There will be a reduction of rainfall activities in most parts of Somalia in the coming three days with exception of Puntland regions where moderate rains are expected in the last day of the forecast period. Moderate rains are also foreseen within the Ethiopian highlands in the next three days.

The rainfall forecast for the next three days points towards light to moderate of up to 30mm in parts of Bari, Nuugal, Sool aand Sanaag regions all in the north eastern parts and Bakool region in the south as well in the upper parts of the Ethiopian highlands. The rest of the country is expected to remain dry during the same period.

Light rains are expected to be experienced in parts of Sanaag and Togdheer regions in the northern parts of Somalia and a few places in the southern regions bordering Ethiopia. The Ethiopian highlands whose rainfall contribute significantly to the river flow of Juba and Shabelle Rivers inside Somalia are also expected to receive light to moderate rains within the forecast period. The rest of the country will receive little or no rains in the same period.

The rainfall forecast for the next three days points towards light rains of up to 30mm cumulatively in the inland parts of Somaliland and Puntland. The Upper parts of the Ethiopian highlands may experience moderate rains while rest of the country is expected to remain dry during the same period.

There will be a significant reduction of rainfall activities in most parts of the country in the coming three days. Light rains are expected in a few pockets in the southern parts of the country. The central and northern parts of Somalia will remain dry in the same period. Dry conditions are also foreseen tin the Ethiopian highlands during the forecast period.

Moderate rains have been reported in parts of Somaliland and Puntland in the last 24 hours. The rainfall forecast for the next three days points towards light rains of up to 40mm cumulatively in the inland parts of Somaliland and Puntland. The Upper parts of the Ethiopian highlands may experience light rains while rest of the country is expected to remain dry during the same period.

According to the recently issued Seasonal Climate Forecast for the Greater Horn of Africa by the IGAD Climate Prediction and Applications Centre (ICPAC) in Kampala, Uganda, the 2016 Deyr rains in Somalia are expected to be below normal to near normal - with a 40% probability of experiencing below normal rains and a 35% probability of near normal rains in the entire country. The upper catchments of the Juba and Shabelle Rivers in Ethiopia are also expected to record depressed rains during the season. Please see attached for more details. Please note that this is a consensus forecast designed for a regional audience that addresses the rainfall totals summed over the three-month period from October to December, 2016. SWALIM and other technical partners will keep updating this forecast and monitoring performance of the rains for shorter time periods and will update you throughout the Deyr season via regular bulletins.

The Deyr 2016 (October to November) rainfall forecast points towards near-normal to below-normal rains within the Juba and Shabelle River basins. However, flooding along the two rivers may still occur, especially in areas with open river banks / weak river embankments, in the event of increased river flow. SWALIM has updated the status of the river breakages by mapping them using available Very High Resolution (VHR) satellite imagery and a Digital Elevation Model (DEM); as well as verifications based on field observations where feasible. Three types of breakages have been identified, namely; open, potential and closed. The open breakages are those that are still open during the month of September 2016. The potential breakages represent points that have weak river embankments or have experienced breakages in the recent past and where minimal or no interventions have taken place. This includes breakages closed using sand bags. The closed breakages are those that were previously open but have since been closed using heavy machinery, which prevents further flooding in the short to medium term. The attached maps show the open and potential river breakages along the two rivers. In summary, seven (7) open points along the Shabelle and 63 along the Juba have been identified. Several other points with potential of breaking have been identified and need to be strengthened. It is worth noting, however, that the methodology relies heavily on satellite images with limited field verification. Open breakages might have been omitted in some cases where satellite images may not have been very clear (e.g. heavy cloud cover) or were not available at all. Maps of the status of river breakages, with detailed information, have been produced at large scale and hard copies can be obtained from SWALIM offices. This information is also available on the SWALIM Flood Risk and Response Management Information System (http://frrims.faoswalim.org/rivers/breakages).

Prosopis juliflora is a drought-tolerant fast-growing tree species originating from South and Central America with a high invasion potential in arid and semi-arid areas in Africa. It was introduced in Somaliland in the 1980s and is reported to have spread vigorously since. Despite being recognized as a serious issue in the country, the actual scale of the problem is unknown. In this study, we mapped the species in a study area that includes the capital, Hargeisa, using Landsat 8 satellite imagery. During a field campaign in 2015, we collected canopy-level spectral signatures of P. juliflora and native trees to analyse the potential use of spectral data in discriminating the invasive species. P. Juliflora was found to be generally distinguishable because of its greater vigour during the dry season. We tested the accuracy of the random forest classifier and different classification set-ups, varying the spatial resolution (original 30m vs pan-sharpened 15m) and image acquisition dates (during the wet season, the dry season and a combination of the two). Best overall accuracy (84%) was achieved by using pan-sharpened data from the two seasons. About 30 years since its introduction, the invasive species was detected in 9% of the total investigated area with highest occurrence in the proximity of human settlements and along seasonal watercourses. © 2016 The Authors. Land Degradation and Development published by John Wiley & Sons, Ltd.

Prosopis spp is a fast and aggressive invader threatening many arid and semi-arid areas globally. The species is native to the American dry zones and was introduced in Somaliland for dune stabilization and fuel wood production in the 1970’s and 1980’s. Its deep rooting system is capable of tapping into the ground water table thereby reducing its reliance on infrequent rainfalls and near-surface water. The competitive advantage of Prosopis is further fuelled by the hybridization of the many introduced sub species that made the plant capable of adapting to the new environment and replacing endemic species. This study aimed to test the mapping accuracy achievable with Landsat 8 data acquired during the wet and the dry seasons within a Random Forest (RF) classifier, using both pixel- and object-based approaches. Maps are produced for the Hargeisa area (Somaliland), where reference data was collected during the dry season of 2015. Results were assessed through a 10-fold cross-validation procedure. In our study, the highest overall accuracy (74%) was achieved when applying a pixel-based classification using a combination of the wet and dry season Earth observation data. Object-based mapping were less reliable due to the limitations in spatial resolution of the Landsat data (15–30 m) and problems in finding an appropriate segmentation scale.

We are pleased to share Issue 11 of our newsletter “SWALIM Update” for the period January 2016 – April 2016.

The Gu 2016 season started off well in advance in some parts of the country during the third dekad of March and continued to spread spatially in the first and second dekads of April. Other parts especially in Puntland and southern regions had a late start of the season which also ended early. The distribution of the rains were normal to below normal with an exception of north western regions which saw above average rains compared to the long termmean for the period under review. Some places that recorded depressed rains include Sanaag, Bari, north of Sool, south of Mudug, Galgaduud, Bakool, Hiraan, Middle Juba, Lower Juba and Lower Shabekke. The poor rains which also had an early cessation raises a concern especially in Puntland where drought conditions have been present for a long time. With no more rainfall expected in the coming months, most of Puntland regions and the coastal areas of Mudug and Galgaduud regions remain under drought conditions. The north west parts of Somaliland recorded above average rains. Other areas that received good rains include south of Togdheer and Sool regions. Some parts of the south and central regions within Bay and Bakool regions also received good rains. The rains were well received by the communities especially in the northern parts which had a prolonged dry period. This came as a relief for many people who experienced drought conditions in parts of the country. The Ethiopian highlands experienced heavy rains that led to increased river flow inside Somalia leading to floods in some sections of Juba and Shabelle Rivers. In general the rains led to improved soil moisture conditions that were favourable for both crops and pasture growth. Enhanced rains also led to replenishment of water reservoirs. However, negative impacts were also felt such as floods that caused destruction of properties, infrastructure and loss of livestock. The floods affected about 100,000 people with 72,000 of them being displaced.

This dataset was digitized directly from Sentinel-2 imagery of 25th May 2016 to show the areal extent of Belet Weyne flooding. Sentinel-2 image resolution of 10m was downloaded free of charge from European Space Agency (ESA)

This dataset was digitized directly from Landsat-8 imagery of 12th May 2016 to show the areal extent of Jowhar flooding. Please note that the flooded area might not be exact due to the cloud cover hindering the interpretation. Landsat-8 image resolution of 15m was downloaded free of charge from USGS Earth Explorer

The town of Belet Weyne and its environs experienced one of the biggest floods in recent history. The floods, which lasted over 10 days were caused by overbank spillage from Shabelle River following heavy rains experienced in the Ethiopian highlands over the past one month. The floods covered about 60% (591 ha) of the entire town, resulting to mass displacement. This map depicts the peak of the flood extent, as observed from 10 meters resolution Sentinel-2 satellite image of 25th May 2016

The three days rainfall forecast calls for more rains in northern parts of the country while light rains are expected in the central and southern parts. There is a high risk of flash floods in the coastal areas of Bari and Nugaal regions. The river levels remain high in both Juba and Shabelle, with high risk of flooding along the two rivers.

Wet conditions persist in many parts of Somalia as a result of heavy rains in the country. The Ethiopian highlands have been receiving heavy rains in the last few weeks. Following these heavy rains, river  levels have increased drastically along the Juba and Shabelle Rivers. Further more, flash floods have been reported in some areas in Puntland and Somaliland due to heavy rains in those areas. The 3 days rainfall forecast (Map-1) points towards continued heavy rains with an increase towards the end of the week (Map-2). Given the rainfall forecast, observed river levels along the  two rivers are expected to continue rising further, especially in downstream areas. Today’s river level at Belet Weyne along the Shabelle River is 6.60m. These high levels area expected to be transmitted further downstream with a likelihood of flooding. There is therefore a high risk of flooding in the coming few days along the Shabelle River, while a moderate risk of flooding is foreseen along the Juba River. The foreseen heavy rains are also likely to cause flash floods in built up and low lying areas within Somaliland, Puntland (especially in Bari and Nugaal regions) and the central parts of the country.

Widespread rains are expected across Somalia in the next three days. The northern regions of the country are expected to receive moderate to high rains, while in the central and southern regions the forecast points towards light to moderate rains. The upper catchments of the Juba and Shabelle rivers are also expected to receive moderate to high rains within the same period. The river levels remain high in both Juba and Shabelle, with high risk of flooding along the Middle and Lower Shabelle; while in Middle and Lower Juba the risk of flooding is moderate.

During the week that ended on 23 May 2016, there was a significant reduction of rainfall activities in most areas of Juba and Shabelle basins inside Somalia as well as the Ethiopian highlands with most stations recording little or no rainfall. For the last one week River levels at Belet Weyne remained at bank full resulting to flooding in the town and surrounding areas which has caused displacements and damage of properties. This flood wave is expected to be transmitted downstream with a moderate risk of flooding along the River. River levels along the Juba have been reducing for the last few days. Given the rainfall forecast and the reducing trend there is minimal risk of flooding along the River.

Light to moderate rains are expected across Somalia in the next three days. Along the coastal areas of Bari and Nugal regions the forecast calls for moderate to high rains; while in the Ethiopian highlands scattered light to moderate rains will be experienced in the forecast period. There is a high risk of flash floods in the coastal areas of Bari and Nugaal regions. The river levels remain high in both Juba and Shabelle, with high risk of flooding along the two rivers.

Heavy rains have been reported in parts Somalia over the last two days. Consequently, river levels have gone up with cases of river flooding in Gedo, Hiraan and Middle Shabelle regions in the south. Flash floods were also reported in parts of Puntland following the heavy rains. The three days rainfall forecast calls for reduced rainfall activities in the country, however, some parts in Lower Juba and northern regions may experience moderate rains. The river levels remain high in both Juba and Shabelle, with high risk of flooding along the Shabelle; while in Middle and Lower Juba the risk of flooding is moderate.

Wet conditions are expected to persist across Somalia in the next three days. The northern regions of the country are expected to receive moderate to high rains, while in the central and southern regions the forecast points towards light to moderate rains. The upper catchments of the Juba and Shabelle rivers are also expected to receive moderate to high rains within the same period. Given the forecast and the rising levels, there remains a high risk of flooding along the Middle and Lower Shabelle; while in Middle and Lower Juba the risk of flooding is remains moderate.

Observed river levels of the Shabelle River in Somalia have remained high for the last few weeks. This has been attributed to heavy rains in the upper parts of the Ethiopian highlands during the months of April and May. The River level at Belet Weyne in Hiran is currently at bank full and has remained so for the last one week as seen in Figure 1. This has resulted in over bank spillage leading to riverine floods in Belet Weyne town and the surroundings. There has been a significant reduction of rainfall activities both in Somali and the Ethiopian highlands. The high river levels being observed in Belet Weyne currently are due to the large amount of water coming from the upstream reaches in Ethiopia. Unofficial reports from Ethiopia indicate that there has been flooding in some areas and the flood water is now getting back to the river. In additional to this, there are minimal water abstractions in Ethiopia for irrigation and other purposes following the heavy rains in the highlands since April. It is expected that the flood wave will be transmitted downstream of Belet Weyne in the coming days. Currently the river levels at Bulo Burti are very high and in less than five days this high levels will be reflected in Jowhar. There is therefore high risk of flooding in the coming few days in the Middle and lower reaches of the Shabelle river given the current situation. Areas to watch include Jowhar town and its environs; where the river level is currently high and other riverine towns in the lower Shabelle region. The situation could be further exacerbated by weak river embankments and open river banks. For more information on this and related issues please visit: http://systems.faoso.net/frrims/rivers/floods

Light rains are expected in a few pockets of central and northern regions in Somalia in the coming three days. The rest of the country is expected to remain dry within the same period. There still remains a high risk of flooding along the Juba and Shabelle Rivers owing to the high river levels and existing open and weak river banks.

During the week that ended on 3rd May 2016, moderate to heavy rains were experienced in most areas of Juba and Shabelle basins inside Somalia as well as the Ethiopian highlands. Mataban in Hiraan region recorded a total of 115mm in the week while Bur Hakaba in Bay region received a total of 92mm during the same period. Satellite rainfall estimates also indicates moderate to heavy rainfall amounts during the same period within the Juba and Shabelle basins. The rainfall forecast for the coming week indicates a possibility of moderate to heavy rains in two river basins both in Somalia and within the Ethiopian highlands. River levels have been increasing since mid April due to heavy rains received within the basins. Currently, the levels are above the normal at this time of the year at all monitoring stations along the two rivers. Given the rainfall forecast and the rising river levels there is a foreseen high risk of flooding in the middle and lower reaches of Shabelle River while moderate risk of flooding is foreseen along Juba during the forecast period.