Your search found 11 records
1 Wagener, T.; Franks, S.; Gupta, H. V.; Bogh, E.; Bastidas, L.; Nobre, C.; de Oliverira Galvao, C. (Eds.) 2005. Regional hydrological impacts of climatic change: impact assessment and decision making. Proceedings of the International Symposium on Regional Hydrological Impacts of Climate Variability and Change with an Emphasis on Less Developed Countries (S6) held during the 7th Scientific Assembly of the International Association of Hydrological Sciences (IAHS), Foz do Iguaco, Brazil, 3-9 April 2005. Part 1. Wallingford, UK: International Association of Hydrological Sciences (IAHS). 356p. (IAHS Publication 295)
Climate change ; Hydrological factors ; Impact assessment ; Decision making ; Agricultural development ; River basins ; Water resources ; Water management ; Coastal area ; Stream flow ; Catchment areas ; Semiarid climate ; Lakes ; Population growth ; Air pollution ; Land cover change ; Hydroelectric schemes ; Flooding ; Evapotranspiration ; Watersheds ; GIS ; Arid zones ; Semiarid zones ; Sea water ; Water temperature ; Alluvial aquifers ; Models ; Satellite observation ; Forecasting ; Afforestation ; El Nino-Southern Oscillation ; Case studies / South America / North America / Europe / Africa / Asia / Brazil / Argentina / USA / Greece / Balkan Peninsula / West Africa / Benin / Cameroon / Lebanon / Nepal / Pakistan / India / China / Western Australia / Northeast Brazil / Trinidad / Vietnam / Eastern Australia / La Plata Basin / Taquari River Basin / Patagonia / Aliakmon River Basin / Black Sea / Volta Basin / Logone-Chari Plain / Himalayan Basin / Upper Indus Basin / Ganga Basin / Damodar River Basin / Yellow River Basin / Susannah Brook / Nordeste / St. Joseph Watershed / Himalayas / Red River Basin / Indian Ocean
(Location: IWMI HQ Call no: 577.22 G000 WAG Record No: H046622)
(0.44 MB)
2 Low, P. S. 2005. Climate change and Africa. Cambridge, UK: Cambridge University Press. 369p.
Climate change ; Adaptation ; Desertification ; Flooding ; Drought ; Disaster risk reduction ; Sustainable development ; Energy resources ; Biomass ; Electricity ; Solar energy ; Atmospheric chemistry ; Organic volatile compounds ; Air pollution ; Carbon ; Emission reduction ; Ozone depletion ; Soil microorganisms ; International agreements ; Natural resources ; Transport ; Sea level ; Biodiversity ; Islands ; El Nino-Southern Oscillation ; Indigenous organisms ; Population growth ; Capacity building ; Case studies ; SADC countries / Africa / Ethiopia / Kenya / Egypt / Ghana / Botswana / Tanzania / Zambia
(Location: IWMI HQ Call no: 577.22 G100 LOW Record No: H047089)
(0.33 MB)
3 Islam, Z.; Gan, T. Y. 2015. Potential combined hydrologic impacts of climate change and El Nino Southern Oscillation to South Saskatchewan River Basin. Journal of Hydrology, 523:34-48. [doi: https://doi.org/10.1016/j.jhydrol.2015.01.043]
Climate change ; El Nino-Southern Oscillation ; Hydrological factors ; Stream flow ; Runoff ; Forecasting ; Models ; River basins ; Precipitation ; Temperature / Canada / Alberta / South Saskatchewan River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H047439)
(1.52 MB)
A physically based land surface scheme, the Modified Interaction Soil Biosphere Atmosphere (MISBA) of Kerkhoven and Gan (2006) was used to assess the future streamflow of the South Saskatchewan River Basin (SSRB) of Alberta under the combined impacts of climate change and El Nino Southern Oscillation (ENSO). Potential impacts of climate change on the streamflows of 15 sub-basins of the SSRB for the 2010–2039 (2020s), 2040–2069 (2050s) and 2070–2099 (2080s) were simulated by MISBA based on 30 years (1961–1990) of re-analysis data of the European Centre for Mid-range Weather Forecasts (ERA-40) adjusted with climate scenarios projected by four General Circulation Models (GCMs) for three Special Report on Emissions Scenarios (SRES) emissions (A1FI, A21, B21) of Intergovernmental Panel on Climate Change (IPCC). Next, the combined impacts of climate change and ENSO are simulated by driving MISBA with the ERA-40 dataset re-sampled for active El Nino and La Nina episodes adjusted for climate projections of 2050s. Under SRES climate projections alone, MISBA simulated an overall decrease in streamflow for sub-basins of SSRB in 2020s, 2050s, and 2080s. While under a combined impact of climate change and ENSO, a further decrease (increase) in the streamflow of SSRB by 2050s was simulated if the climate anomaly considered was El Nino (La Nina).
4 Seyoum, W. M. 2018. Characterizing water storage trends and regional climate influence using GRACE observation and satellite altimetry data in the Upper Blue Nile River Basin. Journal of Hydrology, 566:274-284. [doi: https://doi.org/10.1016/j.jhydrol.2018.09.025]
Water storage ; Trends ; Satellite observation ; Precipitation ; Rain ; Drought ; Climate change ; El Nino-Southern Oscillation ; Water resources ; River basins ; Lakes / Ethiopia / Upper Blue Nile River Basin / Lake Tana
(Location: IWMI HQ Call no: e-copy only Record No: H048988)
(2.49 MB)
Climate variability along with increase in the demand for water resources highlights the need for better understanding of the link between regional climate and terrestrial water storage. This paper examined the variation of terrestrial water storage in relation to climatic influences over the Upper Blue Nile (UBN) River Basin from GRACE Terrestrial Water Storage Anomaly (TWSA), satellite altimetry, rainfall, and Multivariate El NiñoSouthern Oscillation Index (MEI) anomaly data. Although there is no statistically significant (a = 0.05) longterm trend in terrestrial water variation and rainfall in the basin (lake storage, TWSA, and rainfall, pvalue = 0.45, 0.48, and 0.55, respectively), in the last decade, two visible droughts occurred between 2002 and 2004, and 2009 and 2010, which resulted in water deficit in the basin, where below average rainfall, TWSA, and lake height (storage) were observed during these periods. Extreme rainfall analysis from Standardized Precipitation Index (SPI) and strong connection between wet season rainfall, lake height, and TWSA, respectively, indicate interannual terrestrial water storage dynamics in the UBN Basin is strongly influenced by climate. Further, the El Niño-Southern Oscillation (ENSO) influences rainfall in the UBN Basin, specifically the peak rainfall season (June-September), which shows negative correlation (r = -0.62) with MEI anomaly values, which indicates that the El Niño case (positive MEI values) is linked to the dry conditions in the basin. The findings of this study, combined with studies such as socioeconomic impact of drought, will facilitate better planning and management of water resources in water stressed regions. Furthermore, this study demonstrates the application of a combination of satellite and other hydrologic data in understanding the hydro-climatic condition of a remote basin.
5 Higley, M. C.; Conroy, J. L. 2019. The hydrological response of surface water to recent climate variability: a remote sensing case study from the central tropical Pacific. Hydrological Processes, 33(16):2227-2239. [doi: https://doi.org/10.1002/hyp.13465]
Surface water ; Climate change ; Hydrological factors ; Remote sensing ; Case studies ; Freshwater ; Groundwater ; Evaporation ; El Nino-Southern Oscillation ; Satellite imagery ; Landsat ; Normalized difference vegetation index ; Islands / Pacific Islands / Kiribati / Kiritimati
(Location: IWMI HQ Call no: e-copy only Record No: H049284)
(2.56 MB)
For small tropical islands with limited freshwater resources, understanding how island hydrology is influenced by regional climate is important, considering projected hydroclimate and sea level changes as well as growing populations dependent on limited groundwater resources. However, the relationship between climate variability and hydrologic variability for many tropical islands remains uncertain due to local hydroclimatic data scarcity. Here, we present a case study from Kiritimati, Republic of Kiribati (2°N, 157°W), utilizing the normalized difference vegetation index to investigate variability in island surface water area, an important link between climate variability and groundwater storage. Kiritimati surface water area varies seasonally, following wet and dry seasons, and interannually, due to hydroclimate variability associated with the El Niño/Southern Oscillation. The NIÑO3.4 sea surface temperature index, satellite-derived precipitation, precipitation minus evaporation, and local sea level all had significant positive correlations with surface water area. Lagged correlations show sea level changes and precipitation influence surface water area up to 6 months later. Differences in the timing of surface water area changes and variable climate-surface water area correlations in island subregions indicate that surface hydrology on Kiritimati is not uniform in response to climate variations. Rather, the magnitude of the ocean–atmosphere anomalies and island–ocean connectivity determine the extent to which sea level and precipitation control surface water area. The very strong 2015–2016 El Niño event led to the largest surface water area measured in the 18-year data set. Surface water area decreased to pre-event values in a similarly rapid manner (<6 months) after both the very strong 2015–2016 event and the 2009–2010 moderate El Niño event. Future changes in the frequency and amplitude of interannual hydroclimate variability as well as seasonal duration will thus alter surface water coverage on Kiritimati, with implications for freshwater resources, flooding, and drought.
6 Ault, T. R. 2020. On the essentials of drought in a changing climate. Science, 368(6488):256-260. [doi: https://doi.org/10.1126/science.aaz5492]
Drought ; Climate change ; Soil water content ; Precipitation ; Evapotranspiration ; Water resources ; El Nino-Southern Oscillation ; Observation ; Models
(Location: IWMI HQ Call no: e-copy only Record No: H049653)
(0.88 MB)
Droughts of the future are likely to be more frequent, severe, and longer lasting than they have been in recent decades, but drought risks will be lower if greenhouse gas emissions are cut aggressively. This review presents a synopsis of the tools required for understanding the statistics, physics, and dynamics of drought and its causes in a historical context. Although these tools have been applied most extensively in the United States, Europe, and the Amazon region, they have not been as widely used in other drought-prone regions throughout the rest of the world, presenting opportunities for future research. Water resource managers, early career scientists, and veteran drought researchers will likely see opportunities to improve our understanding of drought.
7 Taye, Meron Teferi; Dyer, E.; Charles, K. J.; Hirons, L. C. 2021. Potential predictability of the Ethiopian summer rains: understanding local variations and their implications for water management decisions. Science of the Total Environment, 755(Part 1):142604. [doi: https://doi.org/10.1016/j.scitotenv.2020.142604]
Rain ; Weather forecasting ; Water management ; Decision making ; Oceanic climate ; Temperature ; Climate change ; El Nino-Southern Oscillation ; Precipitation ; Spatial variation ; River basins ; Case studies / Ethiopia / Awash River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050014)
https://www.sciencedirect.com/science/article/pii/S0048969720361337/pdf?md5=58c744b3a1e31d3bceecd1661ae3f3c3&pid=1-s2.0-S0048969720361337-main.pdf
https://vlibrary.iwmi.org/pdf/H050014.pdf
https://vlibrary.iwmi.org/pdf/H050014.pdf
(4.89 MB) (4.89 MB)
Understanding the influence of large-scale oceanic and atmospheric variability on rainfall over Ethiopia has huge potential to improve seasonal forecasting and inform crucial water management decisions at local levels, where data is available at appropriate scales for decision makers. In this study, drivers of Ethiopia‘s main rainy season, July-September (JAS), are investigated using correlation analysis with sea surface temperature (SST). The analysis showed local spatial variations in the drivers of JAS rainfall. Moreover, the analysis revealed strong correlation between March to May (MAM) SST and JAS rainfall in particular regions. In addition to the influence of SSTs, we highlighted one of the mechanisms explaining the regional pattern of SST influence on Ethiopian rainfall, the East African Low-Level Jet. Moreover, examining the occurrence of large-scale phenomena provided additional information, with very strong ENSO and positive IOD events associated with drier conditions in most part of Ethiopia. A sub-national analysis, focused at a scale relevant for water managers, on the Awash basin, highlighted two distinct climate zones with different relationships to SSTs. June was not included as part of the rainy season as in some areas June is a hot, dry month between rainy seasons and in others it can be used to update sub-seasonal forecasts with lead time of one month for JAS rainfall. This highlights the importance of understanding locally relevant climate systems and ensuing sub-seasonal to seasonal forecasts are done at the appropriate scale for water management in the complex topography and climatology of Ethiopia.
8 Sorensen, J. P. R.; Davies, J.; Ebrahim, Girma Y.; Lindle, J.; Marchant, B. P.; Ascott, M. J.; Bloomfield, J. P.; Cuthbert, M. O.; Holland, M.; Jensen, K. H.; Shamsudduha, M.; Villholth, Karen G.; MacDonald, A. M.; Taylor, R. G. 2021. The influence of groundwater abstraction on interpreting climate controls and extreme recharge events from well hydrographs in semi-arid South Africa. Hydrogeology Journal, 29(8):2773-2787. [doi: https://doi.org/10.1007/s10040-021-02391-3]
Groundwater extraction ; Groundwater recharge ; Well hydrographs ; Semiarid climate ; Catchment areas ; Groundwater table ; Rain ; River flow ; Stream flow ; Extreme weather events ; El Nino-Southern Oscillation ; Hydrogeology ; Boreholes ; Spatial distribution ; Land use / South Africa / Limpopo / Mogalakwena Catchment / Sand River Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H050671)
https://link.springer.com/content/pdf/10.1007/s10040-021-02391-3.pdf
https://vlibrary.iwmi.org/pdf/H050671.pdf
https://vlibrary.iwmi.org/pdf/H050671.pdf
(6.26 MB) (6.26 MB)
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 Nino– 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.
9 Nayak, M. A.; Hassan, W. U. 2021. A synthesis of drought prediction research over India. Water Security, 13:100092. [doi: https://doi.org/10.1016/j.wasec.2021.100092]
Drought ; Forecasting ; Monsoons ; Meteorological factors ; Precipitation ; Soil moisture ; Stream flow ; Runoff ; Monitoring ; El Nino-Southern Oscillation ; Modelling / India
(Location: IWMI HQ Call no: e-copy only Record No: H050641)
(2.74 MB)
A major section of India’s economy is directly linked with water-dependent food and energy systems. Skillful predictions of droughts play a pivotal role in sustainable water management and evading serious damages to agriculture production and economy of a region. Recent decades have witnessed valuable advances in scientific understanding and prediction of droughts in India. In this review, we synthesize major sources of drought predictability over different regions in India. We find that a few large-scale atmospheric and oceanic circulation patterns and regional scale hydrometeorological variables are key to understanding and predicting drought occurrences. We also present a concise summary of major statistical and dynamical forecasting-based modelling efforts in drought predictions. Although major strides have been taken in drought prediction in the recent decades, important gaps remain in understanding the onset and spatio-temporal dynamics of droughts.
Further, many opportunities of improving the skill of drought prediction over India are envisaged, and many impending challenges are highlighted. The overall picture is that significant efforts and investments are critical for understanding and skillfully predicting droughts over India.
Further, many opportunities of improving the skill of drought prediction over India are envisaged, and many impending challenges are highlighted. The overall picture is that significant efforts and investments are critical for understanding and skillfully predicting droughts over India.
10 Worako, A. W.; Haile, Alemseged Tamiru; Taye, Meron Teferi. 2021. Streamflow variability and its linkage to ENSO events in the Ethiopian Rift Valley Lakes Basin. Journal of Hydrology: Regional Studies, 35:100817. [doi: https://doi.org/10.1016/j.ejrh.2021.100817]
Stream flow ; River basins ; El Nino-Southern Oscillation ; Hydrology ; Indicators ; Trends ; Catchment areas ; Watersheds ; Climate change / Ethiopia / Rift Valley Lakes Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050726)
https://www.sciencedirect.com/science/article/pii/S221458182100046X/pdfft?md5=86a8808571a62fee3a94a2ad0492e4ca&pid=1-s2.0-S221458182100046X-main.pdf
https://vlibrary.iwmi.org/pdf/H050726.pdf
https://vlibrary.iwmi.org/pdf/H050726.pdf
(2.08 MB) (2.08 MB)
Study Region: The Ethiopian Rift Valley Lakes basin is found in the main Ethiopian Rift Valley system.
Study Focus: Understanding the hydrological impact of El Niño-Southern Oscillation (ENSO) is of a paramount importance for society since it substantially affects the environmental and socio-economic conditions. The relation between ENSO indicators (SOI, MEI and Niño3.4) and streamflow magnitude was statistically evaluated with partial correlation, cross correlation, extreme streamflow indices and streamflow deficits to provide empirical evidence on how ENSO phases (La Niña and El Niño) affect streamflow variability. Trends of streamflow and ENSO indicators were tested using the non-parametric Mann-Kendall test.
New Hydrological Insights for the Region: Our findings indicate that the partial correlation between the catchment area and ENSO effect on streamflow were not statistically significant at p < 0.05 after removing the south-north gradient. The direction of the ENSO effect is spatially inconsistent since El Niño (La Niña) causes positive deviation in some catchments and negative deviation for other catchments. Though statistically insignificant, reduced flow is detected for many catchments during El Niño years. For most catchment, the extreme high flow has a larger magnitude during La Niña than El Niño whereas the extreme low flow has a larger magnitude during El Niño than La Niña years. Overall, the relationship between ENSO and streamflow of the study area is found spatially inconsistent and statistically insignificant for most catchments.
Study Focus: Understanding the hydrological impact of El Niño-Southern Oscillation (ENSO) is of a paramount importance for society since it substantially affects the environmental and socio-economic conditions. The relation between ENSO indicators (SOI, MEI and Niño3.4) and streamflow magnitude was statistically evaluated with partial correlation, cross correlation, extreme streamflow indices and streamflow deficits to provide empirical evidence on how ENSO phases (La Niña and El Niño) affect streamflow variability. Trends of streamflow and ENSO indicators were tested using the non-parametric Mann-Kendall test.
New Hydrological Insights for the Region: Our findings indicate that the partial correlation between the catchment area and ENSO effect on streamflow were not statistically significant at p < 0.05 after removing the south-north gradient. The direction of the ENSO effect is spatially inconsistent since El Niño (La Niña) causes positive deviation in some catchments and negative deviation for other catchments. Though statistically insignificant, reduced flow is detected for many catchments during El Niño years. For most catchment, the extreme high flow has a larger magnitude during La Niña than El Niño whereas the extreme low flow has a larger magnitude during El Niño than La Niña years. Overall, the relationship between ENSO and streamflow of the study area is found spatially inconsistent and statistically insignificant for most catchments.
11 de Oliveira-Junior, J. F.; Shah, M.; Abbas, A.; Iqbal, M. Shahid; Shahzad, R.; de Gois, G.; da Silva, M. V.; da Rosa Ferraz Jardim, A. M.; de Souza, A. 2022. Spatiotemporal analysis of drought and rainfall in Pakistan via Standardized Precipitation Index: homogeneous regions, trend, wavelet, and influence of El Nino-Southern Oscillation. Theoretical and Applied Climatology, 149(1-2):843-862. [doi: https://doi.org/10.1007/s00704-022-04082-9]
Drought ; Rain ; Precipitation ; Time series analysis ; El Nino-Southern Oscillation ; Trends ; Spatial distribution ; Meteorological stations / Pakistan
(Location: IWMI HQ Call no: e-copy only Record No: H051166)
(3.26 MB)
The phenomenon of drought is common in the world, especially in Pakistan. El Niño-Southern Oscillation (ENSO) influences the spatial and temporal variability of drought and rainfall in Pakistan. Therefore, the objectives of this study are to identify homogeneous rainfall regions and their trend regions, as well as the impact of ENSO phases. In this study, monthly rainfall data from 44 weather stations are used during 1980–2019. Moreover, descriptive and exploratory statistics tests (e.g., Pettitt and Mann-Kendall—MK), Sen method, and cluster analysis (CA) are evaluated along with the annual Standardized Precipitation Index (SPI) on spatiotemporal scales. ENSO occurrences were classified based on the Oceanic Nino Index (ONI) for region 3.4. Using the cophenetic correlation coefficient (CCC) and a significance level of 5%, seven methods were applied to the rainfall series, with the complete method (CCC > 0.9082) being the best. According to the CA method, Pakistan has four groups of homogeneous rainfall (G1, G2, G3, and G4). Descriptive and exploratory statistics showed that G1 differs from the other groups in size and spatial distribution. Pettitt’s technique identified the most extreme El Niño years in terms of spatial and temporal drought variability, along with the wettest months (March, August, September, June, and December) in Pakistan. Non-significant increases in Pakistan’s annual precipitation were identified via the MK test, with exceptions in the southern and northern regions, respectively. No significant increase in rainfall in Pakistan was found using the Sen method, especially in regions G2, G3, and G4. The severity of the drought in Pakistan is intensified by El Niño events, which demand attention from public managers in the management of water resources, agriculture, and the country’s economy.
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