3 results about "Annual average" patented technology

The application discloses a kind of river and lake health evaluation method, system, equipment and medium, wherein the method obtains the health index data and multi-year average daily flow sequence set of river and lake;The multi-year average daily flow sequence set is divided into annual cycle, and a plurality of annual cycle data are obtained, and the empirical distribution of adjacent annual cycle data in time is different;All the annual cycle data are processed to generate a grade evaluation table, and a cycle evaluation table corresponding to each annual cycle data is obtained;According to the health index data, all the cycle evaluation tables are evaluated by health mapping, and the health evaluation result of the river and lake is obtained.The method can effectively improve the objectivity and accuracy of river and lake health evaluation.The application relates to the field of hydrological science and technology.

This invention discloses a method for calculating the equivalent annual average temperature of tunnels in cold regions considering non-uniform ventilation. It can calculate both the equivalent annual average temperature and the equivalent coldest month's average temperature considering non-uniform ventilation, providing a theoretical method for calculating these two indicators and improving the accurate characterization of coldness in tunnels. This method provides key calculation parameters for determining the thickness of insulation layers in cold-region tunnels considering non-uniform ventilation. Furthermore, the equivalent annual average temperature of tunnels in cold regions calculated using this method plays an important role in guiding the design of drainage and waterproofing systems and active ventilation control in cold-region tunnels, leading to more accurate and rational frost protection designs for these tunnels.

This invention discloses a method for detecting extreme hydrological events in a watershed and determining changes in hydrodynamic conditions, belonging to the field of water conservancy engineering technology. The specific steps include: S1, calculating the annual runoff distribution difference coefficient and characteristic flow process; S2, screening extreme flood and extreme drought events, i.e., extreme flood condition: selecting the annual maximum flow Q from the historical sequence. max The first 1% quantile value; extreme drought conditions: selecting the minimum value of the runoff distribution difference coefficient λ to characterize the minimal difference in water volume between the flood season and the non-flood season; S3, determining typical hydrological events by analyzing the relationship between characteristic flow and annual average flow; S4, analyzing the water depth-flow relationship and classifying extreme flood types; S5, deriving the physical formula of the water depth-flow relationship; S6, analyzing and verifying the differences in hydrodynamic conditions for extreme floods. This invention can solve the problems of insufficient sensitivity of traditional methods to short-duration extreme hydrological events and the lack of quantitative analysis of hydrodynamic mechanisms under extreme events.