Bulletin of Surveying and Mapping ›› 2025, Vol. 0 ›› Issue (9): 51-58.doi: 10.13474/j.cnki.11-2246.2025.0909

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Remote sensing estimation of aquatic vegetation biomass in Ulansuhai Lake

GONG Liangchen1, XU Dongpo1,2, KUANG Zhen2, FAN Yingchun2, DONG Jiahui1,2   

  1. 1. Wuxi Fisheries College of Nanjing Agricultural University, Wuxi 214081, China;
    2. Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences(Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture and Rural Affairs), Wuxi 214081, China
  • Received:2025-02-11 Published:2025-09-29

Abstract: Aquatic vegetation plays an irreplaceable role in the ecological balance and water purification of rivers and lakes.Biomass,as an important biophysicochemical indicator of aquatic vegetation,not only reflects primary productivity but also plays a key role in assessing nitrogen and phosphorus reserves and carbon sequestration in water bodies.To address the challenge of comprehensively surveying aquatic vegetation biomass in the complex lake vegetation environment of Ulansuhai Lake and to account for the spectral response differences between emergent and submerged plants,this study proposes a biomass estimation model combining remote sensing data with field survey data.Using Landsat 8 imagery and data from 32 field sampling points,and based on ENVI and Matlab software,a partial least squares regression model for the retrieval of aquatic vegetation biomass in Ulansuhai Lake is developed and its accuracy assessed.The results showed that the estimation accuracies of the biomass retrieval models for emergent plants and submerged plants reached 92.93%and 79.80%,respectively.This indicates that the partial least squares regression model is suitable for retrieving aquatic vegetation biomass under small sample conditions and can achieve high accuracy in complex lake vegetation environments.The total biomass of aquatic vegetation in Ulansuhai Lake in June and September 2023 was 781.6×104 and 791.9×104 t,respectively,with emergent plants accounting for 78.03%and 76.82%.Compared to June 2023,the area of emergent plants in Ulansuhai Lake decreased in September,the average biomass per unit area increased,and there was no significant change in spatial distribution; The biomass of submerged plants show a notable increase,with the area expanding,approaching the historical high from 1988(102.06 km2).This research provides scientific evidence for subsequent lake ecological management,health assessment,and water quality restoration in Ulansuhai Lake.

Key words: Ulansuhai, aquatic vegetation, biomass inversion modeling, partial least squares regression, vegetation index

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