LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 6 of total 6

Search options

  1. Article ; Online: A novel framework for turbidity source apportionment of the urban lakeside river network

    Renhua Yan / Jing Yao / Feng Tian / Junfeng Gao

    Ecological Indicators, Vol 154, Iss , Pp 110561- (2023)

    2023  

    Abstract: Turbidity source apportionment is essential but complex for precise environmental rehabilitation of worldwide urban lakeside river networks impaired by turbidity. A new turbidity source analysis framework including in-situ sampling, vessel monitoring, ... ...

    Abstract Turbidity source apportionment is essential but complex for precise environmental rehabilitation of worldwide urban lakeside river networks impaired by turbidity. A new turbidity source analysis framework including in-situ sampling, vessel monitoring, remote sensing, and hydrodynamic modelling was proposed, where the critical processes of flow reversal from the turbid lake, navigation, and urban non-point source in urban lakeside river networks were explicitly considered. The case study results showed that the turbidity problem (mean value was 211.3 nephelometric turbidity units (NTU)) was primarily led by suspended inorganic matter (58%), followed by suspended organic matter (19%) and other matter. The Tiaoxi River and busy shipping contributed most to the annual total suspended solids load of the target river, with the same percentage of 34%. The turbid Lake Taihu provided 64,663 tonnes and 31% of the total suspended solids load, focusing on the autumn and winter months. Tiaoxi River load was highly concentrated on the storm events, which accounted for 71.4% of the annual Tiaoxi River source (209846 tonnes). The large water volume of reverse flow and the high TSS concentration of Lake Taihu in the autumn and winter months accounted for the seasonal change in Lake Taihu’s TSS load. The coronavirus disease lockdown reduced the mean monthly total suspended solids concentration of 152.4 mg/L in November and December 2019 to 49.2 mg/L in January and February 2020, by limiting the waterway transportation and the market demand for building materials. The river estuary’s vegetation interception belt, shipping restriction and rerouting, and integrated catchment management were advised to mitigate the urban river network turbidity.
    Keywords Turbidity ; Source analysis ; Lakeside river networks ; Flow reversal ; Shipping ; Ecology ; QH540-549.5
    Subject code 333
    Language English
    Publishing date 2023-10-01T00:00:00Z
    Publisher Elsevier
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Article ; Online: Modeling the hydrological effects of climate and land use/cover changes in Chinese lowland polder using an improved WALRUS model

    Renhua Yan / Junfeng Gao / Lingling Li

    Hydrology Research, Vol 47, Iss S1, Pp 84-

    2016  Volume 101

    Abstract: Hydrological processes in lowland polders, especially those for paddy rice planting, are affected by complicated factors. The improved Wageningen Lowland Runoff Simulator (WALRUS) model incorporates an irrigation and drainage scheme, and a new stage– ... ...

    Abstract Hydrological processes in lowland polders, especially those for paddy rice planting, are affected by complicated factors. The improved Wageningen Lowland Runoff Simulator (WALRUS) model incorporates an irrigation and drainage scheme, and a new stage–discharge relationship to account for hydrological processes in multi-land-use polder with paddy fields and pumping stations. Here, this model was applied to assess how climate and land use changes affected the runoff of a Chinese polder in Poyang Lake basin in the past two decades. Simulated results showed that the runoff in the autumn–winter transition and midsummer months increased significantly, whereas those in the other months decreased slightly during the period of 1996–2005, primarily affected by climate change. For the period of 2006–2014, the runoff in the autumn–winter transition and midsummer increased, while that in the other months declined, affected by both climate and land use/cover changes. The land use/cover change resulting from the conversion of rice–wheat rotation to dominantly double-rice cropping and the expansion of residential area, increased the runoff during this period by demanding more irrigation water from the outside basin.
    Keywords agricultural polder ; climate change ; improved walrus model ; land use/cover change ; modeling ; runoff ; River ; lake ; and water-supply engineering (General) ; TC401-506 ; Physical geography ; GB3-5030
    Subject code 550
    Language English
    Publishing date 2016-12-01T00:00:00Z
    Publisher IWA Publishing
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article: A Phosphorus Dynamic model for lowland Polder systems (PDP)

    Huang, Jiacong / Junfeng Gao / Renhua Yan

    Ecological engineering. 2016 Mar., v. 88

    2016  

    Abstract: Estimating phosphorus export from the lowland polder areas is a critical step for controlling phosphorus loading of a watershed. However, most existing models assumed lowland polder area to be a freely draining catchment, and did not adequately represent ...

    Abstract Estimating phosphorus export from the lowland polder areas is a critical step for controlling phosphorus loading of a watershed. However, most existing models assumed lowland polder area to be a freely draining catchment, and did not adequately represent its phosphorus dynamics. To better estimate the phosphorus sink and source of the polder systems, a process-based Phosphorus Dynamic model for lowland Polder systems (PDP) consisting of six modules was developed to simulate the daily phosphorus exchanges between lowland polder systems and their surrounding rivers. The unique pattern of water and phosphorus dynamics in polder systems (i.e., manual operation of water exchange between the polder and its surrounding rivers and the phosphorus dynamics in the water area) was accounted for in PDP. Based on a dataset collected from Polder Jian located in Lake Taihu Basin, China during 2014, seven sensitive parameters in PDP were identified based on sensitivity analysis, and were optimized using Genetic Algorithm. A k-fold cross-validation method was used to assess model goodness-of-fit, and resulted in an acceptable model with an r2 (coefficient of determination) value of 0.594. The case study in Polder Jian showed the reliability of PDP to estimate the phosphorus source and sink from polder systems. Such estimation is helpful for water managers to identify the phosphorus source, and thus take corresponding measures to control the aquatic eutrophication.
    Keywords algorithms ; basins ; case studies ; data collection ; dynamic models ; eutrophication ; lakes ; phosphorus ; rivers ; watersheds ; China
    Language English
    Dates of publication 2016-03
    Size p. 242-255.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1127407-4
    ISSN 0925-8574
    ISSN 0925-8574
    DOI 10.1016/j.ecoleng.2015.12.033
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 5865: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  4. Article: Methane levels in five shallow lakes in China: Effect of lake paludification

    Li, Lingling / Bin Xue / Longjuan Cheng / Renhua Yan / Shuchun Yao

    Quaternary international. 2018,

    2018  

    Abstract: Understanding methane dynamics in lakes is relevant for assessing the natural source of greenhouse gases. Paludification is one of the most common phenomena of lake degeneration, which would have significant influence on CH4 dynamics. However, the actual ...

    Abstract Understanding methane dynamics in lakes is relevant for assessing the natural source of greenhouse gases. Paludification is one of the most common phenomena of lake degeneration, which would have significant influence on CH4 dynamics. However, the actual variety of CH4 dynamics by lake paludification is not yet clear. We investigated CH4 concentrations and production potentials in five shallow lakes located in the east China. The CH4 concentrations and production potentials were significantly higher (approximately 5–10 times) in the lakes with greater paludification degrees and had no significant difference among other lakes with low and similar paludification indexes. High CH4 levels in the paludificated lakes can be associated with the increase of sediment organic matter content and decrease of water depth due to the accelerated sedimentation and outspread of macrophytes during the lake paludification. Similarly, organic matter supply might be a limitation for CH4 production in the lakes with low paludification degrees. These results indicate that lake paludification is probably a main reason for the significant CH4 differences among the studied lakes. This study draws attention to lakes with paludification tendency when making CH4 emission budgets in shallow lakes.
    Keywords greenhouse gas emissions ; greenhouse gases ; lakes ; macrophytes ; methane ; methane production ; organic matter ; sediments ; China
    Language English
    Size p. .
    Publishing place Elsevier Ltd
    Document type Article
    Note Pre-press version
    ISSN 1040-6182
    DOI 10.1016/j.quaint.2018.08.004
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Article: Spatial–temporal patterns of methane dynamics in Lake Taihu

    Li, Lingling / Bin Xue / Renhua Yan / Shuchun Yao / Yuqiang Tao

    Hydrobiologia. 2018 Oct., v. 822, no. 1

    2018  

    Abstract: Lakes are important source of atmospheric methane (CH4). Especially for large and shallow lakes, accurate CH4 emission budgets must consider the spatial and seasonal heterogeneity which characterize these ecosystems. CH4 concentrations in sediment and ... ...

    Abstract Lakes are important source of atmospheric methane (CH4). Especially for large and shallow lakes, accurate CH4 emission budgets must consider the spatial and seasonal heterogeneity which characterize these ecosystems. CH4 concentrations in sediment and lake water and CH4 fluxes from sediment were analysed in selected open water areas of Lake Taihu, the third largest freshwater lake in China, to test the hypothesis that CH4 concentrations and fluxes differ both spatially and temporally in relation to biological and environmental features. The results showed that Lake Taihu was a source of CH4 throughout the year. The observed CH4 concentrations and fluxes were higher in the north-western and south-eastern areas of the lake, and lower in the central area. This spatial heterogeneity in methane emissions was mainly related to local organic matter content, plant characteristics, deposition rate and sediment features. Seasonally, CH4 showed stronger emissions in summer. These results suggest that the analysis of CH4 dynamics in shallow lakes should consider the habitat heterogeneity and the different sources of organic matter. Furthermore, the CH4 emission budget should at least include high and low temperature periods to decrease temporal bias.
    Keywords ecosystems ; freshwater lakes ; greenhouse gas emissions ; habitats ; methane ; organic matter ; plant characteristics ; sediments ; spatial variation ; summer ; temperature ; China
    Language English
    Dates of publication 2018-10
    Size p. 143-156.
    Publishing place Springer International Publishing
    Document type Article
    ZDB-ID 214428-1
    ISSN 1573-5117 ; 0018-8158
    ISSN (online) 1573-5117
    ISSN 0018-8158
    DOI 10.1007/s10750-018-3670-4
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 73/704: Show issues
    Einzelsign.: Show issues
    4' 96/5026: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Article: Modeling the impacts of water transfer on water transport pattern in Lake Chao, China

    Huang, Jiacong / Junfeng Gao / Lingyan Qi / Renhua Yan / Zhiming Zhang

    Ecological engineering. 2016 Oct., v. 95

    2016  

    Abstract: Water transport pattern plays an important role in determining water and pollution transport, and is worth our investigation. In this study, a hydrological model (Xinanjiang) and a hydrodynamic model (Environmental Fluid Dynamics Code, EFDC) were coupled ...

    Abstract Water transport pattern plays an important role in determining water and pollution transport, and is worth our investigation. In this study, a hydrological model (Xinanjiang) and a hydrodynamic model (Environmental Fluid Dynamics Code, EFDC) were coupled to investigate the impacts of a water transfer project on the water transport pattern of Lake Chao, China. The Xinanjiang model simulated the inflow discharges for the EFDC model. The validation results were acceptable with a Nash–Sutcliffe coefficient of 0.74 and 0.84 for the Xinanjiang and EFDC models. Based on the calibrated models, four simulations were implemented and compared to evaluate the impacts of the water transfer project on the water transport pattern, described by water age and residence time. The simulation results revealed that the water transfer project had the potential to shorten water age and residence time of the lake, however, should be carried out by considering the influences of wind conditions and water transfer route. This study demonstrated a successful adaption of water age and residence time for describing water transport pattern, and highlighted the importance of model coupling approach in addressing multidisciplinary questions from the complex natural ecosystem.
    Keywords ecosystems ; hydrodynamics ; hydrologic models ; lakes ; water pollution ; wind ; China
    Language English
    Dates of publication 2016-10
    Size p. 271-279.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1127407-4
    ISSN 0925-8574
    ISSN 0925-8574
    DOI 10.1016/j.ecoleng.2016.06.074
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 5865: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top