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11.
Visitor use surveys and water quality data indicates that high visitor use levels of two rivers in Puerto Rico does not appear
to adversely affect several water quality parameters. Optimum visitor use to maximize visitor defined satisfaction is a more
constraining limit on visitor use than water quality. Our multiple regression analysis suggests that visitor use of about
150 visitors per day yields the highest level of visitor reported satisfaction, a level that does not appear to affect turbidity
of the river. This high level of visitor use may be related to the gregarious nature of Puerto Ricans and their tolerance
for crowding on this densely populated island. The daily peak visitation model indicates that regulating the number of parking
spaces may be the most effective way to keep visitor use within the social carrying capacity. 相似文献
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H. Glenn Earhart 《Environmental management》1984,8(1):81-86
Correlation curves were developed relating nephelometric turbidity units (NTU) with total suspended solids (TSS) for diked upland dredged material placement site effluents of three US Army Corps of Engineers (COE) maintenance dredging projects in the Chesapeake Bay, Maryland. The procedure was developed in an effort to ensure compliance with Maryland's 400 milligrams per liter (mg/l) TSS standard for COE dredging projects. Samples of the sediments to be dredged were collected and analyzed, correlating turbidity readings with TSS determined by standard gravimetric techniques. The correlation curves were provided to the COE inspectors to measure the effluent with a turbidity meter and to extract a TSS concentration from the correlation curve. Samples collected and analyzed after initiation of the dredging indicated that the correlation curves were an overestimate of the actual TSS concentrations of the effluent discharges. The procedure, endorsed by the State of Maryland, provided immediate on-site TSS analysis eliminating the previously encountered delays in obtaining gravimetric analysis of effluent discharges and potential contract management problems. 相似文献
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J. Ojeda E. Sanchez A. Fernandez-Palacios J. M. Moreira 《Journal of Coastal Conservation》1995,1(2):109-118
This paper deals with the application of satellite images to characterize some aspects of the circulation dynamics of the
Tinto-Odiel estuary using turbidity patterns as ‘natural tracers’. 15 images (Landsat TM and Spot HRV) were processed to provide
synoptic, instantaneous views of the circulation patterns under different environmental conditions. In addition, a comparison
was made between results of oceanographic field work, using biplanes and fluorescent tracers, and satellite image turbidity
patterns used as ‘ground truth’ data for specific hydroclimatic situations. This approach allowed (1) the identification and
mapping of dynamic processes of interest during a theoretical tidal cycle, (2) the elaboration of additional information on
the ‘flow schemes’ at the mouth of the estuary with improved spatial and temporal resolution, and (3) the supply of basic
data to improve the knowledge of exchange processes between estuarine and coastal waters. The results of this study are considered
to be useful for the management of the estuarine system. 相似文献
15.
Many California streams have been adversely affected by sedimentation caused by historic and current land uses, including
timber harvesting. The impacts of timber harvesting and logging transportation systems on erosion and sediment delivery can
be directly measured, modeled, or inferred from water quality measurements. California regulatory agencies, researchers, and
land owners have adopted turbidity monitoring to determine effects of forest management practices on suspended sediment loads
and water quality at watershed, project, and site scales. Watershed-scale trends in sediment discharge and responses to current
forest practices may be estimated from data collected at automated sampling stations that measure turbidity, stream flow,
suspended sediment concentrations, and other water quality parameters. Future results from these studies will provide a basis
for assessing the effectiveness of modern forest practice regulations in protecting water quality. At the project scale, manual
sampling of water column turbidity during high stream flow events within and downstream from active timber harvest plans can
identify emerging sediment sources. Remedial actions can then be taken by managers to prevent or mitigate water quality impacts.
At the site scale, manual turbidity sampling during storms or high stream flow events at sites located upstream and downstream
from new, upgraded, or decommissioned stream crossings has proven to be a valuable way to determine whether measures taken
to prevent post-construction erosion and sediment production are effective. Turbidity monitoring at the project and site scales
is therefore an important tool for adaptive management. Uncertainty regarding the effects of current forest practices must
be resolved through watershed-scale experiments. In the short term, this uncertainty will stimulate increased use of project
and site-scale monitoring. 相似文献
16.
无人监测船在城市内河水质监测中的应用 总被引:1,自引:0,他引:1
采用无人船监测技术结合镇江市内河水质状况普查工作,大于120 h的航行试验,总航行里程约为90 km,对建成区水体中的氨氮(NH3-N)、溶解氧(DO)、氧化还原电位(ORP)和浊度进行原位监测,结果表明,通过合理选择搭载相应的测量电极,无人监测船能够满足地表水测量数据准确度的要求,同时可实现研究区域的监测全覆盖,提升了地表水环境监测的工作效率。 相似文献
17.
浊度传感器应用于连续监测污水厂进水悬浮颗粒浓度的研究 总被引:1,自引:0,他引:1
为使城市污水处理厂更合理高效的运营,可对进水悬浮颗粒浓度的实时监测来实现。通过对进水水样的悬浮颗粒浓度测量值与相应浊度值建立的关系曲线,达到对污水处理厂进水悬浮颗粒浓度(mg/L)的连续实时监测。文中给出了浊度传感器的校准方法,并建立浊度-悬浮颗粒浓度关系曲线,将其应用于某城市污水处理厂,得到单位时间进水悬浮颗粒总量的实时连续图。 相似文献
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Suspended sediment, nitrogen and phosphorus concentrations and exports during storm-events to the Tuross estuary, Australia 总被引:4,自引:0,他引:4
This paper presents a process for estimating pollutant loads from water quality data, to improve catchment-scale modelling in the region for resource management purposes. It describes a program to estimate suspended sediment, total and dissolved nitrogen and phosphorus loads to the Tuross estuary from the Tuross River catchment (1810 km(2)) of coastal southeast Australia. Event-based water quality sampling results obtained during storm events in 2005 are presented. Event 1, during July 2005 was the largest storm event in terms of peak flow for 3.5 years. Other events monitored were also in July, November and December 2005. The early July 2005 event had a flow-weighted mean suspended sediment (SS) concentration during the first 4 days of 63 mg L(-1). Of the events monitored, this was unusual as it was preceded by drought and had the largest SS concentrations (peaking at 180 mg L(-1)) during the rising-stage. In contrast, the November event had a much lower flow-weighted SS mean (28 mg L(-1)), even though peak flow magnitudes were similar. The July and November 2005 events had peak flows of 12,360 and 11,330 ML day(-1). Low-cost rising-stage siphon samplers were used to collect samples during the rapidly rising phase of these events. The use of such samplers and consideration of time-lead/lag flow adjustments, quantified using cross-correlation analysis to account for hysteresis effects, were incorporated into the load estimation techniques. The technique is a potentially useful approach for understanding relationships between water quality concentrations and flow for modelling catchment source strengths and transport processes. 相似文献
20.
Zhen Shi Jie Xu Xiaoping Huang Xia Zhang Zhijian Jiang Feng Ye Ximei Liang 《环境科学学报(英文版)》2017,29(7):72-84
Nutrients, dissolved and particulate organic carbon and plankton (bacterio-, phyto- and zoo-) were compared in the turbidity maximum zone (TMZ) and adjacent areas (non-TMZ) in the Pearl River estuary. Our results showed that high levels of suspended substances had marked effect on dynamics of nutrients and plankton in the TMZ. Based on the cluster analysis of total suspended solids (TSS) concentrations, all stations were divided into two groups, TMZ with average TSS of 171 mg/L and non-TMZ of 45 mg/L. Suspended substances adsorbed PO43 − and dissolved organic carbon, resulting in higher particulate phosphorus and organic carbon (POC) and lower PO43 − and DOC in the TMZ, compared to the non-TMZ. However, suspended substances had limited effect on nitrogenous nutrients. Phytoplankton growth was light-limited due to high concentrations of suspended substances in the TMZ and a peak of phytoplankton abundance appeared in the non-TMZ. In contrast, the highest bacterial abundance occurred in the TMZ, which was likely partly responsible for low DOC levels. Two peaks of zooplankton abundance observed in the TMZ and non-TMZ in the Pearl River estuary were primarily supported by bacteria and phytoplankton, respectively. Our finding implied that high levels of suspended solids in the TMZ affect the trophic balance. 相似文献