Comparison Of Pollution Into Water Catchments From Snowmelt-Runoff Vs Rainfall-Runoff

Urbanization has accelerated in recent years worldwide, and cropland and woodlands have been converted to roads, buildings, and other paved areas. This development has increased the impermeability of urban surfaces and changed the build-up and wash-off processes of nonpoint source (NPS) pollutants.

As a climate-driven event, NPS pollution can be caused by rainfall- or snowmelt-runoff processes over and through the ground, which would concentrate natural and anthropogenically deposited pollutants and transport them to receiving water bodies, such as rivers, lakes, seas, or groundwater (Hu and Huang 2014). Typically, NPS processes involve rainfall-runoff and snowmelt-runoff, while their driving force is wet deposition, which includes rainfall and snowfall inputs. During the wet season, rainfall NPS originates from direct rainfall-runoff processes. During the winter season, snowmelt NPS results from the natural melting of snow into surface water.

Previous studies on snow and snowmelt mainly focused on three aspects: exporting mechanism, model simulation and control measures. Although these studies have discussed the characteristics of snow and snowmelt from different viewpoints, there was still lack of systematic researches into snowmelt NPS from source to output in urban areas.

Furthermore, the characteristics and mechanisms of snowmelt NPS and rainfall NPS are different. Comparatively, rainfall NPS has attracted more attention, and the management of water quality has mainly focused on rainfall NPS. However, the source and output processes of snowmelt NPS and rainfall NPS are different, and the methods used to manage rainfall NPS are not applicable to snowmelt NPS. Thus, it is also necessary to explore the output process of snowmelt NPS and rainfall NPS.

Exploring the characteristics of snowmelt NPS and rainfall NPS in a typical urban catchment in Beijing, China

In this study, three factors relating to urban NPS, including surface dust, snowmelt, and rainfall-runoff processes, were analyzed comprehensively by both field sampling and laboratory experiments. Considering the city’s dense population, frequent traffic activity, and typical impervious surfaces, we chose the study area around Beijing Normal University (BNU), Beijing, China (Fig. 1), which is located between the 2nd Ring Road and the 3rd Ring Road of Beijing and belongs to the downtown.

Through comprehensive consideration of the impact of land use and geographical location on surface water pollution, our research intends to monitor the surface rainfall-runoff and snowmelt at three sampling sites, including roads from an office area and a traffic-heavy area and the roof of a building. In addition, the pollutant concentrations in surface dust were closely related to the concentration of pollutants in the runoff. Surface dust on impervious surfaces (roads and roofs) was more easily washed off by runoff, and thus, surface dust was also collected to analyze leaching ratios of pollution.

The study revealed that dust deposition contributed more pollutants in winter and spring, and these built-up pollutants showed low leaching ratios, indicating that most NPS pollutants were particulate forms. Underlying snow has higher COD, TSS, Cu, Fe, Mn and Pb concentrations than surface snow, while higher EMCs of most pollutants were observed in road snowmelt. In addition, the snowmelt NPS had higher COD, TSS and metal content than rainfall NPS, indicating the importance of controlling snowmelt pollution for effective water quality management.

These findings are described in the article entitled Comparison between snowmelt-runoff and rainfall-runoff nonpoint source pollution in a typical urban catchment in Beijing, China, published in the journal Environmental Science and Pollution Research. This work was led by Lei Chen, Xiaosha Zhi, Zhenyao Shen, Ying Dai, and Guzhanuer Aini from Beijing Normal University.

References

  • Hu H, Huang G (2014) Monitoring of Non-Point Source Pollutions from an Agriculture Watershed in South China. Water 6(12): 3828-3840

About The Author

Zhenyao Shen

Zhenyao Shen is a researcher at the University of Beijing Normal School of Environment.

Speak Your Mind!

READ THIS NEXT

Science Can Now Make Wood Just As Strong As Steel

When most people think about strong materials they tend to put steel up there; steel is definitely stronger than wood. But now scientists have developed a way to make wood stronger than steel. In an article published in the scientific journal, Nature, a group of scientists has put forward the way in which wood can […]

Exploring Spatial Representation In Artificial Intelligence Systems

Artificial Intelligence¬†has made great progress in the last decade, in particular, thanks to recent developments in¬†machine learning. As a consequence, we often read in the news that artificial systems now perceive the world as we do and sometimes even outperform humans in some specific tasks.¬†However, are these claims justified? Looking more thoroughly at the intricate […]

The Ambitious & Risky Race To Colonize Mars

Space exploration is the final frontier left to explore by humanity. In many science fiction novels, we have colonies from all corners of the solar system from the Moon to Mars. While these were once thoughts to ponder, we are slowly coming around to the idea of creating space stations and bases on both the […]

Wireless Sensors Are To Be Self-Powered And Self-Identified Instantaneously When Triggered Mechanically 

Sensors are a type of transducer that can convert, measure, and change information into electrical signals for analysis, monitoring, etc, and can be used to measure the temperature, pressure, etc. of physical variables, such as pH value, gas chemical concentration, glucose concentration, etc., of biochemical variables. Sensors, particularly wireless sensor networks, are the foundation of […]

The Use Of Metamaterials For New Information Systems

Metamaterial has gradually cemented its place in the past 20 years as an area of exciting research and drawn broad attention from the physics and engineering communities, owing to its exotic electromagnetic (EM) behaviors. However, metamaterials have conventionally been described by effective medium parameters and governed by physical principles. They can be compared to, in […]

Microplastics Pollution: Scientists On The Road To Consensus

Microplastics (plastic particles smaller than <5 mm) are an ever-increasing problem around which discoveries of important and unpredicted consequences to society and nature are occurring at an accelerated pace [4]. Studies of microplastics pollution have flourished, helped by efficient science communication [5] until the issue reached policy/decision makers. Techniques to sample and characterize these pollutants […]

Solubility In Sub- And Supercritical Ethanol

Extraction by subcritical and supercritical ethanol has been applied to many materials for the recovery of useful products from them. The treatment of coals and oil shales with these solvents may yield liquid fuels and many plant biomass materials are sources of bio-active products when subjected to extraction with ethanol at the named conditions. The […]