Application of Regional Nutrient Management Model in Tunxi Catchment: In Support of the Trans‐boundary Eco‐compensation in Eastern China

Abstract

The first trans-provincial watershed eco-compensation pilot project has been implemented in Xin'anjiang River watershed, standing between China's Anhui Province and Zhejiang Province. The project purpose is to solve the trans-boundary pollution issue, while ensuring sustainable use of water resources. Models have been proved to be effective tools for identifying major environmental objectives, especially in regard to the watershed management of agricultural non-point source pollution. The regional nutrient management (ReNuMa) model was employed to interpret the main environmental problem (nitrogen contamination) generated within Tunxi catchment, the headstream of Xin'anjiang River watershed. After collecting and processing the available data and parameters, ReNuMa simulated stream flow, sediment yields and dissolved nitrogen loads on a monthly scale from 2000 to 2010 and thus estimated total nitrogen loads. Sensitivity and scenarios analysis were done to infer effective management options. The results showed that source apportionments of N loads emphasized the contribution proportion of each pollution source and characterized the temporal variations caused by natural and anthropogenic factors. Effective countermeasures were elicited by a series of scenarios analysis for water quality improvement. The application of the ReNuMa model showed usefulness to plan N management strategy for policy makers, which in turn helped reduce the N loads draining to the downstream, and gained mutual benefits from the ongoing transprovincial watershed eco-compensation pilot project.

Estimation of the Source Apportionment of Phosphorus and Its Responses to Future Climate Changes Using Multi-Model Applications

“…Based on the outputs of the model applications, the non-point sources from farmland discharge through runoff and septic systems discharge through groundwater were detected as the current main contributing sources of Dis-P in studied watershed. The fluxes and source apportionments of Dis-P were variable in different months, in accordance with previous studies [34,46,47,49].…”

“…The ReNuMa model was employed to estimate the hydrochemical processes of the studied watershed. It was developed using the Microsoft Excel platform with Visual Basic for Applications (VBA) code based on the algorithms of Generalized Watershed Loading Functions (GWLF) with continuous updates and broad applications in recent years [20,34,35]. The newest version of ReNuMa (2.2.2) was used in this project, which has the same algorithms for watershed hydrological estimation as GWLF.…”

“…The parameter uncertainty analysis feature of ReNuMa was operated based on 5% perturbation of normal distribution for all calibrated parameters with 250 iterations [18,34], which could permits relatively quantitative analysis of the effect of parameter uncertainty on simulation uncertainty. The time series of observed and modeled monthly streamflow and Dis-P fluxes, as well as their uncertainties, during the research period are given in Figure 3.…”

A modification of the Regional Nutrient Management model (ReNuMa) to identify long-term changes in riverine nitrogen sources

“…Due to its attributes, the ReNuMa model has been widely applied for simulating temporal variations of river discharge and riverine nutrient sources in a range of watersheds with contrasting climate, geology and land use (Brandmeyer et al, 2007;Woodbury et al, 2008;Liu et al, 2012;Xie, 2012;Sha et al, 2013Sha et al, , 2014Huang, 2014;Li et al, 2014;Lu et al, 2014). These previous studies using ReNuMa were successfully validated for N dynamics at relatively short-time scales (< 10 years).…”

Spatiotemporal Dynamics of Nitrogen Transport in the Qiandao Lake Basin, a Large Hilly Monsoon Basin of Southeastern China

“…understood [24,49]. It has been known for several decades that these factors have seriously compromised water quality in the basin [27]. China's first transboundary Payment for Ecosystem Services (PES) plan was consequently established in the QLB in 2012 [50,51].…”