ABSTRACT: A flood control reservoir protects valuable developments on the downstream flood plain by storing flood waters and releasing them at a rate that will reduce the downstream damage. The water surface level of the flood pool behind the dam can fluctuate considerably during the occurrence of a large magnitude flood causing severe impacts on shoreline vegetation and water based recreation facilities located in the flood pool. A mathematical simulation model describing shoreline vegetative succession in response to flooding is presented. Plant species are grouped into ecologically similar compartments. Differential equations describing compartment intrinsic growth, intraspecies competition, interspecies competition, and other growth limiting factors are solved numerically. The model is used to evaluate the impacts of various operating policies on plant succession for a new reservoir in Central Iowa. 相似文献
Gaza Strip is considered as one of the armed conflicts prone areas in Middle East. Several intensive conflicts occurred in Gaza Strip in 2008, 2012, 2014 and 2021. These conflicts caused massive destroying the infrastructures, facilities, and buildings, which affected all services and activities in Gaza Strip. One of the major post-conflict issues in Gaza strip is the management of resulted demolition waste including its removal, sorting, recycling, and material recovery. In May 2021, over than 370,000 tons of demolition waste composed of rubbles and debris was generated during 11 days of armed conflict. The accumulated previous experience of rubbles and debris removal and recycling in Gaza Strip supported to perform a quick management approach for safe removal of the post-conflict demolition waste and reuse/recycle the resulted waste materials in various applications. The sorting and transporting process of concreate and non-concreate rubble elements of the waste were carried out in cooperation between local and international agencies as emergency recovery-funded projects. The most proportion of rubbles are concrete aggregates, thus, the material recovery was conducted through crushing process for concrete rubbles and then reusing it for road rehabilitation or producing concrete building blocks. The large concrete blocks reused to be placed for shoreline protection for specific area along Gaza beach. The recycling of post-conflict demolition waste management projects in Gaza Strip brought economic and social benefits through the reuse and recycle of resources and creation of job opportunities. In conclusion, although the post-conflict demolition waste management is quite different from municipal/industrial waste management in Gaza Strip, it is conducted through applying similar techniques of disaster waste management in waste removal, and those of construction and demolition (C&D) waste management in sorting, crushing, and sieving for recycling.
Environmental Science and Pollution Research - Caddisfly larvae occur in streams and rivers, and many caddisfly species build protective cases using material from their habitat such as sand grains.... 相似文献
Geochemical study of groundwater from a structurally deformed granitic terrain near Hyderabad (India) was carried out to understand
and evaluate the hydrogeochemical processes and quality of groundwater. Several trace elements (Fe, Mn, Be, Al, V, Cr, Co,
Ni, Cu, Zn, As, Sr, Mo, Cd, Sb, Ba, Pb, U) along with major ions and minor elements were precisely estimated in shallow and
drilled wells to know the suitability of water for drinking and irrigation purposes. Analytical data shows that pH and major
ion chemistry in dug wells and bore wells do not vary significantly, while some trace elements (Fe, Mn, Al, Be, Co, Pb, U
and Zn) vary in dug wells and bore wells, which can be attributed to differential mineral weathering and dissolution/precipitation
reactions along fractures/joints. Although the water is not potable, it was found to be suitable for irrigation with little
danger in the development of harmful level of exchangeable sodium. It is inferred that the chemical composition of the groundwater
in this region is likely to have its origin from silicate weathering reactions and dissolution/precipitation processes supported
by rainfall and groundwater flow. 相似文献
The study, which measured the concentrations of Hg, Pb, Cd, Zn and As in various fish tissues (muscle, gill and liver) of
10 fish species (Abramis brama danubii, Alburnus alburnus alburnus, Barbus meridionalis petenyi, Carassius auratius gibelio, Cyprinus carpio, Lepomis gibossus, Leuciscius cephalus cephalus, Perca fluviatilis fluviatilis, Rutilus rutilus, Scardinus erythrophtlalmus erythrophtlalmus) collected in the Šalek lakes, is the first survey regarding metal concentrations in fish species with samples originating
from Slovene lakes, while only a limited number of such studies have been carried out in southeastern Europe. Since these
lakes are situated in the close vicinity of the largest Slovene thermal power plant, the study provides an insight into the
potential impact of increased levels of metals in the environment as well as an estimate of the contamination of fish tissues
with metals. Furthermore, it was possible to compare the results obtained with those from other studies regarding metal levels
in freshwater fish species. The mean metal concentrations of different tissues irrespective of species varied in the following
ranges: Zn 4.31–199 mg/kg ww, Pb 0.01–0.48 mg/kg ww, As 0.02–0.44 mg/kg ww, Hg <0.01–0.31 mg/kg ww, Cd < 0.01–0.19 mg/kg ww.
In general, higher contents of Hg were found in muscles and livers than in gills and higher contents of As in gills and livers
than in muscles, respectively. The accumulation of Pb and Zn was most pronounced in gills. The result obtained regarding metal
concentrations in fish revealed that the ecosystems of the Šalek lakes are not polluted with Hg and Pb, slightly loaded with
As and Cd and moderately polluted with Zn. In addition, the potential human health risk due to fish consumption was assessed.
This showed that the estimated weekly intakes for all metals were far below provisional permissible tolerable weekly intakes
determined by WHO/FAO. The consumption of fish from the Šalek lakes, therefore, does not pose a risk to human health. 相似文献
This study aims to evaluate the potential of greywater availability in Muscat Governorate in the Sultanate of Oman, to establish
a methodology for greywater quantity estimation, to test greywater quality in order to assess reuse potential, and to examine
public acceptance for reuse.Total fresh water consumption and greywater generation from different household sources were measured
by water meters in five selected households during summer and winter. Additionally, a survey was designed and conducted in
five administrative areas of Muscat Governorate, with the objective of testing a methodology for estimating greywater generation
potential in these areas. Collected data were compared with that used by the Ministry of Housing, Electricity and Water, Sultanate
of Oman. The survey covered a total of 169 houses and 1,365 people. Greywater samples were collected and analyzed from showers,
laundries, kitchens and sinks in some of these households to determine their water quality parameters. Statistical analysis
results indicated that there is no significant variance in the total fresh water consumption between data used by the ministry
and those measured and estimated during this study, highlighting the applicability of the tested method. The study concluded
that the average per capita greywater generation rate is 151 Lpcd. Greywater production ranged from 80 to 83% of the total
fresh water consumption and most of the greywater is generated from showers. Further, 55 to 57% of the greywater generated
in a typical Omani household originated from the shower, 28 to 33% originated from the kitchen, 6 to 9% originated from laundry,
and 5 to 7% originated from sink, which constitutes approximately 81% of the total fresh water consumption. The physical,
chemical, and biological analyses of the grab samples revealed that greywater contains significant levels of suspended solids,
inorganic constituents, total organic carbon, chemical and biochemical oxygen demands, total Coliforms and Escherichia Coliform
bacteria. The public acceptance survey illustrated that approximately 76% of the respondents accepted the reuse of greywater
for gardening, 53% for car washing and 66% for toilet flushing. 相似文献
The paper presents the application of thermal remote sensing for mapping hydrocarbon polluted sites. This has been achieved by mono-window algorithm for land surface temperature (LST) measurements, using multi-date band 6 data of Landsat Thematic Mapper (TM). The emissivity, transmittance and mean atmospheric temperature were used as critical factors to estimate LST. The changes in the surface emissivity due to oil pollution alter the apparent temperature, which was used as a recognition element to map out oil polluted surfaces. The LST contrast was successfully used to map spatial distribution of hydrocarbon pollution in the Burgan Oil field area of Kuwait. The methodology can be positively used to detect waste dumping, oil spills in oceans and ports, besides environmental management of oil pollution at or near the land surface. 相似文献