Modelling the relationship between catchment attributes and wetland water quality in Japan

Abstract

AbstractThe influence of catchment attributes has been examined to find out whether variations in water quality indicators [electrical conductivity (EC), pH, turbidity, dissolved oxygen (DO), total dissolved solid (TDS), total nitrogen (TN), dissolved organic nitrogen (DON), dissolved inorganic nitrogen (DIN), temperature and nitrogen] could be explained by them for 24 wetlands in west Japan. Urban areas (%) were positively (P ≤ 0.05) correlated with EC (r = 0.67), TDS (r = 0.69), TN (r = 0.92), DON (r = 0.60), [NH4+] (r = 0.47) and with [NO2−] (r = 0.50). Forest areas (%) were inversely (P ≤ 0.05) correlated with EC (r = −0.62), TDS (r = −0.68), TN (r = −0.68) and [NH4+] (r = −0.55) and with DON (r = −0.43). Agricultural area (%) was positively (P ≤ 0.05) correlated with EC (r = 0.40), TDS (r = 0.45), TN (r = 0.44) and [NH4+] (r = 0.56) and with both areas (%) of grey lowland soil (r = 0.60) and diluvial sand (r = 0.58). Area (%) of regosol was positively correlated with DO (r = 0.42) but inversely with DON (r = −0.44, P ≤ 0.05). Rhyolite was positively (P ≤ 0.05) correlated with the TN (r = 0.46) but inversely with DON (r = −0.49) and [NH4+] (r = −0.47). Regression models were developed for the water quality indicators including EC (r2 = 0. 62), (r2 = 0.90), (r = 0.52), TN (r = 0.86), DIN (r2 = 0.74) and DON (r2 = 0.54) at 0.01 ≤ P ≤ 0.05. In the models, no significant contribution has been observed for catchment geometric features of the wetlands on water quality indicators. Copyright © 2014 John Wiley & Sons, Ltd.