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 in the Ruaha River under the Msembe Bridge (center of image) on January 23, 2023. The image corresponds with 3.2km in the width. (Click to enlarge)

Surface overflow advancing to Park HQ

The surface flow in the Ruaha River between N’giriama and Msembe (Park HQ) slowly advances. On January 8, 2023 there is still a section of the river 21.3km upstream of the Msembe Bridge with zero flow from the Ihefu Swamp while water supplied from local cachments already flows under the bridge.

The dry section of the Ruaha River on January 8, 2023. The width of the image is 4km and located some 21.3km upstream of the Park HQ (Msembe Bridge). Click image to enlarge.

The overflow from Ihefu Swamp still did not reach the Park HQ on January 6, 2023 (see image below) while flow downstream of the inlet at the Park HQ continued at least on January 3, 2023.

Zero Flow from Ihefu Swamp at 38.5km as the bird flies upstream of the Msembe Bridge (Park HQ) on January 6, 2023. The width of the image corresponds with some 2.5km.

Zero Overflow Ihefu Continues in 2023

On January 2, 2023 zero overflow from Ihefu swamp continues, according to Landsat 8 image of same section of the Ruaha River as the Sentinel-2 image below of December 17, 2023. The Ruaha River section is 9.7km downstream from the N’giriama Sill (as the birds flies).

The drainage from the Usangu Rice Plain is still not adaquate on December 17, 2022 to reach the outflow of the Ihefu Swamp, although abstraction for rice irrigation seems to increase according to the expanded inundated area at the two main irrigated schemes on the Usangu Rice Plain

The isolated pools in the Ruaha River downstream of the Ihefu Swamp outlet on December 17, 2022 indicate absence of overflow sustains. (Sentinel-2)

Although cloud cover suggest the arrival of the rains Overflow of Ihefu Swamp still absent on December 12, 2022 concluding from the isolated pools 7.3 km downstream (as the birds flies) of the Ngiriama Outlet.

The purple isolated pools in the Ruaha on December 12, 2022. The widt of the image is some 4km.

The previous post (below) with hope for return of the overflow from the swamp proves futile on December 7, 2022 with suspected traces of growing pools of water (trickle surface flow) 11 km downstream of the N’giriama Sill Outlet of the swamp vanished on December 7, 2022. Compare images on both dates below.

Compare shrinking pools on December 7, 2022 with the growth of pools by flow or local rains on November 29, 2022 (images of right and below). Click on image to enlarge
Click on image to enlarge

Trickle of Overflow Ihefu Swamp

The modest rains which started November 2022 have increased the flow in the Ruaha River which has now passed the Ihefu Swamp and trickle over the N’giriama Sill at the out let. This is concluded from the “Land and Water” composite of Sentinel-2 bands (20m/px) which show growth of the pools 11km downstream of N’giriama. The first image below is from November 29, 2022 and the second is taken with zero overflow from the swamp on November 17, 2022. The trickle at N’giriama is not yet enough to reach the Park Headquarter 63km downstream (as the bird flies).

The blues in the Ruaha Riverbed flanked by the line of riverine trees (near infrared) are filling depressions as result of the returned overflow from the November Rains the image is from November 29, 2022
The same section of the Ruaha River on the left 11km downstream of the Ihefu Overflow on the November 17, 2022 with zero overflow. The widt of the image represents some 2km.

Zero Overflow Ihefu Swamp

The rains mid-November 2022 which were adequate to get the drainage from the Usangu Rice Plain flow again, have not been adequate for overflow from the Ihefu Swamp, concluding from the November 17, 2022 satellite images (below). The zero (over)flow from the swamp is demonstrated by the image from the Ruaha River section, some 40km downstream of the N’giriama Outlet.

The virtual drainage assessment station (VDAS Idunda) on 40km d/s of N’giriama on the 20m/px (B8A, B11, B04) shows a dry Ruaha Riverbed and two pools in the bottom center and upper right corner of the image. The dark spot in the bend of the river close to the VDAS idunda, is the shade of cloud in the south west. The width of the image is about 6km. The image is from November 17, 2022. (Click to enlarge)

Burned Ihefu Swamp November 2022

Every year with the reduced, to zero inflow, in the swamp, the vegetation is burned. With the bare plains and inadequate fodder for the herds it is probably the cattle owners, who burn the swamp vegetation for regrowth of grass. Compare the infra red image below with the NBR composite image immediately following.

Sentinel 2, November 4, 2022 – 40m/px image of swamp vegetation (red) black burned swamp vegetation (black) with smoke being visible in the upper left of the image. The low flow Ruaha River channel enters from the west at the bottom left into the swamp and leaves the swamp in the top center (North) but on this date there is no flow out of the swamp (zero flow). Click to enlarge for the scale see upper left.
Brown and Dark brown are the presenting the burned swamp vegetation , while the green color is remaining wet swamp vegetation on November 4, 2022. COmpare with infrared image above.

Overflow Ihefu Swamp receding to N’giriama

The recession of the surface flow of the Ruaha which started some 222km downstream as the Ruaha River dried at Mtera mid-July 2022 has now reached the N’giriama Sill on September 18, 2022 some two months later. The high resolution image of the Ruaha River 7.5km downstream of the sill of August 23, 2021 still shows some overflow over the sill which is in the south. The three channels draining water from the pool at the bottom of the image. The next sentinel-2 image of September 18, 2022 with 5m resolution suggests the channels do not hold anymore water or very minor flow.

High resolition image Ruaha River 7.5km downstream of N’giriama Sill on August 23, 2022.
The same section of the Ruaha River as on the image above on September 18, 2022.
Pools still feeding subsurface flow in the riverbed on Sepyember 18, 2022. The section of the Ruaha is 40km downstream of the N’giriama overflow of the Ihefu swamp. Compare image below of same location at VDAS Idodi. (Click to enlarge)

With zero flow 2 kilometers upstream of the Msembe Bridge (ParkHQ) on September 5, 2022 the Ruaha surface flow has now receded between N’giriama and the Idodi VDAS 40 km upstream of the N’giriama Sill.

The surface flow between the pools 2km upstream of the Msembe Bridge has stopped as can be seen on the image of September 5, 2022. The high resolution image of the same section of the Ruaha River is on the right. Click image to enlarge.
High resolution image of the dry Ruaha River section on December 16 2016. Click to enlarge.
Compared to the 5m/px of Sentinel-2 (above left) the 15m/px for the panchromatic Landsat8 image of the same section of the Ruaha River 2km upstream of the Msembe Bridge is also helpful to check surface flow connecting the pools with standing water which are the dark spots. The Landsat 8 image is from September 5, 2022. (Click to enlarge)
Surface flow from Ihefu swamp has retreated to less than 40 km from the N’giriama Sill. The image is from September 5, 2022. Click to enlarge.

Zero Flow at Ruaha Park HQ on August 21, 2022

Zero flow is assessed at the Ruaha Park HQ on August 21, 2022. The related image is found here

Zero Overflow N’giriama not yet stable 2022

In the absence of a clear remote observation of zero flow at the Msembe Bridge the flow status of the overflow from Ihefu is checked on August 16, 2022 and flow reduction between August 11, 2022 and August 16, 2022 is not observed in this period.

Two kilometers upstream of Msembe Bridge on August 16, 2022. Compare with image of August 11, 2022 below. (Click to enlarge)
Overflow at Idodi VDAS still stable between August 16 and August 11, 2022. Forty kilometers upstream of the Msembe Bridge (Park HQ). Compare with August 9, 2022 below.

Overflow N’giriama becomes zero 2022

The overflow from the Ihefu swamp at the N’giriama Sill is currently measured by the Ministry of Natural Resources and Tourism. The flow monitor monitors extremely low flow and zero flow to verify the predictions and observations at downstream VDAS locations. And to timely alert the authority based on the flow status on the ground.

The flow at the N’giriama bedrock which dams the drainage water from Ihefu like a weir, is searching channels in the rock to rush down the slope. The high resolution image below is taken on August 23, 2021. The small turbulent passage compares with the 10m/px near infrared image one day later. Zero flow that year kicked-in on November 15, 2021. Assessment of the relation of the flow at the N’giriama Sill and the downstream VDAS at idodi and ultimately the zero flow at Msembe Bridge (Park HQ) in 2021, reveals that as expected zero overflow from the Ihefu Swamp will reduce due to “natural losses” and dry (zero flow) first close to the Msembe Bridge first. At the same time still a trickle will may overflow from the swamp and at some sections where subsurface flow adds up to the Ruaha River flow.

The trickle from Ihefu Overflow at N’giriama Sill (see August 9, 2022) dries before it reaches Msembe Bridge (Park HQ) on August 11, 2022. Sentinel-2 NIR. (click to enlarge)
High Resolution Ruaha Riverbed during zero flow period of suspected zero overflow from Ihefu at 2km upstream from Msembe Bridge (Park HQ) on December 25, 2016 (click to enlarge)
Near or Zero Flow at Ngiriama Overflow (3.5km downstream) of the Ihefu Swamp on August 9, 2022

Overflow Ihefu at Idodi Section Ruaha

Near or Zero Overflow in the Ruaha River some 26.5km downstream (as the bird flies) of the N’giriama Sill on August 9, 2022. The blurred canals connecting two pools of water in the center of the image can be subsurface flow or surface flow but in whatever case inadequate flow to keep the Ruaha River flow up to the Msembe Bridge at the Park HQ much longer. The location is 40km upstream (as the bird flies) of the Msembe Bridge (Park HQ). The Ruaha is expected to dry soon at Msembe.(click to enlarge)