632 research outputs found
Evaluating GIS based water budget components applicability and availability for the Lagan River catchment
Using open-access data sets on water and soil from Swedish authorities and compiling them in a QGIS-programme made it possible to present and visualise the water budget of the Lagan River Catchment. Based on the estimations of the water volume in groundwater reservoirs and lakes the total maximum available volume in the Lagan River Catchment area was determined to be 9.36 km3. Of this 75.9% (7.10 km3) is found within groundwater reservoirs and 24.1% (2.26 km3) is present in lakes. This study indicates that GIS-based parameters are useful for specifying what a water budget in a catchment area looks like.The use of GIS-based parameters also allows for the development of interactive maps which can be used to visualize different conditions in the catchment area. In addition, many people who work with water management have a good habit of using GIS tools. Utilizing open data sources means that the number of additional measurements can be kept low. Furthermore, the use of open sources contributes to increased transparency in the development proces
Solid Waste Management in Jordan
Solid waste became one of the major environmental problems in Jordan, which has been aggravated over the past 15 years by the sharp increase in the volume of waste generated as well as qualitative changes in its composition. The challenges face solid waste management (SWM) in Jordan are numerous. Financial constraints, shortage of proper equipment and limited availability of trained and skilled manpower together with massive and sudden population increases due to several waves of forced migration. In this work we discussed these challenges; the main problems which stand against developing this sector to sustainable levels in the coming future are identified. Suggestions and recommendations that should be taken in consideration for developing the sector are also presente
The emission potential from municipal solid waste landfill in Jordan
A comprehensive study was conducted to monitor the emission potential from solid waste landfilled in Jordan over a period of 292 days using an anaerobic lysimeter. A 30 kg waste sample reflecting the typical municipal solid waste (MSW) streams generated in Jordan was used to simulate the influence of climate on the emission potential of landfills located in semi-arid areas. The experimental results demonstrated that a significant amount of leachate and landfill gas was produced. The methane content was found to be more than 45% and the leachate produced reached 15.7 l after 200 days. However, after 260 days the gas and leachate production rate became negligible. A significant amount of heavy metal traces was found in the leachate due to mixed waste disposal. Changes in biogas and leachate quality parameters in the lysimeter revealed typical landfill behaviour trends, the only difference being that they developed much more quickly. In view of current landfill practices in Jordan and the effect of climate change, the results suggest that landfill design and operational modes need to be adjusted in order to achieve sustainability. For this reason, optimized design parameters and operational scenarios for sustainable landfill based on the country’s climatic conditions and financial as well as technical potential are recommended as a primary reference for future landfills in Jordan as well as in similar regions and climates
A joint power and desalination plant for Sinai and the Gaza Strip
Desalination can be a cost-effective way to produce fresh water and possibly electricity. The Gaza Strip has had a complex hydro-political situation for many years. Gaza is bordered by the Mediterranean sea in the west, by Israel in the north and east and by Egypt in the south. Water and electricity consumption in the Gaza Strip is expected to increase in the future due to the increasing in population. In this paper, a solution for Sinai and the Gaza Strip is suggested involving the building of a joint power and desalination plant, located in Egypt close to the border of Gaza. The suggested joint project would increase drinking water supply by 500,000 m3/d and the power supply by 500MW, whereof 2/3 is suggested to be used in Gaza and 1/3 in Sinai. The present lack of electricity and water in Gaza could be erased by such a project. But Egypt will probably gain more. More water and electricity for the future development of Sinai and Gaza; a significant value will be added to the sale of Egyptian natural gas; more employment opportunities for Sinai people; the domestic market for operation and maintenance of desalination plants can be boosted by the suggested project; Egypt may naturally and peacefully increase its cooperation with and presence in Gaza, which should lead to increased security. This type of project could also get international support and can be a role-model for cooperation and trust-building between neighbours
Two-phase forest inventory using very-high-resolution laser scanning
In this study, we compared a two-phase laser-scanning-based forest inventory of stands versus a traditional field inventory using sample plots. The two approaches were used to estimate stem volume (VOL), Lorey's mean height (HL), Lorey's stem diameter (DL), and VOL per tree species in a study area in Sweden. The estimates were compared at the stand level with the harvested reference values obtained using a forest harvester. In the first phase, a helicopter acquired airborne laser scanning (ALS) data with >500 points/m2 along 50-m wide strips across the stands. These strips intersected systematic plots in phase two, where terrestrial laser scanning (TLS) was used to model DL for individual trees. In total, phase two included 99 plots across 10 boreal forest stands in Sweden (lat 62.9 degrees N, long 16.9 degrees E). The single trees were segmented in both the ALS and TLS data and linked to each other. The very-high-resolution ALS data enabled us to directly measure tree heights and also classify tree species using a convolutional neural network. Stem volume was predicted from the predicted DBH and the estimated height, using national models, and aggregated at the stand level. The study demonstrates a workflow to derive forest variables and stand-level statistics that has potential to replace many manual field inventories thanks to its time efficiency and improved accuracy. To evaluate the inventories, we estimated bias, RMSE, and precision, expressed as standard error. The laser-scanning-based inventory provided estimates with an accuracy considerably higher than the field inventory. The RMSE was 17 m3/ha (7.24%), 0.9 m (5.63%), and 16 mm (5.99%) for VOL, HL, and DL respectively. The tree species classification was generally successful and improved the three species-specific VOL estimates by 9% to 74%, compared to field estimates. In conclusion, the demonstrated laser-scanning-based inventory shows potential to replace some future forest inventories, thanks to the increased accuracy demonstrated empirically in the Swedish forest study area
Fewer, tastier tomatoes: Expanding the use of saltwater in agriculture
As the world experiences increasing freshwater crises, researchers turn to saline waters. Can the use of saltwater be expanded? The development of appropriate practices for the use of saline waters for irrigation requires an adequate understanding of how salts affect waters, soils and plants, as FAO states in their book The use of saline waters for crop production, 1992. Plants can grow in saline waters, if the salinity of the soil is controlled and monitored, and the soil salt content is not allowed to increase past a level that damages the plants. Irrigation of salt tolerant plants with slightly saline waters offers a substantial opportunity to increase the yearly crop production of the world
IT BENEFITS MANGEMENT IN LOCAL GOVERNMENT: A COMPARATIVE CASE STUDY
Information technology (IT) is increasingly presented as a driving force for service and efficiency improvement in local governments. However, achieving these goals in creating value from IT investments is a significant challenge for local government organizations. Practitioners and researchers have proposed numerous approaches to IT benefits management, but our knowledge of current practices and capabilities in local government IT management is still limited. Thus, in this paper we present an investigation of what characterizes IT benefits management in local government in order to understand and improve current practices. Through a comparative case study of two Danish municipalities, we have analyzed the different characteristics of benefits management. Based on this analysis we propose an initial framework for understanding IT benefits management in local government
Polymerase chain reaction is superior to serology for the diagnosis of acute Mycoplasma pneumoniae infection and reveals a high rate of persistent infection
<p>Abstract</p> <p>Background</p> <p>Diagnosis of <it>Mycoplasma pneumoniae </it>(MP) infection is traditionally based on serology, which may require more than two weeks for diagnostic antibodies to develop. PCR-based methods offer earlier diagnosis. During a community outbreak of MP infection, we compared semi-nested and real-time PCR of oropharyngeal swabs with serology for diagnosis of MP infection at different time points after disease onset. PCR-positive individuals were followed longitudinally to assess the persistence of MP DNA in throat secretions. We also studied carriage of MP among household contacts and school children.</p> <p>Results</p> <p>MP infection was diagnosed in 48 of 164 patients with respiratory tract infection. Forty-five (29%) had detectable MP DNA in oropharynx. A significant increase in MP IgG IgG titre or MP IgM antibodies was detected in 44/154 (27%) subjects. Two MP PCR-positive patients lacked antibody responses. Sera were missing from another two patients. The agreement between serology and PCR was good, κ = 0.90.</p> <p>During the first three weeks after disease onset the performance of PCR was excellent and all patients but one were detected. In contrast, only 21% of the patients with confirmed MP infection were positive by serum 1 during the first symptomatic week (56% during the second and 100% during the third week). Only 1/237 (0.4%) school children was positive by PCR. This child had respiratory symptoms. Eighteen of 22 (75%) symptomatic household contacts were MP PCR positive.</p> <p>Persistence of MP DNA in the throat was common. Median time for carriage of MP DNA was 7 weeks after disease onset (range 2 days – 7 months). Adequate antibiotic treatment did not shorten the period of persistence. Bacterial load, measured by quantitative real-time PCR declined gradually, and all followed patients eventually became PCR-negative.</p> <p>Conclusion</p> <p>PCR is superior to serology for diagnosis of MP infection during the early phases of infection. Persistent, sometimes long-term, carriage of MP DNA in the throat is common following acute infection, and is not affected by antibiotic therapy. Asymptomatic carriage of MP even during an outbreak is uncommon.</p
The Impact of Lake Water Quality on the Performance of Mature Artificial Recharge Ponds
Artificial groundwater recharge is commonly used for drinking water supply. The resulting water quality is highly dependent on the raw water quality. In many cases, pre-treatment is required. Pre-treatment improves the drinking water quality, although how and to what extent it affects the subsequent pond water quality and infiltration process, is still unknown. We evaluated two treatment systems by applying different pre-treatment methods for raw water from a eutrophic and temperate lake. An artificial recharge pond was divided into two parts, where one received raw water, only filtered through a micro-screen with 500 µm pores (control treatment), while the other part received pre-treated lake water using chemical flocculation with polyaluminium chloride (PACl) combined with sand filtration, i.e. continuous contact filtration (contact filter treatment). Water quality such as cyanobacterial biomass, microcystin-LR as well as organic matter and nutrients were measured in both treatment processes. We found cyanobacterial biomass and microcystin-LR level after the contact filter treatment was significantly different from the control treatment and also significantly different in the pond water. In addition, with contact filter treatment, total phosphorus (TP) and organic matter removal were significantly improved in the end water, TP was reduced by 96 % (< 20 µg/L) and the total organic carbon (TOC) was reduced by 66 % instead of 55 % (TOC content around 2.1 mg/L instead of 3.0 mg/L). This full-scale onsite experiment demonstrated effective pre-treatment would benefit a more stable water quality system, with less variance and lower cyanotoxin risk. In a broader drinking water management perspective, the presented method is promising to reduce cyanotoxin risk, as well as TP and TOC, which are all predicted to increase with global warming and extreme weather
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