Soil moisture monitoring
There are 28 soil moisture probes installed in the scheme. These probes are installed in pairs, and each pair of probes sends its readings at 15 minute intervals to a nearby radio transmitter, from where it is transmitted to a server in the JIA office in Vioolsdrift. Each probe measures the moisture content and temperature in the soil at five different depths between 20 cm and 80 cm.
The location of the soil moisture probes can be seen on the map below.
The raw data is automatically sent to an on-line database where a software scheduling program analyses the data (with periodic intervention by the service provider). The software generates a report for each monitoring site containing the proposed irrigation schedule for the next seven days. Some of the probe’s data is however still only available via manual download onto a laptop.
The map below provides the spatial distributions of the soil moisture probes during 2013. The actual soil moisture data for the probes with on-line data can be seen by selecting the individual soil probe’s marker and selecting the appropriate data link. The map also provide the canal sections and names, as well as the detailed field information by selecting an individual irrigated field.
Legend: Probes with Online Data; Probes with manually downloaded Data; Canal Section Names; Canals; Irrigated Fields
No provision was made for control structures (flumes) in the canal system when it was built. Ideally there should have been a measuring flume at the inlet to each canal section, as well as at the spill positions.
Comprehensive alterations to the canal will be necessary to accommodate such structures, as these will reduce the available head, and therefore the capacity, of the canal.
The measuring devices includes one ultrasonic, 8 pressure senors and 9 electroning flow meters. Unfortunately all the metered data is only available via manual downloads and is not readily available.
The map below provides the spatial distributions of all flow measurements in the JIA. None of the data is curently available on-line except for the monitored flow data at the Department of Water Affairs of South Africa’s gauging weir (D8H003) – data can be access for the weir by selecting the marker and following the links. The map also provide the canal sections and names, as well as the detailed field information by selecting an individual irrigated field.
Legend: Block Flow; Weir and Canal ; Pump Flow; Canal Section Names; Canals; Irrigated Fields
Raw data is accessible from this password protected folder.