Top PDF Sinkhole monitoring and early warning: An experimental and successful GB-InSAR application

Sinkhole monitoring and early warning: An experimental and successful GB-InSAR application

Sinkhole monitoring and early warning: An experimental and successful GB-InSAR application

The reason for this probably lies in a general lack of sinkhole culture in people's awareness and also in the intrinsic dif ficulties of detecting sink- hole deformations before the collapse. One of these dif ficulties is caused by the abrupt nature they can manifest, especially in the case of bedrock or caprock collapse, where the involved material is mainly governed by brittle behaviour ( Gutiérrez and Guerrero, 2008 ). On the other hand we may expect that, in the case of cover collapse, measurable plastic defor- mation may occur days before the failure; we can also speculate that the entity of such deformation, when occurring, should be in the order of a few millimetres to a few centimetres. These expectations seem to be con firmed by the few cases of sinkhole prediction that can be found in the literature ( Nof et al., 2013; Jones and Blom, 2014 ). These authors were able to detect precursor deformations of sinkholes, respectively, through new generation satellite interferometry (Cosmo SkyMed constel- lation) and through airborne interferometry along the Dead Sea and in Louisiana.
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Application and reliability of techniques for landslide site investigation, monitoring and early warning – outcomes from a questionnaire study

Application and reliability of techniques for landslide site investigation, monitoring and early warning – outcomes from a questionnaire study

Abstract. The presented questionnaire study summarizes an evaluation of approaches, techniques and parameters of slope-instability investigation and monitoring of their occur- rence, reliability and the applicability of the monitoring tech- niques for early warning. The study is based on information collected from 86 monitored landslides in 14 European and Asian countries. Based on the responses, lidar ALS (airborne laser scanners), geophysical logging, aerial photographs, re- sistivity surveying, GB InSAR (ground-based synthetic aper- ture radar interferometer) and the refraction seismic were considered the most reliable methods for investigation of structure and character of landslides. Especially lidar ALS and geophysical logging were ranked high despite their ap- plication at relatively few landslides. Precipitation amount, pore-water pressure and displacement monitored by wire ex- tensometers, dGPS and total stations, followed by air temper- ature and EM-emissions monitoring and displacement mon- itored by the TM 71 crack gauge were considered the most promising parameters for early warning.
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Review of Monitoring and Early Warning Technologies for Cover-Collapse Sinkholes

Review of Monitoring and Early Warning Technologies for Cover-Collapse Sinkholes

Tkach et al. (1986) came up with BOTDR technology. Horiguchi et al. (1995) measured strain- and temperature- induced changes in Brillouin frequency shift. Bao et al. (2001) conducted a series of experiments both in the laboratory and outdoors and took temperature compensation into account for strain measurement. Their accuracy of strain measurement was improved to 5 m. Jiang et al. (2006) applied BOTDR to measure soil deformation in the process of sinkhole collapse in a large-scale model experiment. The experimental results showed that BOTDR would be a reliable technology to monitor and predict sinkhole collapse or subsidence, especially along linear infrastructure constructions. Guan et al. (2012) found that key factors affecting the application of BOTDR included changes of stress field distribution, void size change during the formation of the void, and the difference of responding sensitivity to the stress field change among different optical fibers. Case Study 3 – Application of BOTDR to forecast soil void development in Chaoshan village, Tongling, Anhui, China
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Evaluation of passive samplers as a monitoring tool for early warning of Dinophysis toxins in shellfish

Evaluation of passive samplers as a monitoring tool for early warning of Dinophysis toxins in shellfish

Weekly monitoring of harmful algal bloom (HAB) species provides Dinophysis densities (from 0–5, 5–10, 10–15, 15–20 m) at a single station and time of day, but the diurnal vertical migration (DVM) of each species combined with short-term variability associated with the local wind-driven circulation and tides may lead to dramatic changes in vertical distribution on a scale of days (wind shifts) and hours (diurnal tidal cycle). In contrast, SPATT discs accumulate toxins from the previous 7 days and integrate vertical distribution variability. Therefore, we cannot always expect good correlations between toxins adsorbed by the resins and co-occurring Dinophysis densities. Integrated water column samples also integrate vertical discontinuities. A good example of these discrepancies between integrated versus single-depth samples [4] was the almost mono-specific bloom of D. ovum detected with the pumped size-fractioned plankton concentrate on 12 June, that in the 0–5 m hose sample co-occurred (50% of each) with D. acuminata. The data show that a marked density gradient was formed at about 3 m depth on 12 June when the pump sample was collected, and D. ovum was probably aggregated in a thin layer just where the pump intake was cast (Figure 7). Preferential aggregation of D. ovum in near surface layers of the water column (where the pump samples were taken) would also explain the dominance of this species until late June in the plankton concentrates, whereas D. acuminata was dominant in the monitoring water column samples at 0–5 m. These early peaks of D. ovum and D. acuminata did not lead to any accumulation of toxins in the SPATT at any depth. Either cells from early stages of the bloom did not release any toxins or they were forming very short-lasting thin layers embedded in a diatom-dominated microplankton community.
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Demonstration of the validity of the early warning in online monitoring system for nuclear power plants

Demonstration of the validity of the early warning in online monitoring system for nuclear power plants

Figure 3 shows the principles of the early warning system using the AAKR technique. Various variables measured by the instruments of the power plants are collected and estimates are calculated by comparing the measured data with a memory vector based on the historical data. In order to improve the accuracy of the signal estimation, the signals constituting the memory vector are analyzed and grouped based on correlation analysis among them (P. Baradi et al., 2011). And the reliability of the estimate is secured by generating the memory vector of the past 18 months of data in one cycle.
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Strategies for rock slope failure early warning using acoustic emission monitoring

Strategies for rock slope failure early warning using acoustic emission monitoring

Grossreifling trial site is situated in Styria, Austria about 1.5 km north of Grossreifling [Latitude 47.673932, Longitude 14.709952] on the left bank of Enns River, which is one of the largest Austrian tributaries of the Danube River. The site consists of a steep conglomerate slope that threatens a section of the railway line St. Valentin-Tarvisio at Km 91,400 (Figure 6). The Grossreifling trial site was set up in April 2014 as a complementary component of the Sentinel for Alpine Railway Traffic (SART) project. SART is a pilot project that aims to increase the safety of alpine railways through reducing the risk of damage to tracks and trains due to rock falls, and providing a cost saving alternative to expensive dynamic rock fall barriers. The system takes advantage of a dual approach: early warning of imminent rockfalls, given by acoustic emission generated within the rock constituting the slope, and detection of rock fall occurrence, provided by a light static catch fence instrumented with movement sensors that give information about the debris that detaches from the slope and impacts the fence (Figure 6). The two subsystems share a common control centre, which issues warnings and alarms to the rail traffic operator, providing enough information to take action, specifically slow down or stop the railway traffic (although this control function is not implemented in the pilot phase).
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Evaluation of passive samplers as a monitoring tool for early warning of dinophysis toxins in shellfish

Evaluation of passive samplers as a monitoring tool for early warning of dinophysis toxins in shellfish

A systematic monitoring of HABs and lipophilic toxins (LC-MS) in picked cells of Dinophysis and in plankton concentrates led to confirmation of D. acuminata and D. acuta as the main sources of OA in Galician shellfish, D. acuta of DTX2 and both D. acuta and D. caudata of PTX2. Discrepancies between toxin per cell estimates and those from plankton concentrates suggest increased amounts of released toxins in the water during late stages of the bloom, which are attached to organic aggregates retained in the filters and not taken up by mussels. Likewise, discrepancies between toxins in plankton concentrates and those accumulated by the SPATT suggest zooplankton and shellfish faecal pellets as the source of PTX2SA in the resins. Model simulations showed best-fit between weekly toxin accumulation by the SPATT discs and the toxin content of Dinophysis cells per volume of water, estimated from a constant value of toxin content for each species, averaged from LC-MS analyses of picked cells. OA and PTX2 can persist “dissolved” in the water for weeks but DTX2 is less stable. Monitoring of Dinophysis cells with appropriate spatial (integrated samples) and temporal frequency provides earlier warning of DSP outbreaks than SPATT resins, which allow detection of toxins with a similar timing than that of detection in shellfish tissues by LC-MS analyses in regulatory centers. In addition, SPATT accumulation of toxins overestimates that taking place in shellfish and subject to loss terms (enzymatic transformation, fecal pellet elimination); further, SPATT continues accumulating toxins for weeks after Dinophysis cells become undetectable and mussels are depurated. SPATT provides a valuable tool for the study of Dinophysis population and their toxin dynamics, in particular if deployed in areas and depths not subject to regular surveillance. Further, it has the potential to be a relatively simple method which may provide a more efficient regulatory action, cost-savings, enhanced environmental toxin detection and a monitoring perspective that is less susceptible to the variability of discrete phytoplankton and shellfish sample collections. However, SPATT does not represent a practical gain for early warning of DSP outbreaks in aquaculture sites subject to routine monitoring of HABs and phycotoxins and for the time being should remain as a complementary tool to traditional sampling.
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A Study about the 3S-based Great Ruins Monitoring and Early-warning System

A Study about the 3S-based Great Ruins Monitoring and Early-warning System

Large-scale urbanization construction and new countryside construction, frequent natural disasters, and natural corrosion pose severe threat to the great ruins. It is not uncommon that the cultural relics are damaged and great ruins are occupied. Now the ruins monitoring mainly adopt general monitoring data processing system which can not effectively exert management, display, excavation analysis and data sharing of the relics monitoring data. Meanwhile those general software systems require layout of large number of devices or apparatuses, but they are applied to small-scope relics monitoring only. Therefore, this paper proposes a method to make use of the stereoscopic cartographic satellite technology to improve and supplement the great ruins monitoring index system and combine GIS and GPS to establish a highly automatic, real-time and intelligent great ruins monitoring and early-warning system in order to realize collection, processing, updating, spatial visualization, analysis, distribution and sharing of the monitoring data, and provide scientific and effective data for the relics protection, scientific planning, reasonable development and sustainable utilization. 1. Preface
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Predictive Modeling Of Sinkhole Hazards Using Synthetic Aperture Radar Interferometry (Insar) Subsidence Measurements And Local Geology

Predictive Modeling Of Sinkhole Hazards Using Synthetic Aperture Radar Interferometry (Insar) Subsidence Measurements And Local Geology

77 on the NSD. This formula will allow municipalities to assess their risk for subsidence/collapse of caverns on mined salt domes through geospatial analysis of readily available information (e.g. salt dome contours and cavern statistics) even if subsidence data is unavailable. It will also allow municipalities to identify high risk areas for further monitoring (e.g. remote sensing collection) to refine modeling results. Using this analysis, the Oxy-Geismar Well 3 would have been assigned a high probability of collapse. Based on these initial results, it was assessed that incorporation of ongoing subsidence data into the model was required to increase its accuracy. Map algebra formulas 2, 3 and 4, discussed in the next section, are attempts to include subsidence in the model and manipulate the weights to achieve the highest possible risk factor for Oxy-Geismar Well 3.
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Application of wireless tracer GPRS riverbed scour monitoring for disaster warning

Application of wireless tracer GPRS riverbed scour monitoring for disaster warning

The results indicate that the proposed method can be used as a potential tool for practical applications such as monitoring bridge and embankment perfor- mance, particularly during typhoon-induced flood events and provide early warning of failure risk. In future, it is expected that the scouring mechanism around the hydraulic structures in intermittent rivers in Taiwan can be thoroughly investigated. Moreover, the real-time dynamic scouring processes will pro- vide valuable information for assessing sediment transport, the improvement of the hydraulic structure designs and the application of the landslide or debris flow warning system.
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Semantic interpretation of InSAR estimates using optical images with application to urban infrastructure monitoring

Semantic interpretation of InSAR estimates using optical images with application to urban infrastructure monitoring

 the scattering amplitude and phase of each scatterer,  and their 3D positions and motion parameters, e.g. linear deformation rate and amplitude of seasonal motion. The scatterers’ 3D positions in SAR coordinates are converted into a local Cartesian coordinate system, such as Universal Transverse Mercator (UTM), so that the results from multiple data stacks with different viewing angles can be combined. For our test area Berlin, two TerraSAR-X high resolution image stacks – one ascending orbit, the other descending orbit – are processed. These two point clouds are fused to a single one, following a feature-based matching algorithm which estimates and matches common building edges in the two point clouds (Wang & Zhu, 2015). Figure 2 is the fused point cloud which provides a complete monitoring over the whole city of Berlin.
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Early Warning Systems

Early Warning Systems

medical admissions. 25 C O N C L U S I O N In recent years, there has been significant research within the medical community regarding the prevention of clinical deterioration among hospital patients. The detection and management of deteriorating ward patients is a highly complex process influenced by a variety of factors. Early detection and intervention through early warning systems (EWS) are essen- tial to prevent serious, often life-threatening events, as they have already shown promising results in significantly lowering mortality rates. Among other factors, the perception of nurses plays a vital role in EWS. The context within deterioration is detected and reported as an important consideration that will influence the design and support the reliability of EWS with the potential of better administration of the bed availability of an intensive care or coronary care unit. The successful im- plementation of EWS requires support from hospital leaders, including senior medical and nursing personnel. Nursing man- agers of general wards in developing countries should consider implementation of early warning scoring observation charts validated at national level. However, early warning scoring systems must be viewed only as a major decision- making tool and should not be used to replace clinical judgment.
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Early warning characteristics of monitoring and evaluation systems on the "functionality" of municipal service delivery processes

Early warning characteristics of monitoring and evaluation systems on the "functionality" of municipal service delivery processes

The first sub-section posits a conceptual question related to M&E and EWS; are they conceptually related?. The second sub-section explains the importance of information to any kind of management, and how different kinds of information are used for different types of management, such as Risk Management (RM), Disaster Management (DM), Strategic Management (SM), M&E and EWS. It also discusses how various M&E information are determined by the purpose, planning and design of the M&E. It also presents the roles of and effects of ToC and LogFrame in and on the quality and usefulness of M&E information. The third sub-section is about methodology: how information is monitored and collected. It describes a number of management tools such as SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis, and the Balanced Scorecard approach that provide a means to identify and create a list of weaknesses, threats and risks that are required to be addressed. After that, it also discusses the limitations of those tools and approaches to monitor and capture early warning signals or indicators of any problems and introduces a theory and a model that can be applied to overcome their limitations. They are Weak Signals Theory and Four Essential Elements of an EWS model. The last sub-section discusses the application of information for different purposes and ends, which include EWS purposes and objectives (Table 2.2).
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Early warning monitoring of natural and engineered slopes with Ground- Based Synthetic Aperture Radar

Early warning monitoring of natural and engineered slopes with Ground- Based Synthetic Aperture Radar

The  basic  idea  of  GBInSAR  for  slope  monitoring  was  derived  from  satellite  technology.  Since  the   1990s,   with   the   launch   of   ERS-­‐1   (1991),   JERS-­‐1   (1992),   RADARSAT-­‐1   and   ERS-­‐2   (1995),   satellite-­‐ based   SAR   has   been   able   to   exploit   the   phase   information   in   radar   images   to   detect   ground   displacements   (Borgeaud   et   al.   1994;   Srivastava   et   al.   1996).   These   developments   of   satellite   technology  had  an  early  follow-­‐up  in  analogue  ground-­‐based  radar  systems  in  the  late  1990s.   In   the   year   2000,   various   authors   (Pieraccini   et   al.   2000a,   b;   Tarchi   et   al.   2000)   established   the   principles   of   ground-­‐based   interferometry   for   monitoring   buildings   and   for   terrain   mapping.   Finally,  in  2003,  in-­‐field  application  of  the  technique  was  demonstrated  for  remote  detection  of   slope  movements  (Tarchi  et  al.  2003;  Pieraccini  et  al.  2003).  In  those  early  days,  GBInSAR  systems   were  based  on  laboratory  equipment  (i.e.  vector  network  analysers)  adapted  for  in-­‐field  use.   This  remained  the  standard  until  the  first  design  of  a  custom  radar  (Pieraccini  et  al.  2004),  which   was  later  developed  and  placed  on  the  market  (in  2007)  by  IDS  SpA.  More  traditional  radars  using   real-­‐aperture  antennas  were  already  being  used  for  monitoring  mine  slope  stability  (Reeves  et  al.   2000).   Currently,   RAR   and   synthetic-­‐aperture   radar   (SAR)   are   both   popular   instruments   for   displacement  monitoring  of  natural  and  engineered  slopes.  
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Sinkhole Physical Models to Simulate and Investigate Sinkhole Collapses

Sinkhole Physical Models to Simulate and Investigate Sinkhole Collapses

Professor, Civil, Environmental and Construction Engineering, University of Central Florida 4000 Central Florida Blvd., Orlando, Florida, 32816, USA, Manoj.Chopra@ucf.edu Introduction Sinkhole is a ground surface depression that occurs with or without any surface indication. Sinkholes commonly occur in a very distinctive terrain called karst terrain. This terrain mainly has a bedrock of a carbonate rocks such as limestone, dolomite, or gypsum. Sinkholes develop when the carbonate bedrocks are subjected to dissolution with time to form cracks, conduits, and cavities in the underground bedrock. These features allow the overburden soils (on top of the carbonate bedrock) to transport through them to the underground cavities, which results in surface collapse due to the upward progression of the soil cavity toward the ground surface. Sinkholes vary in shapes and sizes. They have different shapes such as inverted cone, shallow bowl, and shaft shapes. Also, they can range from less than a meter to hundreds of acres and from 30 cm to 30 meters in depth (Waltham et al., 2005).
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An online operational rainfall monitoring resource for epidemic malaria early warning systems in Africa

An online operational rainfall monitoring resource for epidemic malaria early warning systems in Africa

demic outbreaks have been known to occur along the Nile River margins in the northern half of the country. Uganda's malaria control programme, however, had found the maps to be reasonably accurate and a useful monitoring resource. Further dialogue with malaria con- trol programmes in West Africa and Southern Africa also raised the point that a single dekadal rainfall anomaly map could raise an alert; when in fact the rainfall levels were not abnormally high – but just 10 days earlier than 'normal'. This suggested that additional information about the temporal distribution of rainfall was necessary. In order to respond to these issues, USGS and WHO- HealthMapper agreed to collaborate on the development of the dekadal anomaly maps in a format which could be downloaded, viewed and archived by surveillance staff directly in HealthMapper, a basic mapping and surveil- lance software developed by WHO's Communicable Dis- ease Surveillance and Response Department http:www.who.int/csr/mapping/tools/healthmapper/ health mapper/en/. In addition to the most recent map, it is possible to download the dekadal maps for the previous six months and begin to construct a seasonal time series. The integration of the rainfall anomalies maps within HealthMapper also allowed the users to improve their analyses by combining ancillary data related to malaria directly on top of the rainfall anomalies maps for their country. Figure 3 provides an example for Niger.
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Deliverable 9.4. Report on the use of monitoring as knowledge based assessment and early warning tool

Deliverable 9.4. Report on the use of monitoring as knowledge based assessment and early warning tool

The dynamic system is currently implemented is composed by two strong motions recorders with 16 bits ADC analysers provided with batteries. One triaxial force balance accelerometer is connected to each recorder by cable. Two points were selected to install the sensors. One sensor was installed at the base of the structure near the chancel, and the other sensor at the top of the nave and in the extrados. The sampling frequency is equal to 100 Hz. It must be noted that the actual number of sensors installed in the church is not enough to monitor the mode shape changes. During a first phase and until further sensor upgrade, the dynamic monitoring is carried out in terms of resonant frequencies. The sampling is undertaken with the following schedule: (1) the recorders are activated for low acceleration levels and are therefore activated when a micro tremor (or strong wind) occurs at the site; (2) every month, a record of 10 minutes is performed to detect frequency shifts (Figure 6); this allows to separate the influence of environmental conditions and to compare the consecutive dynamic responses before and after the occurrence of significant events; (3) seasonally, 10 minutes records are taken every hour and during one complete day to observe, again, the influence of environmental conditions in the dynamic response of the church. In particular, these measurements allowed the detection of a clear influence of the temperature on the static behaviour of the structure. For the study of the environmental and loading effects all data acquired in the strong motion recorders are used.
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Preface: Landslide early warning systems: monitoring systems, rainfall thresholds, warning models, performance evaluation and risk perception

Preface: Landslide early warning systems: monitoring systems, rainfall thresholds, warning models, performance evaluation and risk perception

Moreover, the works included in the special issue describe early warning systems at very different stages of employ- ment. Some of them are well established and have been op- erated for years (Devoli et al., 2018); others could be more properly defined as preliminary studies aimed at addressing landslide hazard and establishing a scientific and technical basis for the buildup of a LEWS (Uzielli et al., 2018). It should be remarked that the establishment of a LEWS is a complex task, and before operating a warning system, several preliminary steps are usually required. This is reflected by the content of this special issue, in which different steps of this process are accounted for: the establishment of landslides– rainfall correlations (Liu et al., 2018), the definition of a runout simulation model (Melo et al., 2018), the definition of predictive models (Greco and Pagano, 2017), the setting up of prototypes (Intrieri et al., 2017; Canli et al., 2018), the validation and the performance evaluation of the predictive early warning model (Peres et al., 2018; Segoni et al., 2018a), the performance of operational LEWSs through case stud- ies (Devoli et al., 2018) and the evaluation of risk percep- tion (Chaturvedi et al., 2018). A relevant subject covered by many articles included in the special issue is the definition of rainfall thresholds for landslide prediction (e.g., Pan et al., 2018; Peres et al., 2018; Vaz et al., 2018), a highly de- bated topic among the landslide community that often over- laps to LEWSs (Segoni et al., 2018b). The most debated un- resolved issues in rainfall threshold research include the fol- lowing
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Study on Monitoring and Early Warning of Karst Collapse Based on BOTDR Technique

Study on Monitoring and Early Warning of Karst Collapse Based on BOTDR Technique

The selection of optical fiber types Generally, optical fiber contains fiber core, cladding, coating layer, restrictive coating, etc. Different structure and external bonding method will influence the sensi- tivity of measurement (Liu et al., 2006). Specific to working conditions like highway roadbed construction, according to existing conditions and experiments, the choice of Corning’s single-mode tight tube optical fiber is ideal in practical application. Its major parameters are: core diameter/ cladding diameter/ tight tube diameter are 83/ 125/ 900μm; maximum tension long-term 3.0N;
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A Water Monitoring and Early Warning System of COD Using UV-Vis Spectroscopy

A Water Monitoring and Early Warning System of COD Using UV-Vis Spectroscopy

Abstract: A distributed remote water monitoring and early warning system was proposed, which used the UV-Vis spectroscopy, GPS, GIS, 4G network, COD solution and database technology, to solve the problems including long detection cycle, limited scale and the lack of early warning mechanism of the water monitoring. 50 groups of original water sample from Ciqikou to Chaotianmen of Jialing River in Chongqing, China (every 5 km decorate a monitoring node, every 60 minutes collect data) was selected to study distributed remote water monitoring and early warning system of COD in UV-Vis spectroscopy based on 4G networks. The results indicated that through the system, not only the real-time display and storage, historical data query and warning function of water quality monitoring information could be achieved, but also the status of the water quality environment on the basis of COD can be reflected, which has a strong practicability and can provide environmental monitoring departments with real-time water quality information.
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