Abstract: The invention provides a method for preventing super large-scale floods and debris flows. First, the scale corresponding to certain standard floods in the watershed is evaluated based on field investigations and historical data. Second, the design standards of the system are chosen based on the prevention of super large-scale floods, and the design standard of critical control engineering is further determined. Finally, the design methods of check dams with different functional zones are proposed according to the design standards of critical control engineering. The invention allows part of the key control dam to fail under safe operating conditions of the entire system by increasing the cross-sectional areas and the flow discharges. The unbroken foundation of the dam can effectively control the channel entrainment and regulate the cross-sectional discharge. The design is helpful in mitigating giant floods and debris flows, thus protecting downstream infrastructures.

Abstract: The present disclosure relates to a prediction method and system for an initiation volume of a debris flow slope source. The prediction method includes: dividing a debris flow source slope to be predicted into soil columns; determining a positional relationship between a selected central soil column and six adjacent soil columns around; calculating a most unfavorable sliding surface of the soil column and an unbalanced force on the sliding surface according to an upper bound theorem of a limit analysis; determining whether the most unfavorable sliding surface is unstable; determining a mode and a size of a force exerted by an unstable soil column on a surrounding soil column according to a break status of a connection bond of a lateral tensile stress of the central soil column; and finally determining whether the soil column is fluidized, and predicting an initiation volume of the debris flow source slope.

Abstract: The method for preventing and controlling glacial lake outbreak flood and related debris flows by the present invention is mainly controlling the scale of the floods by separating water and rocks and dispersing its energy step by step. The cascading amplification effects of floods can be reduced by controlling the initiation of source material with energy dissipation by using ground sills, groups of piles, and placed large stones and prefabricated artificial structures. The diversion dam built in the downstream area discharge floods in different layers, which can quickly guide water to the main river. The preconstructed engineering system can be used in a timely manner to prevent and control floods and debris flows induced by a sudden outburst of glacial lakes in areas with important facilities and inhabitants enduring the risk of natural hazards. Prevention and control systems can separate floods and debris flows and dissipate their energy.

Abstract: A method for forming a test flume usable in hydraulic engineering and debris-flow hazard mitigation is provided. The test flume has a foundation flume and an expansion flume. The expansion flume has a lower edge connected to an upper edge of the foundation flume. A hydraulic radius of the test flume is determined based on a model test. A width of the foundation flume is selected based on a size of the test site of the model test. A coefficient is obtained and a width of the test flume is obtained. A cross section curve equation of the expansion flume is obtained based on the hydraulic radius of the test flume, the coefficient, the width of the test flume and the width of the foundation flume. The test flume is formed based on the cross section curve equation of the expansion flume.

Abstract: A device for monitoring and identifying a mountain torrent and debris flow and a method for early warning of disasters relate to the technical field of debris flow protection. The device includes a computation device, sensors, an amplifier and an analog-to-digital converter. The sensors convert an acquired impact force signal into a digital signal by the amplifier and the analog-to-digital converter, and transmits the digital signal to the computation device. The computation device utilizes the digital signal to compute an energy coefficient of a liquid impact signal and a solid-liquid impact energy ratio, and a debris flow mode is monitored and identified in combination with a threshold range of the energy coefficient and a threshold range of the solid-liquid impact energy ratio. The device identifies the nature of the mountain torrent and debris flow through time-frequency analysis of an impact force signal generated by the debris flow to sensors.

Abstract: A method for a whole-process numerical simulation and hazard forecast of a mountain disaster is provided. The method includes: S1, a high space-time rainfall forecast of a mountain area; S2, a hydrodynamic process and numerical simulation: establishing a hydrodynamic process model and solving the hydrodynamic process model; S3, a motion model and numerical simulation of a mountain torrent and debris flow disaster; and S4, a risk analysis and hazard forecast of a small watershed disaster. The present invention predicts disaster hazard and dynamically and quantitatively evaluates risk loss according to a whole-process scenario simulation of the disaster driven by a climate forecast result, improves current disaster level forecasts to hazard forecasts, and serves for accurate disaster preventions and accurate rescues.

Abstract: The invention provides a method for preventing super large-scale floods and debris flows. First, the scale corresponding to certain standard floods in the watershed is evaluated based on field investigations and historical data. Second, the design standards of the system are chosen based on the prevention of super large-scale floods, and the design standard of critical control engineering is further determined. Finally, the design methods of check dams with different functional zones are proposed according to the design standards of critical control engineering. The invention allows part of the key control dam to fail under safe operating conditions of the entire system by increasing the cross-sectional areas and the flow discharges. The unbroken foundation of the dam can effectively control the channel entrainment and regulate the cross-sectional discharge. The design is helpful in mitigating giant floods and debris flows, thus protecting downstream infrastructures.

Abstract: The method for preventing and controlling glacial lake outbreak flood and related debris flows by the present invention is mainly controlling the scale of the floods by separating water and rocks and dispersing its energy step by step. The cascading amplification effects of floods can be reduced by controlling the initiation of source material with energy dissipation by using ground sills, groups of piles, and placed large stones and prefabricated artificial structures. The diversion dam built in the downstream area discharge floods in different layers, which can quickly guide water to the main river. The preconstructed engineering system can be used in a timely manner to prevent and control floods and debris flows induced by a sudden outburst of glacial lakes in areas with important facilities and inhabitants enduring the risk of natural hazards. Prevention and control systems can separate floods and debris flows and dissipate their energy.

Abstract: A device for monitoring and identifying a mountain torrent and debris flow and a method for early warning of disasters relate to the technical field of debris flow protection. The device includes a computation device, sensors, an amplifier and an analog-to-digital converter. The sensors convert an acquired impact force signal into a digital signal by the amplifier and the analog-to-digital converter, and transmits the digital signal to the computation device. The computation device utilizes the digital signal to compute an energy coefficient of a liquid impact signal and a solid-liquid impact energy ratio, and a debris flow mode is monitored and identified in combination with a threshold range of the energy coefficient and a threshold range of the solid-liquid impact energy ratio. The device identifies the nature of the mountain torrent and debris flow through time-frequency analysis of an impact force signal generated by the debris flow to sensors.

Abstract: ABSTRACT OF THE DISCLOSURE A method for regulating and controlling discharge flow of a dammed lake includes steps of: (S1) estimating a most dangerous discharge condition; (S2) based on the most dangerous discharge condition, calculating a structural internal force of the steel flexible net; (S3) based on the internal force of the steel flexible net, calculating an anti-slide embedded depth at two sides of the steel flexible net; (S4) based on the most dangerous discharge condition, manually excavating a channel; and (S5) based on the anti-slide embedded depth at the two sides of the steel flexible net, embedding the steel flexible net into a barrier dam. According to the present invention, the steel flexible net is laid on the upstream slope of the barrier dam, two sides of the steel flexible net is embedded into the slope body with gravels of the barrier dam, and cooperates with the channel for usage.

Abstract: The present invention discloses a tower-shape integrated ecological purification device for domestic sewage in a small town. The device includes a water storage and filter pond, a medium reverse osmosis pond, an amphibious biological reaction system, and an aquatic biological reaction system. The amphibious biological reaction system and the aquatic biological reaction system are alternately connected from the top down. The amphibious biological reaction system and the aquatic biological reaction system form an alternating dry and wet, oxidation-reduction compound environment. Plant absorption, biological substrate transformation, aeration, and strengthening medium adsorption are combined to form a multi-stage plant-microbe-animal integrated ecological purification treatment process/device. The present invention achieves the efficient purification and acceptable discharge of domestic sewage in small towns.

Abstract: The present disclosure discloses a method for assessing soil health of cultivated land, which adopts “three sets of dual index assessment systems”, that is an index system for current soil function and a healthy soil function required by crops, an index system for current soil nutrition and healthy soil nutrition required by crops, and an index system for current crop output of cultivated land and a crop output expected by cultivated land users or owners. The method solves the shortcomings of the existing assessment systems that the existing soil health assessment index system has no hierarchy and applicability. This method includes using deviating degree of ratio R e.g., the index current value C/index health value E of measured dual index from 1 as well as it is simple, and the assessment result may directly determine the indicators or factors that can be used for guiding soil improvement and conservation.

Abstract: A method for forming a test flume usable in hydraulic engineering and debris-flow hazard mitigation is provided. The test flume has a foundation flume and an expansion flume. The expansion flume has a lower edge connected to an upper edge of the foundation flume. A hydraulic radius of the test flume is determined based on a model test. A width of the foundation flume is selected based on a size of the test site of the model test. A coefficient is obtained and a width of the test flume is obtained. A cross section curve equation of the expansion flume is obtained based on the hydraulic radius of the test flume, the coefficient, the width of the test flume and the width of the foundation flume. The test flume is formed based on the cross section curve equation of the expansion flume.

Abstract: A flexible barrier includes: posts, retaining ropes and a metal net; wherein each of the posts comprises a post body and a post foundation hinged; the retaining ropes includes longitudinal retaining ropes, top retaining ropes, intermediate retaining ropes, and diagonal retaining ropes connected between the posts and the metal net; wherein a lower portion of the metal net is obliquely arranged towards a downstream of a slope; the metal net is loose when no impact is applied and a bottom of the metal net is fixed with short anchors; the bottom of the metal net has a redundancy and is folded towards a upstream of the slope or buried in the slope.

Abstract: An asymmetric debris-flow discharge channel is provided. The debris-flow discharge channel has a main drainage channel for discharging a debris flow and an auxiliary channel provided outside of the main drainage channel. The side walls of the auxiliary channel are integrated with the side walls of the main drainage channel or provided outside of the side walls of the main drainage channel. The debris-flow discharge channel also has a break section integrated into a side wall of the auxiliary channel. The top width of the break section is equal to the top width of the auxiliary channel A method for designing and building the asymmetric debris-flow discharge channel is also provided, which provides a lower initial cost, higher safety performance, and a lower maintenance cost at the operating stage.

Abstract: A method of designing a box-type energy-dissipating section of a box-type energy-dissipating mudflow diversion flume. Firstly, the longitudinal gradient J of the flume and the roughness coefficient n 0 of a fully-lined flume bottom (1) are determined. Then, the parameters of the box-type energy-dissipating section are set, and related parameters are substituted into a formula for calculation, so that the overall roughness coefficient n of the flume is obtained. Further, the flow velocity of the mudflow is calculated by means of the Manning formula. Finally, the flow velocity of the mudflow is compared with the non-scouring and non-silting velocity allowed by the flume, and the design value of the box-type energy-dissipating section is obtained through final optimization. The method factors in the longitudinal gradient J of the flume, the length L of the box-type energy-dissipating section, the width b of the box-type energy-dissipating section, and the average diameter D of filler stones.

Abstract: An asymmetric debris-flow discharge channel is provided. The debris-flow discharge channel has a main drainage channel for discharging a debris flow and an auxiliary channel provided outside of the main drainage channel. The side walls of the auxiliary channel are integrated with the side walls of the main drainage channel or provided outside of the side walls of the main drainage channel. The debris-flow discharge channel also has a break section integrated into a side wall of the auxiliary channel. The top width of the break section is equal to the top width of the auxiliary channel A method for designing and building the asymmetric debris-flow discharge channel is also provided, which provides a lower initial cost, higher safety performance, and a lower maintenance cost at the operating stage.

Abstract: A new experimental device for debris flow simulation, including a material supply device, a flow channel, a stacking groove, a pole, a first high-speed camera, a second high-speed camera, a fixing frame, and a sliding rail. The material supply device is used to release the debris flow simulation material to the flow channel, to realize the start of the debris flow simulation. The stacking groove is used for the accumulation of the debris flow. The pole is used to support the stacking groove and adjust the slope of the stacking groove. The fixing frame is used to fix the first high-speed camera. The second high-speed camera can monitor the movement of the debris flow. The invention can flexibly simulate the movement characteristics of various debris flow and obtain the test data, so as to provide data support for the subsequent study.

Abstract: A three-dimensional multi-point and multi-index early warning method for risk at a power grid tower in a landslide section, including: (1) classifying the risk level of each index; (2) obtaining the value of various indexes of the power grid tower in a landslide section during a certain period of time. (3) calculating the single-index measure of each index, and obtaining the evaluating matrix of the single index measure; (4) determining the weight of each index; (5) calculating the multi-index comprehensive measure of the landslide and power tower; (6) introducing the confidence level ? to determine the comprehensive risk level of the power tower instability; (7) performing early warning based on risk level. The invention greatly improves the warning accuracy of the landslide, and realizes the accurate judgment and warning of danger of the tower.

Abstract: A method of designing a box-type energy-dissipating section of a box-type energy-dissipating mudflow diversion flume. Firstly, the longitudinal gradient J of the flume and the roughness coefficient n 0 of a fully-lined flume bottom (1) are determined. Then, the parameters of the box-type energy-dissipating section are set, and related parameters are substituted into a formula for calculation, so that the overall roughness coefficient n of the flume is obtained. Further, the flow velocity of the mudflow is calculated by means of the Manning formula. Finally, the flow velocity of the mudflow is compared with the non-scouring and non-silting velocity allowed by the flume, and the design value of the box-type energy-dissipating section is obtained through final optimization. The method factors in the longitudinal gradient J of the flume, the length L of the box-type energy-dissipating section, the width b of the box-type energy-dissipating section, and the average diameter D of filler stones.