Background
Umvoto Africa was contracted by the City of Cape Town to construct a weather station in the Cape Flats area. The station will provide up-to-date data to input into a numerical model. Recharge, abstraction, rainfall, and evaporation are just some of the parameters required to sustainably manage the Cape Flats Wellfield, which plans to abstract groundwater from the Cape Flats Aquifer for input into the Western Cape Water Supply System. The wellfield is one of many initiatives of the City’s climate change resilience plans, and Disaster Risk Reduction strategies.
Construction
The procurement, construction and commissioning of the Philippi Weather Station was implemented by the Environmental & Climate Department of Umvoto Africa. The weather station design features a 6-meter mast mounted into a cement base, supported by stainless steel cables under constant tension to withstand the strong south-easterly wind forces across the Cape Flats.
Damian Hans and Paul Lee of Umvoto Africa finalizing the Philippi Weather Station capable of recording accurate meteorological data of the Cape Flats study area.
Outcome
After two weeks of construction and one week of testing all the sensors, the weather station was commissioned on the 6th May 2021. The Philippi Weather Station records air temperature, relative humidity, atmospheric pressure, rainfall, wind speed, wind direction, solar radiation as well as actual evaporation from an evaporation pan. In addition to this, the CR800 data logger provided by Campbell Scientific provides evaporation and evapotranspiration using the Penman-Monteith equation. Data on actual evaporation across the Cape Flats is spatially and temporally scarce so it was decided to also incorporate an Evaporation Pan (A-Pan) into the system. Umvoto will, in the next few months, closely monitor actual evaporation and compare it with the more commonly available theoretical computations to understand the relationship at a site-specific level.
Data Gathering
The data is collected remotely via a cellular network connection. Data is automatically downloaded every day at midnight and is stored on the Umvoto Server Database. Data undergoes a rigorous quality control process before it is passed on to the hydrologists and hydrogeologists.
