1
|
Jiang W, Dai Z, Mei X, Long C, Binh NA, Van CM, Cheng J. Profiling dynamics of the Southeast Asia's largest lake, Tonle Sap Lake. Sci Total Environ 2024; 917:170444. [PMID: 38290675 DOI: 10.1016/j.scitotenv.2024.170444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 02/01/2024]
Abstract
Lakes, as vital components of the Earth's ecosystem with crucial roles in global biogeochemical cycles, are experiencing pervasive and irreparable worldwide losses due to natural factors and intensive anthropogenic interferences. In this study, we investigated the long-term dynamic patterns of the Tonle Sap Lake, the largest freshwater lake in the Mekong River Basin, using a series of hydrological data and remote sensing images between 2000 and 2020. Our findings revealed a significant decline in the annual average water level of the lake by approximately 2.1 m over 20 years, accompanied by an annual average reduction in surface area of about 1400 km2. The Tonle Sap Lake exhibited episodic declines in water level and surface area, characterized by the absence of flooding during the flood season and increasing aridity during the dry season. Furthermore, the shoreline of the lake has significantly advanced towards the lake in the northwestern and southern regions during the dry season, primarily due to sedimentation-induced shallowing of the lake edge depth and decreased water levels. In contrast, lake shorelines in the eastern region remained relatively stable due to the constructed embankments for the protection of the cultivated farmland. While the seasonal fluctuations of the Tonle Sap Lake are regulated by regional precipitation in the Mekong River Basin, the prolonged shrinking of the lake can be mainly ascribed to intensive anthropogenic activities. The interception of dams along the upper Mekong River has resulted in a decrease in the inflow to Tonle Sap Lake, exacerbating its shrinkage. Moreover, there are minor impacts from agricultural land expansion and irrigation on the lake. This study highlights the driving forces behind the evolution of Tonle Sap Lake, providing valuable information for lake managers to develop strategies aimed at conserving and restoring the ecological integrity of the Tonle Sap Lake.
Collapse
Affiliation(s)
- Wenting Jiang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Zhijun Dai
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China.
| | - Xuefei Mei
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Chuqi Long
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China
| | - Nguyen An Binh
- Ho Chi Minh City Institute of Resources Geography, Vietnam Academy of Science and Technology, Ho Chi Minh City, Viet Nam
| | - Cong Mai Van
- Faculty of Civil Engineering, Thuyloi University, Hanoi, Viet Nam
| | - Jinping Cheng
- Department of Science and Environmental Studies, The Education University of Hong Kong, New Territories, Hong Kong, China
| |
Collapse
|
2
|
Li Z, Deng F, Gong J, Xiang L, Han Y, Zheng P, Zhao E. Lake dynamics in Tibetan Plateau during 1990-2020 and exploratory factor analyses using Google Earth Engine. Environ Sci Pollut Res Int 2023. [PMID: 36635472 DOI: 10.1007/s11356-023-25206-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 01/04/2023] [Indexed: 01/14/2023]
Abstract
Tibetan Plateau (TP) lakes are crucial water resources for many countries, and the region is sensitive to climate change, so the TP lakes' dynamics have always been the focus of TP research. Given the vastness of the TP, the diversity of topography, geomorphology, and meteorological features, and the significant disparities in precipitation between river basins, it is vital to examine lake dynamics and influencing variables from the basin's perspective. Based on Landsat imageries and supported by Google Earth Engine, lakes were mapped from 1990 to 2020. Results show that the TP lake's number and area have increased significantly in recent 30 years except for a noticeable shrinkage from 1990 to 1995 and a slight decrease from 2013 to 2015. The lake area in the endorheic region basin area has grown obviously, with the most significant dynamics in the Qiangtang Basin, where the lake's number and total area have increased by about 30% over the 30 years. In contrast, the lake areas in the outflow region basins were relatively stable. The dynamics were obviously affected by temperature, but the influencing factors and degree of influence on different river basins vary. The lake area in the Amu Dayra Basin and the Yellow Basin was more closely related to precipitation, and the lake area in the Hexi Basin was more related to temperature. The results provide a comprehensive understanding of lake spatial-temporal dynamics in the Tibetan Plateau and its river basins and a reference for studying lake long time series.
Collapse
|
3
|
Douglas Greene SB, LeFevre GH, Markfort CD. Improving the spatial and temporal monitoring of cyanotoxins in Iowa lakes using a multiscale and multi-modal monitoring approach. Sci Total Environ 2021; 760:143327. [PMID: 33239199 DOI: 10.1016/j.scitotenv.2020.143327] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/19/2020] [Accepted: 10/25/2020] [Indexed: 06/11/2023]
Abstract
Cyanobacterial harmful algal blooms (CyanoHABs) are pervasive and negatively impact lake water quality, resulting in economic losses and public health risks through exposure to cyanotoxins. Therefore, it is critical to better monitor and understand the complexity of CyanoHABs, but current methods do not fully describe the spatial and temporal variability of bloom events. In this work, we developed a framework for a multiscale and multi-modal monitoring approach for CyanoHABs combining drone-based near-range remote sensing with analytical measurements of microcystin cyanotoxins and chlorophyll-a. We analyzed weekly beach monitoring samples from 37 lakes geographically distributed across the state of Iowa (USA) over a 15-week period in the summer of 2019 to quantify ELISA (bioassay), 12 microcystin congeners (LC-MS/MS), and chlorophyll-a. We developed a novel microcystin congener-normalized equivalent toxin metric to compare CyanoHAB impacted waters; this microcystin-LR normalized sum-of-congeners approach yields lower predicted toxicity than parallel ELISA results suggesting ELISA is conservative for assessment. A significant linear relationship existed between chlorophyll-a and microcystin for lakes throughout Iowa (R2 = 0.39, p < 0.001); lakes with low watershed:lake area ratio and long residence times exhibited a stronger correlation. We then developed a novel geometry-based image processing approach to allow for stitching over-water drone images, a previous barrier in photogrammetry. We applied our mutli-modal framework to a case study on Green Valley Lake to assess initial viability and predicted microcystin concentrations within 33%. We concluded that multispectral imaging is possible but may presently be insufficient for predicting microcystin concentrations due to limitations in the spectral capabilities of the multispectral camera, but technologies are quickly advancing, and lightweight hyperspectral imaging could soon become feasible for investigating spatial bloom variability on lakes.
Collapse
Affiliation(s)
- Sarah B Douglas Greene
- Department of Civil & Environmental Engineering, University of Iowa, 4105 Seamans Center, Iowa City, IA 52242, United States; IIHR-Hydroscience & Engineering, 100 C. Maxwell Stanley Hydraulics Laboratory, Iowa City, IA 52242, United States
| | - Gregory H LeFevre
- Department of Civil & Environmental Engineering, University of Iowa, 4105 Seamans Center, Iowa City, IA 52242, United States; IIHR-Hydroscience & Engineering, 100 C. Maxwell Stanley Hydraulics Laboratory, Iowa City, IA 52242, United States.
| | - Corey D Markfort
- Department of Civil & Environmental Engineering, University of Iowa, 4105 Seamans Center, Iowa City, IA 52242, United States; IIHR-Hydroscience & Engineering, 100 C. Maxwell Stanley Hydraulics Laboratory, Iowa City, IA 52242, United States.
| |
Collapse
|
4
|
Zhou Y, Dong J, Xiao X, Liu R, Zou Z, Zhao G, Ge Q. Continuous monitoring of lake dynamics on the Mongolian Plateau using all available Landsat imagery and Google Earth Engine. Sci Total Environ 2019; 689:366-380. [PMID: 31277004 DOI: 10.1016/j.scitotenv.2019.06.341] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 06/12/2019] [Accepted: 06/21/2019] [Indexed: 06/09/2023]
Abstract
Lakes are important water resources on the Mongolian Plateau (MP) for human's livelihood and production as well as maintaining ecosystem services. Previous studies, based on the Landsat-based analyses at epoch scale and visual interpretation approach, have reported a significant loss in the lake areas and numbers, especially from the late 1990s to 2010. Given the remarkable inter- and intra-annual variations of lakes in the arid and semi-arid region, a comprehensive picture of annual lake dynamics is needed. Here we took advantages of the power of all the available Landsat images and the cloud computing platform Google Earth Engine (GEE) to map water body for each scene, and then extracted lakes by post-processing including raster-to-vector conversion and separation of lakes and rivers. Continuous dynamics of the lakes over 1 km2 was monitored annually on the MP from 1991 to 2017. We found a significant shrinkage in the lake areas and numbers of the MP from 1991 to 2009, then the decreasing lakes on the MP have recovered since circa 2009. Specifically, Inner Mongolia of China experienced more dramatic lake variations than Mongolia. A few administrative regions with huge lakes, including Hulunbuir and Xilin Gol in Inner Mongolia and Ubsa in Mongolia, dominated the lake area variations in the study area, suggesting that the prior treatments on these major lakes would be critical for water management on the MP. The varied drivers of lake variations in different regions showed the complexity of factors impacting lakes. While both natural and anthropogenic factors significantly affected lake dynamics before 2009, precipitation played increasingly important role for the recovery of lakes on the MP after 2009.
Collapse
Affiliation(s)
- Yan Zhou
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
| | - Jinwei Dong
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Xiangming Xiao
- Department of Microbiology and Plant Biology, Center for Spatial Analysis, University of Oklahoma, Norman, OK 73019, USA; Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan University, Shanghai 200438, China
| | - Ronggao Liu
- State key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhenhua Zou
- Department of Microbiology and Plant Biology, Center for Spatial Analysis, University of Oklahoma, Norman, OK 73019, USA
| | - Guosong Zhao
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Quansheng Ge
- Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
| |
Collapse
|
5
|
Yang J, Holbach A, Wilhelms A, Qin Y, Zheng B, Zou H, Qin B, Zhu G, Norra S. Highly time-resolved analysis of seasonal water dynamics and algal kinetics based on in-situ multi-sensor-system monitoring data in Lake Taihu, China. Sci Total Environ 2019; 660:329-339. [PMID: 30640101 DOI: 10.1016/j.scitotenv.2019.01.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 01/04/2019] [Accepted: 01/05/2019] [Indexed: 06/09/2023]
Abstract
Predicting algal blooms is challenging due to rapid growth rates under suitable conditions and the complex physical, chemical, and biological processes involved. Physico-chemical parameters, monitored in this study by a high-resolution in-situ multi-sensor system and derived from lab-based water sample analyses, show the seasonal variation and have different degrees of vertical gradients across the water column. Through analyzing the changes and relations between multi-factors, we reveal pictures of water quality dynamics and algal kinetics. Nitrate has regular seasonal changes different to the seasonal patterns of total dissolved Phosphorus. Positive correlations are found between Chlorophyll a fluorescence and temperature, wind-induced resuspension and mixing promote the augment of Cyanobacteria fluorescence (Phycocyanin) signal. While the resuspension can also result in the increase of turbidity and affect the light environment for hydrophytes, the algal scums are the main reason for the high turbidity on the surface, which lower the illumination radiation in the water body. Those parameters are the primary dominants responsible for the change of algae from our monitoring data, which could be used as indicators for the dynamic changes of algae in the future.
Collapse
Affiliation(s)
- Jingwei Yang
- Institute of Applied Geosciences, Working Group Environmental Mineralogy and Environmental System Analysis (ENMINSA) Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, Germany.
| | - Andreas Holbach
- Institute of Applied Geosciences, Working Group Environmental Mineralogy and Environmental System Analysis (ENMINSA) Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, Germany
| | - Andre Wilhelms
- Institute of Applied Geosciences, Working Group Environmental Mineralogy and Environmental System Analysis (ENMINSA) Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, Germany
| | - Yanwen Qin
- Chinese Research Academy of Environmental Sciences, Dayangfang 8, Anwai Beiyuan, Beijing 100012, PR China
| | - Binghui Zheng
- Chinese Research Academy of Environmental Sciences, Dayangfang 8, Anwai Beiyuan, Beijing 100012, PR China
| | - Hua Zou
- School of Environmental and Civil Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Boqiang Qin
- Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, 73 East Beijing Road, 210008 Nanjing, PR China
| | - Guangwei Zhu
- Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, 73 East Beijing Road, 210008 Nanjing, PR China
| | - Stefan Norra
- Institute of Applied Geosciences, Working Group Environmental Mineralogy and Environmental System Analysis (ENMINSA) Karlsruhe Institute of Technology, Kaiserstraße 12, 76131 Karlsruhe, Germany
| |
Collapse
|