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Girma Kebbede dr. 《GeoJournal》1991,23(2):99-106
Conclusion For the overwhelming majority of the Ethiopian refugees in urban Sudan, there seems to be no end to their plight. Their lives are in limbo. When they left their homeland most thought thei exile would be temporary. They sought temporary refuge only until the conditions at home improved and they might return in safety. Unfortunately, the conditions for their repatriation have never developed. Armed conflicts in Ethiopia still continue to rage unabated. the regime in power also continues to abuse fundamental human rights.Many of the refugees also thought they would have peace and security and, perhaps, a decent livelihood in their asylum home. These have not materialized either. The Sudan, faced with numerous problems, including civil war, drought, famine, huge external debt (in excess of $12 billion), open unemployment, and pervasive underemployment, is not even able to cope adequately with the basic needs of its own citizens, let along that of a refugee population of over a million. Worse, refugees are blamed for every problem from bread and water shortages to skyrocketing rents and have become convenient targets for harassment by the frustrated public.Others hoped for resettlement in another country. However, for the vast majority of refugees, resettlement opportunities elsewhere are virtually impossible to attin. The industrial countried are unwilling to grant asylum to large numbers of Third World refugees. These countries content that most Third World refugees are not victims of political persecution but simply migrants in search of better economoc opportunities. The few refugees to whom these countries are willing to grant asylum are those with the best qualifications: the young, the educated, and the highly skilled.As long as the current status quo in Ethiopia remains unaltered, voluntary repatriation is highly unlikelt. On the contrary, one sees more and more evidence in the country of continued uprooting of masses of people from their homes and land. It is sad that, goven the immense contradictions in the country, the possibility of negotiated solutions to the wars and a return to democracy is nowhere in sight. The plight of hundred of thousands of innocent women and men will not be solved anytime in the immediate future of them to return home in safety, peace, and dignity. For most of these refugees the future is uncertain, probably unpleasant, possibly bleak. 相似文献
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Although it is well known that the vast majority of the time only a portion of any watershed contributes run‐off to the outlet, this extent is rarely documented. Also, the power law form of the streamflow and contributing area (Q‐Ac) relationship has been known for a half century, but it is uncommon for it to be quantified, and time series of contributing area extensive enough to calculate its frequency distribution are almost non‐existent. Data from the Canadian Prairies, where there are extensive estimates of contributing area during the median annual flood, imply that the power law coefficient for any Q‐Ac curve is a function of flow magnitude and return period. These data also suggest that regional flood frequency curves are a construct of Q‐Ac curves from individual basins. This paper will discuss research that attempted to reproduce the Q‐Ac curves for the La Salle River Watershed with a semidistributed numerical hydrological model, MESH‐PDMROF. The model simulated streamflow reasonably well (Nash Sutcliffe values = 0.62) compared with published examples of comparable models applied in the region. Estimates of the coefficient and exponent of the Q‐Ac power law function ranged from 0.08–0.14 and 0.9–1.12, respectively. These exponent values were lower than those of regional flood frequency curves and support the theory that regional flood frequency curves are a construct of Q‐Ac curves. Simulations of the area contributing to the median annual flood were lower (0.3) than those derived from independent topographic analysis (0.9) described in earlier literature though there is uncertainty in both these estimates. This uncertainty was extended across the flood frequency distribution and may be too large to definitively verify the study hypothesis. 相似文献
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Sorensen James P. R. Davies Jeff Ebrahim Girma Y. Lindle John Marchant Ben P. Ascott Matthew J. Bloomfield John P. Cuthbert Mark O. Holland Martin Jensen K. H. Shamsudduha M. Villholth Karen G. MacDonald Alan M. Taylor Richard G. 《Hydrogeology Journal》2021,29(8):2773-2787
There is a scarcity of long-term groundwater hydrographs from sub-Saharan Africa to investigate groundwater sustainability, processes and controls. This paper presents an analysis of 21 hydrographs from semi-arid South Africa. Hydrographs from 1980 to 2000 were converted to standardised groundwater level indices and rationalised into four types (C1–C4) using hierarchical cluster analysis. Mean hydrographs for each type were cross-correlated with standardised precipitation and streamflow indices. Relationships with the El Niño–Southern Oscillation (ENSO) were also investigated. The four hydrograph types show a transition of autocorrelation over increasing timescales and increasingly subdued responses to rainfall. Type C1 strongly relates to rainfall, responding in most years, whereas C4 notably responds to only a single extreme event in 2000 and has limited relationship with rainfall. Types C2, C3 and C4 have stronger statistical relationships with standardised streamflow than standardised rainfall. C3 and C4 changes are significantly (p <?0.05) correlated to the mean wet season ENSO anomaly, indicating a tendency for substantial or minimal recharge to occur during extreme negative and positive ENSO years, respectively. The range of different hydrograph types, sometimes within only a few kilometres of each other, appears to be a result of abstraction interference and cannot be confidently attributed to variations in climate or hydrogeological setting. It is possible that high groundwater abstraction near C3/C4 sites masks frequent small-scale recharge events observed at C1/C2 sites, resulting in extreme events associated with negative ENSO years being more visible in the time series.
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Batsuren Dorjsuren Denghua Yan Hao Wang Sonomdagva Chonokhuu Altanbold Enkhbold Davaadorj Davaasuren Abel Girma Asaminew Abiyu Lanshu Jing Mohammed Gedefaw 《Environmental Earth Sciences》2018,77(20):725
Land cover and vegetation in Lake Baikal basin (LBB) are considered to be highly susceptible to climate change. However, there is less information on the change trends in both climate and land cover in LBB and thus less understanding of the watershed sensitivity and adaptability to climate change. Here we identified the spatial and temporal patterns of changes in climate (from 1979 to 2016), land cover, and vegetation (from 2000 to 2010) in the LBB. During the past 40 years, there was a little increase in precipitation while air temperature has increased by 1.4 °C. During the past 10 years, land cover has changed significantly. Herein grassland, water bodies, permanent snow, and ice decreased by 485.40 km2, 161.55 km2 and 2.83 km2, respectively. However, forest and wetland increased by 111.40 km2 and 202.90 km2, respectively. About 83.67 km2 area of water bodies has been converted into the wetland. Also, there was a significant change in Normalized Difference Vegetation Index (NDVI), the NDVI maximum value was 1 in 2000, decreased to 0.9 in 2010. Evidently, it was in the mountainous areas and in the river basin that the vegetation shifted. Our findings have implications for predicting the safety of water resources and water eco-environment in LBB under global change. 相似文献
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Seasonal variations in the biomass (Chl a) and primary production (14C-method) of phytoplankton were studied during 12 months of 2005 in the three Ethiopian Rift Valley Lakes (ERVL) Ziway, Awassa and Chamo. Chl a showed an average value of 40, 20, and 30 mg m−3 for the three lakes, respectively. Integrated areal primary production for the total phytoplankton (g C m−2 d−1) varied 2-fold in the three lakes but on different levels, from 0.67–1.8 in L. Ziway, 1.8–4.6 in L. Awassa, and 1.0–2.6 in L. Chamo. The overall photosynthetic efficiency of utilizing photosynthetically active radiation by the phytoplankton on molar basis (mmol C mol of photons−1) resulted in an average value of 1.4 for L. Ziway, 3.5 for L. Awassa and 1.6 for L. Chamo. Among the different factors regulating phytoplankton primary productivity, light penetration and nutrients were the most important in the three lakes. The seasonal variations of incident radiation (most values between 5 and 7 E m−2 h−1) and water temperature (most values between 22 and 24 °C) were small and unlikely to result in the marked differences in phytoplankton primary production. Although relative increase in nutrient concentrations occurred following the rainy periods, the major algal nutrients were either consistently low (nitrate and/or silicate) or high (phosphate and/or ammonium) and remained within a narrow range for most of the study period in all the three lakes. Consequently, phytoplankton biomass and primary production seem to be maintained more by nutrient regeneration or turnover (facilitated by high temperature) than by allochthonous nutrient input. This would be coupled with wind-induced mixing that would play an important role in determining hydrographic characteristics (water column structure) and the associated redistribution of nutrients and phytoplankton, the availability of light and subsequently the spatial (vertical) and temporal patterns of phytoplankton production in these three ERVL. Phytoplankton production (PP) is regarded as a good predictor of fish yield in lakes and seasonal measurements of PP is a prerequisite for good such estimates. 相似文献
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Menna Biniyam Yisehak Mesfin Henok Shiferaw Gebrekidan Atkilt Girma Siyum Zenebe Girmay Tegene Melaku Takele 《Theoretical and Applied Climatology》2022,149(1-2):621-638
Theoretical and Applied Climatology - Meteorological drought is among the key climate-related risks affecting Ethiopia. It indicates a shortage of precipitation over a long period, usually for a... 相似文献
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Gebre Girma Gezimu Isoda Hiroshi Rahut Dil Bahadur Amekawa Yuichiro Nomura Hisako 《GeoJournal》2021,86(2):843-864
GeoJournal - This study examines the impact of gender differences on maize productivity in Dawuro Zone, southern Ethiopia. Our study addressed the limitations of the previous studies in two ways.... 相似文献