mm ）was estimated on the day of human chorionic gonadotropin（HCG）administration. Results：Among 66 cycles, 26（39.4%） cycles resulted in pregnancy, perifollicular blood flow resistance index（Rl）, peak systolic velocity/end diastasis velocity（S/D） of non-pregnant group was significantly higher than that of the pregnant group （P 〈 0.004）. When RI 〈 0.49, the pregnancy rates, fecundation rates, fertilization rates, metaphase numbers for the of second meiosis oocytes increased evidently （P 〈 0.05）, but there were no statistical difference in gonadotropin dosage, cycle frequency, infertility years, ages, estradiol（E2）on the day of HCG administration, numbers of oocyet retrieved and high-quality embryo rates （P 〉 0.05 ）. There were no statistical difference between non-pregnant group and pregnant group in S and D （P 〉 0.05 ）. There was no correlation between periFollicular blood flow RI and follicular diameter by linear regression analysis. Conclusion：Our study shows that perifollicular blood flow RI and S/D are effective indices of predicting the pregnancy outcome of IVF-ET.

Chemiluminescence detection of permanganate index (COD_(Mn)) by a luminol-KMnO_4 based reaction

A novel chemiluminescence （CL） system for determination of permanganate index （CODMn） combined with flow injection analysis has been proposed in this study. On the basis of the chemiluminescent reaction of luminol-KMnO4 system, light emission caused by luminol-KMnO4 system was detected by the photomultiplier tube, and its intensity caused by the appearance of KMnO4 after sample digestion was inversely proportional to CODMn. Effects for CODMn determining such as pH, concentrations and interference were investigated in detail. A detection limit of 0.3 mg/L CODMn with a linear range of 0.3-200 mg/L for its theoretical CODMn was obtained under the optimized experimental conditions. The relative standard deviation was 4.3% for 5.0 mg/L CODMn （n = 11）. This CL flow system for determining CODMn was simple, rapid, and suitable for automatic analysis. The data obtained by the present method were fairly in good agreement with those obtained by the standard titrimetric method. It has been applied to determine real samples with satisfactory results.

IS: Interest Set to Enhance Flow Transmission in Named-Data Networking

Named-data Networking(NDN) is a promising future Internet architecture, which introduces some evolutionary elements into layer-3, e.g., consumer-driven communication, soft state on data forwarding plane and hop-byhop traffic control. And those elements ensure data holders to solely return the requested data within the lifetime of the request, instead of pushing data whenever needed and whatever it is. Despite the dispute on the advantages and their prices, this pattern requires data consumers to keep sending requests at the right moments for continuous data transmission, resulting in significant forwarding cost and sophisticated application design. In this paper, we propose Interest Set(IS) mechanism, which compresses a set of similar Interests into one request, and maintains a relative long-term data returning path with soft state and continuous feedback from upstream. In this way, IS relaxes the above requirement, and scales NDN data forwarding by reducing forwarded requests and soft states that are needed to retrieve a given set of data.

COLOR FLOW IMAGING OF HEPATIC CARCINOMA

Color flow imaging(CFI)ultrasound technique can discover the tumor vascularity and superimposed it to convontional B-mode ultrasonogram in real-time. The flow velocity on spectral Doppler sonogram can be measured by setting the sample volume to any selected site.One hundred and thirty-six patients with solid hepatic space-occupied lesions had been admitted and 113 cases were confirmed by operation and pathology,23 patients were strongly suspected by hepatic angiography (HAA).Ninety nine patients with 109 nodules were finally diagnosed as hepatic cellular carcinoma(HCC).According to color flow distribution pattern,3 kinds of color configuation had been nominated.Tumor vascularity discovered by CFI,especially the arterial blood flow was easy to be recognized,and its emerge rate was quite different between HCC group(94.5%)and hemangioma(HCH)group(17.07%)(P<0.01).Spectral Doppler studies were also carried out in these cases and the detectability of arterial flow in HCC group(95.41%)was much higher than that to HCH group (21. 95%) (P<0. 005).Resistant index(RI)and pulsatile index(PI)could be used to differentiate HCC (>0. 50 and >0.80 respectively)from HCH (P<0.001 and P<0.001 respectively).Arterial-portal(A-P) shunt could also be detected by CFI and spectral Doppler(mostly its Vmax>0.6m/s).The detection rate of A-P shunt was 64% in HCC group,but no case could be detected in HCH group.

Industrial flow of lead in China

The rules on industrial flow of lead were studied for theoretical foundation of nonrenewable resource conservation and environmental improvement. A model of lead flow in lead product life cycle was developed through lead flow analysis and was used to analyze the relationship between lead product system and its environment, thus the rules on industrial flow of lead were obtained. The results show that increasing eco-efficiency will favor both resource conservation and environmental improvement. Several indices were proposed to evaluate the lead flow. As for application, the lead-flow for China in 1999 was analyzed and the reasons for low eco-efficiency were identified. In the end, some countermeasures were proposed to improve eco-efficiency, and the future lead ore consumption and environment quality were forecasted.

Hydrological Modeling: A Better Alternative to Empirical Methods for Monthly Flow Estimation in Ungauged Basins

Water resource is required for agricultural, industrial, and domestic activities and for environmental preservation. However, with the increase in population and growth of urbanization, industrialization, and commercial activities, planning and management of water resources have become a challenging task to meet various water demands globally. Information and data on streamflow hydrology are, thus, crucial for this purpose. However, availability of measured flow data in many cases is either inadequate or not available at all. When there is no gauging station available at the site of interest, various empirical methods are generally used to estimate the flow there and the best estimation is chosen. This study is focused on the estimation of monthly average flows by such methods popular in Nepal and assessment of how they compare with the results of hydrological simulation. Performance evaluation of those methods was made with a newly introduced index, Global Performance Index (GPI) utilizing six commonly used goodness-of-fit parameters viz. coefficient of determination, mean absolute error, root mean square error, percentage of volume bias, Nash Sutcliff Efficiency and Kling-Gupta Efficiency. This study showed that hydrological modeling is the best among the considered methods of flow estimation for ungauged catchments.