CN-121980120-A - Method for calculating river water and electricity reserve in small data or no data area based on remote sensing data

CN121980120ACN 121980120 ACN121980120 ACN 121980120ACN-121980120-A

Abstract

A river water and electricity reserve calculation method for a small data area or a non-data area based on remote sensing data comprises the steps of selecting a river section, extracting river mask information, extracting a river center line and a river width, extracting river water level information, estimating the maximum and minimum river flow, estimating river flow and annual flow through a AMHG model, calculating the water head difference of the upper section and the lower section of a river section, and calculating the river water and electricity reserve. By combining multisource remote sensing data and AMHG models, the difficult problem of river hydraulic resource estimation under the condition of lacking measured runoff data can be solved, and quick and quantitative assessment of river water and electricity accumulation can be realized. The invention is suitable for the early planning and energy potential evaluation of the hydropower engineering in the small data area or the no data area.

Inventors

BAI JUAN
ZHUO YUE
YAN BAIKUN
ZHANG YICHI
XING NAICHEN
GUO YI
GAN FUPING

Assignees

中国自然资源航空物探遥感中心

Dates

Publication Date: 20260505
Application Date: 20251224

Claims (9)

1. A method for calculating river water and electricity reserve in a small-data or non-data area based on remote sensing data is characterized by comprising the following steps: Selecting river sections without branches and flowing into and out of a river channel, and selecting 10-20 sections along the river channel; Secondly, river mask information extraction, namely performing cloud removal pretreatment on satellite remote sensing image data, extracting a water mask, and removing non-river water in the water mask to obtain a river mask; step three, extracting the center line and the width of the river, namely keeping the space position of the sections unchanged, and calculating the center line and the width of the river corresponding to mask information of different river channels of each section; Step four, river water level information extraction, which is to determine a reference section of a river based on the deviation condition of a river central line and extract river water level information corresponding to different river widths of each section according to SWOT_L2_HR_ RiverSP data; Step five, estimating the maximum flow rate and the minimum flow rate of the river of the reference section by adopting the following formula based on the river width information and the water level information of the reference section: Q Lowfilter =W min *H min *V min Q Hifilter =W max *H max *V max H min =L min -L 0 H max =L max -L 0 wherein Q Lowfilter is minimum flow rate of a reference section river, m 3 /s;Q Hifilter is maximum flow rate of the reference section river, m 3 /s;W min is minimum flow width in different phases of the reference section, m, W max is maximum flow width in different phases of the reference section, m, H min is minimum flow depth in different phases of the reference section, m, H max is maximum flow depth in different phases of the reference section, m, L min is minimum water level in different phases of the reference section, m, L max is maximum water level in different phases of the reference section, m, L 0 is elevation of the reference section water bottom, m, V min is minimum flow rate, m/s, default value is 0.1, V max is maximum flow rate, m/s, default value is 5; step six, AMHG, estimating river flow and annual flow by using a model: Estimating the river flow of the satellite passing date by substituting the long-time-sequence river width information into AMHG model, confirming whether the parameter adjusting result is reasonable or not based on the maximum and minimum flow of the river with the reference section determined in the step five, and re-adjusting parameters if not, so as to obtain the finally estimated river flow; Step seven, calculating the water level difference of the upper and lower sections of the river reach based on SWOT_L2_HR_ RiverSP data; And step eight, river water and electricity reserve calculation, namely calculating the annual runoff based on the river flow obtained in the step six, substituting the annual runoff and the water head difference of the upper section and the lower section of the river reach into a river water and electricity reserve calculation formula, and calculating the river reach water and electricity reserve.
2. The method for calculating river water and electricity reserve in a small data or no data area based on remote sensing data according to claim 1, wherein in the second step, a water mask is extracted by combining a normalized vegetation index, an enhanced vegetation index and an improved normalized difference water index, and non-river water in the water mask is removed to obtain a river mask, wherein the normalized vegetation index, the enhanced vegetation index and the improved normalized difference water index have the following calculation formulas, NDVI = [NIR-R]/[NIR+R] EVI = 2.5*[NIR-R]/[1+NIR+6*R-7.5*B] MNDWI = [G-SWIR]/[G+SWIR] The method comprises the steps of dividing pixels with water signals stronger than vegetation signals into water bodies by using MNDWI > EVI or MNDWI > NDVI, and removing mixed pixels of the water bodies and vegetation by using EVI <0.1 to obtain a water body mask, wherein the NDVI is a normalized vegetation index, the EVI is an enhanced vegetation index, the MNDWI is an improved normalized difference water body index, the R is red band reflectivity, the G is green band reflectivity, the NIR is near infrared band reflectivity, the B is blue band reflectivity, the SWIR is short wave infrared band reflectivity.
3. The method for calculating river water and electricity accumulation in a small data area or a no data area based on remote sensing data according to claim 1, wherein in the third step, river mask information of different time phases is substituted into RivWidth _v04 software to calculate the river width corresponding to all pixels of the center line of a river segment, and the river width of each section is obtained by screening in combination with river section information.
4. The method for calculating river water and electricity accumulation in a small data or no data area based on remote sensing data according to claim 1, wherein in the fourth step, the reference section of the river is determined based on the deviation condition of the center line of the river, specifically, the river section with the center line of the river kept consistent in different time phases is selected as the reference section.
5. The method of claim 1, wherein in the sixth step, AMHG is a model river flow calculation and constraint formula as follows, Wherein Q is the river flow of the satellite passing date, m 3 /s;a x 、b x is the parameter of a certain section, the value range adopts default values of [1, 500], [0.01, 0.80] respectively, E is the specific constant of the river channel, the slope of a x 、b x logarithmic linear relation is defined, w x is the width of the certain section of the river at a certain time phase, m is the number of each section of the river at the certain time phase, the numerical subscript in x 1 ,x 2 ,...,x n is the number of each section of the river, w glob is the average value of the widths of all sections at the certain time phase in the river reach and is obtained by remote sensing images, p and y are experience parameters determined by the change of the section widths, and mean refers to the average value based on all sections.
6. The method for calculating river water and electricity reserves with little data or no data area based on remote sensing data according to claim 5, wherein in the step six, whether the parameter adjusting result is reasonable or not is confirmed based on the maximum and minimum flow rates of the river with the reference section determined in the step five, the method specifically comprises the steps of calculating and comparing the maximum flow rate Q Hifilter and the minimum flow rate Q Lowfilter of the river with the reference section in the river to be measured, determining the minimum standard value Q min of the river with the minimum standard value Q max of the river, comparing the maximum standard value Q max of the river with the maximum flow rate Q min and Q max of the river, and confirming that the parameter adjusting result is reasonable if Q min ≤Q≤Q max .
7. The method for calculating river water and electricity reserves with little or no data area based on remote sensing data according to claim 5, wherein in the step six, whether the parameter adjusting result is reasonable or not is confirmed based on the maximum and minimum flow rates of the river of the reference section determined in the step five, the method specifically comprises the steps of calculating the maximum flow rate Q Hifilter and the minimum flow rate Q Lowfilter of the river of the reference section at the most downstream position in the river channel to be measured, taking the Q Hifilter of the section as a standard value Q max of the maximum flow rate of the river, taking the Q Lowfilter of the section as a standard value Q min of the minimum flow rate of the river, comparing the Q value of the river flow rate with the Q min and the Q max , and confirming that the parameter adjusting result is reasonable if the Q min ≤Q≤Q max .
8. The method for calculating river water and electricity accumulation in a small data area or a no data area based on remote sensing data according to claim 1, wherein in the step six, the annual flow is calculated based on the river flow, wherein the annual flow is calculated by calculating discontinuous river flow according to month to obtain month average flow, and multiplying each month average flow by the number of days per month to accumulate, and the specific formula is as follows: wherein: The average flow of the ith month is m 3 /s;Q ij , the river flow of the j days of the passing date of the ith month satellite, m 3 /s, the total number of days of the passing date of the ith month satellite, Q annual , the annual flow and m 3 ;day i are the number of days of the ith month.
9. The method of claim 1, wherein in the step eight, the river water electricity accumulation calculation formula is as follows, Wherein P is water and electricity reserve power, MW, k is a conversion coefficient, k=2.778× -4 , g is gravity acceleration, m/s 2 , and the value is 9.81; is the average annual diameter flow of the upper and lower sections of the river reach or the annual average flow of the whole river reach, m 3 ; is the water level difference of the upper and lower sections of the river reach, m.

Description

Method for calculating river water and electricity reserve in small data or no data area based on remote sensing data Technical Field The invention relates to a method for calculating river water and electricity reserve of a small data area or a non-data area based on remote sensing data, which can solve the problem of measuring and calculating the river water and electricity reserve of the small data area, develops an application mode of the small data area/the non-data area combined with remote sensing technology and energy planning, belongs to the field of remote sensing hydrology and is suitable for hydraulic resource estimation. Background Water resources are an important foundation for national energy strategy and sustainable development. The theoretical reserve of river water and electricity can reflect the total amount of water energy resources possibly owned by a river under ideal conditions. The estimation of river water and electricity reserve is a core basis for estimating the water energy endowment of a country or region, making energy development planning and early-stage decision-making of water conservancy and hydropower engineering. The method is scientifically and accurately estimated, and has great significance for optimizing the energy structure and realizing the 'double carbon' strategic target. The river water and electricity accumulation is mainly determined by the upstream and downstream water level difference and flow, and has strong dependence on the average flow data for many years. Traditional hydrographic observation relies on long-term, continuous and reasonably distributed in-situ hydrographic observation data (such as flow velocity, flow rate, section morphology and the like) to obtain and calculate key parameters, namely water head and flow rate, and faces the bottleneck of 'less data'. The satellite remote sensing technology can obtain river water level, width and other information in a large scale, and the satellite remote sensing technology still faces serious challenges in the aspect of directly estimating the key hydraulic parameter-flow. Most of hydraulic models based on remote sensing (such as inversion of traditional Manning formulas) still need to rely on a small amount of measured flow data for parameter calibration, and cannot get rid of dependence on ground observation fundamentally. In addition, the current common DEM data calculation of the upstream and downstream water level difference is limited by the sampling precision of a topographic map or a remote sensing image and the surface coverage change, and the elevation error is usually large. Disclosure of Invention The invention aims to provide a method for calculating river water and electricity reserve in a small-data or non-data area based on remote sensing data, which is independent of on-site hydrologic observation, can accurately estimate river flow, directly acquire near-real-time water surface elevation by using SWOT data, can remarkably improve the calculation precision of upstream and downstream water level differences, realizes the rapid and reliable estimation of river water and electricity reserve in a small-data area, and provides a unified and comparable data basis for calculating the global river water and electricity reserve. The invention aims to solve the main technical problems of directly estimating key hydraulic parameters (annual average flow and water level) based on remote sensing data under the serious shortage or series too short limit of measured data, and obtaining key parameters of AMHG model, namely maximum flow and minimum flow of river for the river without measured runoff data. The invention relates to a method for calculating river water and electricity reserve in a small-data or non-data area based on remote sensing data, which comprises the following specific steps: Selecting river sections without branches and flowing into and out of a river channel, and selecting 10-20 sections along the river channel; Secondly, river mask information extraction, namely performing cloud removal pretreatment on satellite remote sensing image data, extracting a water mask, and removing non-river water in the water mask to obtain a river mask; step three, extracting the center line and the width of the river, namely keeping the space position of the sections unchanged, and calculating the center line and the width of the river corresponding to mask information of different river channels of each section; Step four, river water level information extraction, which is to determine a reference section of a river based on the deviation condition of a river central line and extract river water level information corresponding to different river widths of each section according to SWOT_L2_HR_ RiverSP data; Step five, estimating the maximum flow rate and the minimum flow rate of the river of the reference section by adopting the following formula based on the river width information and the water leve