CN-121997825-A - Lake water age estimation method, electronic equipment and storage medium

CN121997825ACN 121997825 ACN121997825 ACN 121997825ACN-121997825-A

Abstract

The invention discloses a lake water age estimation method, electronic equipment and a storage medium. The method comprises the steps of obtaining multi-source remote sensing data, underwater topography data, meteorological data and hydrological flow data of a target lake, inverting to obtain vegetation distribution data, constructing a space-time dynamic resistance surface reflecting the internal water flow movement resistance of the lake, calculating the hydrological effective distance from each space unit in the lake to the source point based on the space-time dynamic resistance surface by taking at least one outlet of the lake as the source point, estimating the reference two-dimensional water age of the lake, judging the vertical layering state of the lake, calculating the ageing coefficient representing the retention effect of the bottom water body, correcting the reference two-dimensional water age by using the ageing coefficient, and generating the three-dimensional water age field of the lake, wherein the plane and the vertical difference can be reflected. The method solves the problems that the traditional hydrologic model is complex in calculation, seriously depends on intensive on-site hydrologic mapping and flow velocity observation, and is difficult to apply to a large-scale lake group or areas lacking measured data.

Inventors

HUANG CHANG
ZHU HONGYU
Yao Youru

Assignees

安徽师范大学

Dates

Publication Date: 20260508
Application Date: 20260313

Claims (10)

1. The lake water age estimation method is characterized by comprising the following steps of: acquiring multisource remote sensing data, underwater topography data, meteorological data and hydrological flow data of a target lake; Based on the underwater topography data, inversion from the multi-source remote sensing data to obtain vegetation distribution data, and extraction of wind field data from the meteorological data, constructing a space-time dynamic resistance surface reflecting the resistance of the internal water flow movement of the lake; Taking at least one outlet of the lake as a source point, and calculating the hydrological effective distance from each space unit in the lake to the source point based on the space-time dynamic resistance surface; estimating a reference two-dimensional water age of the lake based on the hydrologic effective distance and the overall water change period of the lake obtained from the hydrologic flow data; Based on the surface water temperature inverted by the multi-source remote sensing data and the air temperature and the air speed provided by the meteorological data, determining the vertical layering state of the lake, and calculating an aging coefficient representing the retention effect of the bottom water body; And correcting the reference two-dimensional water age by using the ageing coefficient to generate a lake three-dimensional water age field capable of reflecting plane and vertical differences.
2. The method of estimating the water age of a lake of claim 1, wherein constructing a space-time dynamic resistance surface reflecting the resistance to movement of the water flow in the lake comprises: Calculating a topographic resistance factor according to the water depth data, wherein the topographic resistance factor and the water depth are in a negative correlation; Calculating a vegetation resistance factor according to the vegetation index data, wherein the vegetation resistance factor and a vegetation index value form a positive correlation; calculating a wind field resistance factor according to wind field data, wherein the wind field resistance factor and the effective wind area length are in a negative correlation; and carrying out normalization treatment on the terrain resistance factor, the vegetation resistance factor and the wind field resistance factor, and then carrying out weighted superposition based on a weighted linear superposition method to generate the space-time dynamic resistance surface.
3. The method of claim 2, wherein calculating the effective wind zone length comprises traversing each effective pixel of all spatial units, determining a ray from the unit along the prevailing wind direction for any spatial unit on the lake water surface, and calculating the length of a line segment in the lake interior portion after the ray intersects the lake water boundary, the length value being the effective wind zone length of the spatial unit.
4. The method for estimating the water age of a lake according to claim 1, wherein the specific formula for estimating the reference two-dimensional water age of the lake is: ; Wherein, the As the reference two-dimensional water age, In order to integrate the effective distance of hydrology, Is the average hydrologic effective distance of the whole lake, For the whole water-changing period of the lake, And Is an empirical coefficient.
5. The method for estimating the water age of a lake according to claim 1, wherein the rule for determining the vertical layering state of the lake is that the lake is determined to be in a stable layering state when the average daily wind speed is continuously lower than a first threshold value and the temperature difference between the surface water temperature and the air temperature is continuously greater than a second threshold value within a preset number of days, and the lake is determined to be in a mixed state otherwise.
6. The method for estimating the water age of a lake according to claim 1, wherein the specific formula for characterizing the aging coefficient of the retention effect of the water body at the bottom layer is: When the stable layered state is judged, the water age of the underlying water body is increased, and an aging coefficient is defined : ; Wherein, the As a factor of the ageing which is to be used, In order to set the parameters of the system, Is the temperature difference between the surface water temperature and the air temperature, For the wind speed of the wind, Is the depth of water; when it is determined that the mixing state is to be established, 。
7. The method for estimating the water age of a lake according to claim 1, wherein the method for generating the three-dimensional water age field of the lake reflecting the difference between the plane and the vertical direction is as follows: When the mixed state is determined, the aging coefficient of the full water column ; When it is determined that the layered state is stable, Wherein K (z) is a function of depth z; Is defined as a water layer based piecewise function: Surface layer ; Middle layer ; Bottom layer ; Wherein, the And The defined thickness of the surface layer and the bottom layer are respectively, and H is the maximum depth of the lake; the relative intensity of the mid-layer retention effect is characterized as the mid-layer attenuation coefficient.
8. The method for estimating the water age of a lake according to claim 1, further comprising performing superposition analysis on the three-dimensional water age field and a water quality parameter space distribution map of synchronous remote sensing inversion to identify a water quality risk area caused by overlong water age.
9. An electronic device comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are in communication with each other through the communication bus, the memory is used for storing a computer program, and the processor is used for realizing the lake water age estimation method according to any one of claims 1-8 when executing the program stored on the memory.
10. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein a computer program which, when executed by a processor, implements the steps of a lake water age estimation method according to any one of claims 1-8.

Description

Lake water age estimation method, electronic equipment and storage medium Technical Field The invention relates to the field of lake water age estimation. In particular to a lake water age estimation method, electronic equipment and a storage medium. Background In recent years, lake water exchange capacity mainly depends on the average index of the whole lake, namely 'water exchange period', and the water ages of different areas (such as a lake bay, a shoal and a deep water area) in the lake cannot be quantified. Although the traditional hydrologic model can simulate the hydrodynamic process, the traditional hydrologic model is complex in calculation, depends on a large amount of actually measured hydrologic data and is difficult to apply under the conditions of a large range and a long time sequence. Although the remote sensing technology is widely applied to inversion of water surface temperature and water quality parameters, a method for directly quantifying the difference between the hydrodynamic process in the lake and the water age space is lacking. Therefore, the invention provides a lake water age estimation method, electronic equipment and a storage medium, and a method for efficiently and dynamically describing the water exchange space difference in the lake. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, one purpose of the invention is to provide a lake water age estimation method, which is to couple hydrologic resistance and vertical layering effect, utilize lake multisource remote sensing data, underwater topography and other data to construct a space-time dynamic resistance surface to calculate hydrologic effective distance, combine vertical aging coefficients to correct, and finally generate a water age field capable of reflecting real space-time pattern of water exchange efficiency in the lake. The method comprises the following steps of: acquiring multisource remote sensing data, underwater topography data, meteorological data and hydrological flow data of a target lake; constructing a space-time dynamic resistance surface reflecting the water flow movement resistance in the lake based on the underwater topography data, vegetation distribution data obtained by inversion from the multi-source remote sensing data and wind field data extracted from the meteorological data; Taking at least one outlet of the lake as a source point, and calculating the hydrological effective distance from each space unit in the lake to the source point based on the space-time dynamic resistance surface; Estimating and obtaining a reference two-dimensional water age of the lake based on the hydrological effective distance and the integral water change period of the lake obtained from the hydrological flow data; Based on the surface water temperature inverted by the multi-source remote sensing data and the air temperature and the air speed provided by the meteorological data, determining the vertical layering state of the lake, and calculating an aging coefficient representing the retention effect of the bottom water body; And correcting the reference two-dimensional water age by using the ageing coefficient to generate a lake three-dimensional water age field capable of reflecting plane and vertical differences. In some implementations, constructing a spatiotemporal dynamic resistance surface reflecting resistance to movement of water flow within a lake includes: Calculating a topographic resistance factor according to the water depth data, wherein the topographic resistance factor and the water depth are in a negative correlation; Calculating a vegetation resistance factor according to the vegetation index data, wherein the vegetation resistance factor and a vegetation index value form a positive correlation; calculating a wind field resistance factor according to wind field data, wherein the wind field resistance factor and the effective wind area length are in a negative correlation; and carrying out normalization treatment on the terrain resistance factor, the vegetation resistance factor and the wind field resistance factor, and then carrying out weighted superposition based on a weighted linear superposition method to generate the space-time dynamic resistance surface. In some implementations, calculating the effective wind zone length includes traversing each effective pixel on all spatial units, determining a ray from the unit along the prevailing wind direction for any spatial unit on the lake water surface, calculating the length of a line segment located in the lake interior portion after the ray intersects the lake water boundary, and taking the length value as the effective zone length of the spatial unit. In some implementations, the specific formula for estimating the reference two-dimensional water age of the lake is: ; Wherein Age_2D is a reference two-dimensional water Age, L_combined is a comprehens