Basin design flood calculation method based on conceptual hydrological model

Basin design flood calculation method based on conceptual hydrological model

  • CN 107,730,151 B
  • Filed: 11/21/2017
  • Issued: 07/23/2021
  • Est. Priority Date: 11/21/2017
  • Status: Active Grant
First Claim
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1. A basin design flood calculation method based on a conceptual hydrological model comprises the following steps:

  • step 1, collecting and processing typical rainfall flood process data;

    the flow data collected in the step 1 preferably adopts the flow data of the reference hydrological station before warehousing, and if the reference hydrological station is located at the downstream of the reservoir, the flow of the reference hydrological station needs to be subjected to reduction calculation processing;

    step 2, selecting and rating a conceptual hydrological model;

    the step 2 comprehensively considers different rainfall runoff characteristics of the drainage basin, and selects any one of a Xinanjiang model, a water tank model or an SCS model as a conceptual hydrological model with wide application and simple parameters as an alternative;

    step 3, judging the applicability of the hydrological model in the research basin;

    in the step 3, the rainfall data, the flood flow data and the evaporation data collected and processed in the step 1 are substituted into the conceptual hydrological model selected and calibrated in the step 2 for simulation, a simulation result is compared with actually measured flow process data, and a simulated flood peak, a flood relative error and a certainty coefficient are used as evaluation standards of the applicability of the model in the application basin;

    calculating the qualified rate by using the relative error within 30% and the certainty coefficient of more than 50%, and selecting a model with the best simulation effect as an optimal model for basin design flood calculation;

    step 4, substituting design rainstorm to obtain design flood;

    the selection of the rainstorm designed in the step 4 is transferred to the regional rain type given in the regional hydrological chart set or the selected historical typical field sub-flood, the drainage basin historical maximum flood with the flow record is used, the time-period rainfall sub-flood ratio is used as the distribution rain type, the obtained time-period design rainstorm value is used as the input item of the optimal model screened in the step 3, and the evaporation data is simulated by adopting the average time-period evaporation value in the flood season and being brought into the optimal model screened in the step 3;

    step 5, comparing the instantaneous unit line method and the original design result of the engineering to participate in the certification;

    in the step 5, an instantaneous unit line method commonly used for flood design in medium and small watersheds is selected, the required calculation data of the instantaneous unit line method is intensively searched from the hydrological map of the corresponding region, and the hydrological model algorithm, the instantaneous unit line algorithm and the original engineering design flood value are mutually referred and verified during engineering design;

    step 6, designing a flood process in the drainage basin;

    the step 6 is applied to watersheds with different rainfall runoff characteristics to simulate designed flood, changes empirical generalization in the calculation of the original designed flood, analyzes a watershed runoff yield mechanism from the perspective of a rainfall runoff yield theory, and deduces the designed flood from a physical process, so that the accuracy of the designed flood is improved.

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