Current Issue : July - September Volume : 2018 Issue Number : 3 Articles : 5 Articles
The authors explore the uncertainty implied in the estimation of changes in flood frequency\ndue to climate change at the basins of the Cedar River and Skunk River in Iowa, United States.\nThe study focuses on the influence of climate change on the 100-year flood, used broadly as a\nreference flow for civil engineering design. Downscaled rainfall projections between 1960ââ?¬â??2099 were\nused as forcing into a hydrological model for producing discharge projections at locations intersecting\nvulnerable transportation infrastructure. The annual maxima of the discharge projections were used\nto conduct flood frequency analyses over the periods 1960ââ?¬â??2009 and 1960ââ?¬â??2099. The analysis of\nthe period 1960ââ?¬â??2009 is a good predictor of the observed flood values for return periods between 2\nand 200 years in the studied basins. The findings show that projected flood values could increase\nsignificantly in both basins. Between 2009 and 2099, 100-year flood could increase between 47%\nand 52% in Cedar River, and between 25% and 34% in South Skunk River. The study supports a\nrecommendation for assessing vulnerability of infrastructure to climate change, and implementation\nof better resiliency and hydraulic design practices. It is recommended that engineers update existing\ndesign standards to account for climate change by using the upper-limit confidence interval of the\nflood frequency analyses that are currently in place....
This article envisions urban agriculture as a solution to address global warming by\ndecreasing the urban heat island effect while also addressing many other urban sustainability\nissues, such as multi-functionality, creating new commons, amenities and ecosystem services,\nreinventing urbanity, encouraging community building by growing local food, and enhanced water\nmanagement. This article examines how urban design and planning can promote this solution to\nreconfigure more sustainable and resilient cities. A crucial aspect is that urban planning should evolve\nfrom its traditional prescriptive form to adaptive planning. An important point in adaptive planning\nis that anybody concerned should be associated with the decision-making process, which requires\nthe involvement of citizens in the decisions that affect them....
Degradation of organic pollutants in wastewater was investigated by photocatalysis\nmethod using anatase modification of titanium-dioxide (TiO2) catalyst\nwith different structures. Laboratory experiments were carried out with industrial\nwastewaters consisting of different contents of organic pollutants.\nTwo types of TiO2 catalyst: TiO2 having a size near to nanoparticles (about 3 -\n4 micron in size) and the nanostructured 15 nm sized TiO2 were used to find\noptimum conditions of photocatalytic degradation and removal of organic\ncompounds from wastewater. This paper discusses the effect of various parameters\non the degradation rate including the catalyst concentration, process\nduration as well as the catalytic effectiveness of the TiO2 particles� size. In addition,\nthe effect of UV and visible light sources on the degradation process\nwas studied. The process performed with nanostructured TiO2 catalyst under\nvisible light was very successfully allowing best degradation of organic compounds....
Based on stable hydrogen and oxygen isotope data (�´18O, �´D) and meteorological\nobservation data for complete hydrological annual precipitation from 2016 to 2017 in the monsoon\nmarginal region of northern China (Fengxiang and Ningwu), the isotopic characteristics of\nprecipitation and the sources of water vapor in these two regions combined were studied. The results\nshowed that �´18O and �´D values in the wet season (June through September) were higher than in the\ndry season (October to May of the following year) in Fengxiang and Ningwu. The intercept and slope\nof the meteoric water line in the two regions were somewhat low, revealing that the water vapor in the\nrainfall comes mainly from the tropical ocean. On a synoptic scale, significantly positive correlations\namong dry season precipitation, �´18O, and temperature manifested temperature effects, but in the\nwet season, the temperature effect was not significant. On a monthly scale, a relationship did not\nexist between the change in trend of the average value of monthly weighted �´18O in precipitation and\nthe average temperature change value in the two regions. However, in the wet season, significantly\nnegative relationships can be found between the average monthly weighted �´18O in precipitation\nand rainfall amount, which indicated a remarkable rainout effect. Further investigation revealed\nthat continuous precipitation made the values of �´18O and �´D more negative under the same source\nof water vapor (the rainout effect). Because the annual rainfall in the monsoon marginal region\nof Northern China is mainly made up of monsoon rainfall, the oxygen isotope index of geological\nand biological records, such as stalagmites and tree rings, which inherit meteoric water isotope\ninformation, can be used to reconstruct past rainfall changes in northern China....
A deep temperate lake, Lake Kuttara, Hokkaido, Japan (148 m deep at maximum) was\ncompletely ice-covered every winter in the 20th century. However, ice-free conditions of the lake\nover winter occurred three times in the 21st century, which is probably due to global warming.\nIn order to understand how thermal regime of the lake responds to climate change, a change in\nlake mean water temperature from the heat storage change was calculated by integrating observed\nwater temperature over water depths and by numerical calculation of heat budget components based\non hydrometeorological data. As a result, a temporal variation of lake mean water temperature\nfrom the heat budget calculation was very reasonable to that from the observed water temperature\n(determination coefficient R2 = 0.969). The lowest lake mean temperature for non-freeze was then\nevaluated at âË?â??1.87 ââ??¦C, referring to the zero level at 6.80 ââ??¦C. The 1978ââ?¬â??2017 data at a meteorological\nstation near Kuttara indicated that there are significant (less than 5% level) long-term trends for air\ntemperature (+0.024 ââ??¦C/year) and wind speed (âË?â??0.010 m/s/year). In order to evaluate the effects of\nclimate change on freeze-up patterns, a sensitivity analysis was carried out for the calculated lake\nmean water temperature. It is noted that, after two decades, the lake could be ice-free once per every\ntwo years....
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