Drought prediction is an important non-engineering measure to improve drought prevention and resistance. This paper firstly evaluated the ability of multi-scalar standardized precipitation evapotranspiration index (S_SPEI) to identify drought events in Henan Province. Then a drought prediction model based on particle swarm algorithm optimized extreme learning machine (PSO-ELM) was constructed, which used S_SPEI as model outputs and major drought-causing climate system indices selected by Information Changing Rate and Conditional Mutual Information-Based Input Feature Selection Method (ICR-CMIFS) as model inputs. The applicability of the PSO-ELM model in drought prediction in Henan Province was verified by comparing the drought prediction results of this model with standard extreme learning machine (ELM) and differential evolutionary algorithm optimized extreme learning machine (DE-ELM) models. The results show that the S_SPEI-3 can effectively identify specific drought events in Henan Province and reflect the drought situation in Henan Province accurately in terms of time and space; The main drought-causing climate system indices in Henan Province screened by ICR-CMIFS are the western Pacific paratlantic area index and the NINO index; The PSO-ELM model can predict drought in Henan Province accurately, and the prediction accuracy is better than that of the DE-ELM model and standard ELM model, which has better applicability in drought prediction of Henan Province.

Aiming at the problems of high economic cost and difficult construction of the anti-seepage scheme designed for the dam site area of the concrete face dam of the lower reservoir of a pumped storage power station, a three-dimensional finite element model was established according to the actual engineering situation of the lower reservoir site. Firstly, the distribution of seepage field and the factors such as seepage gradient and seepage flow in each part of the reservoir area under the design anti-seepage scheme were calculated. Then the effects of different curtain depth and the change of curtain length of left and right dam abutment on seepage gradient and seepage flow were analyzed. Finally, the optimization suggestions for the design anti-seepage scheme were put forward. The results show that the curtain depth of the dam site area can be shortened to 3 Lu line, and the curtain length of the dam abutment on the left and right banks can be shortened by about 10 m. Therefore, the project cost can be reduced and the construction progress can be accelerated on the basis that the key parts of the dam site area can meet the seepage stability and the total seepage flow can be effectively controlled.

In order to solve the control problem of rainfall runoff and pollutants in highway service area, SWMM model was used to establish hydrology and water quality model of Tieshan service area. Based on the selection principle of LID measures and the site conditions of Tieshan service area, the control efficiency of rainfall runoff and pollutants in the service area were studied under four schemes of without LID measures, combination of infiltration pavement and green roof, combination of sunken lawn and green roof, and combination of permeable pavement and sunken lawn under different rainfall return periods. The results show that the three combined LID measures can effectively reduce the rainfall runoff, peak runoff, pollutant concentration and total pollutant load in the service area, among which the LID combined measure scheme of permeable pavement and sunken lawn has the best effect on pollution interception and emission reduction. In addition, the LID measures are more effective in controlling rainfall runoff and pollutants when the rainfall intensity is low than that is high.

Columns are commonly used in water conservancy project to support the upper structure. In order to ensure the stability of the upper structure, it is necessary to monitor the deformation of the column to ensure that the inclination angle of the column is within the allowable range. The non-contact measurement and high-precision point cloud data acquisition was carried out by the total station scanner used waveform digital ranging technology. During the acquisition process, the three-dimensional coordinates of each observation station were calculated by the rear intersection method, and the observation data was unified into a coordinate system. Data registration avoided the transmission of observation errors. This paper proposed a method for calculating the tilt deformation of the column using the point cloud. After collecting the two phases of the point cloud data, the deformation was calculated based on the true pair of points, and the point and surface optimization algorithm was used to reduce the error, and the tilt angle of the column was calculated. Finally, a simulation test of the tilted deformation of the column was designed to verify the accuracy of the deformation calculation method. The test results show that the actual inclination angle is 0°16'49", the calculated inclination angle is 0°16'57", the algorithm error is less than 20', which meets the requirement of deformation monitoring in high-rise structure. Therefore, the deformation calculation method can be applied to the field of column tilt deformation monitoring.

In order to solve the problem of interval flow inversion of cascade hydropower stations, taking the cascade hydropower stations in the middle and lower reaches of the Dadu River basin as an example, the characteristic curve correction of the six reservoirs in the basin was carried out. In order to accurately calculate the inflow and outflow of each reservoir by correcting each characteristic curve, and make the flow inversion rate of each interval meet the requirements, four correction methods of characteristic curve correction methods were proposed with the goal of minimizing the flow inversion rate, which includes single-point discrete optimization, multi-point discrete optimization, curve cluster overall translation optimization, and distinguishing different water head/water level translation optimization. The simulation calculation shows that although each curve correction method has certain effect, the distinguishing different water head/water level translation optimization method has the best effect. After using this method to correct the characteristic curve, the interval flow inversion rates of PuSheng and GongTong decreased from 53% and 77.96% to 13.93% and 4.37%, respectively. Although the flow inversion rates in the remaining intervals has slightly increased after correction, they are all within a reasonable range. It can be seen that the curve correction method effectively reduces the inversion rate of interval flow and improves the consistency of runoff series, which can provide a data basis for the accurate water regulation of cascade hydropower stations in the Dadu River basin.

Geostress field plays an important role in the stability of tunnel surrounding rock. Based on the in-situ stress results and geological conditions in the cracked area of the secondary lining concrete of the Qinling water conveyance tunnel from Hanjiang-to-Weihe, three-dimensional hydraulic fracturing method was used to analyze the in-situ stress of the surrounding rock in Qinling tunnel. The results show that the maximum principal stress on the cross section of the horizontal hole is 16.3-37.9 MPa and the minimum principal stress on the cross section is 2.4-9.1 MPa in the horizontal drilling depth range of 9.2-26.6 m. In the vertical drilling depth range of 3.8-20.7 m, the maximum horizontal principal stress is mainly 21.5-30.5 MPa, the azimuth average is N57°E, and the minimum horizontal principal stress is mainly 12.7-16.5 MPa. The maximum and minimum and the spatial maximum principal stress are 24.3 MPa, 14.4 MPa and 24.6 MPa respectively, which are nearly horizontal distribution. The stress field of surrounding rock at the test site of tunnel rock mass is mainly horizontal stress and the rock mass stress is classified as "high in-situ stress".

Based on the GMS software, a numerical model of groundwater flow in the Linfen Basin was established to predict the groundwater level under different driving factor scenarios, and the impact of different driving factors on groundwater level changes was quantified. The results show that only in the precipitation scenarios (dry, normal, and wet), the variation of shallow groundwater is greater than that of confined groundwater. When the precipitation is from 458.8 mm to 568.0 mm, the absolute value of the difference in the annual average water level change rate of the shallow groundwater is 0.11 m; Only under the pressure extraction scenario (extraction volume in 2018 as the benchmark), both shallow groundwater and confined groundwater have great changes. When the pressure extraction increases from 0% to 50%, the absolute value of the annual average water level change rate difference between shallow groundwater and middle-deep confined water is 0.16 m and 0.25 m, respectively; Under the situation of the rising water level of the Fenhe River, only the shallow groundwater on both sides of the river will be affected to a certain extent. The research results can provide a certain scientific basis for the rational utilization of groundwater in the Linfen Basin.

In order to explore the relationship between macro and micro characteristics of hybrid fiber reinforced concrete under freeze-thaw cycles, rapid freeze-thaw cycle tests were carried out with freeze-thaw cycles and fiber volume content as variables. The test results show that under different freeze-thaw cycles, the compressive strength has a positive correlation with air content, bubble spacing coefficient and average chord length of bubbles, and a negative correlation with specific surface area of pores, while the freeze-thaw damage and pore parameters have an opposite law, and they all change approximately linearly; The larger the freeze-thaw cycles, the lower the compressive strength, the greater the freeze-thaw damage, the greater the air content, the bubble spacing coefficient and the average chord length of bubbles, and the smaller the specific surface area of pores; The incorporation of hybrid fibers optimizes the pore structure and improves the frost resistance.

Aiming at the problem that the reliability calculation results of embankment slope stability are not accurate due to the fact that the correlation between variables cannot be considered in two-dimensional independent distribution, based on 171 sets of test data of the shear strength of the Yangtze River embankment shoreline soil, Copula function was used to study the correlation between the shear strength parameters of the Yangtze River embankment shoreline soil. The AIC and BIC criteria were used to identify the optimal edge distribution and Copula function, and a two-dimensional joint distribution model was constructed. The influence of data volume on the identification of correlation structure between parameters was analyzed. The results show that the two-dimensional joint distribution model based on Copula function can accurately characterize the correlation between soil parameters of the Yangtze River embankment shoreline; When the data volume is more than 24 groups, AIC and BIC criteria can accurately identify the optimal Copula function, which provides a reference for the reliability calculation of embankment slope and the construction of Copula function model.

In view of the problem that the compaction coefficient of cement improved silty fine sand road in Gobi area is difficult to meet the standard after the completion of rolling inspection as an engineering material, after comprehensive analysis, it is found that the timeliness of cement improved silty fine sand is not considered in on-site construction and inspection. Through the design of compaction test and unconfined compression test of cement improved silty fine sand under different delay time, the influence of delay time on the compaction characteristics and strength characteristics of cement modified silty fine sand was analyzed. Considering the strength change of Subgrade in seasonally frozen area after freeze-thaw cycle, the freeze-thaw cycle test of cement modified silty fine sand under the influence of delay time was designed. The results show that with the increase of delay time, the maximum dry density of cement modified silty fine sand first increases and then decreases, and the optimal water content first increases, then tends to be flat and then increases; The saturated 7 d unconfined compressive strength and the strength after freeze-thaw cycle decreased gradually with the increase of delay time; The structure formed by cement hydration inside admixture has been destroyed after being rolled and formed, reducing the cement effectiveness.