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Heavy Metal Contents in Surficial Sediment of Banjir Kanal Barat and Babon Rivers, Semarang, Central Java, IndonesiaTakarina, Noverita 06 1900 (has links)
Bottom sediment (0 -5 cm) along the Banjir Kanal Barat (Garang River) and Babon Rivers which are situated in Semarang, Central Java, Indonesia were analyzed for their trace/heavy metals content Eight elements namely Nickel (Ni), Copper (Cu), Lead (Pb ), Chromium (Cr), Cadmium (Cd), Zinc (Zn), Iron (Fe), and Manganese (Mn) were investigated. Their concentrations provide information related to the industrial and municipal discharge. There are serious concerns about the contamination in the study area, and previous studies found some elevated concentration of several metals (trace elements). Total metal analyses of the fine (< 63 μm) sediment fraction by Atomic Absorption Spectrophotometer using strong acid digestion indicated high (Ni, Cu, Zn, and Mn) metal contamination. Weak acid digestion of total sediments (whole fraction) showed relatively low Cd to moderately (Cu, Cr, and Pb) levels. High Iron concentration was detected using X-RF Fluorescence.
The result of trace/heavy metal and sediment characteristic analyses were statistically processed by Spearman's Rank Correlation analyses. In the Babon River, weak acid digestion results found a strong correlation between organic carbon and Chromium. Sediment characteristics, particularly in terms of organic carbon, appeared to be the primary factor controlling metal concentration. In Babon River, strong acid digestion showed that most metals were highly correlated with Mn (𝘱 < 0.05) , except Zn. In Banjir Kanal Barat River, weak acid digestion results show that Copper (Cu) was highly correlated with organic carbon. From strong acid digestion results significant relationship was found between Zn and Mn (𝘱 < 0.05) . Analyses of surficial sediment in Banjir Kanal Barat River demonstrate very little significant correlation between metals and sediment characteristics. This condition probably reflected the diverse nature of metal input into the system, either originated from point or non-point sources. However, statistical (t-test) analyses suggested that there were contamination of Ni, Cu, and Zn in both rivers. Most of these values exceeded the Canadian Standard/Guidelines for contaminated soils and sediments. In addition, t-test result also showed different levels of contamination between Banjir Kanal Barat and Babon Rivers. Mean values indicated higher contamination in Banjir Kanal Barat River compared to Babon river. / Thesis / Master of Science (MS)
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Urban Ontario River Regimes: An Analysis of Four Major WatershedsGrohn, Shelby January 2024 (has links)
The effects of urbanization on river systems are not well understood as appropriate field parameters for representing such changes require years of consistent monitoring data for an accurate comparison. Furthermore, due to their varying degrees of urbanization and management efforts, conditions are not consistent even within the same watersheds so representative sites are difficult to distinguish. This level of data is not typically available for watersheds in Ontario due to budget and personnel constraints of organizations undertaking such monitoring activities. To direct monitoring and management efforts more effectively, a comparative aerial imagery analysis was undertaken for a ~50-year timeline for twenty study sites across the Mimico Creek, Etobicoke Creek, Highland Creek, and Duffins Creek watersheds as well as a comprehensive field analysis to characterize current conditions. A statistical analysis that included a Pearson correlation coefficient analysis and stepwise regression utilizing values obtained through the Stream Power Index for Networks (SPIN) tool and manual calculations including three ratios from Wood-Smith & Buffington (1996) was also completed. These ratios included: bankfull width (Wbf)/bankfull depth (hbf), D50/bankfull depth (hbf), and critical shear stress (τc50)/bankfull shear stress (τbf). Results indicated a strongly negative correlation between entrenchment and the Wbf⁄hbf ratio and positive correlations of varying strengths between the τc50⁄τbf ratio and both the Wbf⁄hbf and D50⁄hbf ratios. Though weak, percent imperviousness and specific stream power were able to predict the τc50⁄τbf ratio. Finally, t-tests between sites categorized as “rural” (≤30% imperviousness) and “urban” (>30% imperviousness) revealed when a control is placed on drainage area, increases in specific stream power, D50, bankfull width, bankfull depth, and slope is observed in “urban” areas. It is believed that such statistical parameters could be considered applicable as a first order estimate of further stream pattern analyses but are not strong enough correlations to be utilized for design purposes. / Thesis / Master of Science (MSc) / The effects of urbanization on river systems are not well understood as appropriate field parameters for representing such changes require years of consistent data for an accurate comparison which is not typically available in Ontario due to budget and personnel constraints. To direct monitoring and management efforts more effectively, a comparative aerial imagery analysis, field study, and statistical analysis comprised of a Pearson correlation coefficient analysis and stepwise regression were undertaken for twenty sites across four major watersheds in the Greater Toronto Area (GTA). Values obtained through the Stream Power Index for Networks (SPIN) tool and manual calculations of entrenchment and three ratios from Wood-Smith & Buffington (1996) were utilized. Results indicate that statistical parameters such as the ability for specific stream power and imperviousness to predict the shear stress ratio can be considered applicable initial estimates of river patterns but are not strong enough for design purposes.
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The role of infrastructure development in metropolitanization of the Pearl River Delta鍾偉康, Chung, Wai-hong, Laurence. January 1994 (has links)
published_or_final_version / Urban Planning / Master / Master of Science in Urban Planning
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From engineered channel to functioning stream ecosystem : rates, patterns and mechanisms of development in a realigned river channelPerfect, Charles January 2010 (has links)
1. Realigning rivers is becoming common as a solution to conflicting needs of land development and ecosystem preservation. Although an increasing number of projects are monitored, exactly how these channels develop as functional stream ecosystems is still poorly understood. Mining in the upper catchment of the River Nith (Scotland) required the realignment of 3km (approx.) of river. The engineered channel was designed around sound geomorphological principles of sediment transport and supply with a sinuous planform and pool-riffle sequences along the installed gravel-bed. 2. A comprehensive survey covering biotic and abiotic development was devised and implemented to test models and hypotheses relating to the development riverine habitats over the first three years. 2. Physical habitat development at the reach scale was investigated using fixed-point photography and differential GPS surveys of the thalweg and of cross-sectional form every 100m. This revealed the development of a relatively diverse streambed habitat in response to both the channel slope and planform. However, other than at meander bends where asymmetry developed over several years, little change was observed to the form of the engineered riverbanks. 3. Kick-net surveys of benthic invertebrate communities at 10 sites showed a negative relationship between specific measures of diversity and downstream distance during the early stages of development. (e.g. Richness with chainage at the 6 month stage) but the relationship degrades rapidly and is likely in part to appear as a result of low population densities. 4. Survey of transects through the riparian zone perpendicular to the river indicated that colonisation by vegetation is also related to distance along the realignment but physical habitat and geographical factors play a more dominant role over development (Canonical correspondence analysis of vegetation data in 2007) 5. Many of the indices of diversity for both biotic and abiotic elements of the ecosystem proved ineffective at detecting development at the reach scale. This may be because significant changes occur at a smaller scale than was detected by the surveys. It is likely that greater resolution is required to detect more ecologically meaningful relationships and patterns. 6. Overall study shows constructed realignments can rapidly develop a diverse streambed community within 24 months. Riparian communities are slower to develop because of the slow development of riverbank habitat diversity. Other ecosystem properties such as resilience and connectivity may take much longer.
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The determination of acceptable Hippopotamus (Hippopotamus, Amphibius, Linn.) densities in the Crocodile River, outside the Kruger National ParkEksteen, J.J. January 1993 (has links)
A research report submitted to the Faculty of Science,
University of the Witwatersrand, Johannesburg, in partial
fulfilment of the requirements for the degree Master of
Science in Quantitative Conservation Biology, 1993 / The aim of the study was to provide a basis for the
determination of acceptable hippo densities along the
Crocodile River, outside the Kruger National Park. Hippo
densities have to be acceptable to land-user~, who suffer
hippo damage, and to the conservation authority,
responsible for the resources along the river. Hippo
nllmbers and distribution in the study area were determined
by using a combination of aerial census and ground count.
The hippo population number was estimated at 88 animals.
Hippo distribution was influenced by flow speed of water.
No hippos were observed in river sections with steep
gradients, (>6.0 m/km) , while major herds were observed at
low gradients «3.5 m/km). A mean density of 0.6 hippo per
km was calculated, with a maximum of 2,5 hLppoe Zkm at
Kaapmuiden, next to the Kruger National Park. TPA Nature
Conservation records on hippo complaints were analyzed, and
no relationship between the occurrence of hippo damage and
hippo density could be found. There were strong indications
that hippo damage are caused by individual problem hippo ,
The majority of land-users (92 %) supported the
conservation of hippos. The size of the area available to
hippo was determined for distances of 5 kn. up- and downriver
from the major hippo herds.
hippo could move away from the river was 336
restriction when compared to the generally assumed hippo
grazing range of 3.2 km. Hippo access to grazing was
assessed by determining the effective grazing area. / MT2017
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Hydrogeologic Investigation of the Klamath Marsh, Klamath County, OregonMelady, Jason Michael 01 June 2002 (has links)
Klamath Marsh is a wetland complex that lies in the rain shadow of the Cascade Range in the Williamson River sub-basin of the Klamath Basin. The marsh lies directly east of Crater Lake in an area inundated by pyroclastic-flow and -fall deposits from the Holocene eruptions of Mount Mazama. The physical characteristics of rocks of Pleistocene versus Pliocene age combined with NNW -striking fault systems divide the Williamson River basin into two distinct hydrogeologic regimes. The northwestern regime includes the east slope of the Cascades and consists of at least 150 m of interbedded sand, gravel, and stacks (15 to 45 m) of thin (3-5 m) and vesiculated basalt lava flows. Mean annual precipitation ranges from 150 cm near the crest of the Cascades to 50 cm near Klamath Marsh. Moderate to high yield (100 to 4000 gpm) water wells, springs and flowing wells suggest high permeability and ground water potential. The southeastern regime is underlain by Pliocene pyroclastic flows (∼ 40 m) and lava flows (>30 m). Mean annual precipitation ranges from 70 cm in the highlands to 50 cm in the lowlands. Low-yield (20-100 gpm) water wells and perched unconfined aquifers in Holocene pumice deposits suggest low permeability and low ground water potential in areas underlain by the pyroclastic flows. Volumetric analysis of inflows and outflows in Klamath Marsh for 2000 indicates approximately 86% of inflow is from groundwater and 14% from surface water, with nearly 200 x 10⁶ m³ of water removed by evapotranspiration
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Macroinvertebrate drift abundance below Bonneville Dam and its relation to juvenile salmonid food habitsMuir, William Douglas 01 January 1990 (has links)
There is a paucity of information concerning the invertebrate food resources available to juvenile salmonids in the Columbia River as they migrate seaward. Construction of mainstream dams has altered the temperature cycle, flow regime, and substrate which indigenous invertebrates were adapted to. Studies on how the macroinvertebrate community has adapted to these alterations have been neglected. This study was undertaken to help fill this void.
Macroinvertebrate drift samples were collected over a three year period in the Columbia . River downstream from Bonneville Dam. Samples were collected with a D-ring plankton net fished on the bottom for one-half hour. Two sites were sampled; Ives Island (RKM 230), from 1987 through 1989, and Lady Island (RKM 193), in 1988 and 1989.
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The Holocene Sedimentary Framework of the Lower Columbia River GorgeGates, Edward Breed 08 April 1994 (has links)
The Columbia River is the largest fluvially dominated estuary in the Pacific Northwest, yet the Holocene transgressive fill of this system has not previously been studied. Nearly 1500 industry borehole and water well records in the lower Columbia River basin (LCRB) were analyzed. These records document the sedimentary infilling of the lower 120 miles of the drowned river valley that occurred during the Holocene marine transgression (10-0 ka) . Of particular importance is a key stratigraphic marker horizon of volcanic tephra that has been identified throughout the LCRB. INAA was used to determine the geochemical composition of the target tephra layer. The tephra geochemistry was then compared to geochemical data from potential Cascade source volcanos to determine whether the tephra layers are geochemically related, and the possible age and source of the tephra. The geochemical comparisons indicate that the suspect tephra horizon was derived from the climax eruption of Mount Mazama approximately 6845 years ago. Cross-sections have been constructed that record the lateral and longitudinal depositional development of the river basin. Sediment grain size distribution data have also been compiled and shows that grain size distribution does not change with respect to subsurface elevation within the LCRB. The results indicate that the LCRB has been dominated by fine sand deposition throughout the Holocene period, and silt and clay sized fractions were bypassed through the system to be deposited offshore. A total volume of 74.6 km3 of sediment has accumulated in the basin since the time of the catastrophic floods 12,700 years ago. Sediment volume analysis was used to predict past fluvial sediment supply rates and sediment retention. The volume of sediment deposition from early to late Holocene time has decreased by a factor of 2.4. Sedimentation rates in the basin are estimated from a basin isopach of the Holocene fill and from an extrapolated sediment sea-level curve. Basin sedimentation rates ranged from 12. 6 mm/yr-1 for the early Holocene to 2. 5 mm/yr-1 for the late Holocene period. This factor of 5 decrease in the sedimentation rate also indicates that the Columbia River bypassed much of its fine grained fraction through to the marine environment during the mid-late Holocene.
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Fish-Habitat Associations in a Large Dryland River of the Murray-Darling Basin, AustraliaBoys, Craig Ashley, n/a January 2007 (has links)
Many aspects concerning the association of riverine fish with in-channel habitat remain
poorly understood, greatly hindering the ability of researchers and managers to address
declines in fish assemblages. Recent insights gained from landscape ecology suggest
that small, uni-scalar approaches are unlikely to effectively determine those factors that
influence riverine structure and function and mediate fish-habitat associations. There
appears to be merit in using multiple-scale designs built upon a geomorphologically-derived
hierarchy to bridge small, intermediate and large spatial scales in large rivers.
This thesis employs a hierarchical design encompassing functional process zones
(referred to hereafter as zones), reaches and mesohabitats to investigate fish-habitat
associations as well as explore patterns of in-channel habitat structure in one of
Australia's largest dryland river systems; the Barwon-Darling River.
In this thesis, empirical evidence is presented showing that large dryland rivers are
inherently complex in structure and different facets of existing conceptual models of
landscape ecology must be refined when applied to these systems. In-channel habitat
and fish exist within a hierarchical arrangement of spatial scales in the riverscape,
displaying properties of discontinuities, longitudinal patterns and patch mosaics. During
low flows that predominate for the majority of time in the Barwon-Darling River there
is a significant difference in fish assemblage composition among mesohabitats. There is
a strong association between large wood and golden perch, Murray cod and carp, but
only a weak association with bony herring. Golden perch and Murray cod are large
wood specialists, whereas carp are more general in there use of mesohabitats. Bony
herring are strongly associated with smooth and irregular banks but are ubiquitous in
most mesohabitats. Open water (mid-channel and deep pool) mesohabitats are
characterised by relatively low abundances of all species and a particularly weak
association with golden perch, Murray cod and carp. Murray cod are weakly associated
with matted bank, whereas carp and bony herring associate with this mesohabitat patch
in low abundance.
Nocturnal sampling provided useful information on size-related use of habitat that was
not evident from day sampling. Both bony herring and carp exhibited a variety of
habitat use patterns throughout the die1 period and throughout their lifetime, with
temporal partitioning of habitat use by juvenile bony herring and carp evident. Much of
the strong association between bony herring and smooth and irregular banks was due to
the abundance of juveniles (<100mm in length) in these mesohabitats. Adult bony
herring (>100mm length) occupied large wood more than smooth and irregular banks.
At night, juvenile bony herring were not captured, suggesting the use of deeper water
habitats. Adult bony herring were captured at night and occupjed large wood, smooth
bank and irregular bank. Juvenile carp (<200mm length) were more abundant at night
and aggregated in smooth and irregular banks more than any other mesohabitat patch.
Adult carp (>200mm length) occupied large wood during both day and night.
There is a downstream pattern of change in the fish assemblage among river zones, with
reaches in Zone 2 containing a larger proportion of introduced species (carp and
goldfish) because of a significantly lower abundance of native species (bony herring,
golden perch and Murray cod) than all other zones. In comparison, the fish assemblage
of Zone 3 was characterised by a comparatively higher abundance of the native species
bony herring, golden perch and Murray cod. A significant proportion of the amongreach
variability in fish assemblage composition was explained at the zone scale,
suggesting that geomorphological influences may impose some degree of top-down
constraint over fish assemblage distribution. Although mesohabitat composition among
reaches in the Barwon-Darling River also changed throughout the study area, this
pattern explained very little of the large-scale distribution of the fish assemblage, with
most of the variability in assemblage distribution remaining unexplained. Therefore,
although mesohabitat patches strongly influence the distribution of species within
reaches, they explain very little of assemblage composition at intermediate zone and
larger river scales. These findings suggest that small scale mesohabitat rehabilitation
projects within reaches are unlikely to produce measurable benefits for the fish
assemblage over intermediate and large spatial scales in the Barwon-Darling River. This
indicates the importance taking a holistic approach to river rehabilitation that correctly
identifies and targets limiting processes at the correct scales.
The variable nature of flow-pulse dynamics in the Barwon-Darling River creates a
shifting habitat mosaic that serves to maintain an ever-changing arrangement of habitat
patches. The inundation dynamics of large wood habitat described in this thesis
highlights the fragmented nature of mesohabitat patches, with the largest proportion of
total in-channel large wood remaining unavailable to fish for the majority of the time.
At low flows there is a mosaic of large wood habitat and with increasing discharge more
potential large wood habitat becomes available and does so in a complex spatial
manner. What results in this dryland river is a dynamic pattern of spatio-temporal
patchiness in large wood habitat availability that is seen both longitudinally among
different river zones and vertically among different heights in the river channel. Water
resource development impacts on this shifting habitat mosaic.
Projects undertaking both fish habitat assessment and rehabilitation need to carefully
consider spatial scale since the drivers of fish assemblage structure can occur at scales
well beyond that of the reach. Fish-habitat associations occurring at small spatial scales
can become decoupled by process occurring across large spatial scales, making
responses in the fish assemblage hard to predict. As rivers become increasingly
channelised, there is an urgent need to apply research such as that conducted in this
thesis to better understand the role that in-channel habitats play in supporting fish and
other ecosystem processes. Habitat rehabilitation projects need to be refined to consider
the appropriate scales at which fish assemblages associate with habitat. Failure to do so
risks wasting resources and forgoes valuable opportunities for addressing declines in
native fish populations. Adopting multi-scalar approaches to understanding ecological
processes in aquatic ecosystems, as developed in this thesis, should be a priority of
research and management. To do so will enable more effective determination of those
factors that influence riverine structure and function at the approariate scale.
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Predicting channel stability in Colorado mountain streams using hydrobiogeomorphic and land use data : a cost-sensitive machine learning approach to modeling rapid assessment protocolsMor��t, Stephanie L. 16 March 2001 (has links)
Natural resource data are typically non-linear and complex, yet
modeling methods often utilize statistical analysis techniques, such as
regression, that are insufficient for use on such data. This research proposes
an innovative modeling method based on pattern recognition techniques
borrowed from the field of machine learning. These techniques make no data
distribution assumptions, can fit non-linear data, can be effective on a small
data set, and can be weighted to include relative costs of different predictive
errors.
Rapid Assessment Protocols (RAPs) are commonly used to collect,
analyze, and interpret stream data to assist diverse management decisions. A
modeling method was developed to predict the outcome of a RAP in an effort
to improve accurate prediction, weighted for cost-effectiveness and safety,
while prioritizing investigations and improving monitoring. This method was
developed using channel stability data collected from 58 high-elevation
streams in the Upper Colorado River Basin. The purpose of the research was
to understand the relationships of channel stability to several
hydrobiogeomorphic features, easily derived from paper or electronic maps, in
an effort to predict channel stability. Given that the RAP used was developed
to evaluate channel stability, the research determined: 1) relationships
between channel stability and major land-use and hydrobiogeomorphic
features, and 2) if a predictive model could be developed to aid in identifying
unstable channel reaches while minimizing costs, for the purpose of land
management.
This research used Pearson's and chi-squared correlations to
determine associative relationships between channel stability and major land-use
and hydrobiogeomorphic features. The results of the Pearson's
correlations were used to build and test classification models using randomly
selected training and test sets. The modeling techniques assessed were
regression, single decision trees, and bagged (bootstrap aggregated) decision
trees. A cost analysis / prediction (CAP) model was developed to incorporate
cost-effectiveness and safety into the models. The models were compared
based on their 1) performance and 2) operational advantages and
disadvantages. A reliable predictive model was developed by integrating a
CAP model, receiving operator characteristic curves, and bagged decision
trees. This system can be used in conjunction with a GIS to produce maps to
guide field investigations. / Graduation date: 2001
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