Predicting the light attenuation coefficient through Secchi disk depth and beam attenuation coefficient in a large, shallow, freshwater lake

Zhang, Yunlin; Liu, Xiaohan; Yin, Yongguang; Wang, Mingzhu; Qin, Boqiang

doi:10.1007/s10750-012-1084-2

Cited by 37 publications

(19 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, an increasing trend of SDD is predicted under the strict sand mining policy and reduced wind speeds. The increase in SDD indicated that more light will be available and that the depth of the euphotic zone will increase [15,22], which may promote the germination and photosynthesis of aquatic vegetation seedlings [38] and thus increase vegetation coverage and primary productivity. Then, the increased vegetation will in turn promote the improvement of water transparency by positive feedback [51].…”

Section: Potential Significance Of This Studymentioning

confidence: 99%

“…Water transparency is an important and direct parameter for describing the optical characteristics of water bodies and their water quality; transparency is widely measured using Secchi disks to obtain Secchi disk depths (SDDs) in freshwater and marine water monitoring [10,11]. Water transparency visually reflects the clarity and turbidity of a water body and can evaluate trophic status and the underwater light field [12][13][14][15]. SDD, total nitrogen, total phosphorus, and chlorophyll a are considered to be the criteria for assessing the eutrophication of lakes [16].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Decline in Transparency of Lake Hongze from Long-Term MODIS Observations: Possible Causes and Potential Significance

Shi

Zhang

et al. 2019

Remote Sensing

Self Cite

View full text Add to dashboard Cite

Transparency is an important indicator of water quality and the underwater light environment and is widely measured in water quality monitoring. Decreasing transparency occurs throughout the world and has become the primary water quality issue for many freshwater and coastal marine ecosystems due to eutrophication and other human activities. Lake Hongze is the fourth largest freshwater lake in China, providing water for surrounding cities and farms but experiencing significant water quality changes. However, there are very few studies about Lake Hongze's transparency due to the lack of long-term monitoring data for the lake. To understand long-term trends, possible causes and potential significance of the transparency in Lake Hongze, an empirical model for estimating transparency (using Secchi disk depth: SDD) based on the moderate resolution image spectroradiometer (MODIS) 645-nm data was validated using an in situ dataset. Model mean absolute percentage and root mean square errors for the validation dataset were 27.7% and RMSE = 0.082 m, respectively, which indicates that the model performs well for SDD estimation in Lake Hongze without any adjustment of model parameters. Subsequently, 1785 cloud-free images were selected for use by the validated model to estimate SDDs of Lake Hongze in 2003-2017. The long-term change of SDD of Lake Hongze showed a decreasing trend from 2007 to 2017, with an average of 0.49 m, ranging from 0.57 m in 2007 to 0.42 m in 2016 (a decrease of 26.3%), which indicates that Lake Hongze experienced increased turbidity in the past 11 years. The loss of aquatic vegetation in the northern bays may be mainly affected by decreases of SDD. Increasing total suspended matter (TSM) concentration resulting from sand mining activities may be responsible for the decreasing trend of SDD.

show abstract

Section: Potential Significance Of This Studymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Decline in Transparency of Lake Hongze from Long-Term MODIS Observations: Possible Causes and Potential Significance

Shi

Zhang

et al. 2019

Remote Sensing

Self Cite

View full text Add to dashboard Cite

show abstract

“…Residual normality was assessed through Anderson–Darling test. The median indices k × SD and Z eu /SD were compared with those proposed in previous studies (Koenings & Edmundson, ; Padial & Thomaz, ; Poole & Atkins, ; Zhang et al, ) through Wilcoxon test. In all cases, a p value of less than .05 was considered statistically significant.…”

Section: Methodsmentioning

confidence: 99%

“…In addition, SD is widely used to estimate k and Z eu due to the ease of its measurement (Cardoso et al, ; Pineda et al, ; Zanco, Pineda, Bortolini, Jati, & Rodrigues, ). The significant correlations between SD and k , and between SD and Z eu , allow for the use of regression models (Padial & Thomaz, ; Zhang, Liu, Yin, Wang, & Qin, ) and indices, which emerge from the product k × SD and the ratio Z eu /SD (Koenings & Edmundson, ). However, SD is subject to limitations because their correlations with k and Z eu are influenced by the partitioning of PAR attenuation between the processes of absorption and scattering.…”

Section: Introductionmentioning

confidence: 99%

Spatio‐temporal variability in underwater light climate in a turbid river‐floodplain system: Driving factors and estimation using Secchi disc

Mayora

Devercelli

2019

River Research & Apps

View full text Add to dashboard Cite

The underwater light climate has important effects on primary producers. The aim of this research was to evaluate its variability in a turbid river-floodplain system. Photosynthetically active radiation (PAR) was measured in the Middle Paraná River during different hydrological phases to (a) analyse the photosynthetically active radiation attenuation coefficient (k) and euphotic depth (Z eu ) as well as their associations with optically active components and (b) develop and evaluate indices and regression models based on Secchi disc (SD) measurements to estimate k and Z eu . Values of k were higher in the fluvial system than in the floodplain and during low-water stage than high-water stage. Particulate components controlled the light climate variability.Chromophoric dissolved organic matter and chlorophyll-a had significant effects during floods. The estimation of k and Z eu was sensitive to temporal but not to spatial variations. The highest prediction accuracy was observed when using specific nonlinear regressions for each hydrological phase, especially for Z eu estimation (low stage: k = 1.76 × SD −0.80 , Z eu = 2.62 × 1/SD −0.80 ; high stage: k = 2.04 × SD −0.53 , Z eu = 2.26 × 1/SD −0.53 ). The indices k × SD and Z eu /SD were significantly different from those proposed for clear water environments. It is concluded that temporal variations should be considered when estimating k and Z eu in turbid river-floodplain systems because of the temporal heterogeneity in optically active components.Considering that ecological implication of the light climate depends on Z eu :depth ratio, we propose to estimate Z eu instead of k. Finally, indices proposed for clear water environments are not recommended to be applied to turbid environments.

show abstract

“…First, Secchi depth (SD, m) was measured during each sampling in 2012. K d was estimated using the relationship found in eutrophic Lake Taihu, where light attenuation was primarily due to inorganic particles (K d = 1.48 SD À1.16 ; Zhang et al, 2012). Second, light profiles were measured during summers at 10-cm-depth intervals in the Szamos and Tisza Rivers with a LiCor 4p quantum sensor (Lincoln, NE, USA).…”

Section: Additional Datamentioning

confidence: 99%

Phytoplankton growth in relation to network topology: time‐averaged catchment‐scale modelling in a large lowland river

Istvánovics

Honti

Kovács³

et al. 2014

Freshwater Biology

View full text Add to dashboard Cite

Summary Using the unregulated, eutrophic Someş River (Romania/Hungary), a tributary of the Upper Tisza River as a model system, we related phytoplankton growth to the structure of river network modified by human intervention. The Time‐Averaged Phytoplankton Increase in Rivers (TAPIR) model was developed by adding two new modules (nitrogen emission and phytoplankton growth) to the PHOSFATE model. The latter was a raster‐based, long‐term average GIS tool that computed the flow tree, mean hydrology and phosphorus concentration at fine spatial resolution in the entire catchment. Long‐term monitoring data at the outflow and phytoplankton profiles obtained along the Someş River in 2012 were used to calibrate the models. In summer 2012, a few centric diatom species dominated the phytoplankton, with mean apparent net growth rate of 2.5 day−1 along a ˜100‐km‐long upstream section of the Someş River. This high growth rate was explained by enhanced benthic retention of meroplanktonic diatoms, while further downstream mean algal biomass varied between 80 and 100 mg Chl m−3. The TAPIR model realistically reproduced observed mean biomass profiles of phytoplankton in the Someş River. According to modelling results, P‐determined biomass capacity prevented further growth of algae along the lower two‐thirds of the river. Channel slope and form were important reach‐scale determinants of phytoplankton recruitment, while the absence of large tributaries along the Someş River resulted in marginal longitudinal changes in dilution and light availability. Therefore, phytoplankton might achieve high biomass in a wide range of instantaneous net growth rates realised under strongly fluctuating environmental conditions, which combined with the abundant nutrients from urban areas underpins advanced eutrophication. Large montane reservoirs on tributaries increased mean water age at the outflow of the Someş catchment by an order of magnitude compared with pristine conditions, but had a negligible overall impact on the phytoplankton of the Someş River. Growth of river phytoplankton is intrinsically linked with network topology, including spatial distribution of nutrient inputs. Stochastic variability in discharge tends to destabilise, while specific network properties may stabilise phytoplankton growth in large rivers. Shallow rivers support meroplanktonic diatoms that, depending on discharge, may have adequate time to develop summer blooms, making shallow rivers particularly susceptible to eutrophication.

show abstract

Predicting the light attenuation coefficient through Secchi disk depth and beam attenuation coefficient in a large, shallow, freshwater lake

Cited by 37 publications

References 29 publications

Decline in Transparency of Lake Hongze from Long-Term MODIS Observations: Possible Causes and Potential Significance

Decline in Transparency of Lake Hongze from Long-Term MODIS Observations: Possible Causes and Potential Significance

Spatio‐temporal variability in underwater light climate in a turbid river‐floodplain system: Driving factors and estimation using Secchi disc

Phytoplankton growth in relation to network topology: time‐averaged catchment‐scale modelling in a large lowland river

Contact Info

Product

Resources

About