The resistivity method can reflect the soil physical index and structural properties, and it has the characteristics of high efficiency, convenience and non-destructive. In this study, the resistivity characteristics and the resistivity model of laterite had been analyzed using the pore water, water content and porosity as the key factors. A correction formula of contact resistance was proposed considering the influence of electrode area, and the resistivity prediction model of laterite had been established by introducing the structural factors to reflect the influence of pore water on the resistivity of laterite. The results show that the proposed contact resistivity correction formula can effectively reduce the test error, the laterite resistivity and structure factors decrease with the increasing water content and porosity with a power function relationship. The correlation of influencing factors of laterite resistivity is sorted as: pore water>water content>porosity. The resistivity prediction model of laterite was constructed with the variables of contact resistance, pore water, water content and porosity, which has high fitting accuracy. Thus, it can provide a reference for evaluating the physical indicators and structural properties of laterite.

In view of the issue of the traditional questionnaire survey method with high human and time costs, a set of resettlement survey system based on B/S framework and cloud platform was designed on the basis of the analysis of the business needs of the survey of post resettlement support monitoring and evaluation of large and medium-sized reservoirs in Ningxia. The system implements the import, update, deletion of historical data, as well as the addition, modification, query, statistical analysis, and other functions of sample information through two subsystems: the household survey of mobile terminal and the data management of PC terminal, and was applied to survey work examples. Compared with the traditional survey method used before, the application results indicate that it has increased the average number of daily survey samples by about 1.5 times, saved 78% of the labor and time costs required for the collation and filing of survey data, and greatly reduced the repeated printing and output of paper survey forms, and to effectively avoided the less of paper data.

Aiming at the shortcomings of hydropower unit vibration signal denoising using ensemble empirical mode decomposition (EEMD), a denoising algorithm based on an improved fruit fly optimization algorithm (RFOA) for optimizing the EEMD noise IMF component threshold was proposed. Firstly, the noise signal was decomposed using the EEMD algorithm to obtain the IMF components, and then the correlation coefficient method was used to determine the noise signal and the effective signal. Then, the RFOA was used to determine the noise signal IMF component threshold. Finally, the sample entropy of the obtained IMF components was used as a feature vector input of the GRNN algorithm for vibration mode recognition. Compared with the wavelet threshold method and the EEMD-GA method, the results show that the proposed algorithm has the highest signal-to-noise ratio and the best denoising effect.

The distribution of measured operating data of hydraulic turbines is non-structural and uneven density. The moving least squares method was used to fit the measured operating parameters to obtain the spatial characteristic surface of the water turbine, which can reflect the local characteristics of data surface and avoid the distortion caused by the differences of data distribution density. The Riyadh criteria was used to perform preliminary data filtering. The support radius was adaptively determined by local fitting across different ranges of discrete sample points. The robust moving least square surface reconstruction model was established combined with the Mahalanobis distance denoising method. Compared with the least squares method, the example calculation results show that the moving least squares method fits the operating characteristics of hydraulic turbines with higher accuracy and supplements the local data effectively. The result can reflect the operating characteristics of hydraulic turbines authenticity, which provides a reference for correcting the operating characteristic curve given by the turbine manufacturer.

The premise of non-conformity traceability and correction of run-off is that there is an accurate and reliable long series measured flow sequence as the calibration reference. For watersheds without long series of measured flow data, the accuracy of calculated flow can be verified through short-term and typical test data to obtain a calibration benchmark. In this study, the accuracy of NHQ curves and discharge curves of Pubugou Reservoir was analyzed and verified based on the ultrasonic flow, combined with the analysis of the level-flow relationship under stable and sudden change working conditions. The research results have proven the accuracy of the outflow calculation of Pubugou reservoir, which provided basic support for tracing and correcting the non-uniformity of cascade runoff.

In response to the evident phenomena of flow separation and backflow, low efficiency, and increased cavitation in the tailrace conduit of the Deneng Xiangjiang Hydropower Station after expansion, computational fluid dynamics (CFD) analysis was employed. Two methods, namely, modifying the shape of the tailrace conduit or replacing the runner, were proposed to improve the flow pattern within the tailrace conduit. Research has demonstrated the effectiveness of both methods, which can provide reference for similar projects.

The deicing effect of wind turbine blades was tested and analyzed based on the air-thermal method. The thermal conductivity efficiency of the paving structure and the influence of blower speed (or frequency) on the deicing efficiency were mainly considered. Firstly, the blade structure and layering structure were introduced, and the thermal conductivity was estimated by measuring the thickness of the layering structure. According to the ice-covered position of the blade in winter, the rationality of the thermal conductivity distribution of the blade during air-thermal deicing was verified. After that, the field blade deicing test was carried out by changing the speed (or frequency) of the blower. The test results reveal the root cause of the unbalanced deicing phenomenon in the process of wind turbine blade deicing by air thermal deicing system. It shows that the higher the speed (or frequency) of the blower is, the better the deicing equilibrium of the blade surface and the more significant the deicing effect are under the premise of ensuring the temperature stability of the outlet of the ventilation pipe. In addition, with the use of larger blower frequency, the internal circulation of the blade was enhanced, and the reasonable setting of the internal circulation structure of the blade can effectively improve the de-icing efficiency and reduce the de-icing consumption time.

For water supply systems with high-lift, the pump-stopping water hammer caused by the power failure is usually greater than the direct water hammer caused by the check valve closing. Based on the Joukovsky equation and the pressure drop law behind the pump, the influence of the check valve closing law on the pressure along the pipeline was studied, and the theoretical value of the optimal closing time (i.e., T_g=T_d) was obtained when a pump trip occurred. The theoretical value was verified by numerical simulation through a practical project. The results show that for high-lift water supply projects, the theoretical closing time of the check valve can minimize the pressure drop along the pipeline when the pump trip occurred.

The water intake mode of pumping station under the condition of large variable water level of water source has great impact on the reliability of water intake, project cost and safety of water intake building, so the reasonable evaluation of different water intake mode is one of the key problems in engineering design. In this paper, a two-level evaluation index system consisting of 3 quantitative indicators and 14 qualitative indicators was constructed. The analytic hierarchy process (AHP), entropy weight method and least square method were used to assign the combination of subjective and objective weights. The method of membership degree and fuzzy comprehensive evaluation was used to evaluate and rank different water intake schemes, and an engineering example was analyzed. The results show that the proposed index system is comprehensive, the weighting method is reasonable, and the evaluation method can better reflect the uncertainty of the scheme selection. The practical engineering example verified the feasibility of the evaluation method.

The fan-shaped central revolving gate is a new type of gate with a significantly different flow pattern from the traditional gate. In order to study the hydrodynamic pressure characteristics of the fan-shaped central revolving gate, model experiment was conducted on the different opening coefficients of the gate based on the 60 m span gate of Wusongjiang regulation project and its energy dissipation design conditions, and the time-average pressure, average fluctuation amplitude, pulsation intensity and spectral characteristics under different opening coefficients were analyzed. The results show that the time-average pressure of the gate blade is positive pressure at each opening coefficient, and the overall pulsating pressure amplitude is relatively stable. The pulsating pressure of each measuring point is close to normal distribution under different opening coefficients. The pulsation intensity changes with the change of the opening and measuring point position. With the increase of the opening coefficient, the pulsation intensity presents a trend distribution of decreasing first and then increasing, and the pulsation intensity belongs to the low-frequency pulsation. The change of the measuring point position in the width direction will affect the pulsation intensity of the measuring point, and the center line pulsation intensity can be used instead of the whole gate pulsation intensity.