Characterizing the effects of stormwater runoff on dissolved organic matter in an urban river (Jiujiang, Jiangxi province, China) using spectral analysis.

The effect of stormwater runoff on dissolved organic matter (DOM) in rivers is one of the central topics in water environment research. Jiujiang is one of the first cities established in the green development demonstration zone of the Yangtze River Economic Belt (Jiangxi Province, China). Three-dimensional excitation-emission matrix fluorescence with parallel factor analysis (3DEEM-PARAFAC) and ultraviolet-visible (UV-Vis) spectroscopy were used to explore the effects of runoff on organic matter in Shili River (Jiujiang, Jiangxi Province, China). The results show that the runoff led to an increase of some critical pollutants and DOM concentrations, especially in the middle reaches of the river. The concentration and relative molecular weight of DOM in water increased as a result of runoff. Three humic-like (C1-C3) and two protein-like (C4 and C5) components of DOM were identified using the PARAFAC model. The sources of the three humic-like components (C1, C2, C3) were consistent, unlike those of the protein-like component C4. Compared with the pre-rainfall period, the content of humus compounds flowing into the river through the early rainwater runoff was lower, which caused the relative content and proportion of humic substances little change and protein-like species increasing. The DOM mainly derived from autochthonous sources, and runoff had limited effect on its characteristics. Jiujiang is a key demonstration city for Yangtze River conservation. Rainwater runoff is one of the pollution sources of urban rivers, which leads to the deterioration of water quality and influences the distribution characteristics of DOM in water bodies. The PARAFAC components could adequately represent different indicators and sources of DOM in urban rivers, providing an important reference for urban river management.

Flood economic assessment of structural measure based on integrated flood risk management: A case study in Beijing.

Flood disasters have appeared more frequently in recent years because of climate change and urbanization, and Integrated Flood Risk Management (IFRM) has emerged as an effective method to reduce damage from these floods. This research studies IFRM methods in three aspects: flood risk identification of high-risk areas, flood risk assessment to quantify economic losses, and flood risk management to identify structural measures with the greatest engineering benefits. These methods were applied to Beijing as a case study, and the results showed that the Zuoan-Road area was a high-risk area with economic losses ranging from 0.7 million to 35.9 million euros over different return periods. There are five structural measures in Zuoan-Road area, with engineering benefits ranging from 0.97 to 1.60 over different return periods, and the one with the greatest engineering benefits had a fifty-year return period. The results of this research can be used to support urban flood risk management in Beijing.

The Water Status in China and an Adaptive Governance Frame for Water Management.

China is increasingly facing water-related problems, such as water scarcity, pollution, and overexploitation of groundwater. This paper discusses the water status in China and claims that governance is the cause of water-related problems. The structure of the current water management is analyzed to conclude that the control-command is a static approach which is less capable of dealing with the uncertainty in the water resources system. An adaptive governance frame is introduced, which highlights the learning process and participation. The learning process avoids making the same mistake twice and the participation ensures the diversity of information, which are both necessary for water resources management.

A two-stage water allocation strategy for developing regional economic-environment sustainability.

In this study, a new two-stage stochastic interval-parameter fuzzy programming strategy model is developed for regional economic-environment sustainability, considering the planning and management of water-resources and water-environment systems under uncertainty. The model is capable in addressing the complexity and uncertainties of the water system，which contains the concepts of economics and environment within an optimization framework. The objective of this research is to develop a participatory integrated assessment model, based on the water benefit and water environment security, with an application in the Sanjiang Plain area, China. The methodology intendeds to capture the complexity and scarcity of water management problems, incorporating the relevant sectors, as well as the different levels of water involved in water management decision. The model is applied through maximizing the benefits of water during livelihood, production and ecology. In addition, the model considers the constraints of water quantity and water quality. Then, a variety of decision results are calculated under different conditions of water shortage. The developed method is applied to plan resources management and develop regional environment sustainability. The generated results can assist the decision makers in not only making resources allocation strategies but also gaining insights into the benefit between economic and environment objective.

Specific vulnerability assessment of nitrate in shallow groundwater with an improved DRSTIC-LE model.

Datong basin is one of the most important agriculture zone of Shanxi Province, China, where intensive fertilizer and pesticide applications cause the groundwater contamination. Hence, it is necessary to carry out groundwater specific vulnerability assessment of nitrate. The prediction accuracy of conventional DRASTIC model for groundwater vulnerability assessment is severely limited by the inherent subjectivity in determining main parameters, rating scales and weighting coefficients. This paper attempts to overcome these problems by changing the evaluation parameters, parameters rating and weight calculation method. Based on the hydrogeological conditions and nitrate pollution characteristics of Datong Basin, the traditional groundwater vulnerability model DRASTIC was improved, called DRSTIC-LE model to assess the specific vulnerability of nitrate, which involves Depth of water table (D), Net recharge (R), Soil media (S), Topography (T), Impact of the vadose zone (I), hydraulic Conductivity (C), land use type (L), and groundwater exploitation (E) as evaluation parameters. And the theoretical weight of each parameter were determined with the aid of the improved weights determination method by the effective combination of the entropy weight method and analytic hierarchy process. Moreover, single-parameter sensitivity analysis was performed to evaluate the effect of each parameter on the groundwater specific vulnerability. According to the results of groundwater specific vulnerability map, very high and high vulnerability mainly situated in central, northern and northeastern portion of study area, with 6.25%, 17.93% of total area, respectively. Also, single-parameter sensitivity analysis represented that I and D are the main parameter which impacts groundwater to pollution while C contributes least to pollution in the Datong basin. The model is validated with the measured nitrate concentration and results have shown better correlation between SVI and nitrate concentration. Additionally, by comparing the correlation between the effective weights and the theoretical weights calculated by the three methods (EW, AHP and EW-AHP method), we can see that prediction accuracy of the EW-AHP method is higher than other methods. The research established the efficacy of EW-AHP method as a method of determining weights and provided a basis for regional control of groundwater nitrate pollution.