scholarly journals Reference and current Trophic Level Index of New Zealand lakes: benchmarks to inform lake management and assessment

2020 ◽  
Vol 54 (4) ◽  
pp. 636-657
Author(s):  
Jonathan M. Abell ◽  
Paul van Dam-Bates ◽  
Deniz Özkundakci ◽  
David P. Hamilton
Keyword(s):  
New Zealand ◽  
Trophic Level ◽  
Lake Management ◽  
Trophic Level Index

Comparative Assessment of Water Quality with the Trophic Level Index and the Delphi Method in Lakes Rotoiti and Rotorua, New Zealand

2010 ◽  
Vol 45 (4) ◽  
pp. 479-489 ◽  
Author(s):  
David Hamilton ◽  
Arkadi Parparov
Keyword(s):  
Water Quality ◽  
New Zealand ◽  
Water Resources ◽  
Water Resources Management ◽  
Trophic Level ◽  
Delphi Method ◽  
Economic Activities ◽  
Lake Ecosystems ◽  
Resources Management ◽  
Trophic Level Index

Abstract We describe a case study involving the application of a water quality (WQ) assessment for Lakes Rotorua and Rotoiti, New Zealand. Our major objective was to compare an established water quality system based on a trophic level index (TLI) against an alternative Delphi method (DM) which uses an assembled expert panel including specialists in limnology and water resources management. The set of water quality indices (WQI) established with DM captures the major uses of water resources of the studied lake ecosystems: conservation and recreation. The set of permissible ranges for individual WQIs assessed with DM allows a “reference state” to be defined for WQ in the study lakes. The TLI and DM were closely correlated when eutrophication was the overarching issue, but much less so when resources and uses of the lake ecosystems were taken into consideration. Water resources management based around the TLI is commonly targeted at oligotrophication of aquatic ecosystems to improve WQ, often in association with reducing economic activities in watersheds. In contrast, the DM allows a more complete assessment that aligns with sustainable management of natural water resources but also includes the need for conservation.

scholarly journals Late Holocene Sediment Deposition in Lake Wairarapa

2021 ◽  
Author(s):  
◽  
Martha Ingrid Trodahl
Keyword(s):  
New Zealand ◽  
Morphological Changes ◽  
Regional Scale ◽  
Hydrological Regime ◽  
Lake Management ◽  
Anthropogenic Influence ◽  
Eastern Shore ◽  
Ecological Value ◽  
The North ◽  
Development Scheme

<p>Lake Wairarapa is a highly modified lacustrine system at the southern end of the North Island, New Zealand. Not only is it situated in a region that is affected by catchment altering natural phenomena such as earthquakes, storms and fire, but both the catchment and hydrology of the lake have also been significantly altered by humans. Polynesian settlers arrived in the area approximately 700BP and proceeded to deforest the lowlands. European settlers began arriving from 1844AD onwards, completing deforestation of the lowlands and Eastern Uplands. In 1964 the Lower Wairarapa Valley Development Scheme was commissioned in an effort to alleviate flooding. This scheme significantly altered the hydrological regime of the lake. Interest in the condition of the lake and associated wetlands, and the realization that it has important recreational, cultural and ecological value, began to develop in the 1990's. This has led to a desire to see the lake restored to a more natural condition while still maintaining its flood protection capabilities. However, the lake has only been monitored over the last several decades. Any evidence of the lakes condition prior to this time is anecdotal and little is known of its natural tendencies and functions. This research has investigated and quantified morphological changes to Lake Wairarapa at the decadal and millenial scale using a combination of aerial photograph analysis, bathymetric survey comparison and lakebed core analysis. Study at these diverse scales has allowed the observed changes to be related to human environmental modification, while also being juxtaposed against natural trajectories of change. It is hoped that this can inform lake management and restoration efforts and provide a benchmark for measuring future changes to the lake, while also addressing wider issues concerning natural versus anthropogenic landscape change at the local and regional scale. The results of this project suggest that the lake has been steadily infilling over the last 6000BP – particularly along the eastern shore. For the two decades after significant hydrological changes to the lake associated with the Lower Wairarapa Valley Development Scheme, the rate of infilling on the eastern shore increased more than tenfold. However, this was accompanied by deepening in other parts of the lake. Today infilling along the eastern shore appears to have returned to natural rates and overall the lake in 2010 is only slightly smaller in volume than in 1975. Longer term anthropogenic influence on the lake and catchment was also evident. In particular Polynesian settlement and subsequent deforestation by fire was apparent in the lakebed cores. This result not only addresses the immediate issue of anthropogenic influence on this particular lacustrine system, but also informs the debate surrounding the dating of Polynesian arrival in New Zealand.</p>

scholarly journals Status of water quality and level of trophic in Juanda Reservoir of Purwakarta Regency, West Java, Indonesia

2021 ◽  
Vol 322 ◽  
pp. 01016
Author(s):  
Iis Jubaedah ◽  
Pigoselpi Anas ◽  
Toni Ruchimat ◽  
Joni Haryadi
Keyword(s):  
Water Quality ◽  
Trophic Level ◽  
Trophic Status ◽  
Class Ii ◽  
Class Iii ◽  
West Java ◽  
Water Quality Status ◽  
Secondary Function ◽  
Quality Status ◽  
Trophic Level Index

Juanda reservoir is one of the reservoirs located in Purwakarta Regency, West Java Province, Indonesia, whose primary function is hydropower, water resources for irrigation, industrial and drinking water, and secondary function for fisheries and tourism activities. Currently, an increase in activities around the existing reservoir has affected its water quality. In order to determine the water quality and trophic level status of the Juanda reservoir, research has been conducted within five stations during the period of August-December 2020. The water quality status includes physical, chemical, and biological parameters that compared with Store standards on Class II and III. Meanwhile, the trophic status was determined by Trophic Level Index (TLI) based on the parameters of transparency, chlorophyll-a, total nitrogen, and total phosphorus. The results show that the water quality status of Juanda reservoir has been contaminated Class III and heavily polluted Class II. The parameters that exceed include ammonia, nitrate, and BOD5. The Juanda reservoir's tropic status was in the eutrophic category, with TLI values ranging from 4.6 to 5.2.

scholarly journals Late Holocene Sediment Deposition in Lake Wairarapa

2021 ◽  
Author(s):  
◽  
Martha Ingrid Trodahl
Keyword(s):  
New Zealand ◽  
Morphological Changes ◽  
Regional Scale ◽  
Hydrological Regime ◽  
Lake Management ◽  
Anthropogenic Influence ◽  
Eastern Shore ◽  
Ecological Value ◽  
The North ◽  
Development Scheme

<p>Lake Wairarapa is a highly modified lacustrine system at the southern end of the North Island, New Zealand. Not only is it situated in a region that is affected by catchment altering natural phenomena such as earthquakes, storms and fire, but both the catchment and hydrology of the lake have also been significantly altered by humans. Polynesian settlers arrived in the area approximately 700BP and proceeded to deforest the lowlands. European settlers began arriving from 1844AD onwards, completing deforestation of the lowlands and Eastern Uplands. In 1964 the Lower Wairarapa Valley Development Scheme was commissioned in an effort to alleviate flooding. This scheme significantly altered the hydrological regime of the lake. Interest in the condition of the lake and associated wetlands, and the realization that it has important recreational, cultural and ecological value, began to develop in the 1990's. This has led to a desire to see the lake restored to a more natural condition while still maintaining its flood protection capabilities. However, the lake has only been monitored over the last several decades. Any evidence of the lakes condition prior to this time is anecdotal and little is known of its natural tendencies and functions. This research has investigated and quantified morphological changes to Lake Wairarapa at the decadal and millenial scale using a combination of aerial photograph analysis, bathymetric survey comparison and lakebed core analysis. Study at these diverse scales has allowed the observed changes to be related to human environmental modification, while also being juxtaposed against natural trajectories of change. It is hoped that this can inform lake management and restoration efforts and provide a benchmark for measuring future changes to the lake, while also addressing wider issues concerning natural versus anthropogenic landscape change at the local and regional scale. The results of this project suggest that the lake has been steadily infilling over the last 6000BP – particularly along the eastern shore. For the two decades after significant hydrological changes to the lake associated with the Lower Wairarapa Valley Development Scheme, the rate of infilling on the eastern shore increased more than tenfold. However, this was accompanied by deepening in other parts of the lake. Today infilling along the eastern shore appears to have returned to natural rates and overall the lake in 2010 is only slightly smaller in volume than in 1975. Longer term anthropogenic influence on the lake and catchment was also evident. In particular Polynesian settlement and subsequent deforestation by fire was apparent in the lakebed cores. This result not only addresses the immediate issue of anthropogenic influence on this particular lacustrine system, but also informs the debate surrounding the dating of Polynesian arrival in New Zealand.</p>

scholarly journals Retrieving the Lake Trophic Level Index with Landsat-8 Image by Atmospheric Parameter and RBF: A Case Study of Lakes in Wuhan, China

2019 ◽  
Vol 11 (4) ◽  
pp. 457 ◽  
Author(s):  
Yadong Zhou ◽  
Baoyin He ◽  
Fei Xiao ◽  
Qi Feng ◽  
Jiefeng Kou ◽  
...  
Keyword(s):  
Trophic Level ◽  
Mean Squared Error ◽  
Rbf Neural Network ◽  
Atmospheric Correction ◽  
Atmospheric Parameter ◽  
Physical Parameters ◽  
Landsat 8 ◽  
Band Ratios ◽  
Model C ◽  
Trophic Level Index

The importance of atmospheric correction is pronounced for retrieving physical parameters in aquatic systems. To improve the retrieval accuracy of trophic level index (TLI), we built eight models with 43 samples in Wuhan and proposed an improved method by taking atmospheric water vapor (AWV) information and Landsat-8 (L8) remote sensing image into the input layer of radical basis function (RBF) neural network. All image information taken in RBF have been radiometrically calibrated. Except model(a), image data used in the other seven models were not atmospherically corrected. The eight models have different inputs and the same output (TLI). The models are as follows: (1) model(a), the inputs are seven single bands; (2) model(c), besides seven single bands (b1, b2, b3, b4, b5, b6, b7), we added the AWV parameter k1 to the inputs; (3) model(c1), the inputs are AWV difference coefficient k2 and the seven bands; (4) model(c2), the input layers include seven single bands, k1 and k2; (5) model(b), seven band ratios (b3/b5, b1/b2, b3/b7, b2/b5, b2/b7, b3/b6, and b3/b4) were used as input parameters; (6) model(b1), the inputs are k1 and seven band ratios; (7) model(b2), the inputs are k2 and seven band ratios; (8) model(b3), the inputs are k1, k2, and seven band ratios. We estimated models with root mean squared error (RMSE), model(a) > model(b3) > model(b1) > model(c2) > model(c) > model(b) > model(c1) > model(b2). RMSE of the eight models are 12.762, 11.274, 10.577, 8.904, 8.361, 6.396, 5.389, and 5.104, respectively. Model b2 and c1 are two best models in these experiments, which confirms both the seven single bands and band ratios with k2 are superior to other models. Results also corroborate that most lakes in Wuhan urban area are in mesotrophic and light eutrophic states.

Phytoplankton-based recovery requirement for urban lakes in the implementation of the Water Framework Directive’s ecological targets

2015 ◽  
Vol 44 (1) ◽  
Author(s):  
Agnieszka Napiórkowska-Krzebietke ◽  
Julita Dunalska
Keyword(s):  
Trophic Level ◽  
Trophic State ◽  
Phytoplankton Bloom ◽  
Ecological Status ◽  
Phytoplankton Assemblages ◽  
Urban Lakes ◽  
Ecological Targets ◽  
Good Ecological Status ◽  
Trophic Level Index

AbstractThis study focused on the determination of the phytoplankton-based recovery requirement, including bloom intensity thresholds in human-affected lakes, helpful in the restoration. The phytoplankton and physicochemical analyses were carried out on seven urban lakes in Kartuzy and Skępe. The Phytoplankton Metric for Polish Lakes was used to assess the ecological status and the Trophic Level Index was used to determine the trophic state. Only one lake had a good ecological status (meeting the WFD requirements for at least good status), whereas other lakes had poor or bad ecological status. All of them were eutrophic or hyper-eutrophic and the summer phytoplankton assemblages were dominated mainly by bloomforming cyanobacteria. The lowest phytoplankton bloom threshold of 2.6 mm

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