Performance study on portable water filters

This study explored the effectiveness of five portable water filters for improving certain physical, chemical and biological parameters related to drinking water quality. The parameters investigated included: turbidity, total suspended solids, true and apparent colour, conductivity, pH, alkalinity, hardness, and heterotrophic plate count. In general, ceramic medium water filters improved water quality the greatest and with the incorporation of activated carbon a further reduction in colour and dissolved solids was possible.     

HARVESTING AS A CONTROL FOR AQUATIC PLANTS1

Studies of the effects of harvesting on hydrophytes in Lake Mendota, Wisconsin indicate that one harvest reduced growth by at least 50%, two harvests reduced it by 75% and three harvests virtually eliminated plant material for the year. The studies also indicated that harvesting one year reduced the biomass the following year, especially in deep water. Three harvests during the previous year were most effective in controlling biomass the second year.     

Characterizing Rainwater Harvesting Performance and Demonstrating Stormwater Management Benefits in the Humid Southeast USA

Rainwater harvesting (RWH) has traditionally been implemented in areas with (semi) arid climates or limited access to potable water supplies; however, recent droughts in the humid southeastern United States have led to increased implementation of RWH systems. The objectives of this study were twofold: (1) present usage characteristics and performance results for four RWH systems installed in humid North Carolina (NC) as compared with systems located in arid/semiarid regions and (2) identify system benefits and modifications that could help improve the performance of RWH systems installed in humid regions of the world. For this study four RWH systems were installed in NC. Their usage was monitored for at least one year and compared with similar studies. Results revealed that dedicated water uses and usage characteristics for RWH systems in NC differed from those previously reported in the literature. Two of the systems studied met 100 and 61% of the potable water demand with designated uses of animal kennel flushing and greenhouse irrigation, respectively. The designated uses yielding the greatest potable water replacement were often seasonal or periodic, thus necessitating the need for identifying and implementing secondary objectives for these systems, namely, stormwater management. Otherwise, the expense and effort required to implement RWH systems in humid areas will most likely preclude their use.     

WATER QUALITY AFTER LOGGING SMALL WATERSHEDS WITHIN THE BULL RUN WATERSHED,OREGON1

ABSTRACT: Road building, clearcutting 25 percent of the watershed, and slash disposal by broadcast burning or by natural decomposition caused changes in water quality of two small streams in the Bull Run Watershed in Oregon, which supplies water to the Portland, Oregon, metropolitan area. Concentrations of suspended sediment increased slightly, primarily owing to construction of a permanent logging road that crossed streams. Changes in nutrient cycling occurred due to logging and slash disposal in both watersheds where cutting was done. NO₃-N concentrations, which increased most where logging residue was left to decompose naturally, increased more than sixfold and commonly exceeded 100 pg/i during the October-June high-flow season for seven years after logging. Where logging slash was broadcast burned, NO₃-N concentrations increased roughly fourfold, but rarely exceeded 50 μg/l, and increases had mostly disappeared six years after slash burning. Changes in outflows of cations and other anions were not apparent. Annual maximum stream temperatures increased 2–3°C after logging, but temperature increases had mostly disappeared within three years as vegetation regrowth shaded the streams.     

Re-Establishing a Sustainable Wetland at Former Lake Karla,Greece, Using Ramsar Restoration Guidelines

Lake Karla, Greece, was almost completely drained in 1962 both to protect surrounding farmlands from flooding and to increase agricultural area. Loss of wetland functions and values resulted in environmental, social, and economic problems. A number of restoration plans were proposed to address these problems. The plan approved by the government in the early 1990s proposed construction of a 4200-ha reservoir solely to improve water storage and flood attenuation functions. However, the Ramsar Scientific and Technical Review Panel states that the primary goal of any restoration project is to create resilient and sustainable ecosystems, as measured on a human timescale, in order to improve the ecological character and enhance the socioeconomic role that the wetland plays in the watershed. This study utilizes Ramsar guidelines for sustainable restoration of Lake Karla. Eight additional restoration measures are proposed based on functional analysis of the wetland to enhance additional wetland functions and support multiple values for humans and nature.     

Dilemmas and challenges for the shelter sector: lessons learned from the Sphere revision process

Key dilemmas and challenges for those involved in the shelter sector are described, based on issues that emerged from the extensive global consultative process undertaken to inform the revision of the Sphere handbook. The range of perspectives on the major themes is presented, with suggestions as to how these issues could be progressed. Themes include the poor definition of the sector and the lack of a consistent approach among the leading shelter actors; the absence of a common terminology; the conflict between "temporary" versus "durable" solutions; the disconnect between technical advisers and the field; the need for greater recognition of local coping strategies and the local context; the involvement of recipients and host governments in policy development; the need for better "how-to" guidance; and the limited incorporation of the emerging themes of livelihoods etc. to date.     

Rainwater conservation and recycling by optimal size on-farm reservoir

Hydrologic and economic analysis of the on-farm reservoir (OFR) was carried out in rainfed rice–mustard cropping systems in Eastern India followed by 2 years of field experiments in 1999 and 2000. The average contribution (average of 2 years) of direct rainfall and surface runoff from the diked crop fields contributed, respectively, about 79.5 and 20.5% to the total OFR inflow. The average contribution of evaporation loss, seepage and percolation loss and supplemental irrigation from the OFR contributed, respectively, about 10.0, 31.2 and 58.8% to the total OFR outflow. There was an average increase of rice yield of 44.0% over the rainfed rice because of application of 8.4 cm supplemental irrigation from the OFR. Thus, with an application of 4.5 cm supplemental irrigation from the OFR, 15.40% increase of mustard yield was recorded in 1999. Economic analysis indicated average net profit of Rs. 700 (US$ 1 = Rupees (Rs.) 44.75 in Indian currency) from a farm area of 800 m². Average values of benefit–cost ratio, internal rate of return and pay back period of the OFR irrigation system were evaluated as 1.17, 14.8%, and 16 years, respectively. The study reveals that the OFR irrigation in small landholders is economically feasible system for rainwater harvesting and providing supplemental irrigation in rainfed farming system.     

PHYSICAL HYDROLOGY AND THE EFFECTS OF FOREST HARVESTING IN THE PACIFIC NORTHWEST: A REVIEW1

The Pacific Northwest encompasses a range of hydrologic regimes that can be broadly characterized as either coastal (where rain and rain on snow are dominant) or interior (where snowmelt is dominant). Forest harvesting generally increases the fraction of precipitation that is available to become streamflow, increases rates of snowmelt, and modifies the runoff pathways by which water flows to the stream channel. Harvesting may potentially decrease the magnitude of hyporheic exchange flow through increases in fine sediment and clogging of bed materials and through changes in channel morphology, although the ecological consequences of these changes are unclear. In small headwater catchments, forest harvesting generally increases annual runoff and peak flows and reduces the severity of low flows, but exceptions have been observed for each effect. Low flows appear to be more sensitive to transpiration from vegetation in the riparian zone than in the rest of the catchment. Although it appears that harvesting increased only the more frequent, geomorphically benign peak flows in several studies, in others the treatment effect increased with return period. Recovery to pre‐harvest conditions appeared to occur within about 10 to 20 years in some coastal catchments but may take many decades in mountainous, snow dominated catchments.     

SUSPENDED SEDIMENT DYNAMICS IN SMALL FOREST STREAMS OF THE PACIFIC NORTHWEST1

This paper reviews suspended sediment sources and transport in small forest streams in the Pacific Northwest region of North America, particularly in relation to riparian management. Mass movements, reading and yarding practices, and burning can increase the supply of suspended sediment. Sediment yields recovered to pre‐harvest levels within one to six years in several paired catchment studies. However, delayed mass movements related to roads and harvesting may produce elevated suspended sediment yield one or more decades after logging. There is mixed evidence for the role of streamside tree throw in riparian buffers in supplying sediment to streams. Harvesting within the riparian zone may not increase suspended sediment yield if near stream soils are not disturbed. Key knowledge gaps relate to the relative roles of increased transport capacity versus sediment supply, the dynamics of fine sediment penetration into bed sediments, and the effects of forest harvesting on suspended sediment at different scales. Future research should involve nested catchments to examine suspended sediment response to forest practices at multiple spatial scales, in combination with process‐based field studies.     

BMP compliance monitoring programs in the Eastern United States

An important aspect of a best management practices (BMP) program is providing credible information on the extent to which BMPs are being applied within the state. This paper, summarizing the responses of a survey to states about their BMP monitoring program, indicates nearly three of four states in the eastern U.S. have monitoring programs to determine if voluntary or mandatory forest practices are being applied. BMP compliance monitoring programs vary extensively among states in such areas as: the agency(s) responsible for undertaking the monitoring, the types of practices monitored, reasons for establishing the monitoring program, and the frequency and costs of compliance monitoring implementation. The survey found that information from compliance monitoring is used to modify forest practice rules or guidelines, redirect education and training programs, and inform policy makers and the general public of forest practice application rates. Major issues associated with implementing compliance monitoring programs as indicated by the survey include: specifying the types of information to be gathered, selecting harvest sites, accessing private property, determining monitoring responsibility, and reporting and using the information collected.