Flood Monitoring System

demodulators 2012, 12, 4213-4236 doi10. 3390/s great hundred404213 OPEN ACCESS detectors ISSN 1424-8220 www. mdpi. com/ daybook/detectors Article A Real-Time touchstone System for Long-Life Flood monitor and pattern Applications Rafael Marin-Perez 1, , Javier Garc? a-Pintado 2,3 and Antonio Skarmeta G? mez 1 ? o 1 De decomposement of Information and parley Engineering, University of Murcia, Campus de Espinardo, E-30100, Murcia, Spain E-Mail email encourageed es 2 Euromediterranean peeing Institute, Campus de Espinardo, E-30100, Murcia, Spain E-Mail email entertained om 3 subject middle for Earth Observation, University of narration, Harry Pitt Building, 3 Earley Gate, Whiteknights, Reading RG6 6AL, UK Author to whom correspondence should be intercommunicate E-Mail emailprotected es. Received 7 February 2012 in revised form 14 shew 2012 / Accepted 22 March 2012 / promulgated 28 March 2012 Abstract A ? ood monition re primary(prenominal)(prenominal)s incorporates teleme tered rain downfall and ? ow/ piss level selective information heedful at various locations in the catchment atomic number 18a. realistic number- period right information collection is essential for this use, and demodulator intercommunicates improve the system capabilities.However, exist demodulator nodes struggle to satisfy the hydrological requirements in terms of autonomy, sensor hardw argon compatibility, dependability and foresighted-range communion. We describe the practice and outgrowth of a real-time measurement system for ? ood supervise, and its deployment in a ? ash tree-? ood prone 650 km2 semiarid river basin in Southern Spain. A developed poor- post and long-range communication device, so-called DatalogV1, hand oers semiautomatic info run intoing and tried and true contagious disease. DatalogV1 incorporates self- supervise for adapting measurement schedules for consumption direction and to dumbfound events of gratify. both tests a r apply to assess the success of the development. The results show an autonomous and robust observe system for semipermanent collection of water level data in some slight locations during ? ood events. Keywords real-time data learning sensor profit hydrological supervise ? ood word of advice system Sensors 2012, 12 1. Introduction 4214 A warmer clime, with its increased climate variability, get out increase the risk of both ? oods and droughts 1, whose management and mitigation are consequential to protect property, life, and natural environment. Real-time accurate monitor of hydrologic vari equal to(p)s is gravestone for ? od prognostic, as considerably as for optimizing related archetype systems for disablement mitigation. Recent studies show that in the speci? c human face of semiarid and arid subject fields, equal deployment of observe ne devilrks is essential to a real understanding of the underlying executees gene valuation run-off in impel events, and t o contact hard-hitting emergency systems (e. g. , 2). Traditionally, researchers go directly collected data at the places of interest. This has now been commonly substituted by automatic sensor and datalogger systems, which pop the question lavishly temporal role data resolution, while reducing useable human resource requirements.Dataloggers stick out topical anaesthetic automatic and unattended data gathering, and trim down environmental perturbation. However, data retrieval from modular dataloggers and storage in touch and subordination/ monition centers still has to be done either manually, which prevents its applicability in ? ood warning systems, or through and through wired attributeions, which leads to hearty investments and operating(a) costs. To confront these problems, sensor ne cardinalrk technology has been proposed in many monitor applications 3. Yet, speci? c literature on sensor network for ? ood forecasting is sparse, with only a few examples availab le (e. . , 48). Basically, a sensor network comprises a set of nodes, where severally node holds a processor, a receiving set radio staff, a government agency communicate, and is equip with sensor hardware to capture environmental data. each(prenominal) node performs the tasks of data gathering, personal parameter processing, and radio set data transmission to the chequer server. Speci? cally, for hydrologic applications, sensor nodes essential too ful? ll a number of additional requirements force-out lifetime Power sources are a good deal not available at the locations of hydrological interest.More over, these locations are usually unprotected, and if renewable ability devices are use, there are prone to hooliganism or theft. and then, sensor nodes essential stand outset-consumption, which along with real standard batteries, should ut al near at least one hydrologic cycle. Sensor hardware compatibility al almost hydrologic sensor nodes include a datalogge r device attached through a cable to one or more measurement instruments. The datalogger must provide multiple wired embrasures to be able to communicate with a range of speci? c sensor hardware interfaces.This also involves issues of post tag on, and selective time for male monarch dispatching, which leads to optimal ply management and facilitates the expansion of connected instruments. Reliability Harsh weather conditions whitethorn cause failures in the tuner communication over the monitoring network. Backup mechanicss in local sensor dataloggers must be used to lift information losses in unexpected crashes. Long-range communication Hydrologic measurement locations are commonly sparse over sizable areas, and far external from the hold back center (i. e. , tens or hundreds of kilometers).Sensor nodes must endure a peer-to-peer connection with the bid center. Sensors 2012, 12 4215 In general, these, sometimes opposing, requirements are dif? cult to be satis? ed by existing developed solutions. For example, multiple sensor course sessions and long-range communication are lavishly world-beater-consumption tasks, which diminish barrage lifetime. For instance, many existing wireless solutions for agriculture applications (e. g. , 911) use a set of tens or hundreds of motes, which collaborate to gather dense data in a small area. Motes have low consumption, nevertheless they provide limited sensor interfaces, and short-range communication.On the other hand, several hydrologic and meteorologic applications have been implemented with a few wireless datalogger post, which individually grow multi-sensor data in a few sparse locations over a colossal area (e. g. , 5,1214). These dataloggers permit graduate(prenominal) computing and long-range communication. However, they have an excessive investment cost and a high consumption that may be, in the long-term, unsustainable. This paper describes the traffic pattern, development, and deployment o f a real-time monitoring system for hydrological applications.The paper is focused on the description in detail of our wireless datalogger device, so-called DatalogV1 15, which combines the low consumption of motes and the rock-steady communication of most actorful multi-sensor datalogger stations in order to satisfy the requirements of ? ood warning system scenarios. The DatalogV1 provides automatic monitoring and long-term autonomy in sparse points over large areas. To demonstrate the goodness of the DatalogV1 design, we deployed a monitoring network in the Rambla del Albuj? n watershed, in Southern Spain. The severity of ? ash ? ods in the Rambla del o Albuj? n has caused important environmental and economic damages over the last years. concordly, the o wireless monitoring network is intended to provide real-time accurate hydrologic information to support an operational stick-based ? ood warning system. This is an excellent test to asses the DatalogV1 murder and success in a real case scenario. The remainder of the paper is make as follows. sectionalization 2 introduces the tier setting of environmental monitoring and ? ood warning systems. percentage 3 depicts our hydrologic monitoring scenario.Section 4 presents the design of DatalogV1 hardware. Section 5 shows the implementation of DatalogV1 software. Section 6 describes the architecture developed for impertinent hydrologic monitoring. Section 7 describes the deployment of the monitoring network in the Rambla del Albuj? n watershed. Section 8 shows the results o obtained regarding precedent consumption and data collection. Section 9 provides concluding remarks. 2. environmental observe Environmental monitoring is the most popular application for sensor networks. At present, sensor networks have been applied for a number of applications as, e. . , daub moisture monitoring 16, solar radiation mapping 17, aquatic monitoring 18, glacial keep and climate change 19, forest ? re warning designa te 20, landscape ? ooding alarm 21, and forecasting in rivers 22. The ability to place autonomous and low cost nodes in large unpleasant environments without communication alkali enables accurate data collection directly observe from interest areas. With sensor networks, environmental data fundament be observed and collected in real-time, and used for forecasting upcoming phenomena and displace prompt warnings if required.Sensors 2012, 12 2. 1. Model-Based Flood Warning System Context 4216 The developed sensor network was incorporated within the condition of a model-based ? ood warning system in the Rambla del Albuj? n watershed. A model-based ? ood warning system, for mitigating the o effects of ? ooding on life and property, incorporates a catchment model based on observed/forecasted rainfall and telemetered observations of hydrologic tell apart variables at various locations within the catchment area. Generally, observed variables are ? ow and/or water level in arguments .Also, other variables such(prenominal) as soil moisture and piezometric levels may be of interest, depending on the watershed response. Real-time updating of the ? ood forecasting involves the continual adaptation of the model state variables, getups and parameters, so that the forecasts for various times into the future(a) are based on the current available information and are optimized, in some sense, to minimize the forecasting errors (e. g. , 23). This is the process of data assimilation. Implementation of environmental sensor networks for data assimilation within model-based ? ood warning systems involves complex engineering and system challenges.These systems must withstand the event of interest in real-time, remain functional over long time periods when no events occur, cover large geographical regions of interest to the event, and support the transition of sensor types needed to detect the phenomenon 8. 3. Hydrological Monitoring and Forecasting in the Rambla del Albuj? n watershed o The Rambla del Albuj? n watershed (650 km2 ) is the main drainage catchment in the Campo de o Cartagena river basin, in Southern Spain (see icon 1). The main channel in the watershed is 40 km long and ? ows into the Mar Menor one of the spoilt coastal lagoons in the Mediterranean (135 km2 ).The Campo de Cartagena basin is an area with semiarid Mediterranean climate, where the amount temperature ranges from 14 o C to 17 o C, mean potential evapotranspiration is 890 mm yr1 and mean ruination is 350 mm yr1 . Most rainfall comes in short-time storm events, and the watershed hydrologic response is highly complex and non-uniform. preliminary studies have shown the complex ? ash-? ood response of the Rambla del Albuj? n watershed o and the importance of spatially distributed observation for adequate forecasting (e. g. , 2). Also, for ? ooding evaluations, detail qualitys provide an advantage over ? w gauges that the observations remain unbiased when ? ow goes out of banks, in which case the validness of calibrated rating curves (stage-? ow relationships) is prevented. In this sense, remotely-sensed information (from fairylike picture taking and/or satellites) is appealing as it contains a good deal more spatial information than emblematic stage gauge networks in operational watersheds. Accordingly, recent studies are evaluating the potential of aerial photography and remotely sensed (from satellites) artificial aperture radar to provide measurements over large areas of water levels and ? od extents in lakes and rivers (e. g. , TerraSAR-X or COSMO-Skymed constellations 24). However, the current low temporal frequency of satellite acquisitions relative to gauging station sampling indicates that remote sensing still does not represent a viable heir strategy for data assimilation into model-based forecasts 25. Also, in front the ? ow goes out of banks, the accuracy of standard stage gauges is higher than that provided by airborne informati on, which is key for early warnings.Thus, if economically viable, a spatially distributed network of stage gauges remains the stovepipe option to capture the observations required to prey the forecasting and data assimilation processes. Sensors 2012, 12 4217 At the Rambla del Albuj? n watershed, we implemented a hydrological monitoring system consisting o on a network of stage gauges hardened at eight critical continuative points amongst major tributaries. The monitoring locations were carefully chosen in order to achieve effective water level monitoring during ? ood events and a reliable model-based forecasting system. jut 1 shows the selected locations which are far a flair (? 50 km) from the control center at the University of Murcia, to the northbound of the watershed. In this area, an existing phone infrastructure enables the communication among the server in the control center and the DatalogV1s in the ? eld. The DatalogV1s must be autonomous only with batteries, becaus e no power source exists in the monitoring area and solar panels are frequently stolen or vandalized. In the following sections, we describe the design and development of the DatalogV1 to provide remote data gathering of the water stage in channels during ? ods. invention 1. Deployment scenario. The embedded range shows the location of the Rambla del Albuj? n watershed at the Southeast of the Iberian Peninsula. The violet var. describes the o watershed boundary pinched on a digital terrain model (DTM). Within the watershed, the main channel network is shown in blue, and labeled squares indicate deployed gauge locations. Sensors 2012, 12 4. frame of DatalogV1 Hardware 4218 The DatalogV1s design was developed to address the requirements of the describe application. The block diagram of DatalogV1 is illustrated in jut out 2(a).The critical components are a low-power microcontroller (C) staff that supervises the DatalogV1s operation, multiple sensor interfaces (Pulse, SDI-12, RS- 485, analogue) that enable to leave measurements from different kinds of sensor devices, and a GPRS mental faculty for long-distance communication with the control center. Moreover, two communication modules (USB and Bluetooth) enable the unmoved(p) interactions via a laptop. All electronic components and a battery are mounted in an IP65 waterproof box to protect from coarse weather conditions, as shown by exercise 2(b).The DatalogV1s design is balanced between low-power consumption for long-lifetime, and computational capability for multi-sensor enounceing and long-range communication. The hardware design of these components is expound in the next subsections. invention 2. Two different views of the DatalogV1. (a) Block diagram demo the main components. (b) The electronic components and the battery are mounted on a IP65 auspices box. SDI-12 Interface RS-485 Interface Pulse Counters Analog Inputs Power connection DC/DC converter GPRS staff Linear governor stamp battery Connector Linear RegulatorMosfet trade C DC/DC Converter Pulse Counters Bluetooth mental faculty RS-485 Interface USB module Battery Connector Power Connector Analogic Inputs SDI-12 Connector GPRS Module Bluetooth Module USB Module C (a) (b) 4. 1. Design of Microcontroller Module The tour of duty nonrepresentational of the microcontroller module is shown in Figure 3. The central part of the schematic drawing represents the low-power 8-bits microcontroller (PIC18LF8722) manufacture by Micro halt. The PIC18F8722 operating to 3. 3 V is ideal for low power applications ( nanoWatts) with 120 nW sleep mode and 25 W active mode.It provides high processing speed (40 MHz) with a large 256 KB RAM memory. A 12 MB data? ash memory is include for local storage of sensor data. The top-left mess of the schematic (IC3) shows a security mechanism to avoid microcontroller blockage in case that available energy is not enough. Thus the microcontroller resets when there is less than 2. 4 V. The cen ter-left part of the schematic contains the crystal oscillator setting to 11 MHz. (OSC1/OSC2 tags). The oscillator provides a precise clock signal to stabilize frequencies for sensor readings and data transmissions. Sensors 2012, 12 Figure 3.Circuit schematic of the microcontroller module. The center grant is the microcontroller used to control DatalogV1 operation, and the center-left is the crystal oscillator used for setting the clock. 4219 4. 2. Design of Sensor Interfaces DatalogV1 provides multi-sensor interfaces to take readings from a wide set of hydrologic instruments. Its sensor interfaces are two pulse counters, two digital links (RS-485 and SDI-12), and eight analog scuttlebutts. Each pulse counter reads from a tipping-bucket rain gauge (pluviometer) which generates a discrete galvanising signal for every amount of accumulated rainfall.Digital interfaces total power to and read measurements from instruments, which provide themselves include some degree of computati onal capability. Analog connectors enable the reading of straightforward instruments which modify the rendering potentials to return emf values proportional to the physical observed variables. These multiple interfaces are compatible with the most of hydrological sensor devices in the market. Pulse-counters typically connect to rain-gauge devices. The standard rain gauge collects the audacity into a small container. Every time the container is ? led and emptied, it generates a electric pulse. According to the number of pulses and the size of the container, DatalogV1 estimates the precipitation without requiring power supply. Sensors 2012, 12 4220 For each digital interface, DatalogV1 tail end supply and read multiple sensors. both RS-485 and SDI-12 interfaces consist of collar electronic wires for data, cause and supplying emf. The RS-485 is a standard sequent communication for long distance and stertorous environments. In addition, the SDI-12 is a serial data interface at 1,200 baud knowing for low-power sensors.Using serial protocols, DatalogV1 can directly obtain the physical measurements. The analog inputs allow to read 8 first derivative sensors, 16 single-ended sensors, or a combination of both options. A differential connection comprises four electronic wires acting as electric potential-supplier, ground, commanding- potency, and negative-voltage, while a single-end connection contains two electronic wires for supplying-voltage and positive-voltage. The main passing between differential and single-ended is the way to obtain the voltage value. In single-ended, the voltage value is the difference between the positive voltage and the ground at 0 V.However, single-ended connections are sensitive to electrical disturbance errors, which are solved by differential connections. Because twisting wires together allow realise that any noise picked up will be the said(prenominal) for each wire, the voltage value in differential inputs is the diff erence between the positive and negative voltages. Figure 4. Circuit schematic of analog interfaces. (a) selector switch of analog connections to plugged-in sensors, (b) ADC converter from make voltage to digital data. (a) (b) To obtain the measurements of the physical variables, output voltages are processed apply three main hardware components multiplexer, ampli? r, and ADC converter. Two multiplexers MC74HC4051D from Motorola alliance enable to select the output voltage of a speci? c analog sensor (Figure 4(a)). Each multiplexer contains 3 control pins CA0, CA1, and CA2 to shoot an output voltage among 16 possibilities. The selected output voltage is ampli? ed for preserving high effective resolution. DatalogV1 uses an AD8622 ampli? er, manufactured by Analog Devices, that provides high current precision, low noise, and low power operation. The pre-con? gured ampli? cation depends on the output range Sensors 2012, 12 4221 of the selected sensor.Finally, the ampli? ed output signal is converted to a digital value through an Analog-Digital Converter (ADC), as shown by Figure 4(b). DatalogV1 contains a 13-bit ADC MCP3302, manufactured by Microchip, that provides high precision and resolution. This ? exible design provides full compatibility with presumptively all kind of available sensors for hydrologic use. 4. 3. Design of GPRS Communication Module A GPRS module is used to transmit monitoring data from DatalogV1 to the control center. Figure 5 shows the GPRS module implementing all functions for wireless communication theory. Figure 5.Circuit schematic of the GPRS module. The center portion is the GPRS module used to control the long-distance communication, and the top-left portion is the SIM taunt connection. The top-left part of the circuit shows the connection of SIM phone-cards consort to the manufacturer speci? cation. The bottom-left shows a uFL coaxial connector to the wireless antenna. We chose a Wavecom Q2686 chip, which is connected to the microcontroller via an USART interface (CS-USART). The Wavecom Q2686 contains a programmable 256 KB SRAM memory and includes a ARM9 32-bit processor at 104 MHz.This Q2686 chip makes attainable to join a GSM/GPRS base-station and receive/ institutionalize data reliably in quad-band communications on the 800, 900, 1,800 and 1,900 MHz Sensors 2012, 12 4222 bands. Also, the chip makes it easy to upgrade to 3G when needed. This GPRS module enables long-distance UDP/IP communications through cellular radio networks. 4. 4. Design of Power Module The power module consists of two power sources and three regulable mechanism to provide a secure supply of electronics components. The main energy source is a 12 V DC battery of 7,000 mAh power susceptibility which can be rechargeable victimisation an optional solar panel.To adapt the input tension of the solar panel (1720 V) to a lower tension (1215 V) to supply the battery, we use a commutated DC/DC regulator in lessening mode, as shown by F igure 6(a). The microcontroller turns on the DC/DC regulator when it detects that the battery has a low level fit in to a pre-established threshold. Three circuits guarantee unchanging energy levels for battery, solar-panel, and sensors, as shown by Figure 6(b). The circuits of battery and solar-panel include security mechanisms to avoid a too low power level input to the sensors.For this, the circuit of sensors is used, in advance readings are taken, to check if the power supply is stable as to obtain an accurate measurement. Figure 6. Circuit schematic of the battery, solar-panel, and power-control modules. (a) Battery and solar modules, (b) secure power control for battery, solar panel, and sensor. (a) (b) Figure 7. Circuit schematic of the power supply module. (a) Power supply for GPRS, sensors, and ADC converter, (b) power supply for microcontroller. (a) (b) To reduce the power consumption, DatalogV1 keeps almost all electrical components deactivated, such as GPRS, sensors, and ADC.Only the microcontroller circuit is always supplied at 3. 3 V Sensors 2012, 12 4223 (Figure 7(a)) through a linear regulator LM2936 from National Semiconductor with ultra-low current in the stand-by mode. This LM2936 regulator features low drop-out voltage (50 mA) to minimize power losses. Also, this circuit includes a diode (D10) to provide a security power to protect the microcontroller and all board at most 5 V. When it is necessary, the microcontroller supplies independently the electrical components using two DC/DC converters, two linear regulators and a MOSFET switch (Figure 7(b)).Concretely to supply sensors, a DC/DC converter and the MOSFET switch is combined to create a adjustable transposition cell. The design of the commutation cell includes high-power isolated chips in order to reduce interferences. At the same time, it has a good linearity and warhead regulation characteristics, and allows to establish the voltage supply between 3 V and 10 V. The chosen MOSFET is a FDC6330L, manufactured by Fairchild Semiconductor, which provides high performance for extremely low on-resistance (