scholarly journals Exploring the water quality driving mechanism in Poyang Lake, the largest freshwater lake in China

2019 ◽  
Vol 20 (2) ◽  
pp. 700-711 ◽  
Author(s):  
Hua Wang ◽  
John Paul Kaisam ◽  
Shaowen Fang ◽  
Yanqing Deng ◽  
Bao Li ◽  
...  

Abstract Poyang Lake, the largest freshwater lake and typical river-connected lake in China, was selected as a research area. A method was first proposed to quantitatively explore the mechanisms driving water quality evolution, in which the weights of horizontal boundary input, self-purification, vertical atmospheric deposition and sediment release could be determined. A two-dimensional water environment model for Poyang Lake was developed in the framework of the Finite Volume Method and calibrated against the field investigated data. Four typical months in a common-water year were determined for numerical experiments to investigate the temporal and spatial water quality driving mechanisms in Poyang Lake. The results suggested that boundary input and self-purification have the greatest effect on dominating the water quality in Poyang Lake, followed by atmospheric deposition and sediment release. The driving weights of these four factors are 57.2%, 26.5%, 9.3%, and 7.0%, respectively. However, the impact on lake water quality of external water quality, aquatic ecosystem structure, precipitation distribution, and meteorological conditions, which are attributed to the disparities in geographical situation, varied significantly with seasons and locations.

2021 ◽  
Vol 13 (9) ◽  
pp. 1683
Author(s):  
Nandini Menon ◽  
Grinson George ◽  
Rajamohananpillai Ranith ◽  
Velakandy Sajin ◽  
Shreya Murali ◽  
...  

Turbidity and water colour are two easily measurable properties used to monitor pollution. Here, we highlight the utility of a low-cost device—3D printed, hand-held Mini Secchi disk (3DMSD) with Forel-Ule (FU) colour scale sticker on its outer casing—in combination with a mobile phone application (‘TurbAqua’) that was provided to laymen for assessing the water quality of a shallow lake region after demolition of four high-rise buildings on the shores of the lake. The demolition of the buildings in January 2020 on the banks of a tropical estuary—Vembanad Lake (a Ramsar site) in southern India—for violation of Indian Coastal Regulation Zone norms created public uproar, owing to the consequences of subsequent air and water pollution. Measurements of Secchi depth and water colour using the 3DMSD along with measurements of other important water quality variables such as temperature, salinity, pH, and dissolved oxygen (DO) using portable instruments were taken for a duration of five weeks after the demolition to assess the changes in water quality. Paired t-test analyses of variations in water quality variables between the second week of demolition and consecutive weeks up to the fifth week showed that there were significant increases in pH, dissolved oxygen, and Secchi depth over time, i.e., the impact of demolition waste on the Vembanad Lake water quality was found to be relatively short-lived, with water clarity, colour, and DO returning to levels typical of that period of year within 4–5 weeks. With increasing duration after demolition, there was a general decrease in the FU colour index to 17 at most stations, but it did not drop to 15 or below, i.e., towards green or blue colour indicating clearer waters, during the sampling period. There was no significant change in salinity from the second week to the fifth week after demolition, suggesting little influence of other factors (e.g., precipitation or changes in tidal currents) on the inferred impact of demolition waste. Comparison with pre-demolition conditions in the previous year (2019) showed that the relative changes in DO, Secchi depth, and pH were very high in 2020, clearly depicting the impact of demolition waste on the water quality of the lake. Match-ups of the turbidity of the water column immediately before and after the demolition using Sentinel 2 data were in good agreement with the in situ data collected. Our study highlights the power of citizen science tools in monitoring lakes and managing water resources and articulates how these activities provide support to Sustainable Development Goal (SDG) targets on Health (Goal 3), Water quality (Goal 6), and Life under the water (Goal 14).


Author(s):  
Moh Sholichin ◽  
Tri Budi Prayogo

Lake Tondano is the largest natural lake in North Sulawesi, Indonesia, which functions as a provider of clean water, hydroelectric power, rice field irrigation, inland fisheries, and tourism. This research aims to determine the effect of land cover types from the Tondano watershed on the lake water quality. The Soil and Water Assessment Tool (SWAT) model was used to evaluate the rate of soil erosion and the pollutant load of various land types in the watershed during the last ten years. Rainfall data is obtained from two rainfall stations, namely Paleloan Station and Noonan Station. The model is calibrated and validated before being used for analysis. We use climatological data from 2014 to 2019. The process of the SWAT model calibration and validation was carried out with the statistical formulas of the coefficient of determination (R2) and Nash-Sutcliffe efficiency (NSE). The results show that the potential for pollution load from the Tondao watershed is organic N of 0.039 kg/ha and organic P of 0.006 kg/ha coming from the agricultural land. The results of this study conclude that the fertility conditions of Lake Tondano are at the eutrophic level, where the pollutant inflow is collected in the lake waters, especially for the parameters of total N (1503697.44kg/year) and total P (144831.36kg/year). The SWAT simulation results show deviation between the modeling and field data collected with the value of R2 = 0.9303, and the significant level ≤ 10.


Diversity ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 296
Author(s):  
Haiming Qin ◽  
Xinyi Cao ◽  
Lanyue Cui ◽  
Qian Lv ◽  
Tingtao Chen

The Poyang water system in Jiangxi Province, China, is important for floodwater storage, diversity maintenance, and the economy of the Poyang Lake watershed. In recent years, pollution has destroyed the ecosystem and impacted human health and the related economy. The water quality of the Poyang Lake watershed and the impact of human interference must be assessed. Conventional analysis and high-throughput sequencing were used to evaluate the structure of both zooplankton and fungi in six sub-lakes of the Poyang Lake watershed under different anthropogenic influences. The sub-lakes included were Dahuchi Lake (in natural preserve, DHC), Shahu Lake (in natural reserve, SH), Nanhu Lake (out of natural preserve, NH), Zhelinhu Lake (artificial reservoir, ZLH), Sixiahu Lake (agricultural lake artificially isolated from Poyang Lake, SXH), and Qianhu Lake (urban lake, QH). The densities and biomass of the zooplankton in DHC, SH, NH were higher compared with those in SXH, ZLH and QH (p < 0.05). Zooplankton distribution of SXH was the most strongly associated with total nitrogen (TN), total phosphorus (TP) and chlorophyll a (Chl a), while QH was highly associated with pH, conductivity (Cond), and water temperature (WT). For fungal diversity, a large number of beneficial fungi, Basidiomycota (phylum level) and Massarina (genus level) were obtained from DHC (55.3% and 27.5%, respectively), SH (54.4% and 28.9%, respectively), and NH (48.6% and 1.4%, respectively), while a large number of pathogenic Chytridiomycota (at phylum level) were identified from SXH (21.0%), ZLH (5.5%), and QH (7.5%). Manmade pollutants have impacted the natural hydrology and water quality and promoted variation between the zooplankton and fungi in the six sub-lakes, reducing the relative abundance of beneficial fungi and increasing the number of pathogens in the environment, which threatens human health and economic production. Understanding the diversity among the zooplankton and fungi in the six sub-lakes of the Poyang Lake watershed may help guide future water management practices.


Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 946 ◽  
Author(s):  
Talita F. G. Silva ◽  
Brigitte Vinçon-Leite ◽  
Bruno J. Lemaire ◽  
Guido Petrucci ◽  
Alessandra Giani ◽  
...  

Worldwide, eutrophication and cyanobacteria blooms in lakes and reservoirs are a great concern for water resources management. Coupling a catchment hydrological model and a lake model has been a strategy to assess the impact of land use, agricultural practices and climate change on water quality. However, research has mainly focused on large lakes, while urban reservoirs and their catchments, especially in tropical regions, are still poorly studied despite the wide range of ecosystem services they provide. An integrated modelling approach coupling the hydrological model Storm Water Management Model SWMM and the lake ecological model DYRESM-CAEDYM is proposed for Lake Pampulha (Brazil). Scenarios of increased imperviousness of the catchment and of reduction in the load of nutrients and total suspended solids (TSS) in dry weather inflow were simulated. Runoff water quality simulations presented a fair performance for TSS and ammonium (NH4+) while the dynamics of total phosphorus (TP) and nitrate (NO3−) were poorly captured. Phytoplankton dynamics in the lake were simulated with good accuracy (Normalized Mean Absolute Error, NMAE = 0.24 and r = 0.89 in calibration period; NMAE = 0.55 and r = 0.54 in validation period). The general trends of growth, decline and the magnitude of phytoplankton biomass were well represented most of the time. Scenario simulations suggest that TP reduction will decrease cyanobacteria biomass and delay its peaks as a consequence of orthophosphate (PO43−) concentration reduction in the lake surface layers. However, even decreasing TP load into Lake Pampulha by half would not be sufficient to achieve the water quality objective of a maximum concentration of 60 µg chla L−1. Increased imperviousness in the catchment will raise runoff volume, TSS, TP and NO3− loads into Lake Pampulha and promote greater cyanobacteria biomass, mainly in the beginning of the wet season, because of additional nutrient input from catchment runoff. Recovering Lake Pampulha water quality will require the improvement of the sanitation system. The lake water quality improvement will also require more sustainable and nature-based solutions for urban drainage in order to reduce non-point pollution through infiltration and retention of stormwater and to enhance natural processes, such as chemical sorption, biodegradation and phytoremediation. The integrated modelling approach here proposed can be applied for other urban reservoirs taking advantage of existing knowledge on Lake Pampulha.


2017 ◽  
Vol 18 (1) ◽  
pp. 299-305
Author(s):  
Hongbin Gao ◽  
Changyou Li ◽  
Biao Sun

Abstract In order to investigate the historical water quality state and identify the factors causing modern environmental degradation in a prairie lake, total organic carbon (TOC), total nitrogen (TN), stable carbon isotopes of organic matter and total phosphorus (TP) from lake sedimentary core with high resolution age frame were analyzed. The results show that the values of proxies (TOC, TN, TP, δ13C, C/N) increased significantly after 2000 compared with before, which indicates Lake Hulun has heightened nutrient level and pollution extent, thus induced growth of algal bloom and water quality deteriorated after 2000. Since the event of decreased river discharge and lowered water level began in 2000 corresponds extremely well with our sedimentary records that nutrients pollution and eutrophication occurred in Lake Hulun at the same moment, the change of river discharge can be seen as the primary and direct reason of lake water quality deterioration in this period. In addition, the increased wind and water erosion as a result of serious and widespread destruction of grassland in Lake Hulun basin is the potential factors for changing the nutrients concentration in Lake Hulun.


In order to protect the quality of the environment and human health, freshwater assets are tremendously important in various ways. To ensure the freshwater resources in the Chittagong region of Bangladesh, we have studied the water quality parameters of Kaptai and Foy’s Lake. This research has done based on the essential surface water standard parameters such as pH, temperature, DO, BOD, COD, TDS, TSS, TS, EC, hardness, turbidity, salinity, total alkalinity, total acidity, SO42-, PO43-, NO3--N, NO2-, CO2, and most of the heavy and toxic metals (As, Cd, Cr, Cu, Co, Fe, Pb, Mn, Ni, and Zn) of two lakes namely Foy’s (Chittagong) and Kaptai (Rangamati) Lakes in Chittagong , Bangladesh. The statistical approaches to sampling were utilized for collecting samples. The samples were assembled from ten different locations of each lake. Samples were conserved using a satisfactory preservation procedure. Water samples from the surface-water assets were collected from various locations, and tide conditions and at various seasons for continual monitoring during the hydrological years 2014-2015. The results showed that Kaptai Lake and Foy’s Lake all physicochemical parameters are within the permissible limit of WHO guidelines. The results also supplied data to view, and quantify the enemy of the impact of climate alter on freshwater resources of this region. The outcomes further showed data for water quality of surface-water resources of greater Chittagong zone to match national and international quality for drinking, agricultural, manufacture and livestock requirements. A strategic water quality management plan has been proposed.


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Heru Dwi Wahjono

Semayang Lake and Melintang Lake in Kutai Kartanegara district, East Kalimantan is one of the biggest lake in Indonesia. Both lakes are located in the Mahakam River Basin and has an important role for economic and ecological activities in the Province of East Kalimantan. In addition to being a source of livelihood for fishermen around the lake, is also as habitat for freshwater mammals Pesut Mahakam that are endangered. Illegal logging in the forest around the lake, causing floods when it rains and water pollution will increase with sediment flowing into the lake. In some areas also get the impact of transportation activities of coal mining industry around the Mahakam River. All this causes silting almost the entire surface of the lake, lead to a reduction of existing fishery potential and cause extinction of Pesut Mahakam. To control pollution in the lake, local government of Kutai Kartanegara has implemented an online monitoring technology to monitor the water quality of the lake in four point location. Monitoring results are used to support local goverment in taking pollution control policies in both lakes. Keywords: Water quality online monitoring system, lake water quality monitoring system, GSM  and SMS technology, multiprobe sensor, telemtry system.


2015 ◽  
Vol 39 (1) ◽  
pp. 6-28 ◽  
Author(s):  
Glenn Watts ◽  
Richard W. Battarbee ◽  
John P. Bloomfield ◽  
Jill Crossman ◽  
Andre Daccache ◽  
...  

Climate change is expected to modify rainfall, temperature and catchment hydrological responses across the world, and adapting to these water-related changes is a pressing challenge. This paper reviews the impact of anthropogenic climate change on water in the UK and looks at projections of future change. The natural variability of the UK climate makes change hard to detect; only historical increases in air temperature can be attributed to anthropogenic climate forcing, but over the last 50 years more winter rainfall has been falling in intense events. Future changes in rainfall and evapotranspiration could lead to changed flow regimes and impacts on water quality, aquatic ecosystems and water availability. Summer flows may decrease on average, but floods may become larger and more frequent. River and lake water quality may decline as a result of higher water temperatures, lower river flows and increased algal blooms in summer, and because of higher flows in the winter. In communicating this important work, researchers should pay particular attention to explaining confidence and uncertainty clearly. Much of the relevant research is either global or highly localized: decision-makers would benefit from more studies that address water and climate change at a spatial and temporal scale appropriate for the decisions they make.


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