Composición química del agua de lluvia y de niebla recolectada en la reserva biológica Monteverde

Se determinó la composición química del agua de lluvia y de niebla en tres sitios en la Reserva Biológica Monteverde, Puntarenas; entre octubre 2009 y enero 2010. Debido a su estado de conservación y a su ubicación geográfica sobre la deriva continental, la Reserva Biológica Monteverde ofrece un sitio de estudio ideal, para el estudio de la composición de las aguas atmosféricas (agua de lluvia y de niebla). Las muestras de agua de niebla se recolectaron al utilizar muestreadores de niebla con líneas de teflón, mientras que las de agua de lluvia se recogieron al emplear muestreadores de lluvia simples y uno de cascada. En ambos tipos de agua se analizaron las especies iónicas más relevantes: H3O+, NH4 +, Ca2+, Mg2+, K+, Na+, Cl-, NO3 - y SO4 2-, al utilizar cromatografía de iones y detección por conductividad eléctrica. Las concentraciones promedio de estas especies en el agua de lluvia estuvieron entre 0,54 ± 0,02 μeq L-1 y 101± 3 μeq L-1, mientras que en el agua de niebla variaron entre 1,00 ± 0,02 μeq L-1 y 93 ± 4 μeq L-1. Además, se presentan el balance iónico y los factores de enriquecimiento con respecto al mar y el suelo de ambos tipos de muestras.

Estudo de caso: minimização e reúso de água em shopping center da região sul do Brasil

The main issues related to water conservation in urban centers are the increase in water supply cost, demand growth, pollution and differences in the distribution of water resources. Water conservation, the controlled and efficient use of water, includes both measures as reasonable means of water reuse. Thus, conservation practices are an effective way to meet demand and supply water to new activities and users without jeopardizing the supplying water bodies and preserving the natural environment. This study aims to examine the water management of a shopping mall and the use of rainwater harvesting combined with greywater reuse. For buildings in general, water loss is common due to leaks in the hydraulic and restroom equipment. These losses, which are caused by a high volume of water used and wasted in the system, are often the result of design errors, incorrect maintenance procedures and users' bad habits In southern Brazil, where there is rainfall almost all year long, water shortages occasionally occur, particularly in some winter mouths. One difficulty that appears on rainwater studies is the proper determination of rainwater volume that can be used to address water supply systems. In this work, the simulation method was used to determine this volume. Thus, simulations with the following variables: rainfall, catchment area and water consumption were performed. For mall's hydraulic systems, segmented alternatives are adopted. That is, focusing on the use of rainwater or greywater reuse. Other alternatives of effluent reuse have been slightly discussed due to sanitary issues, those are effluents from toilets and kitchen sinks. The adoption of greywater may be feasible if there is a significant flow of greywater to comply water demand for toilet flushing. The inspections made in this study found that the quantity of sinks was insufficient to supply an adequate amount of water to toilets and urinals. The greywater reuse system was found to be infeasible in terms of demand and supply of water. Conversely, the rainwater harvesting system was entirely feasible and easily supplied water to all restrooms and contributed to the cooling of the air conditioning system with a short payback period. One of the challenges of this work was the need to compare the actual water consumption with a water consumption parameter used in buildings. Thus, a method that addresses the generation of specific consumption indexes for specific activity (like a mall) was used. The water consumption indices showed that this mall has a satisfactory water management program.

A MORE COMPLETE STREET A STREET FOR EVERYONE TO ENJOY, NORTH EAST STREET, FREDERICK, MARYLAND – A DESIGN INVESTIGATION OF DIFFERENT STREET DESIGN THEORIES

This design-research thesis suggests that the improvement of North East Street performances by using Complete Streets, Green Street, Place Making and Context Sensitive Solution principles and practices. Heavily used by a variety of users, often conflicting with one another, University of Maryland Campus Drive would benefit from a major planning and design amelioration to meet the increasing demands of serving as a city main street. The goal of this thesis project is to prioritize the benefits for pedestrians in the right-of-way and improve the pedestrian experience. This goal also responds to the recent North East Street Extension Phrase I of economic renaissances. The goal of this design-research thesis will be achieved focusing on four aspects. First, the plans and designs will suggest to building mixed use blocks, increase the diversity of street economic types and convenience of people’s living. Second, design and plans will propose bike lanes, separate driving lanes from sidewalks and bike lanes by street tree planters, and narrow driving lanes to reduce vehicular traffic volume and speed in order to reduce pedestrian and vehicle conflicts. Third, plans and designs will introduce bioswales, living walls and raingardens to treat and reuse rain water. Finally, the plans and designs will seek to preserve local culture and history by adding murals and farmers market. The outcome of the design-research thesis project is expected to serve as an example of implementing Complete Streets, Green Street, Place Making and Context Sensitive Solution principles and practices in urban landscape, where transportation, environment and social needs interact with each other.

COMMUNITY KNOWLEDGE, ATTITUDE AND PRACTICES (KAP) ON FLUOROSIS AND ITS MITIGATION IN ENDEMIC AREAS OF ETHIOPIA

Optimum fluoride intake plays an essential role in the prevention of dental caries while fluoride consumption above recommended level interferes with the normal formation of tooth enamel and bones and may increase risk of dental and skeletal fluorosis. The knowledge and practices of endemic communities on etiology of fluorosis will help in its mitigation and prevention. The objective of this study was to investigate the knowledge, attitude and practices of endemic community on fluoride contamination, fluorosis and prevention practices in order to devise coordinated and targeted prevention mechanisms. Focus group discussions (FGD) and key-informant interview were conducted in three dietary areas to collect knowledge, attitude and practices (KAP) of the endemic community in July 2013.The results indicated that health consequences of fluoride contaminated water are fairly understood. None of the discussants mentioned the word “fluoride”. The knowledge and perception of the community on fluoride ingestion is poor. Health extension workers (HEWs) did not teach about fluoride and related health consequences. Dental fluorosis was reported to start at early ages and not commonly perceived as a major problem. However, adolescents worried and felt that they might be singled out when going to other areas. Older people have a skeletal fluorosis, which interferes with their day to day activities. In severely affected people, the teeth were weak and fragile and thus create difficulty in chewing hard foods like unfermented dry flat bread, sugar cane and toasted grains. People prefer rain water rather than water from borehole because of the inconvenient taste of the latter. The endemic communities have no sufficient knowledge and skills on potential sources of fluoride intake, the debilitating effect of high fluoride ingestion, and preventive and mitigatory measures to reduce fluoride intake. The effect of fluoride contamination and mitigatory methods should get sufficient attention by the community, health workers and concerned governmental bodies. The trend of harvesting and using rain water should be encouraged as it reduces fluoride intake. Future studies should focus on information communication on possible fluoride risks, intervention and evaluation studies on defluoridation, rain water harvesting and mitigatory techniques.

Transport of pollutants through the water and subsurface soil using simulated acid rain

The mobility of heavy metals (Zn, Cd, Pb and Ni) was studied in the laboratory acidic leaching two different soils around Ibadan with simulated acid rain. The sampling was carried out from two different sites viz: Orogun and Ilupeju respectively. For Orogun site a depth of 128cm was reached (consisting of four horizons). Different length of polyvinyl chloride (PVC) pipes were cut for different soil horizon depth as observed on the field. The PVC pipes were packed with requires masses of soil. This is then leached using simulated acid rain of different pH of 2.0, 4.0, 6.0 and 8.0 after spiking with known volume of standard solution of metals of interest. It was found that simulated acid rain enhanced the mobility of metals in solution. The pH, Cation Exchange capacity, % clay and organic matter were found to contributed majority to the mobility of metals. Generally as observed, the mobility of metal was to follow the order Zn>Ni>Pb>Cd as the soil is becoming more acidic

Distribution of Rain Gardens in Lincoln Nebraska: Are Rain Gardens more Likely to be Built Near Bodies of Water

Abstract Rain gardens are an important tool in reducing the amount of stormwater runoff and accompanying pollutants from entering the city’s streams and lakes, and reducing their water quality. This thesis project analyzed the number of rain gardens installed through the City of Lincoln Nebraska Watershed Management’s Rain Garden Water Quality Project in distance intervals of one-eighth mile from streams and lakes. This data shows the distribution of these rain gardens in relation to streams and lakes and attempts to determine if proximity to streams and lakes is a factor in homeowners installing rain gardens. ArcGIS was used to create a map with layers to determine the number of houses with rain gardens in 1/8 mile distance increments from the city’s streams and lakes and their distances from a stream or lake. The total area, number of house parcels, and the type and location of each parcel type were also determined for comparison between the distance interval increments. The study revealed that fifty-eight percent of rain gardens were installed within a quarter mile of a stream or lake (an area covering 60% of the city and including 58.5% of the city’s house parcels), and that eighty percent of rain gardens were installed within three-eighth mile of streams or lakes (an area covering 75% of the city and 78.5% of the city’s house parcels). All parcels in the city are within 1 mile of a stream or lake. Alone the number of project houses per distance intervals suggested that proximity to a stream or lake was a factor in people’s decisions to install rain gardens. However, when compared to the number of house parcels available, proximity disappears as a factor in project participation.

Reliability and quality of water isotope data collected with a lowbudget rain collector

RATIONALELow-budget rain collectors for water isotope analysis, such as the `ball-in-funnel type collector' (BiFC), are widely used in studies on stable water isotopes of rain. To date, however, an experimental quality assessment of such devices in relation to climatic factors does not exist. METHODSWe used Cavity Ring-Down Spectrometry (CRDS) to quantify the effects of evaporation on the O-18 values of reference water under controlled conditions as a function of the elapsed time between rainfall and collection for isotope analysis, the sample volume and the relative humidity (RH: 31% and 67%; 25 degrees C). The climate chamber conditions were chosen to reflect the warm and dry end of field conditions that favor evaporative enrichment (EE). We also tested the performance of the BiFC in the field, and compared our H-2/O-18 data obtained by isotope ratio mass spectrometry (IRMS) with those from the Swiss National Network for the Observation of Isotopes in the Water Cycle (ISOT). RESULTSThe EE increased with time, with a 1 increase in the O-18 values after 10days (RH: 25%; 25 degrees C; 35mL (corresponding to a 5mm rain event); p <0.001). The sample volume strongly affected the EE (max. value +1.5 parts per thousand for 7mL samples (i.e., 1mm rain events) after 72h at 31% and 67% RH; p <0.001), whereas the relative humidity had no significant effect. Using the BiFC in the field, we obtained very tight relationships of the H-2/O-18 values (r(2) 0.95) for three sites along an elevational gradient, not significantly different from that of the next ISOT station. CONCLUSIONSSince the chosen experimental conditions were extreme compared with the field conditions, it was concluded that the BiFC is a highly reliable and inexpensive collector of rainwater for isotope analysis. Copyright (c) 2014 John Wiley & Sons, Ltd.

Isotopic composition of water in fog, rain, throughfall and stemflow in the Monte Verde, Costa Rica

Fog deposition, precipitation, throughfall and stemflow were measured in a windward tropical montane cloud forest near Monteverde, Costa Rica, for a 65-day period during the dry season of 2003. Net fog deposition was measured directly using the eddy covariance (EC) method and it amounted to 1.2 ± 0.1 mm/day (mean ± standard error). Fog water deposition was 5-9% of incident rainfall for the entire period, which is at the low end of previously reported values. Stable isotope concentrations (d18O and d2H) were determined in a large number of samples of each water component. Mass balance-based estimates of fog deposition were 1.0 ± 0.3 and 5.0 ± 2.7 mm/day (mean ± SE) when d18O and d2H were used as tracer, respectively. Comparisons between direct fog deposition measurements and the results of the mass balance model using d18O as a tracer indicated that the latter might be a good tool to estimate fog deposition in the absence of direct measurement under many (but not all) conditions. At 506 mm, measured water inputs over the 65 days (fog plus rain) fell short by 46 mm compared to the canopy output of 552 mm (throughfall, stemflow and interception evaporation). This discrepancy is attributed to the underestimation of rainfall during conditions of high wind.

The Effectiveness of Rain Gardens as a Low-Impact Development Strategy for Storm Water Pollution Reduction in Western Washington

Stormwater runoff is a major cause of surface water pollution in western Washington and cost-effective control measures are needed to reduce contamination of receiving waters. This project evaluated the performance efficiency and costs of installing a residential rain garden by inspecting two gardens and testing water quality samples in one. Infiltration through the garden was effective in reducing metals and nutrients as indicated by reductions in copper and nitrate concentrations of 75% and 97%, respectively. The costs were affordable for most homeowners and cost-effective compared to other options. After doing on-site investigations, the storm water manual for the State of Washington was reviewed and eight recommendations were made for improving it.

Water wonders every child should know; little studies of dew, frost, snow ice and rain,

Mode of access: Internet.

Philosophical essays : on the following subjects : I. On the ascent of vapours, the formation of clouds, rain and dew, and on several other phoenomena of air and water, II. Observations and conjectures on the nature of the aurora borealis, and the tails of comets, III. On the principles of mechanicks /

Mode of access: Internet.

Best after rain : waterfall discharges and the tourist experience

Waterfalls attract tourists because they are aesthetically appealing landscape features that are not part of everyday experience. It is generally understood that falls are usually seen at their best when there is a copious flow of water, especially after heavy rain. Guidebooks often contain this observation when referring to waterfalls, sometimes warning readers that the flow may be severely reduced during dry periods. Indeed, many visitors are disappointed when they see falls at such times. Some are saddened when the discharge of a waterfall has been depleted by the abstraction of water upstream for power generation or other purposes. While, for those in search of the Sublime or merely the superlative, size is often important, small waterfalls can give great pleasure to lovers of landscape beauty. According to guidebooks, however, even these falls are usually best seen after rain. Drawing on tourist and travel literature and personal journals from the eighteenth century to the present, and with reference to examples from different parts of the world, this paper discusses the importance of discharge in the tourist experience of waterfalls.

Effects of dry density and grain size distribution on soil-water characteristic curves of sandy soils

The unsaturated soil mechanics is receiving increasing attention from researchers and as well as from practicing engineers. However, the requirement of sophisticated devices to measure unsaturated soil properties and time consumption have made the geotechnical engineers keep away from implication of the unsaturated soil mechanics for solving practical geotechnical problems. The application of the conventional laboratory devices with some modifications to measure unsaturated soil properties can promote the application of unsaturated soil mechanics into engineering practice. Therefore, in the present study, a conventional direct shear device was modified to measure unsaturated shear strength parameters at low suction. Specially, for the analysis of rain-induced slope failures, it is important to measure unsaturated shear strength parameters at low suction where slopes become unstable. The modified device was used to measure unsaturated shear strength of two silty soils at low suction values (0 ~ 50 kPa) that were achieved by following drying path and wetting path of soil-water characteristic curves (SWCCs) of soils. The results revealed that the internal friction angle of soil was not significantly affected by the suction and as well as the drying-wetting SWCCs of soils. The apparent cohesion of soil increased with a decreasing rate as the suction increased. Further, the apparent cohesion obtained from soil in wetting was greater than that obtained from soil in drying. Shear stress-shear displacement curves obtained from soil specimens subjected to the same net normal stress and different suction values showed a higher initial stiffness and a greater peak stress as the suction increased. In addition, it was observed that soil became more dilative with the increase of suction. A soil in wetting exhibited slightly higher peak shear stress and more contractive volume change behaviour than that of in drying at the same net normal stress and the suction.

Investigation on parameters used in warning systems for rain-induced embankment instability

A number of instrumented laboratory-scale soil embankment slopes were subjected to artificial rainfall until they failed. The factor of safety of the slope based on real-time measurements of pore-water pressure (suction) and laboratory measured soil properties were calculated as the rainfall progressed. Based on the experiment measurements and slope stability analysis, it was observed that slope displacement measurements can be used to warn the slope failure more accurately. Further, moisture content/pore-water pressure measurements near the toe of the slope and the real-time factor of safety can also be used for prediction of rainfall-induced embankment failures with adequate accuracy.