Исследование информационных процессов в некоторых повторяющихся играх

Рассматривается неантагонистическая повторяющаяся игра с непрерывным временем. Один раз за всю игру может подействовать возмущающий фактор. Он изменяет существующую ситуацию равновесия на другую. При этом выигрыш второго игрока уменьшается. Найдены равновесные стратегии и оптимальный дискретный режим получения информации. Показано, что наблюдатель оценивает режим получения информации как оптимальный или избыточный в зависимости от модели реальности, которой он пользуется.The non-antagonistic repeated game are considered. The disturbance is able to act once the game. It changes the existing situation of equilibrium for another one. For this the second player gain decreases. The equilibrium strategies and the optimum discrete regime of the information receipt are found. It is shown that observer estimates the regime of the information receipt as the optimum or surplus regime depending on the model of reality which is used by him

Capacitating water lifting service providers reduce risks of crop failure and increase producer confidence in adopting irrigation: LIVES experiences

Global Affairs Canad

Nutrient-Dense Orange-Fleshed Sweetpotato: Advances in Drought-Tolerance Breeding and Understanding of Management Practices for Sustainable Next-Generation Cropping Systems in Sub-Saharan Africa

Almost half of children < 5 years old living in sub-Saharan Africa (SSA) suffer from vitamin A deficiency and 60% suffer from iron deficiency. Thus, there has been a strong commitment to breeding for, promoting awareness of, and delivering adapted pro-vitamin A rich orange-fleshed sweetpotato (OFSP) in SSA during the past two decades and for enhanced iron content since 2014. This review article focuses on major breeding efforts in SSA to enhance the drought tolerance of OFSP and reviews integrated crop management practices for improved and sustained sweetpotato production in SSA farming systems. Under climate change, the frequency and severity of droughts is expected to increase. Technical issues are presented in the context of addressing challenges along the entire value chain to ensure adoption. First, the use of an accelerated breeding scheme reduced the breeding cycle from 8–10 to 4–5 years. Since 2010, 19 drought-tolerant OFSP cultivars have been released in Mozambique, 7 in Malawi, and 2 in South Africa. Moreover, research in four breeding populations using the heterosis exploiting breeding scheme (HEBS) demonstrated that within one breeding cycle of 5 years, clones with significantly higher root yield, abiotic tolerance, host plant resistance to pests and diseases, and early maturity can be produced. In the future, HEBS will be combined with greater use of modern genomic tools, new phenotyping tools, and CRISPR/Cas9-mediated gene editing. Second, beyond genetic enhancements, evidence is presented that using improved crop management systems, existing sweet potato yields can be increased 2–4 times. Current knowledge is reviewed concerning sweetpotato’s role in diverse farming systems, but integrated crop management is clearly under researched. Third, the outlook for drought tolerance breeding indicates that two distinct classes of nutrient-rich cultivars are emerging: (1) Early maturing cultivars (< 4 month growing period) that escape drought but also serve humid environments with small landholding size per capita; and (2) Medium maturing (4–6 month growing period) cultivars that avoid drought, are drought tolerant and exhibit continuous root formation. Increasing commercialization of the crop and climate change will drive demand, and the willingness of farmers to invest in improved sweetpotato crop management

Using AquaCrop as a Decision-Support Tool for Small-Scale Irrigation Systems Was Dictated by the Institutional and Market Incentives in Ethiopia

The threat of water scarcity in sub-Saharan Africa is exacerbated by the expanding agricultural water needs, increasing climate variability and inappropriate land use. It calls for technological and institutional innovations to improve water productivity, while sustaining the resources base. This study was undertaken to examine the effect of deficit and supplementary irrigation for staggered production of potato driven by market opportunities at different periods in northeastern Ethiopia. We used potato (Solanum tuberosum) to demonstrate AQUACrop as a tool for improving water productivity during Belg (short) and Meher (long) rainfall seasons. A field experiment was undertaken using supplementary irrigation at different levels of potato crop water satisfaction (50% ETc, 75% ETc, 100% ETc and rainfed conditions) during the Belg (February–May 2020) and Meher (July–October 2020) seasons. Upon proper calibration of AquaCrop for the local potato variety (Belete), long-term simulations revealed that the mean net irrigation requirements were 249 mm during Belg season while the probability of applying supplementary irrigation during Meher was <10% when the effective precipitation was greater than the crop water requirement (ETc) in more than 75% of the years. Although there was significantly higher potato tuber yield from the 100% ETc than that from the 75% ETc, the latter had higher water supply efficiency than the former. Long-term simulations further revealed that the number of rainfall days was more important than the amount of rainfall during the growing period. We engaged water users' associations to employ the recommendation and enforce supplementary irrigation as predicted by the model and we present farmers' response and reasons for resistance toward water saving approaches. Hence, we concluded that 50% ETc and 75% ETc irrigation levels can still be recommended upon proper scheduling to address long dry spells, especially during the middle growth stages in the face of irrigation conflict. However, the institutional settings and market incentives associated with it are the major drivers of adopting improved irrigation water management practices

Drought vulnerability drives land-use and land cover changes in the Rift Valley dry lands of Ethiopia

The Ethiopian Rift Valley is a dry land zone where for a long time pastoral communities have made their living from acacia-based woodlands. But many pastoralists have changed from a pastoral way of life to mixed farming over time. The aim of this study was to evaluate land-use and land cover (LULC) changes in the Central Rift Valley dry lands of Ethiopia, and determine the role of drought vulnerability as a driver. A combination of GIS/remote sensing techniques, drought vulnerability analyses, field observation and surveying were employed. Because drought vulnerability is linked more closely to the types of land-uses and social contexts rather than only climatological events, it was examined based on locally perceived criteria of drought. Accordingly, the pastoral way of life was vulnerable to severe drought during 25% of the last 28 years while the mixed farming (livestock and maize farming combined) system was vulnerable to severe drought only during 4% of the years. Over the last 5 decades, cultivated lands increased to threefold while the dense acacia coverage declined from 42% in 1965 to 9% in 2010. The observed LULC changes were driven by the interplay of recurrent drought, socioeconomic and institutional dynamics, access to markets and improved technologies such as early-maturing maize cultivars and better land management. Proper policy and technological interventions are required to develop appropriate drought adaptation strategies and avert the increasing degradation of woodlands in the Rift Valley dry lands where a pastoral way of life is still present

Drought vulnerability drives land-use and land cover changes in the Rift Valley dry lands of Ethiopia

The Ethiopian Rift Valley is a dry land zone where for a long time pastoral communities have made their living from acacia-based woodlands. But many pastoralists have changed from a pastoral way of life to mixed farming over time. The aim of this study was to evaluate land-use and land cover (LULC) changes in the Central Rift Valley dry lands of Ethiopia, and determine the role of drought vulnerability as a driver. A combination of GIS/remote sensing techniques, drought vulnerability analyses, field observation and surveying were employed. Because drought vulnerability is linked more closely to the types of land-uses and social contexts rather than only climatological events, it was examined based on locally perceived criteria of drought. Accordingly, the pastoral way of life was vulnerable to severe drought during 25% of the last 28 years while the mixed farming (livestock and maize farming combined) system was vulnerable to severe drought only during 4% of the years. Over the last 5 decades, cultivated lands increased to threefold while the dense acacia coverage declined from 42% in 1965 to 9% in 2010. The observed LULC changes were driven by the interplay of recurrent drought, socioeconomic and institutional dynamics, access to markets and improved technologies such as early-maturing maize cultivars and better land management. Proper policy and technological interventions are required to develop appropriate drought adaptation strategies and avert the increasing degradation of woodlands in the Rift Valley dry lands where a pastoral way of life is still present

Participatory planning of appropriate rainwater harvesting and management techniques in the central rift valley dry lands of Ethiopia

Despite the extensive efforts of rainwater harvesting and management (RWHM) interventions for moisture-stressed areas in Ethiopia, the adoption and wider dissemination of the newly introduced techniques have been generally meager. The objective of this study was, therefore, to develop appropriate RWHM techniques through a participatory planning process in the Central Rift Valley (CRV) dry lands of Ethiopia. To achieve this objective, a combination of literature reviews, focus group discussions, questionnaire surveys, agro-meteorological analyses and field experimentations were undertaken. Perceived agro-meteorological challenges were determined through the questionnaire survey and validated through meteorological data analyses. Potential in situ RWHM techniques were selected in a participatory process and field-tested for two consecutive growing seasons to evaluate their performances. Those techniques which were selected in a participatory process showed statistically higher crop yields than the existing practices under both low and normal rainfall years. The result of this study implied that the introduction of new RWHM techniques can be successful when they are adjusted and modified in accordance with the existing tillage, hoeing and related land management practices. It was concluded that participatory planning of in situ RWHM techniques allows both the utilization of existing knowledge and opportunities while empowering the farmers to select and introduce new practices as per the existing socioeconomic and environmental settings. The new participatory planning approach will augment the recent efforts of promoting various types of RWHM techniques for improved rainfed agriculture in the vast dry lands of Ethiopia

Drought characterization using different indices, theory of run and trend analysis in bilate river watershed, rift valley of Ethiopia

Droughts have become more powerful and frequent, affecting more people for longer periods than any other natural disaster, particularly in eastern Africa. The unprecedented climate change has increased the severity, duration, and frequency of droughts. The objectives of this study were to evaluate performances of different drought indices for spatiotemporal drought characterization in the Bilate river watershed that represents part of the rift valley drylands in Ethiopia. Historical data for 39 years (1981–2019) from seven stations were used for drought analyses using the following indices: Standardized Precipitation Index (SPI), Standardized Precipitation Evapotranspiration Index (SPEI), Reconnaissance Drought Index (RDI), enhanced Reconnaissance Drought Index (eRDI) with different time scale and Self-Calibrated Palmer Drought Severity Index (scPDSI). Among them, SPI, SPEI, RDI and eRDI with 6-month and 9-month time scales were found to be the best correlated drought indices to characterize the historical drought events. Then, using the selected drought indices, temporal drought analysis showed occurrence of major drought events in the years: 1984/85, 1999/2000, 2002/3, and 2009. Some of these years are well known as famine years in some parts of Ethiopia including the study area. The results revealed spatial variation the severity of drought with extreme droughts occurred in the southern part of the Bilate watershed. Application of the theory of run confirmed that the maximum severity and duration of drought were observed at the Bilate Tena station that is located in the southern part of the watershed; the most severe being observed on a 9-month scale during 1984/85. Hossana and Wulbareg stations showed the highest frequency of drought over the study period. The Mann-Kendal trend test statistics showed an increasing trend of drought conditions in the study watershed