Fuzzy Logic-based Data Controlled Wireless Sensor Network Routing Protocol for Flood Early Warning

Floods account for 15% of all natural disasters related deaths. Therefore, early flood warning systems using wireless network of sensors installed in flood prone areas is necessary to provide early notice of impending flood. This research focuses on the use of an energy efficient routing protocol to prolong the life time of the Network. The importance of this is to minimize energy consumption as necessary for reliable field operations. It adopts the use of mandami Fuzzy logic-based data controlled routing protocol (F-DCRP).Simulation was carried out for the F-DCRP, LEACH and Crisp Data controlled routing protocol (DCRP). The performance of the three protocols were obtained and compared. The result showed that Cluster head (CH) load was better shared uniformly among all the nodes. Percentage of packets dropped showed that the proposed F-DCRP was 10% lower compared to DCRP and 50% lower compared to LEACH resulting in more packets sent per round and greater reliability compared to LEACH and DCRP. The network lifetime was also improved by 40 % when compared to LEACH and DCRP.

A Propagation Study of LoRa P2P Links for IoT Applications: The Case of Near-Surface Measurements over Semitropical Rivers

Internet of Things (IoT) radio networks are becoming popular in several scenarios for short-range applications (e.g., wearables and home security) and medium-range applications (e.g., shipping container tracking and autonomous farming). They have also been proposed for water monitoring in flood warning systems. IoT communications may use long range (LoRa) radios working in the 915 MHz industrial, scientific and medical (ISM) band. In this research, we study the propagation characteristics of LoRa chirp radio signals close to and over water in a tropical meadow region. We use as a case study the Colima River in Mexico. We develop a novel point-to-point IoT measurement sounding system that does not require decoding of LoRa propriety bursts and provides accurate power versus distance profiles along the riparian zone of a steeply dropping mountain river. We used this system to obtain the measurements reported in this work, which are also analyzed and modeled. The results show that the LoRa signal propagation over water exhibits a log-normal distribution. As a result of the chirp signal processing, two new experimental path loss models are presented. The path loss results show a considerable degradation of the received signal power over water within vegetation and less signal degradation at antenna heights closer to the water surface.

Knowing what to do substantially improves the effectiveness of flood early warning

Flood warning systems are longstanding success stories in respect to protecting human life, but monetary losses continue to grow. Knowledge on the effectiveness of flood early warning in reducing monetary losses is scarce, especially at the individual level. To gain more knowledge in this area, we analyze a dataset which is unique in respect to detailed information on warning reception and monetary losses at the property level and in respect to amount of data available. The dataset contains 4468 loss cases from six flood events in Germany. These floods occurred between 2002 and 2013. The data from each event was collected by computer aided telephone interviews in four surveys following a repeated cross-sectional design. We quantitatively reveal that flood early warning is only effective in reducing monetary losses when people know what to do when they receive the warning. We also show, that particularly long-term preparedness is associated with people knowing what to do when they receive a warning. Thus, risk communication, training, and (financial) support for private preparedness are effective in mitigating flood losses in two ways: through precautionary measures and more effective emergency responses.

Primarily Results of a Real-Time Flash Flood Warning System in Vietnam

In recent years, losses and damages from flash floods have been steadily increasing worldwide as well as in Vietnam, due to physical factors, human activities, especially under a changing climate. This is a hotspot issue which requires immediate response from scientists and policy-makers to monitor and mitigate the negative impacts of flash floods. This study presents a way to reduce losses through increasing the accuracy of real-time flash flood warning systems in Vietnam, a case study developed for Ha Giang province where the topography is relatively complex with severe flash floods observed. The objective of this paper is to generate the real-time flash flood system based on bankfull discharge threshold. To do this, HEC-HMS model is applied to calibrate and validate observer inflow to the reservoir with nine automatic rain gauges installed. More importantly, on the basic of measured discharge at 35 locations from the fieldtrips, an empirical equation constructed is to identify the bankful discharge values. It bases on the relationship between basin characteristics of river length, basin area and bankfull discharge. The results indicate an effective approach to determine bankfull threshold with the established-empirical equation. On the scale of a small basin, it depicts the consistency of flood status and warning time with the reality. Doi: 10.28991/cej-2021-03091687 Full Text: PDF

AVALIAÇÃO DA PREVISIBILIDADE DO MODELO WRF-HYDRO EM MODELAGENS HIDROMETEOROLÓGICAS COM DIFERENTES RESOLUÇÕES NA BACIA DO TAQUARI-ANTAS

O presente estudo avalia o modelo WRF-Hydro uma ferramenta de previsão acoplada chuva/solo/vazão, buscando aperfeiçoar o grau de agilidade e confiabilidade das previsões na região considerada de grande vulnerabilidade, a bacia hidrográfica do Taquari-Antas/RS, localizada na região Sul do Brasil. A avaliação consistiu em analisar os resultados e a previsibilidade do modelo com diferentes resoluções espaciais na simulação de evento extremo ocorrido em janeiro de 2010. A primeira simulação foi realizada com duas grades do modelo meteorológico com 50 e 10 km e com a rede de canais com resolução de 1000 m. E a outra com três grades de 25, 5 e 1 km para meteorologia e rede de canais com 250 m. Avaliadas usando comparações da magnitude e da variabilidade dos fluxos da superfície da bacia, como precipitação e vazão do modelo com dados observados. Os resultados seguem as observações locais e apresentam bons resultados para servir como ferramenta em sistemas de alerta contra cheias nesta e em outras regiões. Predictability of the Wrf-Hydro Model in Hydrometeorological Modeling with Different Resolutions in the Taquari-Antas Basin A B S T R A C TThe present study evaluates the WRF-Hydro model, a rainfall/soil/flow coupled forecasting tool, aiming to improve the agility and reliability of the predictions in the region considered to be of great vulnerability, the Taquari-Antas/RS basin located in the region South of Brazil. The evaluation consisted of analyzing the results and predictability of the model with different spatial resolutions in the extreme event simulation that occurred in January 2010. The first simulation was performed with two grids of the 50 and 10 km meteorological model and with the channel network with resolution of 1000 m. And the other with three grids of 25, 5 and 1 km for meteorology and network of channels with 250 m. Evaluated using comparisons of magnitude and variability of basin surface fluxes, such as precipitation and flow of the model with observed data. The results follow local observations and present good results to serve as a tool in flood warning systems in this and other regions.Keywords: numerical forecasting, extreme events, WRF-Hydro, hydrological basin monitoring and hydro-meteorological modeling.

Influence of Topographic Characteristics on the Adaptive Time Interval for Diffusion Wave Simulation

Frequent flash floods in recent years have resulted in a major impact on the living environment, urban planning, economic system and flood control facilities of residents around the world; therefore, the establishment of disaster management and flood warning systems is an urgent task, required for government units to propose flood mitigation measures. To conserve the numerical accuracy and maintain stability for explicit scheme, the Courant–Friedrich–Lewy (CFL) condition is necessarily enforced, and it is conducted to regulate the relation between the numerical marching speed and wave celerity. On the other hand, to avoid the problem of flow reflux between adjacent grids in executing 2D floodplain simulation, another restriction on time intervals, known as the Hunter condition, was devised in an earlier study. The objective of this study was to analyze the spatial and temporal distribution of these two time-interval restrictions during runoff simulations. Via a case study of the Komarovsky River Basin in Russia, the results show that at the beginning of a storm, the computational time interval is restricted by the CFL condition along the upstream steep hillsides, and the time interval is subject to the Hunter condition in the mainstream during the occurrence of the main storm. The reason of a reduction in computational efficiency, which is a common problem in conducting distributed routing, was clearly explained. To relax the time-interval restrictions for efficient flood forecasting, the research findings also indicate the importance of integrating modified hydrological models proposed in recent studies.

Fast early flood warning systems exploiting catchment specific behavior

We present a catchment specific emulator based onnon-linear shallow water equations to be used forearly flood warning system in real time.