The relationship of climatic and hydrological parameters to surface water quality in the lower Mekong River

The relationship between climatic, hydrological and water quality parameters of the lower Mekong River flowing through four different countries (Thailand, Cambodia, Lao PDR and Vietnam) was studied. The Mekong River Commission (MRC) secondary data of climatic and hydrological parameters included precipitation, evaporation, average air temperatures, mean water level and discharge flow. Water quality parameters consisted of TSS, NO(3)(-), PO(4)(3-), DO, pH, conductivity, Ca, Mg, Na, K, alkalinity, Cl, SO(4)(2-), Fe, TP, Si and COD. Pearson's correlation was used to determine their relationship. The results reveal that the correlations of climatic, hydrological and water quality parameters in those four countries located along the lower Mekong River had the same trend. Precipitation had fair positive correlations with mean water level (ranging 0.375-0.661), discharge flow (ranging 0.526-0.659) and mean air temperature (ranging 0.515-0.621), however had weak negative correlation with evaporation (ranging 0.169-0.468). Concerning relationship with water quality, the results show that TSS, NO(3)(-), PO(4)(3-), TP and COD had weak to fair positive correlations with precipitation, mean water level, discharge flow. However, DO, pH, conductivity, Ca, Mg, Na, K, alkalinity, Cl, SO(4)(2-) and Si had fair to strong negative correlations with all hydrological parameters. Finally, TSS, alkalinity and conductivity were proposed as sensitive water quality parameters for monitoring impacts of changing climate in the lower Mekong River.     

A statistical model to predict and analyze air surface temperature based on remotely sensed observations

Environmental Science and Pollution Research - Air surface temperature (AST) is a crucial importance element for many applications such as hydrology, agriculture, and climate change studies. The...     

Monitoring of non-point source pollutants load from a mixed forest land use

The aim of this study was to determine the unit load of NPS (non-point source) pollutants including organic variables such as BOD (biochemical oxygen demand),COD (chemical oxygen demand) and DOC (dissolved organic carbon),nitrogen and phosphorus constituents,and suspended solids (SS) and their event mean concentration (EMC) of runoff flows from a water-shed of mixed forest land use by intensive field experiments.Field monitoring for continuous measurements of rainfall,flow,and water quality was conducted over 12 storm events during 2008–2009 using automated and manual sampling methods.The EMCs of individual runoff event were estimated for each water quality constituent based on the flow rate and concentration data of runoff discharge.The average EMCs of BOD,COD,DOC,SS,TN (total nitrogen),NH 4+ -N,NO 3- -N,TP (total phosphorus),PO 43- -P from the mixed forest land were 1.794,3.498,1.462,10.269,0.862,0.044,0.634,0.034,and 0.005 mg/L,respectively.The annual unit loads of BOD,COD,DOC,SS,TN,NH 4+ -N,NO 3- -N,TP and PO 43--P were estimated as 66.9,133.2,55.5,429.8,36.5,1.6,26.9,1.3 and 0.1 kg/(ha·yr),respectively.In addition,affecting parameters on the EMCs were investigated by statistic analysis of the field data.As a result,significant correlations with precipitation,rainfall intensity,and total runoff flows were found in most constituents.     

Health risk assessment and source apportionment of PM2.5-bound toxic elements in the industrial city of Siheung,Korea

Environmental Science and Pollution Research - The emission sources and their health risks of fine particulate matter (PM2.5) in Siheung, Republic of Korea, were investigated as a middle-sized...