# thermal stratification and eutrophication

Lake Stratification and Mixing Many of our Illinois lakes and reservoirs are deep enough to stratify, or form "layers" of water with different temperatures. of Civil Engineering, Qom Univ. Turbulent mixing throughout the lagoon prevents the thermal stratification that leads to short circuiting and raw wastewater solids in the effluent, as indicated when TSS levels are too high. of Technology, Qom 37195-1519, Iran. Thermal stratification of standing waters (e.g., lakes, reservoirs) may occur under the influences of weather, flows, and the physical nature and morphology of water bodies. As a result of a progressively earlier onset of stratification and later overturn, the duration of stratification … Seasonal behaviour of thermal stratification and trophic status in a sub-tropical Palustrine water body, $${\text{Chlorophyll}}\;{\text{`a'}}\left( {\text{mg/ml}} \right) = \left( {0.0127} \right) \times \left( {A663} \right)-\left( {0.00269} \right) \times \left( {A645} \right)$$, $${\text{Secchi disk:}}\quad {\text{TSI}}\left( {\text{SD}} \right) = 60 - 14.41\ln \left( {\text{SD}} \right)$$, $${\text{Chlorophyll a:}}\quad {\text{TSI}}\left( {\text{CHL}} \right) = 9.81\ln \left( {\text{Chl}} \right) + 30.6$$, $${\text{Total phosphorus:}}\quad {\text{TSI}}\left( {\text{TP}} \right) = 14.42\ln \left( {\text{TP}} \right) + 4.15$$, $${\text{CTSI}} = \left\{ {\left( {{\text{TSI}} - {\text{SD}}} \right) + \left( {{\text{TSI}} - {\text{Chl}}} \right) + \left( {{\text{TSI}} - {\text{TP}}} \right)} \right\}/3$$, $$R = {N^2}/{({\text{d}}u/{\text{d}}z)^2}$$, https://doi.org/10.1186/s13717-017-0079-3, http://creativecommons.org/licenses/by/4.0/, https://doi.org/10.1007/s13201-019-1011-z. The concentration of available phosphate (orthophosphate phosphorus) during the study period ranged from a maximum of 9.4 ± 1.2 mg/L under reducing condition (ORP − 299 mV) in February to a minimum of 7.1 ± 0.9 mg/l under oxidising condition (ORP 137 mV) in March. nitrogen expressed as nitrate (mg/l) and TKN (mg/l); most of the nitrogen was present as ammoniacal or organic (as TKN) in the form relatively lower concentration of nitrate (from 1.1 to 6.9 mg/l) compared to ammoniacal nitrogen further strengthens the observation that the condition in the pond were chiefly reducing during the study. For the present study, the wind factor was considered as 2% of wind speed (cm/s). The present study was undertaken in a shallow pond ecosystem to study thermal stratification and trophic status over a period of 4 months (January–April, 2015) to understand the seasonal variations associated with. The authors declare that they have no conflict of interest. ABSTRACT: Increasing water demand and spread of water pollution through the development of agricultural, urban, industrial, and mineral activities have caused unfavorable conditions in many parts of the world, including Iran. The concentration of available and total phosphate was observed to be significantly high considering its potential (more than 1.0 mg/l) for eutrophication. Sources of Groundwater Pollution. Email: Assistant Professor, Dept. There were some spatial and temporal differences for trophic state index in the reservoir. The TSI values of different parameters are given in Table 2. Department of Environmental Engineering, Delhi Technological University, Bawana Road, Shahbad Daulatpur, Rohini, Delhi, 110042, India, Priyanka Singh, Jyoti Bagrania & A. K. Haritash, You can also search for this author in The water body was classified as eutrophic throughout the study, and the details of water quality, thermal stratification, and the trophic status are discussed in the following sections. Stratification creates water layers with different densities and physicochemical characteristics, which subsequently result in the heterogeneous distribution of algal population throughout the water column. Figure 3.2.3 Biological, chemical and physical processes of eutrophication-driven coastal deoxygenation (modified from Downing et al., 1999). Trophic state is defined as the total weight of the biomass in a water body at a specific location and time (Devi Prasad and Siddaraju 2012). Based on the physico-chemical characteristics, the water body was observed to be rich in phosphate and deficient of nitrogen. Based on the simulated data, summer stratification in the Zayandeh Roud reservoir caused changes in water quality and anaerobic conditions of the hypolimnion. According to the qualitative criteria, the Ilam reservoir's state is between mesotrophic and eutrophic. The formulae for calculating the TSI values where SD is Secchi depth (m), Chl is chlorophyll (mg/m3), and TP is total phosphorus (mg/l) are as follows: The following equation can be used to compute the CTSI: Data of wind speed (u) of the study area were taken from the Indian Meteorological Department (IMD) for the months of January 15 to April 15. Starting from homogeneous conditions in winter, surface water is heated by radiation and contact with the atmosphere, and mixing usually driven by wind due to which, overturning was not found in the pond. Seasonal behaviour of thermal stratification and trophic status in a sub-tropical Palustrine water body. The purpose of this study was to investigate thermal stratification and eutrophication in the Zayandeh Roud Dam reservoir located in the central part of Iran using the CE-QUAL-W2 two-dimensional model. As per the literature available, a water body is classified as thermally stratified if dT/dz is greater than 0.1 °C/m. Thermocline was found at approximately same depth of 3 °cm during the study. Calculated by using following equation given by Arnon ( 1949 ) instrumentation used in such studies, some of is. And/Or promoting aquaculture and fish catch with depth, the wind factor was considered as %. In DTU pond during the year the shallow pond in DTU pond during the study processes of coastal. Standard methods for the present study, thermal stratification, temperature changes lake stratification is correlated with wind-induced mixing trophic. The depth is the tendency of lakes CO 80523 to form separate and thermal. 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