Almost Real Time Ruaha River Flow Status – 2024
Last Updated 5 months ago
Ruaha River Flow Monitor Tool (Remote Sensing) Flow Status Today: 15 Days of Zero Flow in 2024
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Alert 3, Sep 27, 2024
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Ruaha River Flow Monitor Tool (Remote Sensing) Flow Status Today: 15 Days of Zero Flow at Park HQ in 2024
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
Alert 3 possibly reached before Alert2 in 2024
To specify the start of the Alert 3 phase is less precise as Alert 2. The drying of branch canal of the Ruaha River at Nyaluhanga (Alert 3). The date of September 27, 2024 is like the flow indication of less than 8cumecs arbitrary. What is interesting is the fact that the period between Alert 2 and Alert 3 is almost zero days. Which has not yet occured so far. The reason could be an alarming drop in discharge from low flow in the Mbarali and Ruaha Rivers, or increased abstraction during the low flow season. The dryness of Usangu Rice Plain in 2024 was already noticed and seems to be related to the early arrival of the Alert 3 Phase. Below the Ruaha flow status at Nyaluhanga as drainage from the Usangu for the last Alert 3 stages are compared. (Click to enlarge images)
Alert 2 announced on September 24, 2024
As the Ruaha Flow stopped at the VDAS section at Mtera according to the September 24 Sentinel 2 image, that dat is adopted for Alert 2 in 2024. Interestingly the Alert 1 threshold value (see posts below) of 0.012km2 performed better than the visual inspection. The water area of the Ruaha at the Alert 1 section dropped between August 20 and August 25 under the 0,012 km2 value one month before Alert 2 as required.
Threshold Evaluation Alert One
Between August 20, and August 25, 2024 the threshold value (0.008km2) dropped under the proposed value of 0.012km2. On August 30, 2024 the threshold is 0.010km2 showing the inaccuracy of the water area estimate assuming absence of rain and continuous decline of flow. The potential of the threshold value becomes of interest if zero flow (Alert Two) occurs between September 25 and September 30, 2024.
Stable area with river water on August 20, 2024
The area with water calculated with Google Earth Engine script on August 20, 2024 is 0.0146km2.
Alert One Announced August 15, 2024
The water area (0.0144km2) of the Alert One section of the Ruaha River has dropped close to the threshold value 0,012km2. It is expected to be reached before the new images on August 20, 2024 will be available. Compare the flow status (NDWI 5m resolution) of the Ruaha River at Mtera on June 17, 2022 four days after Alert One in 2022.
The visual inspection of the Ruaha River Flow Status using false color sentinel-2 images with 5m pixels of the same section and dates at Mtera . (Click to Enlarge Image)
August 10, 2024 flow reduction Ruaha at Mtera
River Flow visually reducing on August 10, 2024 but still not at the critical stage of Alert One (see image June 12, 2022). This is confirmed by the calculated (Google Earth Engine) reduction of water area on the image which has dropped to 0,020km2
August 5, 2024 no clear reduction flow Ruaha (Mtera)
The flow at Mtera (Alert1 VDAS) is still well above the Alert One flow of 2022 (false color on the right) concluding from visually inspection. (click image to enlarge). Also the NDWI water area is calculated at 0.022km2 see post below and does not yet meet the assumed threshold value in with 0.012km2.
The predicted Alert Two or zero flow at Mtera (August 18, 2024), is now expected for mid – September 2024.
Alert One expected between today and Monday
Based on the threshold value of 0.012km2, the Alert One phase is expected to start this week or early next week. On July 31, 2024 the calculated area of water is 0.021km2. Which reflects a reduction of the open water surface area of 25% during the last 5 days. Please check the calculation with the google earth engine javascript via the link above.
The predicted Alert One of July 18, 2024 will be at least three weeks later. In future notable delays in the occurrence of predicted critical flows (like Alert 1) will be the result of interventions by the River Basin Board.
Threshold Level NDWI and Alert One
To minimise (remote) visual monitoring, a threshold value for NDWI values for critically low flow, would be helpful. Currently a water (vs. no-water) area is investigated for the 5m resolution NDWI sample area (0,59km2). The assessed value in 2022 and 2023 at Alert one for water in the Ruaha at Mtera (Area of Interest) is 0,0124 and 0,0118km2(from July 22 and 27). The value on July 26, 2024 is 0.0273km2. Which suggests that Alert One is not yet reached.
Visual inspection of 5m resolution images on July 26, 2024 with the Alert One flow in 2022 support the threshold prediction above.
NDWI comparison low flow Mtera at Alert 1 Station (VDAS) July 17, 2024
Using the improved visualization NDWI mask suggests that still plenty of water is flowing at thhe question is, if the flaw is the result of (1) a poor prediction of the expected date of zero flow (IMERG) (2) Different procedures to create NDWI index images?
The coming days other indicators will be analysed to assess the current flow at Mtera and announce Alert One in time for the 2024 dry season.
Compare flow channel (NDWI)
Improved Visualization Mtera Low Flow Channel
Compare Flow Status Mtera at VDAS Alert One
Update on July 11, 2024, the Ruaha River starts drying in the middle of the flow channel in the river bend . (Click to enlarge image)
On July 6, 2024 further reduction flow in Ruaha at virtual flow station. Compared to Alert One flow status in 2022 (image at the right). Current flow on July 6, 2023 (left image) has not yet declined to Alert One flow level of 2022. (Click to enlarge image)
The flow in the Ruaha at Mtera on July 6, 2024, is still above flow on the day of the Alert One (2022 July 12) level as is demonstrated on the 10m pixel Sentinel-2 images. (Click to enlarge image)
Alert One for 2024 predicted on July 18
Zero flow at Mtera (Alert Two) is predicted on August 18, 2024. This corresponds with the prediction for Alert One (one month before Alert Two observation) on July 18, 2024.
Low Flow Mbarali River diverted
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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
Confirmation Low Flow diversion Mbarali River at New NAFCO headworks on October 7, 2024
Find interpretation of image visit here.
On September 19, 2024 all flow from Mbarali River diverted at New-NAFCO
Although ground truth verification will always be required the remote sensing results with 5m pixels suggests drying of overflow of the weir at New-NAFCO on September 19, 2024. For more detailed analysis see 2023 low flow period
Mbarali River Flow June
Update on July 11, 2024 of the flow status over the New NAFCO headworks in the Mbarali River. The stilling basin is stil having water suggesting more than 2cumecs flow in the river above the headworks.
Detail of the Mbarali River New_NAFCO headworks on June 8, 2024. Compare details stilling basin of the weir in 2023.
Dry Usangu Plain at Alert 1
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Increasingly reduced spill water for boosting drainage Ruaha Park closing in on Alert 2
Update water abstraction and spill from Mbarali and Ruaha River outside rice irrigation season on September 12, 2024
August 23, 2024 spill/pre-irrigation at Kapunga
Compare available water Usangu at Alert 1, 2024
The area with water on the Usangu Rice Plain in August 2024 just before Alert One is less than in previous years (2021 – 2023). The green color represents water (in vegetation, soil and free water). Opportunity for the basin authority to boost drainage from the Usangu Plain to the Ruaha River in the Park becomes less with less water availability in Usangu during the critical low flow period (starting at Alert One).
Late Rice Irrigation Usangu Plain
The NBR sequence of Usangu Rice Plain shows that the spilled drainage water after the rice has matured (June) is reducing rapidly. Which means that re-routing of the low flow to the Great Ruaha in the Park (Nyaluhanga), outflanking the areas with most spill, will benefit sustained flow of the river if started even before the announcement Alert One.
On June 9, 2024 limited reduction of late season irrigation in the Kapunga Ifushiro area accelerating the drying of the Great Ruaha and advancing the occurrence of zero flow at Mtera.
One June 4, 2024 a considerable area is still under irrigation. (NBR)
Critical Low Drainage Usangu, Alert 3 observed
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Alert 3 possibly reached before Alert2 in 2024
To specify the start of the Alert 3 phase is less precise as Alert 2. The drying of branch canal of the Ruaha River at Nyaluhanga (Alert 3). The date of September 27, 2024 is like the flow indication of less than 8cumecs arbitrary. What is interesting is the fact that the period between Alert 2 and Alert 3 is almost zero days. Which has not yet occured so far. The reason could be an alarming drop in discharge from low flow in the Mbarali and Ruaha Rivers, or increased abstraction during the low flow season. The dryness of Usangu Rice Plain in 2024 was already noticed and seems to be related to the early arrival of the Alert 3 Phase. Below the Ruaha flow status at Nyaluhanga as drainage from the Usangu for the last Alert 3 stages are compared. (Click to enlarge images)
Drainage from Usangu Rice Plain at Nyaluhanga on June 4, 2024. (Click to enlarge) The branch canal used for Alert 3, can be distinguished while still holding water.
Overflow N’giriama Sill Ihefu Swamp
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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
Second Zero Flow Period at Park HQ Expected
The screenshot from the Ihefu Swamp Flow Monitor represents the flow status some 16km upstream of the Park HQ (Msembe Bridge) on December 28, 2024. Flow is visibly reduced since the end of October 2024.
Almost Zero Flow VDAS Idunda overflow
Expected drying of Ruaha River at Park HQ with drying supply from the Ihefu Swamp, expected soon. The flow at the Ruaha between Ihefu Swamp and the Park HQ has ceased or almost ceased on October 24, 2024.
Decline Overflow Ihefu after announcement Alert 3, October 2024
Compare reduced flow in Ruaha at Idunda Virtual Drainage Assessment Station (VDAS) of October 2, 2024 with flow status on September 29, 2024. Color of the bands has been rearranged to distinguish flow under cloudy sky.
On September 29, 2024 the flow status of the overflow at N’giriama (Ihefu swamp) is reflected by the Sentinel 2 image with 5m pixels. The 1.87sqkm image is between the Park HQ and Ihefu swamp.
On June 6, 2024 the flow at Virtual Drainage Station (VDAS) at Idunda which reflects the overflow from the swamp, is illustrated in the Sentinel-2 image below.
Flow at Park HQ returned on December 3, 2024
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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
Ruaha River Flow Monitor Tool (Remote Sensing) Flow Status Today: 15 Days of Zero Flow at Park HQ in 2024
Flow Returned between December 1, 2024 and December 6, 2024
Last Updated 5 months agoBased on Landsat imagery on December 1 and December 6, 2024 water returned at the Ruaha Park HQ on approximately December 3, 2024
Flow Ruaha may have returned to be confirmed
NDWI based Water Area values show increase on or before November 28 2024. With the confirmation of increased flow on December 3, 2024 the zero flow period will be corrected.
Recent Rains could be related to the return of the flow. The precipitation in the upper reaches of the ruaha and mbarali rivers is expressed in mm/day using CHIRPS satellite data. In the chart also GSMap realtime data are included for comparison. The gsMap (JAXA) data are for a point in the upper reaches of the Ruaha. The data end in October.
More recent data from JAXA realtime precipitation suggest more rains in November which may have reached the Ruaha River at Msembe (Park HQ) around the end of November. Sustained flow early December will confirm return of flow in the Ruaha Park.
Zero Flow Announced on November 18, 2024
Using the Google Earth Engine developed threshold level for the water area at the VDAS 2km upstream of the Msembe Bridge, the start of the zero flow period is estimated between November 13 and November 18, 2024 as the Water Area within the Area of Interest (see box on image below) dropped under the critical value of 0.002 sqkm. The Msembe Bridge (ParkHQ) is in the upper left and the AoI in the upper left for which the critical ‘water area’ is defined. The graph below shows the water areas in the previous years with 2020 as reference year without occurrence of zero flow. Click on Image to enlarge.
Weeks to Zero Flow at Park HQ October 14, 2024
Comparison of 3m pixels planet.com image with the October 14, 2024 image suggests some one to two weeks from zero flow as is illustrated in image gallery below.
Compare flow channel reduction NDWI based visualization
The combination of images providing improved visualization of the flow reduction is illustrated in the sentinel2 image gallery below.
The NDWI image mask (water and no-water) with 20m resolution is combined with the 10m false color (Band 4, 3, 2) composite and with the resampled 5m false color composite on July 11, 2024. The reduction of the flow channels on July 11 as compared to June 6, 2024 below, is clearly visible and will be helpful to more accurately determine zero-flow. (Click to enlarge images)
Without the NDWI mask the comparison of the flow status at Msembe (Park HQ) of the false color images of June 6 (left) and July 11, 2024 (right) is captured in the gallery below. (Click image to enlarge)
Improved visualization Flow Channels Msembe
The Ruaha River seems swollen at the Msembe bridge to the Ruaha Park HQ (where the white line crosses the river) . Combination of the 20m resolution NDWI image of sentinel2 with the false color image (10m) below on June 6, shows that the actual water channels are holding less water while the water channels are difficult to distinct from wet sediment and wet rock with shallow ponds and vegetation. (click to enlarge image)
Status flow at Ruaha Park HQ on June 6, 2024. False color 10m pixel resolution at Msembe Bridge. (click to enlarge)
Flow Returns in Ruaha River at Mtera
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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
Second Zero Flow Period at Mtera about 2 Weeks
The second zero flow period lasted 2 weeks, at the Mtera section of the Ruaha River some 350km from the source of the river. The river started flowing between January 7 and January 12, 2025. The image is a screenshot from the realtime flow monitor of the Ruaha River.
Zero Flow Ruaha River continuous at Mtera
January 7, 2025 screenshot of the Alert2 VDAS river section shows continued absence of flow just upstream of the confluence of the Great Ruaha River and the Little Ruaha River at Mtera.
Second Zero Flow Period started at Mtera January 2, 2025
Using the Realtime Ruaha River Flow Monitor the drying of the Ruaha River is observed on January 2, 2025. The Ruaha Rver saw the return of flow around December 7, 2025 but without the onset of the seasonal rains and start of rice irrigation on the Usangu Plains resulted in the second zero flow period at Mtera.
Drying Great Ruaha River at Mtera Expected Soon
Without the continuation of the seasonal rains in the upper reaches of the Ruaha and Mbarali Rivers, the return of zero flow at the Park HQ is expected. The increased abstraction at the Usangu Rice Plain is not matched by increased inflow resulting in decrease of flow and already results in drying of the River at Mtera.
Flow in Ruaha River returns at Mtera on December 7, 2024
On December 7, 2024 return of flow at Mtera can be observed some 20km upstream of the Mtera Reservoir. (Due to gap in satellite imagery the precise return cannot be defined remotely but expected between December 3 and December 7, 2024).
Alert Two or zero flow observed on September 24, 2024
Between September 19 and September 24, 2024 Zero Flow in the Ruaha River is observed the frist time during the low flow period after the tice irrigation season. September 24, 2024 is adopted as the start of the Alert 2 phase.
Closing in on zero flow Ruaha River Tanzania
On September 19, 2024 flow in the Ruaha at Mtera is observed.
September 18, 2024 flow status confirmed Ruaha at Mtera
Flow Status Ruaha River Mtera, September 14, 2024
Flow Status Ruaha Zero Flow Section September 9, 2024
Compare satellite images for visual observations Zero Flow Ruaha.
Images below demonstrate the capabilities of the processed Landsat (EOS) from 30m resolution false color (screenshot) the original Sentinel-2 (false color), and the by Maji Yetu processed images of the VDAS Ruaha River section.
The first occurrence of zero flow is monitored over the years at this section at Mtera. The Landsat image is the most recent (September 2, 2024) while the Sentinel-2 images are from August 30, 2024)
Revised Prediction Alert 2 Ruaha at Mtera August 21, 2024
The predicted zero flow at Mtera has been several weeks too early (see below). With the announcement of Alert 1 the expected drying of the Ruaha River at Mtera, is now the end of September 2024.
The current flow on August 20, 2024 at the Ruaha River section is represented by the false color sentinel-2 image (5m). The width of the image is 1.1 km.
Zero Flow Ruaha at Mtera predicted August 18
The flow status at Mtera shows decline and increase of exposed riverbed sediments since June 1. The image in false color is from June 16, 2024 (click to enlarge). Compare the image with the same location on June 1, 2024 below.
On June 1, 2024 the Ruaha River at Mtera is still swollen with water. The predicted first day of zero flow for 2024 is August 18, 2024
