The newest post and image entries are on top of the page. Scroll from the bottom upwards to follow the flow status timeline of the Ruaha River per location
Flow from Ihefu Swamp returns between November 29 and December 2nd, 2023
Zero Overflow 17.5km downstream Ng’iriama
On November 27, 2023 the Ruaha has dried 17.5km downstream (as the bird flies) of the Ng’iriama SIll. It is assumed that the overflow has also ceased at the outflow of the swamp on November 27, 2023 but possibly some days earlier.
Zero Overflow at VDAS (Idunda)
On November 19, the overflow from the Ihefu swamp does not any longer reach the Idunda VDAS (Virtual Drainage Assessment Station) 30 kilometers downstream of the Ng’iriama Sill.
Imagery end October suggests increased overflow
Check of the rainfall in the period preceding the period between October 23 to 30, 2023 confirms that suggested increased flow (October 30) are visual deceptions. The MNDWI (Band11-B3)/(Band11+B3) proves to be more reliable on inspection as is demonstrated by both image sliders below.
Comparison Color Infrared images of October 23 (after) and October 30 (before) to show the reflection on the water surface which may suggest zero flow.
The MNDWI raster on both October 23 (see image gallery previous post) and October 30, 2023 provide the most accurate information on the actual flow status of the Ruaha River between the Ihefu swamp and the Park HQ.
Near zero overflow 31km downstream of Ng’iriama Sill
With detectable flow some 17.5km downstream of the sill, at VDAS 405 (31km) flow seems to dissappear in sediments on October 23, 2023. The upcoming image for the Park HQ may confirm the drying of the Ruaha River in the Park (Msembe Bridge).
De image slider below combines the high resolution image of the Ruaha River between the swamp and the Park Headquarter, at the time the minimal flow from Ihefu swamp gradually dissappears in the sediments on its way to the park HQ.
At the time, still some surface flow is distinguished 17.5km downstream of Ngiriama as on the image of October 23, 2023 below, the surface flow gradually dries further downstream as the above images suggest, possibly recovering here and there with groundwater contributions stored along its banks making still its way to the Msembe Bridge (Park HQ).
Overflow Ihefu Swamp stable mid-October 2023
The overflow from Ihefu swamp seems stable since end of September, 2023. Compare flow over 130m long section of the Ruaha River downstream of Ng’iriama on October 13, 2023 with September 25, 2023, below
Overflow Ihefu Swamp end of September 2023
Comparable Overflow Pattern 2021 and 2023
The comparison slide which compares the Ruaha River section downstream of the Ihefu swamp on July 20, 2023 (left) and August 4, 2023 clearly shows the reduction of the flow and pools in the riverbed. (yellow circle) The flow in the Ruaha on August 4, 2023 compares to August 23, 2021 as shown in the high resolution image f. In that year the Ruaha River dried on November 19, 2021 at the Park HQ (Msembe) and the overflow from the Ihefu swamp stopped on December 9, 2021.
Like the attempt to find years with resembling Ruaha River flow (decline) pattern at the entrance of the Ihefu swamp (monitor drainage), also the decline of outflow from the Ihefu swamp may follow comparable patterns. The images below shows that the current overflow (July 20, 2023) exceeds the flow on August 23, 2021. In that year the overflow dried early December.
Overflow at N’giriama on June 20, 2023
Overflow N’giriama Early June 2023
Some 2.5km downstream of the Ihefu Swamp N’giriama Sill several channels over the base rock are still feasible early June 2023.
