Net Ecosystem Production of a River Relying on Hydrology, Hydrodynamics and Water Quality Monitoring Stations

Abstract

Flow and water quality of rivers are highly dynamic. Water quantity and quality are subjected to simultaneous physical, chemical and biological processes making it difficult to accurately assess lotic ecosystems. Our study investigated net ecosystem production (NEP) relying on high-frequency data of hydrology, hydrodynamics and water quality. The Kanawha River, West Virginia was investigated along 52.8 km to estimate NEP. Water quality data were collected along the river using three distributed multiprobe sondes that measured water temperature, dissolved oxygen, dissolved oxygen saturation, specific conductance, turbidity and ORP hourly for 71 days. Flows along the river were predicted by means of the hydrologic and hydrodynamic models in Hydrologic Simulation Program in Fortran (HSPF). It was found that urban local inflows were correlated with NEP. However, under hypoxic conditions, local inflows were correlated with specific conductance. Thus, our approach represents an effort for the systematic integration of data derived from models and field measurements with the aim of providing an improved assessment of lotic ecosystems.

Explaining temporal shifts of river hydrochemistry observed during storm events

“…Hourly estimations of flow in the Kanawha River in the two locations (Q1 and Q2) were deduced from a developed and calibrated HSPF hydrologic model (Rojano et al, 2020). The Q2 differed with respect to Q1 due to the additional 4,290.4 km 2 of drainage area to the Kanawha River.…”

“…The Q2 differed with respect to Q1 due to the additional 4,290.4 km 2 of drainage area to the Kanawha River. Also, the additional drainage area in Q2 has favored the increase of flow up to 17% when compared to Q1 (Rojano et al, 2020).…”

“…We focused on the Kanawha River, West Virginia, one of the tributaries of the Ohio River in the Central Appalachian Region. The drainage area of the Kanawha River includes a dense chemical industry near urban areas settled for several decades as well as mining activities for coal and shale gas near rural areas that altogether caused prevailing water pollution (Evans & Davies, 1998;Griffith et al, 2012;Orndorff et al, 2015;Petty et al, 2010;Rojano et al, 2020). These anthropogenic activities discharge wastewater to streams together with scattered agriculture runoffs from riverine zones.…”

“…Therefore, this drainage area has been subjected to discharges of pollutants as indicated in the permits issued by the EPA through the national pollutant discharge elimination system (NPDES). The Kanawha River encompasses approximately 31,724 km 2 with many types of wastes, favoring hypoxic conditions and endangering aquatic ecosystems (Rojano et al, 2020). The effects of storms in this study area were investigated taking account water chemistry changes that propagate downstream and impair aquatic life conditions and the adequacy of water for different uses.…”

Integrated Water Resources Research: Advancements in Understanding to Improve Future Sustainability

“…Results showed that streamflow is expected to increase under the low-emission and decrease under the high-emission climate change pathway. In related work, Rojano et al [14] showed that modeled urban flow regimes were correlated to net ecosystem production (NEP), and under hypoxic conditions, local inflows were correlated with specific conductance. Results show the value of using integrated modeling approaches with observed data to resolve big-river challenges.…”