scholarly journals Effects of land use and water quality on greenhouse gas emissions from an urban river system

2020 ◽  
Author(s):  
Long Ho ◽  
Ruben Jerves-Cobo ◽  
Matti Barthel ◽  
Johan Six ◽  
Samuel Bode ◽  
...  

Abstract. Rivers act as a natural source of greenhouse gases (GHGs) that can be released from the metabolisms of aquatic organisms. Anthropogenic activities can largely alter the chemical composition and microbial communities of rivers, consequently affecting their GHG emissions. To investigate these impacts, we assessed the emissions of CO2, CH4, and N2O from Cuenca urban river system (Ecuador). High variation of the emissions was found among river tributaries that mainly depended on water quality and neighboring landscapes. By using Prati and Oregon Indexes, a clear pattern was observed between water quality and GHG emissions in which the more polluted the sites were, the higher were their emissions. When river water quality deteriorated from acceptable to very heavily polluted, their global warming potential (GWP) increased by ten times. Compared to the average estimated emissions from global streams, rivers with polluted water released almost double the estimated GWP while the proportion increased to ten times for very heavily polluted rivers. Conversely, the GWP of good-water-quality rivers was half of the estimated GWP. Furthermore, surrounding land-use types, i.e. urban, roads, and agriculture, significantly affected the river emissions. The GWP of the sites close to urban areas was four time higher than the GWP of the nature sites while this proportion for the sites close to roads or agricultural areas was triple and double, respectively. Lastly, by applying random forests, we identified dissolved oxygen, ammonium, and flow characteristics as the main important factors to the emissions. Conversely, low impact of organic matter and nitrate concentration suggested a higher role of nitrification than denitrification in producing N2O. These results highlighted the impacts of land-use types on the river emissions via water contamination by sewage discharges and surface runoff. Hence, to estimate of the emissions from global streams, both their quantity and water quality should be included.

2021 ◽  
Author(s):  
Jessica Page ◽  
Haozhi Pan ◽  
Zahra Kalantari

<p>Globally, urban areas contribute significantly to the emissions of the greenhouse gases (GHGs) which are leading to anthropogenic climate change. To achieve long-term sustainable development goals, urban regions will need to grow and develop in such a way that they can both provide a good quality of life for all of their inhabitants, and also reduce and offset their GHG emissions to reach and maintain net-zero GHG emissions.</p><p>This work aims to further our understanding of the impact of urban form and growth on GHG emissions, to identify ways in which nature-based solutions (NBS) can be integrated into urban planning to help cities reach net zero emissions while continuing to grow sustainably. We will conduct a high-resolution (1x1km) spatial accounting and mapping of GHG emissions from selected urban anthropogenic activities (residential, commercial, transportation) for Stockholm, Sweden which includes those factors relevant to and impacted by urban form (such as density, land use pattern transportation networks, green spaces) to allow for the analysis of different types of city spatial patterns and planning decisions and their implications in GHG emissions. The results will be further expanded to cities across the European Union (EU) for comparison. Conclusions will be drawn about where and how NBS interventions should be used most effectively to reduce urban GHG emissions and facilitate sustainable city growth in the future.</p><p><strong>Keywords:</strong> Sustainable cities; Land-use; Greenhouse Gas Emissions; Nature-based Solutions</p>


Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2545 ◽  
Author(s):  
Yang Liu ◽  
Chunyi Wang ◽  
Yang Yu ◽  
Yongyu Chen ◽  
Longfei Du ◽  
...  

Urban storm runoff is a major source of pollutants in receiving water bodies. To assess the impact of urban stormwater runoff on an urban river, the runoff process of total suspended solids (TSS), chemical oxygen demand (COD), ammonium (NH4), and total phosphorus (TP) were investigated on road surfaces classified as arterial road (AR), residential area (RA), and industrial area (IA) in the Pingshan River (PSR) watershed in Shenzhen, China. Event mean concentration (EMC) was calculated to analyze the water quality of road runoff, and the dimensionless M(V) cumulative curves were used to estimate the course of decreasing concentration of runoff pollutants during each rainfall event. Multicriteria decision making methods (PROMETHEE-GAIA) were used to identify the linkage between runoff pollutants, land use types, and rainfall intensity. The EMCs of COD and TP in runoff exceeded the class IV level of the water quality standard for surface water (China). RA was a major potential source for NH4, COD, and TP in the river. Controlling the first flush is critical to decrease the effect of road runoff on receiving water bodies, as most runoff pollutants in AR, RA, and IA had a first flush effect during heavy rainfall. The specific management measure for runoff pollution varied with land use type. Reducing road TSS concentrations was effective for controlling runoff pollution in AR and RA because NH4, TP, and COD attached to particulate matter. In IA, the collection and reuse of stormwater in the initial rainfall period were effective for reducing the effect of soluble pollutants in runoff on receiving water bodies. This study provides new information for managing urban road stormwater runoff in different land use types.


Land ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 101 ◽  
Author(s):  
Janis Arnold ◽  
Janina Kleemann ◽  
Christine Fürst

Urban ecosystem services (ES) contribute to the compensation of negative effects caused by cities by means of, for example, reducing air pollution and providing cooling effects during the summer time. In this study, an approach is described that combines the regional biotope and land use data set, hemeroby and the accessibility of open space in order to assess the provision of urban ES. Hemeroby expresses the degree of naturalness of land use types and, therefore, provides a differentiated assessment of urban ES. Assessment of the local capacity to provide urban ES was conducted with a spatially explicit modeling approach in the city of Halle (Saale) in Germany. The following urban ES were assessed: (a) global climate regulation, (b) local climate regulation, (c) air pollution control, (d) water cycle regulation, (e) food production, (f) nature experience and (g) leisure activities. We identified areas with high and low capacity of ES in the urban context. For instance, the central parts of Halle had very low or no capacity to provide ES due to highly compact building styles and soil sealing. In contrast, peri-urban areas had particularly high capacities. The potential provision of regulating services was spatially limited due to the location of land use types that provide these services.


1996 ◽  
Vol 34 (12) ◽  
pp. 33-40 ◽  
Author(s):  
Y. Hosoi ◽  
Y. Kido ◽  
H. Nagira ◽  
H. Yoshida ◽  
Y. Bouda

The inflow of pollutant load from urban areas and the stagnation of water due to sea water intrusion cause the deterioration of river water quality in tidal zone. In order to improve water quality, various measures such as the reduction of pollutant load by sewage systems, discharge control from sewage treatment plants considering river flow, nutrient removal by aquatic plants, and the dredging of bottom sediments have been examined. The choice of these measures depends on the situation of the river environment and finances. In this study, a field survey was carried out in a typical urban river basin, first. Secondly, on the basis of this survey, a mathematical model was formed to simulate flow and water quality. Several purification alternatives designed for the investigated river basin were comparatively evaluated from the viewpoint of the effect of water quality improvement and their cost. Finally, they were prioritized. Through this case study, a planning process of river water quality management was shown.


2012 ◽  
Vol 157-158 ◽  
pp. 945-949 ◽  
Author(s):  
Yu Hui Chen ◽  
Yong Zhang ◽  
Min Sheng Huang ◽  
Yi Fan Zhang ◽  
Feng Zhao ◽  
...  

By constructing a multistage floating-bed system by combination of macrophytes, aquatic animals and aquamats ecobase for ecolgical restoration in a eutrophic urban river, the improvement of water quality and the dynamic variation of phytoplankton was investigated. The results showed that the average removal rates were 9.85%, 15.86%, 24.47% and 12.75%, respectively. phytoplankton quantity was decreased by 22.82×104ind./L and Shannon-Weiner Index was increased by 0.11 averagely, after the restoration work in the demonstration area comparing to control area. The negative correlation between Shannon-Weiner Index of phytoplankton and TN(-0.77, P<0.01) showed that multistage system might effect phytoplankton indirectly through removing nutrients from river, which indicated that the employment of ecological restoration technology of multistage floating-bed system was effective in raising the ecological recovery efficiency of polluted water bodies.


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