Nutrient transport and exchange between the Mekong River and Tonle Sap Lake in Cambodia

The Mekong River in Asia is one of the world's longest rivers. Although it has some highest levels biodiversity and productivity Asia, water quality basin recently deteriorated as a consequence land use changes, dam reservoir construction, population growth, climate change. For first time, this study estimates interannual monthly variabilities nutrient fluxes (nitrate - NO3−) total phosphorus TP) lower Tonle Sap Cambodia, assesses linkage between them. Long-term monitoring data were obtained from Kratie station (in upper reach River), Chroy Changva (just upstream River–Tonle confluence), Prek Kdam (on ~40 km confluence 70 downstream Lake). From 1995 to 2017, estimated flux NO3− was 364 ± 45 kt/y at 557 109 Changva. 2005 TP 100 16 73 19 Considerable seasonal differences observed both River, with 80–90% annual occurring May October. results exchange budget indicated that into Lake ~ 35.8 12.5 8.7 3.3 kt/y, respectively, while these 34.0 13.8 6.6 1.4 system. demonstrate vital source, especially during flood season, its floodplain.