Global thermal pollution of rivers from thermoelectric power plants

Abstract

Worldwide riverine thermal pollution patterns were investigated by combining mean annual heat rejection rates from power plants with once-through cooling systems with the global hydrologicalwater temperature model variable infiltration capacity (VIC)-RBM. The model simulates both streamflow and water temperature on 0.5°×0.5°spatial resolution worldwide and by capturing their effect, identifies multiple thermal pollution hotspots. The Mississippi receives the highest total amount of heat emissions (62% and 28% of which come from coal-fuelled and nuclear power plants, respectively) and presents the highest number of instances where the commonly set 3°C temperature increase limit is equalled or exceeded. The Rhine receives 20% of the thermal emissions compared to the Mississippi (predominantly due to nuclear power plants), but is the thermally most polluted basin in relation to the total flow per watershed, with one third of its total flow experiencing a temperature increase 5°C on average over the year. In other smaller basins in Europe, such as the Weser and the Po, the share of the total streamflow with a temperature increase 3°C goes up to 49% and 81%, respectively, during July-September. As the first global analysis of its kind, this work points towards areas of high riverine thermal pollution, where temporally finer thermal emission data could be coupled with a spatially finer model to better investigate water temperature increase and its effect on aquatic ecosystems.

Hydrothermal mode of the flow­through reservoir­cooler with respect to its morphometric changes

“…In this case, an acceptable increase in the natural water temperature is not higher than 3 о С. In most countries, a technogenic increase in water temperature from the natural level is also limited to 3.0 о С, but in industrial regions this indicator reaches ş5.0 о С [4,5]. However, these comparisons are given for autumn and spring seasons and there are no conclusions about a negative impact of a heat load on flora and fauna over the mentioned seasons.…”

“…RC water area, to which warm water goes through mentioned channel, is shallow water. However, in the near zone (from the water discharge), the most intense cooling of circulating water occurs at [3][4] o С (≈50 % Δt). In addition, it helps to mix colder river water.…”

Thermal pollution impacts on rivers and power supply in the Mississippi River watershed

“…In addition, OTbased plants rely on sufficiently cool river temperatures to maintain optimal thermal efficiency [13,14]. Previous electricity generation vulnerability studies have concentrated on climate and water resource change impacts, while thermal pollution assessments have had a unitary focus on determining the temperature rise on receiving waters [5,[15][16][17][18][19][20][21][22]. In regions where power plants are closely populated along rivers, thermal pollution from upstream plants may cause plant-toplant thermal interference and increase condenser inlet temperatures at downstream OT-based plants, potentially lowering thermal efficiencies and triggering CWA curtailments [23].…”

“…The importance of incorporating higher spatial and temporal resolutions to reliably assess thermal pollution is also yet to be addressed. Thermal pollution and electricity generation vulnerability assessments across large domains are typically executed at a 0.5 • spatial resolution, although few have used higher resolutions (0.05 • , 0.125 • ) [5,16,17,20,21,[24][25][26]. Studies that use coarse spatial resolutions may misgauge the extent of thermal pollution as it forces placement of multiple plants inside a single grid cell and fails to capture finer-scale variations in river discharge, temperatures and thermal equilibration rates.…”

On the occurrence of three non-native cichlid species including the first record of a feral population ofPelmatolapia(Tilapia)mariae(Boulenger, 1899) in Europe

“…show water temperatures above the normal range [1]. In addition to sites that receive warm water by geothermal sources (e.g.…”