Modeling Equitable Distribution of Water: Dynamic Inversion-Based Controller Approach

It is a well-known fact that most of the developing countries have intermittent water supply and the quantity of water supplied from the source is also not distributed equitably among the consumers. Aged pipelines, pump failures, and improper management of water resources are some of the main reasons for it. This study presents the application of a nonlinear control technique to overcome this problem in different zones in the city of Bangalore. The water is pumped to the city from a large distance of approximately 100km over a very high elevation of approximately 400m. The city has large undulating terrain among different zones, which leads to unequal distribution of water. The Bangalore, inflow water-distribution system (WDS) has been modeled. A dynamic inversion (DI) nonlinear controller with proportional integral derivative (PID) features (DI-PID) is used for valve throttling to achieve the target flows to different zones of the city. This novel approach of equitable water distribution using DI-PID controllers that can be used as a decision support system is discussed in this paper.

Seasonal Blowfly Distribution and Abundance in Fragmented Landscapes. Is It Useful in Forensic Inference about Where a Corpse Has Been Decaying?

Blowflies are insects of forensic interest as they may indicate characteristics of the environment where a body has been laying prior to the discovery. In order to estimate changes in community related to landscape and to assess if blowfly species can be used as indicators of the landscape where a corpse has been decaying, we studied the blowfly community and how it is affected by landscape in a 7,000 km(2) region during a whole year. Using baited traps deployed monthly we collected 28,507 individuals of 10 calliphorid species, 7 of them well represented and distributed in the study area. Multiple Analysis of Variance found changes in abundance between seasons in the 7 analyzed species, and changes related to land use in 4 of them (Calliphora vomitoria, Lucilia ampullacea, L. caesar and L. illustris). Generalised Linear Model analyses of abundance of these species compared with landscape descriptors at different scales found only a clear significant relationship between summer abundance of C. vomitoria and distance to urban areas and degree of urbanisation. This relationship explained more deviance when considering the landscape composition at larger geographical scales (up to 2,500 m around sampling site). For the other species, no clear relationship between land uses and abundance was found, and therefore observed changes in their abundance patterns could be the result of other variables, probably small changes in temperature. Our results suggest that blowfly community composition cannot be used to infer in what kind of landscape a corpse has decayed, at least in highly fragmented habitats, the only exception being the summer abundance of C. vomitoria.

The distribution and concentration levels of trace metals in water and sediments of Lake Victoria, Kenya

The water and bottom sediments of Lake Victoria (Kenya) were analysed for A1, Fe, Mn, Zn, Pb, Cu, Cr and Cd. The total metal concentrations were determined and their mean variations and distributions discussed. The bottom lake waters showed higher concentration levels than the surface waters. The range of values (in mg/l) in the bottom and surface lake waters were as follows: Surface Waters: A1(0.08 - 3.98), Fe(0.09 - 4.01), Mn(0.02 - 0.10). Zn(0.01 -0.07), Pb(0.001- 0.007), Cu(not detected - 0.006), Cr(not detected - 0.004). Bottom Waters: A1(0.1 0 - 6.59), Fe(0.23 - 9.64), Mn(0.04 - 0.39), Zn(0.01- 0.08), Pb(0.002 - 0.009), Cu(not detected - 0.03). Cr(not detected -0.002). River mouths and shallow areas in the lake showed higher total metal concentrations than offshore deeper areas. Apart from natural metal levels, varied urban activities and wastes greatly contribute to the lake metal pollution as shown by high Pb and Zn levels in sediments, around Kisumu and Homa Bay areas. Other comparatively high values and variations could be attributed to the varied geological characteristics of the lake and its sediments. Compared to the established W.H.O (1984) drinking water standards manganese, aluminium and iron levels were above these limits whereas zinc, lead, chromium, copper and cadmium were below.

The accumulation of alkylphenols in submersed plants in spring in urban lake, China

The concentrations of alkylphenols (APs) were investigated in water, sediments and submersed macrophytes from the Moon Lake, Wuhan city, China. The water samples contained APs, ranging up to 26.4 mu g l(-1) for nonylphenol (NP) and 0.68 mu g l(-1) for octylphenol (OP). APs were found in the sediment samples with concentrations ranging from 4.08 to 14.8 for NP and from 0.22 to 1.25 mu g l(-1) dry weight for OP. The samples from the site near former sewage inlet showed the highest concentrations of APs in both water and sediments. The results of distribution pattern and dynamics of NP and OP in submersed macrophytes of the Moon Lake showed that the two pollutants were all found in Myriophyllum verticillatum, Elodea nuttallii, Ceratophyllum oryzetorum, and Potamageton crispus collected from the Moon Lake. For NP, M. verticillatum had the highest capacity of accumulation, followed by E. nuttallii, C. oryzetorum and P. crispus. However the distribution pattern of OP differed from that of NP, and the highest amount of accumulation was observed in E. nuttallii, followed by M. verticillatum, P. crispus, and C. oryzetorum. The temporal pattern of APs was also observed in submersed macrophytes from March to May, and the highest accumulation period was in May. (c) 2008 Elsevier Ltd. All rights reserved.

Nonylphenol and octylphenol in urban eutrophic lakes of the subtropical China

The paper studied two estrogenic pollutants, 4-nonylphenol (NP) and 4-tert-octylphenol (OP) in water, suspended particle (SP) and sediments in urban eutrophic lakes. The concentrations of NP ranged from 1.94 to 32.85 mu g/l, 0.876 to 31.13 mu g/l and 3.54 to 32.43 mu g/g dry weight (dw) in water, suspended particle (SP) and sediments, respectively, and that of OP from 0.027 to 1.44 mu g/l, 0.008 to 1.777 mu g/l and 0.058 to 1.245 mu g/g dw in water, suspended particle (SP) and sediments, respectively. An increasing trend in the concentration was noticed in all matrices close to the sewage inlets, which was found to be the major factor affecting the spatial distribution of alkylphenols (APs) in the lakes. Due to restoration of submerged macrophytes, which might accumulate APs, the contaminations of APs in the Little Moon Lake (LML) and the Little Lotus Lake (LLL) were lower than those in the Big, Moon Lake (BML) and the Bier Lotus Lake (BLL). A reasonable correlation of NP and OP was obtained among water, suspended particle and sediment. The possible environmental stress of APs concentration on aquatic organisms in Wuhan urban lakes was also discussed.

Urban functional structure characteristics and transformation in China

The paper analyzes urban functional structure characteristics of Chinese cities in 1996 using the Nelson method. The manufacturing employment percentage is much higher in metropolitan areas but is decreasing from 1989 to 1996. On the other hand, the weight of science, education, culture, hygiene, finance, insurance and real estate increases. The employment structure changes dramatically. Although the urbanization level of China is lower than that of the USA in 1955, the frequency distribution curve of urban functions is similar. The construction, transportation, commerce, finance, insurance, real estate, science, education, culture, hygiene and administration curves are normal. The mining employment converges on minor cities and the distribution is not normal. The urban function has changed with urban scale. The bigger the cities are, the smaller the manufacture, mining and construction employment weights, and the larger are the science, education, finance, insurance, real estate and administration weights. Commerce and transportation are distributed evenly and the difference is less. From the comparison in three zones of China, the employment percentage of manufacture, finance, insurance and real estate is higher in eastern coastal areas, while the employment percentage of science, education, administration is higher in western areas. (C) 2002 Elsevier Science Ltd. All rights reserved.

Spatial distribution of soil heavy metal pollution estimated by different interpolation methods: Accuracy and uncertainty analysis

Mapping the spatial distribution of contaminants in soils is the basis of pollution evaluation and risk control. Interpolation methods are extensively applied in the mapping processes to estimate the heavy metal concentrations at unsampled sites. The performances of interpolation methods (inverse distance weighting, local polynomial, ordinary kriging and radial basis functions) were assessed and compared using the root mean square error for cross validation. The results indicated that all interpolation methods provided a high prediction accuracy of the mean concentration of soil heavy metals. However, the classic method based on percentages of polluted samples, gave a pollution area 23.54-41.92% larger than that estimated by interpolation methods. The difference in contaminated area estimation among the four methods reached 6.14%. According to the interpolation results, the spatial uncertainty of polluted areas was mainly located in three types of region: (a) the local maxima concentration region surrounded by low concentration (clean) sites, (b) the local minima concentration region surrounded with highly polluted samples; and (c) the boundaries of the contaminated areas. (C) 2010 Elsevier Ltd. All rights reserved.

A method of assessing air toxics concentrations in urban areas using mobile platform measurements.

The objective of this paper is to demonstrate an approach to characterize the spatial variability in ambient air concentrations using mobile platform measurements. This approach may be useful for air toxics assessments in Environmental Justice applications, epidemiological studies, and environmental health risk assessments. In this study, we developed and applied a method to characterize air toxics concentrations in urban areas using results of the recently conducted field study in Wilmington, DE. Mobile measurements were collected over a 4- x 4-km area of downtown Wilmington for three components: formaldehyde (representative of volatile organic compounds and also photochemically reactive pollutants), aerosol size distribution (representing fine particulate matter), and water-soluble hexavalent chromium (representative of toxic metals). These measurements were,used to construct spatial and temporal distributions of air toxics in the area that show a very strong temporal variability, both diurnally and seasonally. An analysis of spatial variability indicates that all pollutants varied significantly by location, which suggests potential impact of local sources. From the comparison with measurements at the central monitoring site, we conclude that formaldehyde and fine particulates show a positive correlation with temperature, which could also be the reason that photochemically generated formaldehyde and fine particulates over the study area correlate well with the fine particulate matter measured at the central site.

Deforestation and the spatio-temporal distribution of savannah and forest members of the Simulium damnosum complex in southern Ghana and south-western Togo

Spatio-temporal data on cytotaxonomic identifications of larvae of different members of the Simulium damnosum complex collected from rivers in southern Ghana and south-western Togo from 1975 until 1997 were analysed. When the data were combined, the percentages of savannah blackflies (S. damnosum sensu stricto and S. sirbanum) in the samples were shown to have been progressively increasing since 1975. The increases were statistically significant (P < 0·001), but the rates of increase were not linear. Further analyses were conducted according to the collection seasons and locations of the samples, to account for possible biases such as savannah flies occurring further south in the dry season or a preponderance of later samples from northern rivers having more savannah flies. These analyses showed that the increasing trend was statistically significant (P< 0·0001) only during the periods April to June and October to December. The presence of adult savannah flies carrying infective larvae (L3) indistinguishable from those of Onchocerca volvulus in the study zone was confirmed by examinations of captured flies. The percentages of savannah flies amongst the human-biting populations and the percentages with L3s in the head were higher during dry seasons than wet seasons and the savannah species were found furthest south (5 °25′N) in the dry season. Comparisons of satellite images taken in 1973 and 1990 over a study area in south-western Ghana encompassing stretches of the Tano and Bia rivers demonstrated that there have been substantial increases in urban and savannah areas, at the expense of forest. This was so not only for the whole images but also for subsamples of the images taken at 1, 2, 4, 8 and 16 km distant from sites alongside the River Tano. At every distance from the river, the percentages of pixels classified as urban or savannah have increased in 1990 compared with 1973, while those classified as degraded or dense forest have decreased. The possibility that the proportionate increases in savannah forms of the vectors of onchocerciasis, and hence in the likelihood of the transmission of savannah strains of the disease in formerly forested areas, were related to the decreases in forest cover is discussed.

The comparative advantage of the public sector in the development of urban water supply

This paper addresses the potential of public water operations in achieving developmental goals such as the Millennium Development Goals, and argues that the public sector has a comparative advantage in developing water services. The global importance of the public sector in urban water supply is examined through a review of current practice in the world's largest cities, including operational presence and distribution and ongoing trends. Empirical evidence shows that, in transition and developing countries, public operators are capable of undergoing successful reform. One explanatory factor is proposed to be the creation through the public sphere of highly interconnected networks among stakeholders. Such accountability networks act as vehicles for the generation and distribution of public knowledge among stakeholders, which in turn inform rational decision making on the reform and management of operations.

Aquatic Distribution And Heterotrophic Degradation Of Polycyclic Aromatic-Hydrocarbons (PAH) In The Tamar Estuary

Variations in the concentrations and microheterotrophic degradation rates of selected Polycyclic Aromatic Hydrocarbons (PAH) in the water column of the Tamar Estuary were investigated in relation to the major environmental variables. Concentrations of individual PAH varied typically between i and 50 ng l−1 Based on their observed environmental behaviour the PAH appeared divisible into two groupings: (1) low molecular weight PAH incorporating naphthalene, phenanthrene and anthracence and (a) the larger molecular weight homologues (fluoranthene, pyrene, chrysene, benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)-pyrene). Group 1 PAH showed a complex distribution throughout the estuary with no significant correlations with either salinity or suspended particulates. Based on their relatively low particle affinity and high water solubilities and vapour pressures, volatilization is proposed as an important process in determining their fate. Microheterotrophic turnover times of naphthalene varied between x and 30 days, and were independent of suspended solids with maximum degradation rates located in the central and urban regions of the Estuary. When compared with the flushing times for the Tamar (3–5 days), it is probable that heterotrophic activity is important in the removal of naphthalene (and possibly the other Group 1 PAH) from the estuarine environment. In contrast Group 2 PAH concentrations exhibited highly significant correlations with suspended particulates. Highest concentrations occurred at the turbidity maximum, with a secondary concentration maximum localized to the industrialized portion of the estuary and associated with anthropogenic inputs. Laboratory degradation studies of benzo(a)pyrene in water samples taken from the estuary showed turnover times for the compound of between 2000 and 9000 days. Degradation rates correlated positively with suspended solids. The high particulate affinity and microbial refractivity of Group 2 PAH indicate sediment burial as the principal tate of these PAH in the Tamar Estuary. Estuarine sediments contained typically 50–1500 ng g−1 dry weight of individual PAH which were comparable to the levels of Group 2 PAH associated with the suspended particulates. Highest concentrations occurred at the riverine end of the estuary resulting from unresolved inputs in the catchment. Subsequent dilution by less polluted marine sediments together with slow degradation results in a seaward trend of decreasing concentrations. However, there is a secondary maximum of PAH superimposed on this trend which is associated with urban Plymouth.

Controls on the contemporary distribution of lake thecamoebians (testate amoebae) in the Greater Toronto Area and their potential as water quality indicators.

Thecamoebians were examined from 71 surface sediment samples collected from 21 lakes and ponds in the Greater Toronto Area to (1) elucidate the controls on faunal distribution in modern lake environments; and (2) to consider the utility of thecamoebians in quantitative studies of water quality change. This area was chosen because it includes a high density of kettle and other lakes which are threatened by urban development and where water quality has deteriorated locally as a result of contaminant inputs, particularly nutrients. Fifty-eight samples yielded statistically significant thecamoebian populations. The most diverse faunas (highest Shannon Diversity Index values) were recorded in lakes beyond the limits of urban development, although the faunas of all lakes showed signs of sub-optimal conditions. The assemblages were divided into five clusters using Q-mode cluster analysis, supported by Detrended Correspondence Analysis. Canonical Correspondence Analysis (CCA) was used to examine species-environment relationships and to explain the observed clusterings. Twenty-four measured environmental variables were considered, including water property attributes (e.g., pH, conductivity, dissolved oxygen), substrate characteristics, sediment-based phosphorus (Olsen P) and 11 environmentally available metals. The thecamoebian assemblages showed a strong association with phosphorus, reflecting the eutrophic status of many of the lakes, and locally to elevated conductivity measurements, which appear to reflect road salt inputs associated with winter de-icing operations. Substrate characteristics, total organic carbon and metal contaminants (particularly Cu and Mg) also influenced the faunas of some samples. A series of partial CCAs show that of the measured variables, sedimentary phosphorus has the largest influence on assemblage distribution, explaining 6.98% (P < 0.002) of the total variance. A transfer function was developed for sedimentary phosphorus (Olsen P) using 58 samples from 15 of the studied lakes. The best performing model was based on weighted averaging with inverse deshrinking (WA Inv, r jack 2= 0.33, RMSEP = 102.65 ppm). This model was applied to a small modern thecamoebian dataset from a eutrophic lake in northern Ontario to predict phosphorus and performed satisfactorily. This preliminary study confirms that thecamoebians have considerable potential as quantitative water quality indicators in urbanising regions, particularly in areas influenced by nutrient inputs and road salts.

The photography and the motion landscape in the urban expressway

A new kind of photographic representation, called movement-image is proposed and discussed to record the visual experience of the journey through urban highways. It consists of performing long exposure photographic shots while the track is traversed, thus registering a time-panorama which includes landscape signs and inner spaces of the ways involved. This proposal is linked to the limitations of representing these expressways, if they are understood as structures of instrumental origin, where the resulting experience comes from moving at high speed through the territory. In al almost all cases the aesthetic approach or urban integration with the city and landscape are excluded. In this sense, although such structures may be an opportunity to collect, build and colonize the urban landscape, the lack of adequate representation of the phenomenon causes a difficulty in its understanding and transformation. The options for representation using photography is assumed, knowing its own particular tradition in the use of long exposures, for the expression of the mobile, and the multiple visual attention, divided or weakened.

Climate change response in Europe: What's the reality? Analysis of adaptation and mitigation plans from 200 urban areas in 11 countries

Urban areas are pivotal to global adaptation and mitigation efforts. But how do cities actually perform in terms of climate change response? This study sheds light on the state of urban climate change adaptation and mitigation planning across Europe. Europe is an excellent test case given its advanced environmental policies and high urbanization. We performed a detailed analysis of 200 large and medium-sized cities across 11 European countries and analysed the cities' climate change adaptation and mitigation plans. We investigate the regional distribution of plans, adaptation and mitigation foci and the extent to which planned greenhouse gas (GHG) reductions contribute to national and international climate objectives. To our knowledge, it is the first study of its kind as it does not rely on self-assessment (questionnaires or social surveys). Our results show that 35 % of European cities studied have no dedicated mitigation plan and 72 % have no adaptation plan. No city has an adaptation plan without a mitigation plan. One quarter of the cities have both an adaptation and a mitigation plan and set quantitative GHG reduction targets, but those vary extensively in scope and ambition. Furthermore, we show that if the planned actions within cities are nationally representative the 11 countries investigated would achieve a 37 % reduction in GHG emissions by 2050, translating into a 27 % reduction in GHG emissions for the EU as a whole. However, the actions would often be insufficient to reach national targets and fall short of the 80 % reduction in GHG emissions recommended to avoid global mean temperature rising by 2 °C above pre-industrial levels. © 2013 Springer Science+Business Media Dordrecht.