Assessing the Impact of Management Options on Water Allocation in River Mubuku-Sebwe Sub-Catchments of Lake Edward-George Basin, Western Uganda

Limited studies in East Africa and particularly in Uganda have been carried out to determine and map water use and demands. This study aimed at assessing the impact of management options on sustainable water allocation in environmentally sensitive catchments of Mubuku and Sebwe of Lake Edward-George basin in Western Uganda. We used hydro-meteorological data analysis techniques to quantify the available water. We applied Mike Hydro model to allocate water to the different ongoing developments in the catchment based on 2015 and 2040 water demand management scenarios. We used the Nile Basin Decision Support System to assess the sustainability of the different water management scenarios for sustainable water resources use. Reliability computation did not consider hydropower in this study. Results show that water available in 2015 was 60 MCM/YR and 365 MCM/YR for Sebwe and Mubuku, respectively and is projected to decrease by 15% and 11% by the year 2040 under climate scenario RCP8.5. We project water demand to rise by 64% for domestic, 44% for livestock, 400% for industry, 45% for hydro power and 66% for irrigation by 2040. Mubuku water demand is projected to increase from 5.2 MCM in 2015 to 10.7 MCM in 2040. Mubuku available water is projected to fall from 364.8 to 329.8 MCM per annum. Sebwe water demand is projected to increase from 9.7 MCM in 2015 to 22.2 MCM in 2040 and its available water is projected to fall from 60 to 52 MCM per annum by the year 2040 from 2015. Water managers ought to allocate water based on the reliable water allocation which prioritizes domestic and environmental water demands, allocates 90% of industrial demand, 70% of irrigation and 60% of livestock demand. We recommend institutionalizing this model to guide water allocation in the Mubuku-Sebwe sub catchments. Water users should employ more efficient water use techniques to achieve high reliability and sustainable water resources management.

THE ISHANGO BONE: The World's First Known Mathematical Sieve and Table of the Small Prime Numbers

This paper aims to show that the Ishango bone, one of two bones discovered in the1950s buried in ash on the banks of Lake Edward in Democratic Republic of Congo(formerly Zaire), after a nearby volcanic eruption, is the world's first known mathematicalsieve and table of the small prime numbers. The bone is dated approximately 20,000BC.Key to the demonstration of the sieve is the contention that the ancient Stone Agemathematicians of Ishango in Central Africa conceived of doubling or multiplication by 2in a more primitive mode than modern Computer Age humans, as the process of"copying" of a singular record (that is, a mark created by a stone tool as encountered inStone Age people's daily experience). Similarly, the doubling of any number was, bylogical extension, a process of copying of any number of records (marks) denoting aninteger, thereby doubling the exhibited number (marks). Some evidence for this processof "copying" and thus representing numbers as consisting of "copies" of other numbers,is displayed on the bone and can still be found to exist in the number systems ofmodern Africans in the region.Unlike previous speculations on the use of the bone tool by other studies, the ancientmethod of sieving of the small primes suggested here is notable for unifying (making useand explanation of) all columns of the Ishango bone; whilst all numbers exhibited forman essential part of the primitive mathematical sieve described. Furthermore, it is statedthat the middle column (M) of the bone inscriptions houses the calculations of theIshango Sieve. All numbers deduced in the middle calculation column relate to aprocess of elimination of the non-prime numbers from the sequence of numbers1,2,3,4,5,6,7,8,9,10 (although numbers 1 and 2 are omitted). The act of elimination isproven by the display of the numbers deduced in the middle column; namely: 4, 6, 8, 9,and 10 and the subsequent omission of these same numbers from the following listleaving only: 5, 7 at the bottom of column M.This elimination process described above is repeated to obtain the primes 11,13,17,19when eliminating non-primes from the sequence 11,12,13,14,15,16,17,18,19,20.However, only calculations for the sequence 1 to 10 (for numbers above 2) aredisplayed in column M; as if to exemplify the Ishango Sieve method for the benefit ofposterity.

Revalidation of Enteromius alberti and presence of Enteromius cf. mimus (Cypriniformes: Cyprinidae) in the Lake Edward system, East Africa

A revision was done on the species of Enteromius Cope, 1867 (Cypriniformes: Cyprinidae) from the Lake Edward system with a smooth, flexible third unbranched dorsal fin ray without serrations. Specimens with these characteristics had previously been attributed to E. perince and E. stigmatopygus. A combination of a genetic (COI, mtDNA) and a morphometric approach was used. Based on the COI gene, we found two groups with a distance of 8.5%, though neither of the two corresponded to E. perince or E. stigmatopygus. One group revealed to be conspecific with E. alberti, previously a synonym of E. stigmatopygus, described from the Rutshuru River, May-Ya-Moto (DRC, Lake Edward system), and revalidated here. In addition, E. cercops, described from the Nzoia River (Kenya, Lake Victoria basin), is put in synonymy with E. alberti. The second group was most similar to E. mimus, but differed morphologically somewhat from the types of E. mimus. Therefore, specimens of this group were identified as E. cf. mimus. Morphologically, E. alberti can be separated from E. cf. mimus based on a higher number of lateral line scales and smaller values for interorbital width, pre-pelvic distance, body depth, maximum and minimum caudal peduncle depth, head width and head depth.