基于 LoRa 的洪水传感器监测帮助打造智慧城市

The metropolitan region in Southeastern Virginia called “Hampton Roads” is prone to flooding. The area is home to two million citizens and 14 military installations, including Langley Air Force Base and Naval Station in Norfolk, the largest naval complex in the world. Like many of the 665 coastal communities in the U.S., this region regularly floods during moderate to heavy rains and high tides. Hampton Roads has the additional burden of experiencing land subsidence – the ground is sinking as sea level water is rising.

反复的洪水使社区的道路积水严重，车辆无法通行。诺福克市 IT 开发总监通过当地 Makerspace 找到了电气和系统工程师 Jim Gray，共同商讨该市的长期洪涝问题。他们最初开展了一项创新试点项目，旨在让城市随时了解水位高低和哪些道路无法通行。该项目现在发展为 Green Stream Technologies，利用了 Semtech 的 LoRa 器件和无线射频技术（LoRa 技术）。

End-to-End Flood Monitoring Solution

Green Stream Technologies is an environmental technologies company. The business helps to create smarter, safer, more resilient communities with the power of Internet of Things (IoT) technology and data analytics.

Green Stream’s end-to-end flood monitoring solutions are designed using commercial, off-the-shelf ultrasonic sensors and easy to deploy LoRa-enabled gateways. The data is communicated over a network provided by Senet, a leading provider of LoRaWAN® services platforms that enable IoT connectivity.

The Green Stream Technologies’ flood sensors are autonomous, requiring no external power or wired network connection. Each sensor is a self-contained, weather-proof, solar- powered unit that comes with a universal mounting bracket and extension arm. They are small enough to be installed on top of crosswalks, light or electric poles and bridges. The rugged devices are positioned above a body of water or over dry land.

Green Stream Technologies’ systems measure the distance from the surface to the LoRa-enabled sensor and calculates precise water height and depth. The data sampled is communicated in six-minute intervals to gateways and sent to the Green Stream Cloud. The flood data can be viewed on Green Stream Technologies’ web-based dashboard or mobile devices. Green Stream Technologies also integrates into consumer smart phone apps like Waze and direct warning systems that provide push notifications.

Easy Deployment with LoRa Technology

When Green Stream Technologies looked at connectivity options, Wi-Fi did not provide the range needed and cell technology was not practical due to its battery consumption requirements. LoRa Technology was the preferred choice for its long-range, low-power capabilities and small footprint. Senet, a contributing member of LoRa Alliance®, provides LoRaWAN-based network connectivity.

After a series of product prototyping, refinement and calibration testing, the first Green Stream Technologies’ deployment occurred in the City of Norfolk in April 2017, specifically in the Ghent neighborhood and around the Hague Footbridge. Deployments in Virginia Beach and numerous communities in North Carolina soon followed.

Green Stream Technologies’ main customers are municipalities – at the state or local level – and private environmental firms. Green Stream Technologies’ sales cycle is quite fast as system expenses often fall under pre-defined expenditure caps, eliminating the requirement for a cumbersome RFP process.

A Solution Built to Scale

The company is expanding beyond Hampton Roads and coastal communities into U.S. inland communities around the Missouri River basin and into parts of the globe where Senet has deployed its network infrastructure.

Green Stream Technologies 与欧道明大学海洋、地球和大气科学系的海平面上升专家合作，共同建立一个标准模型并在新区域部署，以确定需要多少支持 LoRa 的传感器以及应将它们放置在哪里。Green Stream Technologies 还致力于开发一种预测分析模型，利用地下水饱和度传感器和超本地天气数据，快速预测洪水发生前会发生什么。

Learn more about Green Stream Technologies and Senet, and explore more LoRa-based use cases for Smart Cities.

Semtech、Semtech 徽标、LoRa 和 LoRaWAN 是 Semtech Corporation 或其附属公司的注册商标或服务标志。