The exploitation status of these target species were then assessed by computing exploitation rates (E from mortality parameters as well as from size indicators i.e., assessing the size distribution of fish catches relative to the size at maturity (L m,the size that provides maximum cohort biomass (Lopt and the abundance of mega-spawners. Mortality parameters were determined from length-converted catch curves and empirical models. Von Bertalanffy growth parameters and their confidence intervals were determined from modal progression analysis using ELEFAN I and applying the jackknife technique. A total of 20 097 fish specimens (distributed as 7 933 tilapia, 6 025 catfish and 6 139 common carp were measured for the analysis. In Lake Koka (Ethiopia, very little is known about the vital population parameters and exploitation status of the fishery target species: tilapia Oreochromis niloticus,common carp Cyprinus carpióand catfish Clarias gariepinus.Our study, therefore, aimed at determining the vital population parameters and assessing the status of these target species in Lake Koka using length frequency data collected quarterly from commercial catches from 2007-2012. Studies on the population dynamics and stock assessment on fishery target species are thus imperative to sustain their fisheries and the benefits for the society. Stock assessment of fishery target species in Lake Koka, Ethiopiaįull Text Available Effective management is essential for small-scale fisheries to continue providing food and livelihoods for households, particularly in developing countries where other options are often limited. The depth up to the lowest bed was between 25 and 85 m, the resistivity of each bed was between 9 and 8,000 ohmm, polarizability higher than 10 mV/V, and relatively large thickness. For the results of analysis, four to seven beds were detected from the resistivity. Geology of surveyed plateau consists of a basement of Pliocene tuffs and Quaternary Pleistocene sediments covering on the surface. Ground water exploration was conducted using this method at Otaki village, Hokkaido. In the case of vertical exploration, measurements are repeated with fixed potential electrodes by extending the distance between current electrodes. For the Schlumberger method, potential is measured at the center between potential electrodes during flow of dc current between current electrodes. Ltd., Tokyo (Japan) Suzuki, T [Hokkaido Development Bureau, Hokkaido Development Agency, Sapporo (Japan)įor ground water exploration using vertical Schlumberger exploration method, measurement and analysis combined with induced polarization ( IP) effect were conducted as trial. Kondo, M Sakurada, H [Sumiko Consultants Co. You can try out Koka live at koka/tutorial.Īpplication of vertical electrical sounding combined with induced polarization method in ground water exploration IP koka wo koryoshita hiteikoho suichoku tansa no chikasui chosa eno tekiyoĮnergy Technology Data Exchange (ETDEWEB) Finally, our system is implemented fully in a new language called Koka and has been used successfully on various small to medium-sized sample programs ranging from a Markdown processor to a tier-splitted chat application. Through the state effect, we can also safely combine state with let-polymorphism without needing either imperative type variables or a syntactic value restriction. Similar to Haskell's `runST` we show how we can safely encapsulate stateful operations. For example, if an expression can be typed without an _exn_ effect, then it will never throw an unhandled exception. Moreover, we show that our effects are not just syntactic labels but have a deep semantic connection to the program. A novel feature is that we support polymorphic effects through row-polymorphism using duplicate labels. The type and effect of expressions can also be inferred automatically, and we describe a polymorphic type inference system based on Hindley-Milner style inference. Koka: Programming with Row Polymorphic Effect Typesĭirectory of Open Access Journals (Sweden)įull Text Available We propose a programming model where effects are treated in a disciplined way, and where the potential side-effects of a function are apparent in its type signature. It is located at 8Â☂4'N latitude and 39Â☀5'E longitude (Fig. Koka Dam was built on Awash River, Ethiopia, in 1960 for hydropower and irrigation purposes. Key words/phrases: Ethiopia, Koka Reservoir water loss, leakage rate, subsurface inflow, water balance. To be used for Awash River simulation model. WATER LOSS OF KOKA RESERVOIR, ETHIOPIA: COMMENTS ON