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.

ADVERTISEMENT

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.

ADVERTISEMENT

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

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

Comments

READ THIS NEXT

Kawa Ijen: The Beauty & Nightmare Of The Electric Blue Lava

Kawah Ijen is a basaltic-andesite to dacitic stratovolcano located in the Banyuwangi Regency of East Java. It represents the only […]

Effect Of Chemical Structuring On Physical Architecture In Superhydrophobic And Organic Photovoltaics

Physical structuring is one of the smart ways to explore the maximum capability of a known material, in particular of […]

Scientists May Have Finally Found Out What Causes Dyslexia

There are many different types of learning disorders that affect a significant amount of the world population. They are generally […]

New Treatment Regrows Complete Spinal Cord Injury In Mice

In 1990, legendary soul /funk artist Curtis Mayfield was struck in the back of his neck by a falling light […]

Homeowners Respond To Energy Efficiency Thresholds When Investing In Home Retrofits

Ireland has a system to grade the energy efficiency of residential buildings, called a Building Energy Rating (BER). A BER […]

List Of Animal Names

You’ve surely heard of common animal names like rats, dolphins, rabbits, apes, ducks, pigs and snakes. However, what follows are […]

Strengthening Memories During Sleep

Even though we spend about a third of our lives asleep, the function of sleep is still not fully understood. […]

Science Trends is a popular source of science news and education around the world. We cover everything from solar power cell technology to climate change to cancer research. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. Want to know more?