Diversity analysis of water sources, uses, and flows from source to use in the USA.

Diversifying a system can reduce risk from- and increase resilience to perturbation. For this reason, the concept of diversity has been used in many different fields but its use in analyzing engineering infrastructure has been limited. In particular, the diversity of water sources and uses and the diversity of how sources are connected to uses (flow) have never been analyzed. In addition, the relationships between diversity and economic efficiency of water systems remain uncertain. In this study, we addressed these topics by conceptualizing and quantifying water source, use, and flow diversity in the USA. Water source and water use data were collected from the US Geological Survey for 2000, 2005, and 2010. Diversity was calculated with the Shannon Weaver Index. The overall mean water use diversity by state was 0.79 ±â€¯0.31 (N = 150) and increased from 0.63 ±â€¯0.31 in 2000 to 0.89 ±â€¯0.28 by 2010, reflecting overall decreases in high-use categories, like thermonuclear power, and relative increases in already low domestic use. In contrast, source diversity showed no change over time, with an overall state mean of 0.82 ±â€¯0.28 (N = 150) but varying between states largely due to differences in geographic and climatic factors influencing regional water sources. Water flow diversity also showed no change over time, averaging 1.00 ±â€¯0.43 (N = 150), higher than both source and use diversity. The mean water use efficiency for all states over the study period was 52 ±â€¯60 $/m3 of water and was positively and strongly related to both source and use diversity. Thus, the USA water system diversity is sensitive to factors logically expected to influence both source and use, and directly affects water use efficiency.

Index-based and compliance assessment of water quality for a Brazilian subtropical reservoir / Avaliação da qualidade da água baseada em índices e da conformidade ao enquadramento de um reservatório subtropical brasileiro

ABSTRACT The Passaúna catchment is part of the Upper Iguaçu watershed and includes a water supply reservoir for over 500,000 inhabitants of Curitiba metropolitan region. The aim of this study was to establish the state of reservoir water quality, and whether it has undergone any recent medium- and long-term variations. A physical-chemical-biological assessment was undertaken using nine indicators and three indexes: Water Quality Index (WQI), Trophic State Index (TSI) and Shannon-Weaver Index (H') for macroinvertebrate diversity. Compliance with the prescribed quality standards for the water body was verified using frequency curves. Two WQI calculation approaches were contrasted to test for conditions of partial data unavailability. Temporal trends in key parameters were assessed using Spearman's rank correlation coefficient. WQI results from 1991-2014 indicated that the water quality may be classified as good and improved in the final decade of such period, while most TSI results were in the oligotrophic/mesotrophic range, but with no significant temporal trend. The biodiversity result of H'=1.6 obtained with data acquired in 2014 indicated a moderately degraded ecosystem that is typically associated with flow regulation and a degree of water quality impairment. Such a multi-indicator integrated physical-chemical-biological monitoring approach comprised a robust framework for assessments of medium-long term aquatic health.

RESUMO A bacia do rio Passaúna situa-se na parte superior da Bacia do Rio Iguaçu e inclui um reservatório de águas de abastecimento público para mais de 500 mil habitantes da região metropolitana de Curitiba. O objetivo deste estudo foi avaliar a qualidade das águas desse reservatório e identificar eventuais ocorrências de tendência temporal de variação. O estudo de características físicas, químicas e biológicas do corpo de água envolveu dados históricos e recém-adquiridos de nove indicadores e três índices: Índice de Qualidade das Águas (WQI), Índice de Estado Trófico (TSI) e Índice de Diversidade de Shannon-Weaver (H') para diversidade de macroinvertebrados. A conformidade aos padrões de qualidade prescritos foi analisada com base em curvas de permanência de qualidade de água. Duas formas de cálculo do WQI foram contrastadas para averiguar o efeito de disponibilidade incompleta de dados. Tendências temporais em parâmetros-chave foram buscadas com o teste de correlação de Spearman. Os resultados do WQI, entre 1991 e 2014, indicaram que a qualidade da água do reservatório pode ser classificada como "boa", apresentando tendência estatisticamente significativa de melhoria na última década de tal período. Os resultados obtidos para o TSI ficaram na faixa oligotrófico/mesotrófico e sem tendência significativa de variação temporal. O resultado de biodiversidade do H'=1,6, obtido com dados adquiridos em 2014, indicou um ecossistema aquático moderadamente degradado, tipicamente associado com o represamento de cursos de água e com um certo grau de comprometimento da qualidade da água. A abordagem integradora multi-indicadores de aspectos físicos, químicos e biológicos adotada neste estudo conferiu robustez à avaliação realizada da qualidade de água do corpo de água no médio-longo prazo.

Interrelationship between physico-chemical characteristics of a tropical lake and their impact on biodiversity of planktons.

The physicochemical parameters including temperature, pH, dissolved O2, free CO2, total alkalinity, permanent hardness, salinity, transparency, specific conductivity, BOD, COD, phosphate and nitrate were studied in a tropical lake, called Bonhooghly Lake (situated at Baranagar, Kolkata) around the year 2014 and the correlation between the said parameters, as well as their impact on Biodiversity indices were made. There is stable increase of CO2 content in water from August (27.24 mg l-1) and afterwards due to decaying of plant materials. Therefore there is a slight fall of pH (7.1). Significant negative correlation (p<0.01) between pH and CO2 content was also obtained. It also shows a significant negative correlation with O2 content as well. During February and March transparency of water falls significantly with the increase of algal bloom. It significantly decreases dissolved O2 content and pH but increases free dissolved CO2 (p<0.01). Phosphate has a definite correlation with nitrate content of the Lake, possibly because both are among the most essential nutrients of living system. Increase of one obviously indicates escalation of other. During the early months of the year phosphate and nitrate content of water increased steadily (up to 0.13 and 1.85 mg l-1 respectively) and a very high number of Chlamydomonas(up to15100 l-1) and Chlorella (up to 13140 l-1)were observed. Species richness indices (Menhinick's index) of Phytoplanktons were observed maximum in the month of May, dominance (Simpson's index) in January and diversity (Shannon-Weaver index) in April. Zooplanktons also followed the same trend indicating close interdependence. It was significant that apart from other factors, temperature played a most pivotal role in bringing the diversity in the plankton community.

Biofouling of reverse-osmosis membranes during tertiary wastewater desalination: microbial community composition.

Reverse-osmosis (RO) desalination is frequently used for the production of high-quality water from tertiary treated wastewater (TTWW). However, the RO desalination process is often hampered by biofouling, including membrane conditioning, microbial adhesion, and biofilm growth. The vast majority of biofilm exploration concentrated on the role of bacteria in biofouling neglecting additional microbial contributors, i.e., fungi and archaea. To better understand the RO biofouling process, bacterial, archaeal and fungal diversity was characterized in a laboratory-scale RO desalination plant exploring the TTWW (RO feed), the RO membrane and the RO feed tube biofilms. We sequenced 77,400 fragments of the ribosome small subunit-encoding gene (16S and 18S rRNA) to identify the microbial community members in these matrices. Our results suggest that the bacterial, archaeal but not fungal community significantly differ from the RO membrane biofouling layer to the feedwater and tube biofilm (P < 0.01). Moreover, the RO membrane supported a more diverse community compared to the communities monitored in the feedwater and the biofilm attached to the RO feedwater tube. The tube biofilm was dominated by Actinobacteria (91.2 ± 4.6%), while the Proteobacteria phylum dominated the feedwater and RO membrane (at relative abundance of 92.3 ± 4.4% and 71.5 ± 8.3%, respectively), albeit comprising different members. The archaea communities were dominated by Crenarchaeota (53.0 ± 6.9%, 32.5 ± 7.2% and 69%, respectively) and Euryarchaeota (43.3 ± 6.3%, 23.2 ± 4.8% and 24%, respectively) in all three matrices, though the communities' composition differed. But the fungal communities composition was similar in all matrices, dominated by Ascomycota (97.6 ± 2.7%). Our results suggest that the RO membrane is a selective surface, supporting unique bacterial, and to a lesser extent archaeal communities, yet it does not select for a fungal community.

Monitoring of aphid flight activities in seed potato crops in Serbia.

Aphid flight activities in seed potato fields have been studied by the yellow water traps. It is a good method for monitoring aphids as vectors of viruses, but this study also showed it is a suitable method for insect-diversity research. During the four-year studies, over 11.500 specimens were collected and a total of 107 different taxa of aphids were identified. The most abundant species were polyphagous species, such as: Acyrthosiphon pisum (Haris), Aphis fabae Scopoli, Aphis gossypii Gloverand Brachycaudus helichrysi (Kaltenbach). The results of the studies show that diversity of aphids in different regions of Serbia is similar regardless of the altitude and the diversity of terrain. At most sites it ranged from 2 to 3. The highest value was recorded in Begec, locality in northern part of Serbia, in year 2008, and it was 2.92. The maximum values of the Shannon-Weaver diversity index at all sites were recorded in the first weeks of the monitoring of aphid flight activities. Morisita-Horn similarity index shows no significant differences between sites regardless of altitudes. The sites are grouped by year, not by similarity of relief. In spite of these results, the Chi-square analysis showed highly significant difference in vector frequencies among seasons and sites with more pronounced differences for PVY. As a consequence of differences in vector frequencies, the vector pressure index in some regions was different also. The number of vectors and vector pressure index vary depending on the altitude of localities. At localities at altitudes under 1000 m, they were high. The highest index was at Kotraza, locality in central part of Serbia, in 2007, when PVY index exceeded the value of 180, while for PLRV it was 60. At high altitudes on mountain Golija, above 1100 m, the number of aphids was low, as well as the vector pressure index which indicates that these regions are suitable for producing virus-free seed potato.