Abstract:Based on the development of hydrology science and the basic framework of physical and virtual water coupled flow theory, this study indicated that the process hydrology is an interdiscipline that can reveal the coupled flow law and associated effects of physical and virtual water in complicated system. In addition, this study makes a detailed analysis of the scientific connotation, main characteristics, framework, discipline basis, method system and core tasks of process hydrology. Given the theoretical value and practical significance of process hydrology, it can be concluded that the development of process hydrology can provide measures and new views to cope with new challenges in hydrology that the sustainable developments of nature, economy and society faces.

Abstract:This work selected ²²²Rn as a natural tracer to study the hydraulic exchange processes between the river water and the groundwater in Hailing section, Taizhou City. Samples of river water were collected from the Xintongyang Canal and samples of groundwater containing ²²²Rn were collected from the study area. The hydraulic relationship between river and groundwater was analyzed quantitatively. Based on a 1-D steady state model and a flow balance model, the groundwater inflow and the river water leakage were calculated separately. The ²²²Rn tracer results show that the groundwater inflow mainly occurred during two sections of the Xintongyang Canal, R3~R4 and R7~R9, and the tributaries had little effect on the ²²²Rn activity of river reach. Besides, there is an interaction between river and groundwater along the river. Furthermore, the results of the ²²²Rn method are consistent with the results in qualitative analysis. The upstream flow and downstream flow are the most sensitive parameters of the 1-D steady state model, while the ²²²Rn activity of river is a relatively sensitive parameter.

Abstract:In order to improve the accuracy of precipitation forecasts in the Shihe Catchment of Huaihe River Basin, the data of TIGGE models including JMA, KMA, UKMO, ECMWF and CMA along with the observed data from the rain-measuring stations in the flood season from 2015 to 2017 were used to study the evaluation methods and correction methods of precipitation forecast. On the basis of hit rate, false alarm rate and miss alarm rate, a new three-rate comprehensive index of precipitation forecast was proposed for an entire evaluation. The accuracy of TIGGE precipitation forecast in the Shihe catchment within the 1-7 d prediction period was evaluated by using the root mean square error index and the three rates comprehensive index. The correction methods of precipitation forecast, including the RBF artificial neural network and the ν-SVR support vector regression based on the data of TIGGE models, were proposed and compared with the linear method BREM. The results show that JMA model has the highest accuracy of precipitation forecast, the next two are ECMWF and UKMO, and ν-SVR method is superior to BREM method and RBF method. As a conclusion, the real-time ν-SVR correction method improves the accuracy of precipitation forecast.

Abstract:This study reviewed the environmental behavior of microplastics(including the adsorption of organic pollutants and the release of organic additives after entering water), and the interaction between microplastics and organic pollutants after entering into water body, including its mechanism, influencing factors and biological toxicity. It also analyzed the deficiencies of current researches, and believed that, in order to provide theoretical basis for further study on the behavior and function of microplastics, it is necessary to expand the research on the interaction between microplastics and organic pollutants, such as strengthening the research in the freshwater environment, establishing systematic research system, and paying attention to the effect of biofilm

Abstract:The distribution as well as the spatial and temporal variation of total phosphorus(TP)in the water and sediment, and the heavy metals in the sediment in the main stream of Huaihe River were studied. Samples of water and sediments in 19 sections of the main stream of Huaihe River from the Zhengyangguan to the Hongze Lake were collected from 2014 to 2017. The TP in the water and sediment, and heavy metals(As, Cu, Pb, Zn, and Cd)in the sediment were analyzed to investigate the concentration and distribution along the river. The effects of the flow rate and temperature on the spatial and temporal distribution of the TP in water and sediment, and heavy metals in the sediment were also discussed. The results showed that the concentration of the TP and heavy metals during pre-flood season is more than that after flood season, and the distribution of various forms phosphorus in water during flood season is more uniform. The flow rate and temperature are main influencing factors for this distribution of TP and heavy metals.

Abstract:In order to study the influence of future climate change on runoff in the Poyang Lake Basin, the VIC hydrological model with 0. 1° resolution was constructed and the parameters were calibrated by the uniform design method. The CMIP5 multi-model meteorological dataset were used to drive the VIC model to evaluate the runoff changes in the Poyang Lake Basin under the RCP2. 6, RCP4. 5, and RCP8. 5 scenarios. The results show that under the scenarios of RCP2. 6 and RCP4. 5, the runoff during the future period(2026—2040)is higher than that during the baseline period(2006—2020), and the runoff under the RCP8. 5 scenario is decreasing. The runoff of all models has an increasing trend in the flood season, while it has a decreasing trend in the dry season, which indicated that the occurrence of hydrological extreme events is even more obvious.

Abstract:In order to study the change of water level of rice farmland under controlled irrigation and drainage mode, the parameters of DRAINMOD model and HYDRUS-1D model were determined based on the planting test data of rice pit in 2017, and the correlation coefficient, average deviation and efficiency coefficient were used as the reference evaluation criteria. Comparing the simulated values of farmland water level with the measured values in 2018, the reliability of two models to simulate farmland water level was analyzed. The results show that both the simulation results of DRAINMOD model and HYDRUS-1D model can reflect the actual changes of farmland water level. Correlation coefficients between simulated and measured values are 0. 778 and 0. 849, the average deviations are 2. 051 cm and 1. 809 cm, and the Nash efficiency coefficients are 0. 509 and 0. 360, respectively. There is no significant difference between the simulation results of two models. Both DRAINMOD model and HYDRUS-1D model can be used to simulate the change of water level in rice field under controlled irrigation and drainage, and this conclusion provides a convenient and feasible method for the study of water transport in rice field.

Abstract:To study the compaction mechanism of asphaltic concrete core material from a mesoscopic point of view, a discrete element model including the coarse aggregate, the asphalt mortar and voids were constructed. Then, an inversion method of meso-structural parameters for the PFC(particle flow code)modelling of asphaltic concrete was proposed based on support vector machine model(SVM)and adaptive difference algorithm(ADE). Finally, the model and method were validated by a series of static pressure tests with different temperatures and pressures. The results show that the regression model based on SVM can well build the relationship between the input(parameters to be inverted)and the output(simulated settlement). Additionally, the PFC-simulated compaction settlement with the inverted parameters was very close to that from the physical test. The inversed meso-structural parameters can provide a condition for further study on the meso-mechanism and compaction quality of asphaltic concrete core wall.

Abstract:In order to improve the pozzolanic activity of volcanic rock in Hotan area of Xinjiang and extend its application in concrete engineering, XRD test, chemical method, SEM micro and macro strength index method are adopted, to test and analyze the pozzolanic activity after 060 min calcination of constant temperatures from 800℃ to 1400℃ and with water quenching or natural cooling. Results indicate that with the increase of calcination temperature, the vitreous content of volcanic rocks gradually increased. But when the calcination temperature reaches or exceeds the melting temperature, the crystal diffraction peak obviously disappeared in the XRD test and the vitreous content began to decrease. The content of main oxides in volcanic rock, such as SiO2, Al2O3 and Fe2O3, decreased, and all the contents of two soluble oxides, SiO2and Al2O3, have decreased except the calcination temperature of 800℃. Finally, too high calcination temperature, over 800℃, will result in decreased activity, and the vitreous content of volcanic rocks can be improved to a certain extent by calcining with high temperature. However, high calcining temperature will reduce the dissolved oxide content of volcanic rocks and cause the decline of their macroscopic activity index.

Abstract:As a new type of temporary structure system, the sockettype tubular steel formwork supported system was widely used in all kinds of projects with the feature of high strength supporting system and fast construction speed. In order to balance the security and economy of this kind of supporting system, the risk analysis model was proposed based on the structural reliability analysis and fuzzy set theory. The significant failure modes were analyzed, and the reliability index was obtained by the Monte Carlo simulation method and the interpolation technique. Making the failure probability and the coefficient of failure loss cost to be asymmetric triangular fuzzy number, risk analysis model of sockettype tubular steel formwork supporting system was presented. The results of one case study show that the risk analysis model is realistic and feasible.

Abstract:In order to reduce the requirement of original point cloud preparation for the axis extraction of shield tunnel, a feature extraction method of point cloud is introduced in this study. Firstly, the ring joint point cloud of shield tunnel segment was identified based on the extraction method of crack point cloud with the distance difference feature. Then, the curve fitting of the interstitial points was carried out by the least square method. At last, the central axis of the tunnel is extracted on the basis of the circular seam curve. Experimental results show that the point cloud extraction method based on the distance difference feature can effectively identify the ring seam point cloud, and fit the tunnel central axis on the basis of the ring seam point cloud. Compared with the traditional extraction method, the proposed method is faster, and the extracted central axis is more spatial.

Abstract:Considering problems existing in the design method of safety factor, in order to maintain the uniformity of design and to keep up with the international standards, a reliability design method is used to design the grounding wire and fittings in transmission lines. Through the reliability calibration of grounding wire and fittings designed by the current national standard GB50545—2010 and the industry standard DL/T5154—2012, the partial coefficients of load and resistance for the grounding wire and fittings under the ultimate state are calculated by selecting the target reliability index. The results show that the average reliability indexes of the lowest sag point and the suspension point are 4.372 and 3.968, respectively, when combined with constant load and wind load, and 3157 and 2.898 respectively, when combined with constant load, wind load and ice load. The average reliability index of fittings is 3.99. The average partial coefficient of grounding wire resistance γRis 1.084, the average partial coefficient of constant load γG is 1.072, and the average partial coefficient of wind load γW is 1.828. The average partial coefficient of fittings resistance γR′ is 1.165, the average partial coefficient of the vertical load of grounding wire γQ3 is 1.062, and the average partial coefficient of the wind load of grounding wire γQ5 is 1.797. If the design method based on reliability theory is adopted, it is suggested that the partial coefficients of grounding wire should be taken as γR =1.1, γG=1.2, and γW=1.8, and the partial coefficients of fittings should be taken as γR′ =1.2, γQ3=12, and γQ5=1.8．

Abstract:Load modeling is a fundamental issue in the operation and control of power system, which has very important significance in theory and practice. First, this study reviews existing load modeling achievements, provides an overview of existing load models and methodologies for parameters estimation, identifies current industry practice on load modeling for power system, and summarizes the shortcomings of existing load modeling theory. Then, future prospects are analyzed, including new challenges and new requirements for modeling work resulted from major changes in load characteristics and grid structure, and new opportunities with the rapid development of artificial intelligence and big data. Finally, the future work is summarized as a twostep problem that is “qualitative correctness” of model structure and “quantitative accuracy” of model parameters. The structure of a generalized synthesis load model is proposed considering the active load. To establish the longterm mechanism of load modeling, a “type classified and time classified” load model database, taking the advantage of a variety of online modeling methods as well as the artificial intelligence algorithm, is proposed.