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631.
This study aims to analyse the heavy metal pollutants in Jeddah, the second largest city in the Gulf Cooperation Council with a population exceeding 3.5 million, and many vehicles. Ninety-eight street dust samples were collected seasonally from the six major roads as well as the Jeddah Beach, and subsequently digested using modified Leeds Public Analyst method. The heavy metals (Fe, Zn, Mn, Cu, Cd, and Pb) were extracted from the ash using methyl isobutyl ketone as solvent extraction and eventually analysed by atomic absorption spectroscopy. Multivariate statistical techniques, principal component analysis (PCA), and hierarchical cluster analysis were applied to these data. Heavy metal concentrations were ranked according to the following descending order: Fe > Zn > Mn > Cu > Pb > Cd. In order to study the pollution and health risk from these heavy metals as well as estimating their effect on the environment, pollution indices, integrated pollution index, enrichment factor, daily dose average, hazard quotient, and hazard index were all analysed. The PCA showed high levels of Zn, Fe, and Cd in Al Kurnish road, while these elements were consistently detected on King Abdulaziz and Al Madina roads. The study indicates that high levels of Zn and Pb pollution were recorded for major roads in Jeddah. Six out of seven roads had high pollution indices. This study is the first step towards further investigations into current health problems in Jeddah, such as anaemia and asthma.  相似文献   
632.

Millions of tons of plastic are consumed annually in the world due to its significant characteristics such as durability, flexibility, and low weight. High consumption has made plastic one of the most important municipal solid waste compounds, the quantity of which has increased in recent decades. Plastic solid wastes are known as a threat to the environment, and its efficient management in various aspects such as cost–benefit requires decision-making tools. This study was assessing the cost–benefit of plastic solid waste management by development of an economic model, and definition of different scenarios to change plastic solid waste management status. The results showed that 8971 tons of plastic solid waste were generated annually in the studied city. The plastic solid wastes were finally transferred to either recycling or landfilling site through 5 identified routes. 83 percent of the total recycled plastic solid waste was due to post-separation routes, and only 7.7 percent of the total plastic solid waste was recycled from the source separation route. The economic comparison of scenarios showed that with the aggregation of post-separation routes, the net revenue of plastic solid waste management increases by 334,000 euro per year while increasing the public participation and the ratio of source separation route raises net revenue by 875,000 euro per year, which was the best economic condition among the scenarios. Using life cycle cost method and it’s respected developed economic model truly satisfied the conditions of both, the current plastic solid waste management and the alternative scenarios, and hence can be adopted as a tool for decision-making.

  相似文献   
633.
Environment, Development and Sustainability - Spatial simulation of land-use change scenarios in metropolitan areas is essential for analyzing both the causes and consequences of various future...  相似文献   
634.
Environmental Science and Pollution Research - Since the industrial revolution in the 1800s, plastic pollution is becoming a global reality. This study aims to assess knowledge and attitude about...  相似文献   
635.
This study analyzed changes in hydrology between two recent decades (1980s and 2010s) with the Soil and Water Assessment Tool (SWAT) in three representative watersheds in South Dakota: Bad River, Skunk Creek, and Upper Big Sioux River watersheds. Two SWAT models were created over two discrete time periods (1981‐1990 and 2005‐2014) for each watershed. National Land Cover Datasets 1992 and 2011 were, respectively, ingested into 1981‐1990 and 2005‐2014 models, along with corresponding weather data, to enable comparison of annual and seasonal runoff, soil water content, evapotranspiration (ET), water yield, and percolation between these two decades. Simulation results based on the calibrated models showed that surface runoff, soil water content, water yield, and percolation increased in all three watersheds. Elevated ET was also apparent, except in Skunk Creek watershed. Differences in annual water balance components appeared to follow changes in land use more closely than variation in precipitation amounts, although seasonal variation in precipitation was reflected in seasonal surface runoff. Subbasin‐scale spatial analyses revealed noticeable increases in water balance components mostly in downstream parts of Bad River and Skunk Creek watersheds, and the western part of Upper Big Sioux River watershed. Results presented in this study provide some insight into recent changes in hydrological processes in South Dakota watersheds. Editor's note: This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series.  相似文献   
636.
Scenario‐based and scenario‐neutral impacts assessment approaches provide complementary information about how climate change‐driven effects on streamflow may change the operational performance of multipurpose dams. Examining a case study of Cougar Dam in Oregon, United States, we simulated current reservoir operations under scenarios of plausible future hydrology. Streamflow projections from the CGCM3.1 general circulation model for the A1B emission scenario were used to generate stochastic reservoir inflows that were then further perturbed to simulate a potentially drier future. These were then used to drive a simple reservoir model. In the scenario‐based analysis, we found reservoir operations are vulnerable to climate change. Increases in fall and winter inflow could lead to more frequent flood storage, reducing flexibility to store incoming flood flows. Uncertainty in spring inflow volume complicates projection of future filling performance. The reservoir may fill more or less often, depending on whether springs are wetter or drier. In the summer, drawdown may occur earlier to meet conservation objectives. From the scenario‐neutral analysis, we identified thresholds of streamflow magnitude that can predict climate change impacts for a wide range of scenarios. Our results highlight projected operational challenges for Cougar Dam and provide an example of how scenario‐based and scenario‐neutral approaches may be applied concurrently to assess climate change impacts.  相似文献   
637.
638.
People in the developing world derive a significant part of their livelihoods from various forest products, particularly non-timber forest products (NTFPs). This article attempts to explore the contribution of NTFPs in sustaining forest-based rural livelihood in and around a protected area (PA) of Bangladesh, and their potential role in enhancing households' resilience capacity. Based on empirical investigation, our study revealed that local communities gather a substantial amount of NTFPs from national park despite the official restrictions. Twenty seven percent households (HHs) of the area received at least some cash benefit from the collection, processing and selling of NTFPs, and NTFPs contribute to HHs' primary, supplementary and emergency sources of income. NTFPs also constituted an estimated 19% of HHs' net annual income, and were the primary occupation for about 18% of the HHs. HHs' dependency on nearby forests for various NTFPs varied vis-à-vis their socio-economic condition, as well as with their location from the park. Based on our case study, the article also offers some clues for improving the situation in PA.  相似文献   
639.
In a Mediterranean climate where much of the precipitation falls during winter, snowpacks serve as the primary source of dry season runoff. Increased warming has led to significant changes in hydrology of the western United States. An important question in this context is how to best manage forested catchments for water and other ecosystem services? Answering this basic question requires detailed understanding of hydrologic functioning of these catchments. Here, we depict the differences in hydrologic response of 10 catchments. Size of the study catchments ranges from 50 to 475 ha, and they span between 1,782 and 2,373 m elevation in the rain‐snow transitional zone. Mean annual streamflow ranged from 281 to 408 mm in the low elevation Providence and 436 to 656 mm in the high elevation Bull catchments, resulting in a 49 mm streamflow increase per 100 m (R2 = 0.79) elevation gain, despite similar precipitation across the 10 catchments. Although high elevation Bull catchments received significantly more precipitation as snow and thus experienced a delayed melt, this increase in streamflow with elevation was mainly due to a reduction in evapotranspiration (ET) with elevation (45 mm/100 m, R2 = 0.65). The reduction in ET was attributed to decline in vegetation density, growing season, and atmospheric demand with increasing elevation. These findings suggest changes in streamflow in response to climate warming may likely depend on how vegetation responds to those changes in climate.  相似文献   
640.
The rise in discarded or unwanted medications (UMs) is becoming an issue of great concern, as it has the potential to harm the components of the environment where it is discarded: particularly air, water and soil. To combat this problem, many researchers have investigated the best approach for the collection and proper disposal of UMs. This paper intends to elaborate upon a safe solution for treating this waste, specifically through a process of solidification/stabilization (S/S) that involves mixing UMs with asphalt cement and asphalt concrete mixtures. Volumes of 5, 10, 15 and 20 % of a mixture of UMs were mixed with asphalt cement and the analyzed properties of the mixture of UMs–asphalt included: softening point, ductility, penetration, flash and fire points, specific gravity and rotational viscosity. Marshal stability, flow, air voids, unit weight, voids in mineral aggregate (VMA) and voids filled with binder (VFB) of asphalt concrete mixture were also investigated. Results showed that this approach of S/S is a promising method for dual achievements to solve an environmental problem and to use the waste for road construction.  相似文献   
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