Details

Autor(en) / Beteiligte

• Fink, Gabriel
• Alcamo, Joseph
• Flörke, Martina
• Reder, Klara

Titel

Phosphorus Loadings to the World's Largest Lakes: Sources and Trends

Ist Teil von

• Global biogeochemical cycles, 2018-04, Vol.32 (4), p.617-634

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2018

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Eutrophication is a major water quality issue in lakes worldwide and is principally caused by the loadings of phosphorus from catchment areas. It follows that to develop strategies to mitigate eutrophication, we must have a good understanding of the amount, sources, and trends of phosphorus pollution. This paper provides the first consistent and harmonious estimates of current phosphorus loadings to the world's largest 100 lakes, along with the sources of these loadings and their trends. These estimates provide a perspective on the extent of lake eutrophication worldwide, as well as potential input to the evaluation and management of eutrophication in these lakes. We take a modeling approach and apply the WorldQual model for these estimates. The advantage of this approach is that it allows us to fill in large gaps in observational data. From the analysis, we find that about 66 of the 100 lakes are located in developing countries and their catchments have a much larger average phosphorus yield than the lake catchments in developed countries (11.1 versus 0.7 kg TP km−2 year−1). Second, the main source of phosphorus to the examined lakes is inorganic fertilizer (47% of total). Third, between 2005–2010 and 1990–1994, phosphorus pollution increased at 50 out of 100 lakes. Sixty percent of lakes with increasing pollution are in developing countries. P pollution changed primarily due to changing P fertilizer use. In conclusion, we show that the risk of P‐stimulated eutrophication is higher in developing countries. Key Points Phosphorus loadings to lakes are a major cause of lake eutrophication, yet there are few estimates of the extent of these loadings, including for the world's largest lakes TP loadings to large lakes in developing countries are on the average much larger than to lakes in developed countries The most important source of TP loadings is inorganic fertilizer; the second most important are “background” loadings from atmospheric deposition and catchment weathering of P