Rainwater Flow Research Articles

Canopy for the Tram and Bus Stop "Krefeld Ostwall"

The „Ostwall“, one of Krefeld‘s most important public traffic intersections, is getting modernized completely for the moment. The highlight of the project is the new canopy for the tram and bus stop. It was decided to realize a steel-glass structure, to get most possible transparency. The structure has a length of 125m and a width of 12m. The main structure has 9 column brackets, that are bearing a space truss. These elements are made of steel. For the roofing, partially curved glass elements are used, that are bonded to a stainless steel frame by structural silicone. The slope of the roofing reaches to the gutter in the middle axis of the building. For each side, only one glass element is used, to guarantee a good flow of rain water. The glass elements have a developed length of 5.2m and a width of 2.2m. At the front ends of the structure, spherically curved glass elements are used. The glass roof is accessible for cleaning and inspection work. To get a smooth view of the bottom surface, the glass is bonded under the steel frame, so the silicone bonding is used to bear the self-weight of the glass elements. The pre-fabricated elements are fixed to the main structure at the bottom girder of the framework directly, and at the top girder by a suspension bar. To get a minimized cross section of the stainless steel bars, they are stabilized by the glass elements to prevent them from torsional-flexural buckling.

Characteristics of Near-Surface Part of the Orzesze Beds in the Region of the Main Saddle in View of Weathering Processes

AbstractThe article presents the characterization of a near-surface part of Orzesze beds in the region of the main saddle. The lithological profile of the region in concern has been confirmed to contain claystones with interburdens of sandstones and sands occurring at the surface. Among the claystones, a coal bed was drilled into.Field observations with a video camera, direct observations made in the boreholes and laboratory studies of the obtained rock samples have indicated high levels of weathering of the clastic formations.The weathering processes within the sandstones form fissures and rock voids by means of which rainwater flows freely into the deeper parts of the rock mass.The mineral composition of the sandstones includes mostly quartz, accompanied by plagioclases, micas, breccias and heavy minerals in smaller amounts. The binding material is cement-type and clayey-carbonate. The sands occurring at the surface constitute their eluvium, which is evidenced by similar texture qualities of both the sediments. The claystones contain mostly kaolinite and quartz; in their composition minerals from smectite group were also found. They are characterized by very high absorbability, which leads to their swelling and washing out. It has been found that the weathered parts of rocks indicate significantly lowered compressive strength in comparison to the values assumed in case of the rocks of the Orzesze beds.

When does colonisation of a semi-arid hillslope generate vegetation patterns?

Patterned vegetation occurs in many semi-arid regions of the world. Most previous studies have assumed that patterns form from a starting point of uniform vegetation, for example as a response to a decrease in mean annual rainfall. However an alternative possibility is that patterns are generated when bare ground is colonised. This paper investigates the conditions under which colonisation leads to patterning on sloping ground. The slope gradient plays an important role because of the downhill flow of rainwater. One long-established consequence of this is that patterns are organised into stripes running parallel to the contours; such patterns are known as banded vegetation or tiger bush. This paper shows that the slope also has an important effect on colonisation, since the uphill and downhill edges of an isolated vegetation patch have different dynamics. For the much-used Klausmeier model for semi-arid vegetation, the author shows that without a term representing water diffusion, colonisation always generates uniform vegetation rather than a pattern. However the combination of a sufficiently large water diffusion term and a sufficiently low slope gradient does lead to colonisation-induced patterning. The author goes on to consider colonisation in the Rietkerk model, which is also in widespread use: the same conclusions apply for this model provided that a small threshold is imposed on vegetation biomass, below which plant growth is set to zero. Since the two models are quite different mathematically, this suggests that the predictions are a consequence of the basic underlying assumption of water redistribution as the pattern generation mechanism.

Discussion of “Physical and numerical study of lateral diversion by three-layer inclined capillary barrier covers under humid climatic conditions”

The authors investigated the performance of an inclined threelayer cover with capillary barrier effect (CCBE) system comprising silt, sand, and gravel, subjected to a continuous heavy rainfall (Zhan et al. 2014). They compared numerical results and analytical solutions with respect to effective length of lateral diversion of the inclined three-layer CCBE system. The comparison indicated that the analytical solution proposed by Stormont (1996) is relatively conservative. It should be noted that Stormont’s (1996) analytical solution is only applicable to a two-layer CCBE system. In the discussers’ opinion, this analytical solution should be modified to consider capillary effects contributed by both the upper two layers (i.e., silt–sand) and lower two layers (i.e., sand–gravel) in the three-layer CCBE system. The three-layer (silt—sand–gravel) CCBE system investigated by the authors can be simplified as the sum of silt–sand and sandgravel capillary barriers, as shown in Fig. D1. The infiltrated rainwater is first drained laterally along the silt–sand interface to the tip point at which the hydraulic conductivity of the sand layer is equal to that of the silt layer. Subsequently, rainwater flows into the sand layer and is drained laterally along the sand–gravel interface to the tip point at which the hydraulic conductivity of the gravel layer is equal to that of the sand layer. The lateral diversion length of the three-layer CCBE system, Lthree-layer, should be calculated as

Study on Water Balance in Poteran – A Small Island in East Java, Indonesia

Study on water balance in a small island is essential to be conducted. A small island normally has small catchment areas so that most of the surface rain water flows quickly into the sea. Consequently, it causes limited recharge of rainwater into groundwater. When the usage of groundwater is high, the water demand-supply could be unbalance. It will certainly cause problems, such as seawater intrusion or water crisis. There are numbers of small islands in Indonesia; in most of these islands, the water balance has not been studied yet. This paper discusses water balance in Poteran- a small island in East Java, Indonesia. The island area is only 49.8 km2 with population of nearly 50,000 people. The land use in the island is dominated by agricultural areas. In this study, some investigations are conducted including survey of land-surface area, collecting meteorology and climatology data. Thornthwaite approach is used for computing evapotranspiration in water balanced calculation. The results show soil texture dominant is clay loam, with a land use is corn farming (root depth is 0.8 meters), field capacity is estimated 0.25 and permanent wilting point values is 0.12. Precipitation is 1790mm, the potential evapotranspiration is 2047mm, water surplus is 300mm and water deficit is 557 mm a year. The results suggest that the Poteran Island has limited recharge water that could be lead to a water crisis in the future.

Undercutting the surface keeps liquids at bay

Repellent Surfaces![Figure][1] PHOTO: EGDIGITAL/THINKSTOCK The shape of an umbrella is designed both to protect the holder from falling droplets and to have the collected rainwater flow away from the person underneath. Liu and Kim exploited the idea of an umbrella to make materials with a

Can plants keep ruins dry? A quantitative assessment of the effect of soft capping on rainwater flows over ruined walls

The world's stone heritage is constantly decaying. Rainwater is among the most important causes of stone weathering, both directly by facilitating chemical and physical weathering, and indirectly through promoting algal growth. It has deteriorative effects on historic wall surfaces, especially on the faces of ruined walls without a protective roof. To counter this decay two conservation strategies have been deployed: hard capping, which involves consolidating the wall head using mortar and stone, and soft capping, which involves installing a cap of soil covered by vegetation on the wall head. Amongst many benefits of soft capping, it should absorb more rainwater (in a similar way to the well-studied role of green roofs) and shed water away from the wall face. By simulating rain on hard and soft-capped experimental test walls in a temperate climate, and measuring moisture and runoff dynamics, we found that soft caps lowered the amount of rainwater running down the underlying wall face by more than seven times compared to hard caps, a reduction of 87%. Higher absorption and evaporation rates accounted for 89% of this reduction in surface runoff of soft capped walls, whilst 11% was attributable to water shedding. Soft caps facing North-East shed more water than South-West facing caps, probably because of the greater width of overhanging growth on the North-East facing side. Our findings show that soft capping can be an effective strategy to counter stone decay and algal soiling caused by runoff on historic wall faces.

Examples for elimination of selected groups of petroleum-derived compounds from rainwater and meltwater

This study shows examination results pertaining to the assessment of operation of coalescence separations installed on the way of flow of rainwater and meltwater to Słupia river. The study was performed within Słupia river water protection programme. Content of total suspension as well as concentrations of organic compounds from the BTEX and paraffin group were determined in samples taken from the inlet to and outlet from the separators. It appears from the study performed that in no case admissible content (> 15 mg/dm3) of determined petroleum-derived substances had occurred in the samples of rainwater and meltwater and a high degree of elimination of those compounds, due to separators operation, was achieved. In 13 samples taken from the separator outlet, the admissible total suspension content was exceeded (above 100 mg/dm3). Efficiency of all separators operation reflected in the elimination of total suspension amounted, on average, to 67.5%. The lowest total suspension elimination efficiency has been noted for separator No. 14 (40%).

Effect of canopy interception on spatial variability and isotopic composition of throughfall in Japanese cypress plantations

Summary We conducted a field monitoring experiment examining throughfall in Japanese cypress plantations located in Tochigi Prefecture, eastern Japan. A set of 20 tipping-bucket rain gauges and throughfall collectors were placed in a lattice-like distribution throughout a 10 × 10-m experimental plot to investigate the effect of the forest canopy on the spatial variability of throughfall. The isotopic composition of throughfall and open rainfall were analyzed and compared for each rainfall event. A clear relationship between throughfall rate and the radial distance to the nearest tree trunk was observed when the influence of wind was negligible; however, such a systematic pattern of throughfall was not observed during rainfall events that occurred during windy conditions. The δ 18 O and δD values in throughfall varied considerably, reflecting different rainwater flow paths in the saturated canopy. The analysis of stable isotope ratios in the throughfall and its comparison with isotopic composition of rainwater hitting the canopy can help elucidate the interception processes in the forest canopy.

Caracterização geofísica em aterro de resíduos sólidos para avaliação de condicionantes de instabilidade geotécnica

The disposal of solid waste can create environmental problems, in addition to the potential risk of instability even in planned geotechnical works, such as provisions in stacks or high ends of the landfill, because they represent mere adjustments in civil engineering works. The Leme city, SP, generates about 35 t/day of municipal waste, that are deposited in a landfill located in the Barro Preto neighborhood. This work conducted a geophysical survey, based on geotechnical instability evidence in area, for analysis of the conditioners that cause on the sides leachate resurgence landfill and its relationship to mass movements and ravines installation in cover soil, with consequent waste exposure. The results indicate horizons of low resistivity connected with resurgence points generated by the organic matter decomposition contained in the waste. Such horizons result in leachate concentration in some places, which, in turn, may lead to loss of cohesion of the materials constituting the residues mass. The results are areas with mass flow by rotational movements, which, together with the surface flow of rainwater, evolves into ravines and exposed residues, preferably at the resurgence point. The leachate flow on the surface affects areas beyond the limits at landfill with direct impact on local agriculture and risk to pedestrians using the highway bordered by the landfill beyond the soil and the local aquifer.

Investigation and Research on Depth Distribution in Soil of Radionuclides Released by the TEPCO Fukushima Dai-ichi Nuclear Power Plant Accident

ABSTRACTThe accident of the TEPCO Fukushima Dai-ichi Nuclear Power Plant occurred by the 2011 off the Pacific coast of Tohoku Earthquake on 11 Mar. 2011. It is estimated that totally 1.2-1.5x1016 Bq for 137Cs and 1.5-1.6x1017 Bq for 131I were released until the beginning of Apr. and those radionuclides (RN) were deposited on soil surface and forest etc. widely around Fukushima Pref. This work was carried out as one of the investigations for making the distribution maps of radiation dose rate and soil contaminated by RNs which the MEXT promotes. The Geoslicer investigation on the depth distribution of RNs in soil was performed after 3 months from the accident. The investigation was conducted at 11 locations in Nihonmatsu City, Kawamata Town and Namie Town, and soil samples of depth 50 cm to 1 m were taken. Both of 134Cs and 137Cs were detected in all investigated locations, and 129mTe and 110mAg were detected only in locations where radiation dose rates are high. At many locations investigated, radiocaesium more than 99 % distributed within a depth of 10 cm in soil in the surface layer. On the other hand, RNs tended to distribute to deeper part in soil at locations that are supposed to have been used as farmland than in soil in the surface layer, and radiocaesium more than 99 % in soil at locations that are supposed to have been used as farmland also distributed within a depth of around 14 cm. The apparent diffusion coefficients (Da) of RNs derived from penetration profiles near the surface layer showed a tendency to be higher in soil at locations that are supposed to have been used as farmland (Da=0.1-1.5x10-10 m2/s) than in soil in the surface layer (Da=0.65-4.4x10-11 m2/s), and most Da-values were nearly 10-11 m2/s. The distribution coefficients (Kd) by a batch method were in the range of Kd=2,000-61,000 ml/g for Cs and Kd=0.5-140 ml/g for I. Although the Kd-values are different between cation (Cs+) and anion (I-), the Da-values (134Cs, 137Cs, 129mTe and 110mAg) were similar levels. This is considered to be due to that the Da-values were controlled by dispersion by flow of rain water.

Flood Simulation of Upriver District Considering an Influence of Backwater

This study aims to predict inundation and flood-stricken areas more accurately by simulating flood damage caused by reversible flow of rain water in the upper water system through precise 3D terrain model and backwater output. For the upstream of the South Han-River, precise 3D terrain model was established by using aerial LiDAR data and backwater by area was output by applying the storm events of 2002 including the history of flood damage. The 3D flood simulation was also performed by using GIS Tool and for occurrence of related rainfall events, inundation events of the upriver region of water system was analyzed. In addition, the results of flood simulation using backwater were verified by making the inundation damage map for the relevant area and comparing it with flood simulation's results. When comparing with the results of the flood simulation applying uniformly the gauging station's water surface elevation used for the existing flood simulation, it is found that the results of the flood simulation using backwater are close to the actual inundation damage status. Accordingly, the causes of flood occurred in downstream of water system and upstream that has different topographic characteristics could be investigated and applying the simulation with backwater is proved more proper in order to procure accuracy of the flood simulation for the upriver region.

Temporal and spatial changes in dissolved organic carbon concentration and fluorescence intensity of fulvic acid like materials in mountainous headwater catchments

Dissolved organic carbon (DOC) such as humic substances are key to understanding the aquatic environment in catchments, because they, containing a large number of phenolic and carboxylic acid groups, adsorb many kinds of inorganic materials and also affect nutrition and carbon transport in catchments. To understand the detailed DOC dynamics, we conducted hydrological observations at mountainous headwater catchments dominated by different vegetation types (planted evergreen coniferous forest of 1.29 ha and natural deciduous broadleaf forest of 1.28 ha). The relationship between DOC concentrations and fluorescence intensity of fulvic acid-like materials (F-FAM) were positively correlated in both catchments but different between soil extracts, baseflow, and near surface flow represented by biomat flow. The ratios of change in F-FAM to that in DOC concentration (F-FAM/DOC) were higher in the baseflow (about 6 in both catchments) and lower in the soil extracts (about 4.5 in both catchments, respectively). However, the relationship in stormflow was distributed between the trends of baseflow and soil extracts. The higher F-FAM/DOC in baseflow may thus indicate that DOC (and FAM) in groundwater discharge mainly contributed to the stream flow, and the stormflow mainly reflect subsurface flow through soil during most rainstorms. In contrast, a high F-FAM/DOC ratio (>6) appeared in the stormflow of both catchments especially during large storms of short duration and high intensity following a dry antecedent period. The F-FAM/DOC in biomat flow developing distinctly in the coniferous catchment was high (about 6.5). Thus, rapid shallow subsurface flow through the biomat or near-surface of slopes might explain the unique transport dynamics of DOC and FAM in stormflows with the high F-FAM/DOC ratio. These results imply that the DOC and FAM relationship responds variably depending on both the distribution of soil organic matter and rainwater flow paths in steep slopes as well as on storm size and characteristics.

绿色屋顶径流氮磷浓度分布及赋存形态

为了解绿色屋顶暴雨径流的氮磷浓度分布及赋存形态,在重庆大学构建了两种绿色屋顶,于2009年9月至2011年10月期间进行了绿色屋顶和对照屋面的暴雨径流水质监测。研究结果表明,绿色屋顶暴雨径流pH值在7.7左右,氨氮浓度满足地表水环境质量标准Ⅲ类标准;总氮、总磷、硝酸根的平均浓度分别为3.6-4.4 mg/L、0.17-0.28 mg/L和3.1-3.7 mg/L,均高于降雨雨水浓度;与对照屋面暴雨径流相比,同时期的绿色屋顶暴雨径流中总氮、氨氮和总磷浓度较低,而硝酸根、磷酸根浓度较高。绿色屋顶暴雨径流水质的季节差异明显,夏季污染物浓度较低,而春秋季节污染物浓度较高;总体上看,随绿色屋顶运行时间的延长,暴雨径流中总氮和硝酸根浓度逐渐降低,而总磷和磷酸盐浓度则呈现出一定的波动性。气象因素、降雨雨水水质与绿色屋顶暴雨径流水质的相关性分析表明,气温越高、前期干旱时间越长,越有利于绿色屋顶径流中氨氮浓度的降低;绿色屋顶径流中的总磷和氨氮主要来自降雨。研究结果为绿色屋顶的科学构建和城市暴雨径流管理提供了重要参考。;With the development of urbanization, urban nonpoint source pollution has become the main reason for deterioration of water quality in receiving water body. Green roof is one of the important technologies for controlling urban nonpoint source pollution, which has been taken as an important component of technical system in many advanced concepts for the management of urban stormwater runoff. Green roofs not only provide many general environmental and associated aesthetic, but also play an important role in increasing the green space in densely populated urban areas. So, with increasing of research interests in vegetated roof, more and more such installations are being built in urban regions. However, the water quality of runoff from green roof has been paid little attention so far, and always been consumed clean. Results from recent studies show that green roofs always become source of some pollutants, especially nitrogen and phosphor. The water quality of green roof runoff can be influenced by many factors, such as green roof media, plants vegetated, rainfall intensity, and so on. As long as the water quality issues remain outside the design phase, there is a large potential for green roofs to become pollution sources. So, it is very important to investigate runoff water quality from green roofs under different environment and installation methods. In this paper, in order to investigate the concentrations distribution and composition of nitrogen and phosphor in stormwater runoff from green roofs, two types of green roofs were constructed in Chongqing University and the water quality of storm runoff from them and the reference roof were monitored from September 2009 to October 2011. Results show that green roofs can improve pH of rainwater from 5.5 to 7.7, which indicates the rapid neutralization for the acid depositions and an environmental benefit in case roof runoff is directly discharged to natural water recipients. The concentrations of NH₃-N in runoff from green roof are lower than the value as requested in standard Ⅲ of Environmental Quality Standards for Surface Water, so, nitrification occurs when rainwater flows through green roofs. The mean concentrations of TN, TP and NO₃^--N in storm runoff are 3.6-4.4mg/L, 0.17-0.28 mg/L and 3.1-3.7mg/L respectively, which are higher than that in rain water. Compared with the water quality of contemporaneous stormwater runoff from reference roof, the concentrations of TN, NH₃-N and TP in runoff from green roofs are lower relatively, while the concentrations of NO₃^--N and PO₄^3--P are higher. The water quality of stormwater runoff from green roofs varies significantly with seasons, which is better in summer and worse in spring and autumn. Overall, the concentrations of TN and NO₃^--N in runoff from green roofs decrease gradually when they are operated for long term, while that of TP and PO₄^3--P shows fluctuations. Analysis of Pearson correlations among meteorological factors indicates that the higher temperature and longer drying period, the more decrease of concentration of NH₃-N. The TP and NH₃-N of runoff in green roofs come from rain water primarily. This study can give an important reference for the construction of green roofs and the management of urban stormwater runoff.

OBSERVATIONS OF SALINITY PATTERNS IN SHALLOW GROUNDWATER AND DRAINAGE WATER FROM AGRICULTURAL LAND IN THE NORTHERN PART OF THE NETHERLANDS

ABSTRACTIn studies concerning rainwater lenses on a parcel scale in brackish polder areas it is assumed that infiltrated rainwater flows through the rainwater lens and seeps to the watercourses. This freshwater system is supposed to be superimposed on the brackish diffuse upward seepage system. This study investigates the influence of field drainage on the dynamic behaviour of fresh rainwater lenses and the risk of salinization of the root zone. Observations presented in this paper show that shallow water and salt movements in clayey polders are more complex and more dynamic than previously thought.On 18 parcels 2D geo‐electrical resistivity imaging profiles were measured, which give a good spatial and temporal representation of the salinity distribution of the groundwater. It appears that during wet periods upconing of brackish groundwater appears under pipe drains and ditches, which drain a mixture of fresh meteoric water and deep brackish groundwater. Between drainpipes small rainwater lenses develop. During the dry season, when the groundwater table drops below the drainage level, brackish soil moisture stays behind. Transpiration of the crops rooted in the clayey polder soils result in strong capillary rise of salts, which may even reach the root zone in some places. Copyright © 2011 John Wiley & Sons, Ltd.

The possibility analysis of habitats, origin and reappearance of bloom green alga (Enteromorpha prolifera) on inshore of western Yellow Sea

Combining some information from field investigation of algae along the coastal areas in China and a few pictures materialized from the western Yellow Sea in 2008, authors analyze the necessary conditions and possible water area in China producing a large biomass, some reasons for firestorm, and the possibility of the reappearance of marine bloom green alga Enteromorpha prolifera. The change of habitats and the increase of nutritional levels related to the water area could be considered as direct reasons. It was transferred northward by the combination of the flow of rainwater, wind and alongshore marine current. The original region of large biomass produced is possibly located in the southwestern Yellow sea. It will possibly be appearing again in the coming years or in the future. A summary is also given referring to its reproduction, development and distribution worldwide.

Ten-year chemical evolution of leachate and municipal solid waste incineration bottom ash used in a test road site

The use of municipal solid waste incineration (MSWI) bottom ash for road and car-park construction is an appropriate solution to reduce their disposal and the consumption of natural materials. In addition to leaching tests, the environmental impact assessment of such a waste recycling scenario critically needs for reliable long-term field data. This paper addresses a 10-year pilot site where MSWI bottom ashes have been used as road aggregates in Northern France (oceanic temperate climate). The paper focuses on the long-term evolution of leachate chemistry and the mineralogical transformations of MSWI bottom ash over 10 years. Data interpretation is supported by geochemical modeling in terms of main pH-buffering processes. The leachate pH and concentrations in major elements (Ca, Na and Cl) as well as in Al and heavy metals (Cu, Pb and Zn) quickly drop during the first 2 years to asymptotically reach a set of minimum values over 10 years; similar to those of a reference road built with natural calcareous aggregates. SO 4 release makes exception with a slightly increasing trend over time. Carbonation induced by CO 2 inputs, which leads to the successive dissolution of portlandite, CSH and ettringite, is one of the main phenomenon responsible for the geochemical evolution of leachate. On the other hand, mineralogical observations and batch tests demonstrate a relative stability of the MSWI bottom ash inside the subbase layer. In particular, carbonation may be far to be completed and still in progress after 10 years. This is consistent with preferential rainwater flow and dilution at the road edges combined to diffusion inside the subbase layer.

Fractal analysis of temperature-induced cracking in clays and rocks

Because of their low hydraulic conductivity, clays have been used as a hydraulic barrier to the flow of rainwater into landfills. Similarly, rocks have been used as depository sites for nuclear waste. High temperatures resulting from climatic fluctuations, for clays, or from heat generated by nuclear waste, for rocks, can have detrimental effects on their hydro-mechanical properties, causing cracking. In clays this is the result of desiccation; in rocks it is the result of varying expansion between mineral grains. The present study deals with the evolution and interconnectivity of cracks in clays and rocks as a result of high temperatures, evaluated using the fractal dimension concept.

The Effect Analysis of the Decentralized Rainwater Management System in Korea Apartment Complex

In this study, the effect of the decentralized rainwater management facility in Korean apartment complexes is analyzed. The experimental site is Singal 1 tenant apartment complex in Yongin, Korea. An underground rainwater storage tank, an infiltration barrel and an infiltration trench are applied. Rainwater flows through rainwater management facility and then it is stored or infiltrated into the underground. Experiment is run with the natural rainfall and artificial rainfall. Rainwater runoff reduction and pollution load reduction effect are analyzed. The rate of runoff reduction is compared with runoff discharge. The rate of pollution load reduction is analyzed with the water quality test on the inflow and the outflow.

Past and future colouring patterns of historic stone buildings

The patterns of colour on stone buildings change with time. Buildings were blackened by coal soot, but now mostly diesel particles and in future, wind-driven rain may alter the patterns and oxidation of surface organics. Colouring patterns that outline or shadow architectural elements are publicly more acceptable than those that cut across them e.g. rain streaking. Thresholds of acceptability for blackening can be related to soot loading. When soot loading of the ambient air is high, e.g. near busy roads, buildings are dark and typically viewed as unacceptable. However at lower concentrations (2-3 μg m -3 elemental carbon), building appearance is typically seen as more acceptable. The future offers a potential for variation in building colour, arising through different biological growth under changing climates or the presence of different pollutants. In future urban atmospheres more dominated by organic pollutants a yellowing process may be more important. Diesel soot has many organic compounds that can oxidise to brownish-coloured humic-like (HULIS) materials. We illustrate the development of colour patterns on the Cathedral Church of St John the Baptist, Norwich UK from its opening (beginning of the 20th century) to the end of the 21st century derived from historic photographs, observations and predictions for the future appearance. The latter has to consider removal of deposits by changed rainwater flow and enhanced biological activity. Blackening from coal smoke may have reached a peak around 1960s and 1970s, but diesel soot predominates now.