CN-121997847-A - River reach scale natural runoff simulation method

CN121997847ACN 121997847 ACN121997847 ACN 121997847ACN-121997847-A

Abstract

The invention provides a river reach scale natural runoff simulation method, which relates to the technical field of runoff measurement and calculation, and specifically comprises the following steps of inputting meteorological element data and other auxiliary data into a JULES earth surface model to simulate grid scale runoff, inputting vector river network data and grid scale runoff simulation results into a MizuRoute vector river network converging model to obtain a river reach scale natural runoff simulation result, and predicting future river reach scale natural runoff space-time distribution. The technical scheme of the invention solves the problems that the grid scale in the prior art can not reflect river grades and the natural runoff changes of rivers with different grades can not be explored.

Inventors

LIU CHANG
LIU TAIRAN
Nie Shunqi

Assignees

山东科技大学

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (6)

1. A river reach scale natural runoff simulation method is characterized by comprising the following steps: S1, inputting meteorological element data and other auxiliary data into a JULES earth surface model, and simulating grid scale production flow; S2, inputting vector river network data and the flow simulation result obtained in the step S1 into a MizuRoute vector river network converging model, fusing the vector river network data and the flow simulation result obtained in the step S1 to obtain a river reach scale natural runoff quantity simulation result model, and predicting future river reach scale natural runoff quantity space-time distribution.
2. The method for simulating the natural runoff quantity of the river reach scale according to claim 1, wherein the meteorological element data in the step S1 comprise air temperature, highest temperature, lowest temperature precipitation, snowfall, east wind, north wind, long wave radiation, short wave radiation, air pressure and specific humidity, and the other auxiliary data comprise earth surface coverage, soil properties and hydrologic characteristics.
3. The method for simulating the natural runoff quantity of a river reach scale according to claim 1, wherein the step S2 comprises the following steps: s2.1, converting grid scale stream production data into stream production data based on a hydrological response unit by using a sub-stream domain area weighting method; S2.2, calculating slope confluence and river confluence based on gamma distribution of time parameters and shape parameters; s2.3, calculating the natural runoff of each river segment in the river network by adopting an impulse response mechanism IRF-UH convergence mechanism based on unit lines.
4. The method for simulating the natural runoff of the river reach scale according to claim 1, wherein the vector river network data comprises a river reach ID, an upstream river reach ID, a downstream river reach ID, a river reach gradient, a hydrological response unit ID and a hydrological response unit area.
5. The method for simulating the natural runoff quantity of a river reach scale according to claim 3, wherein the step S2.2 is specifically as follows: gamma distribution Expressed as: ; Wherein, the In order to be able to take time, As a function of the shape parameter(s), As a parameter of the dimensions of the device, Is a Gamma function; the convolution of the gamma distribution and the runoff is used for calculating the runoff distribution of the current time, and the corresponding river reach runoff calculation formula under each future period is as follows: ; Wherein, the In the form of a runoff flow, In order to produce a stream of water, S is the integral variable, which is the maximum duration of the gamma distribution.
6. The method for simulating the natural runoff of the river reach scale according to claim 3, wherein the step S2.3 adopts an IRF-UH river reach converging mechanism to calculate the natural runoff of each river reach in the river reach, and the method is characterized in that: ; Wherein, the For the runoff amount at a certain position in a certain time, And Respectively representing wave velocity and diffusion coefficient; after convolution integration, a runoff calculation formula is obtained: ; ; Wherein, the Is that The flow of product in the time period, As a function of the natural index of refraction, Is a confluence function.

Description

River reach scale natural runoff simulation method Technical Field The invention relates to the field of runoff measurement, in particular to a river reach scale natural runoff simulation method. Background The natural runoff of the river is river runoff which is not influenced by human activities (such as building a dam reservoir, land utilization change and the like), can reflect the natural process law of hydrology under climate change, and is an important source of water resource supply. The method is important to analyze the space-time variation trend of the natural runoff of the river, early warning and management decision of drought and waterlogging disasters, explore the influence of climate change on the land hydrologic process, grasp the global or regional water resource and biochemical cycle process, analyze the carbon emission in the river and the like. Although river diversion information obtained by in-situ measurements and hydrologic sites is most accurate, obtaining river diversion data is limited in many respects. Firstly, the labor cost of the field measurement is high, and the remote area is difficult to reach. Secondly, hydrologic sites are limited by natural conditions, logistic guarantee and other conditions, and have strong non-uniformity in spatial distribution. The available river diversion observations are mainly focused on developed north america and europe, and less on less developed and sparsely populated areas. Again, the number of global hydrologic sites is drastically decreasing and the update rate is slow, and more than 60% of hydrologic sites have not updated river runoff data for decades, which severely restricts timely monitoring of river runoff changes. Currently, terrestrial process models and hydrologic models integrating the physical climate characteristics within a river basin are continually proposed for simulating long-time-series and time-continuous river runoff. The basic principle of simulating river runoff by using a land process mode and a hydrological model is to drive the model by using meteorological data, and the model expresses key hydrological processes such as precipitation, plant interception, subsurface infiltration, confluence and the like in a formulated manner, so that river runoff simulation is realized. The current research scale using analog simulation is still limited to kilometer scale grid scale. Although the continuous optimization of the model improves the grid scale from 100 km to 5 km, the spatial resolution is still low, the key information of the small and medium rivers is missing, and the natural runoff change of the rivers of different grades cannot be reflected. The river reach scale natural runoff simulation not only can reveal the space-time characteristics and the change rule of the small and medium river runoff, but also greatly improves the calculation efficiency. The vector river network space data obtained through high-space-resolution remote sensing observation defines a river between two river nodes as a river segment, and can provide water system characteristic attributes such as width, grade and the like of any river segment of the river network and more accurate position information. The high spatial resolution river network data of the river reach scales are fused, and the understanding of the natural runoff space-time characteristics and change rules of different grades of rivers can be greatly improved by improving the model of the grid scale. In addition, the river natural runoff simulation scheme based on the river reach scale can effectively balance the complex river runoff simulation principle and calculation cost, and improves the model calculation efficiency. The current modeling of the natural river runoff by using a model simulation method is mostly in the grid scale, but the grid scale cannot reflect river grades, and further the natural river runoff change of different grades cannot be explored. In order to explore the space-time distribution of the runoff of high-grade large rivers and low-grade small and medium-sized rivers, a natural runoff modeling method of river reach scale is needed. Therefore, a method for simulating the natural runoff of the river reach scale, which can reveal the space-time characteristics and the change rule of the runoff of the medium and small river, is needed. Disclosure of Invention The invention mainly aims to provide a river reach scale natural runoff simulation method, which aims to solve the problems that the grid scale in the prior art cannot reflect river grades and the natural runoff change of different grades of rivers cannot be explored. In order to achieve the purpose, the invention provides a river reach scale natural runoff simulation method, which specifically comprises the following steps: S1, inputting meteorological element data and other auxiliary data into a JULES ground surface model, and simulating grid scale production flow. S2, inputting vector river netwo