Your search found 8 records
1 De Silva, R. P. (Ed.) 2004. Geo-informatics research and applications: proceedings of the First Symposium on Geo-informatics, Peradeniya, Sri Lanka, 30 July 2004. Peradeniya, Sri Lanka: Geo-Informatics Society of Sri Lanka (GISSL). 202p.
GIS ; Hydrology ; Technology ; Radar ; Models ; River basins ; Lakes ; Urbanization ; Climatology ; Temperature ; Rain ; Runoff ; Flooding ; Erosion ; Watersheds ; Catchment areas ; Groundwater development ; Groundwater assessment ; Water pollution ; Land use ; Land cover ; Case study ; Developing countries / Sri Lanka / Bangladesh / Kenya / Walawe River Basin / Lake Naivasha Basin / Kukule Watershed / Moneragala District / Hambantota / Deduru Oya Upper Watershed / Kndy Lake
(Location: IWMI HQ Call no: 621.3678 G000 DES Record No: H045953)
(0.30 MB)
2 Pandey, Vishnu Prasad; Sharma, Akriti; Dhaubanjar, Sanita; Bharati, Luna; Joshi, I. R. 2019. Climate shocks and responses in Karnali-Mahakali basins, western Nepal. Climate, 7(7):1-24. (Special issue: Social-Ecological Systems, Climate and Global Change Impacts) [doi: https://doi.org/10.3390/cli7070092]
Climate change adaptation ; Risk analysis ; River basins ; Climatology ; Weather hazards ; Drought ; Rain ; Flooding ; Hailstorms ; Crop losses ; Strategies ; Mountains ; Households ; Animal diseases / Nepal / Karnali River Basin / Mahakali River Basin / Mohana River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049418)
(2.29 MB) (2.29 MB)
The Himalayas are highly susceptible to the impacts of climate change, as it consequently increases the vulnerability of downstream communities, livelihoods and ecosystems. Western Nepal currently holds significant potential as multiple opportunities for water development within the country are underway. However, it is also identified as one of the most vulnerable regions to climate change, with both an increase in the occurrence of natural disasters and exacerbated severity and impacts levels. Regional climate model (RCM) projections indicate warmer weather with higher variability in rainfall for this region. This paper combines bio-physical and social approaches to further study and understand the current climate shocks and responses present in Western Nepal. Data was collected from 3660 households across 122 primary sampling units across the Karnali, Mahakali and Mohana River basins along with focus group discussions, which provided a rich understanding of the currently perceived climatic shocks and related events. Further analysis of climatology was carried out through nine indices of precipitation and temperature that were found to be relevant to the discussed climate shocks. Results show that 79% of households reported experiencing at least one type of climate shock in the five-year period and the most common occurrence was droughts, which is also supported by the climate data. Disaggregated results show that perception varies with the region and among the basins. Analysis of climatic trends further show that irregular weather is most common in the hill region, although average reported frequency of irregular weather is higher in the mountain. Further analysis into the severity and response to climatic shocks suggest an imminent need for better adaptation strategies. This study’s results show that a vast majority of respondents lack proper access to knowledge and that successful adaptation strategies must be adapted to specific regions to meet communities’ local needs.
3 Le Coz, C.; van de Giesen, N. 2020. Comparison of rainfall products over Sub-Saharan Africa. Journal of Hydrometeorology, 21(4):553-596. [doi: https://doi.org/10.1175/JHM-D-18-0256.1]
Rain ; Satellite observation ; Models ; Early warning systems ; Monitoring ; Estimation ; Precipitation ; Climatology ; Drought ; Flooding ; Hydrology ; Highlands / Africa South of Sahara
(Location: IWMI HQ Call no: e-copy only Record No: H049787)
https://journals.ametsoc.org/jhm/article-pdf/21/4/553/4926159/jhmd180256.pdf
https://vlibrary.iwmi.org/pdf/H049787.pdf
https://vlibrary.iwmi.org/pdf/H049787.pdf
(3.87 MB) (3.87 MB)
An ever-increasing number of rainfall estimates is available. They are used in many important applications such as flood/drought monitoring, water management, or climate monitoring. Such data are especially valuable in sub-Saharan Africa, where rainfall has considerable socioeconomic impacts and the gauge and radar networks are sparse. The choice of a rainfall product can significantly influence the performance of such applications. This study reviews previous works, evaluating or comparing rainfall products over different parts of sub-Saharan Africa. Three types of rainfall products are considered: the gauge-only, the satellite-based, and the reanalysis ones. In addition to the global rainfall products, we included three regional ones specifically developed for Africa: the African Rainfall Climatology version 2 (ARC2), the Rainfall Estimate version 2 (RFE2), and the Tropical Applications of Meteorology Using Satellite Data and Ground-Based Observations (TAMSAT) African Rainfall Climatology and Time Series (TARCAT). The gauge density, the orography, and the rainfall regime, which vary with the climate and the season, influence the performance of the rainfall products. This review does not focus on comparing results, as many other publications doing so are already available. Instead, we propose this review as a guide through the different rainfall products available over Africa, and the factors influencing their performances. With this review, the reader can make informed decisions about which products serve their specific purpose best.
4 Sharma, C.; Shukla, A. K.; Zhang, Y. 2021. Climate change detection and attribution in the Ganga-Brahmaputra-Meghna river basins. Geoscience Frontiers, 12(5):101186. (Online first) [doi: https://doi.org/10.1016/j.gsf.2021.101186]
Climate change ; River basins ; Precipitation ; Hydrometeorology ; Anthropogenic factors ; Greenhouse gas emissions ; Temperature ; Monsoons ; Climatology ; Models / India / Nepal / China / Bangladesh / Ganga-Brahmaputra-Meghna River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050394)
https://www.sciencedirect.com/science/article/pii/S1674987121000505/pdfft?md5=0fcfe5e55998eba24917d3de574e2166&pid=1-s2.0-S1674987121000505-main.pdf
https://vlibrary.iwmi.org/pdf/H050394.pdf
https://vlibrary.iwmi.org/pdf/H050394.pdf
(2.59 MB) (2.59 MB)
Ganga-Brahmaputra-Meghna (GBM) river basin is the third-largest and one of the most populated river basins in the world. As climate change is affecting most of the hydrometeorological variables across the globe, this study investigated the existence of climate change signal in all four climatological seasons in the GBM river basin and assessed the contribution of anthropogenic activities, i.e., Greenhouse Gases (GHGs) emission in the change. Significant decreasing trends in the monsoon and a small increase in pre-monsoon precipitation were observed. Negligible change was detected in post-monsoon and winter season precipitation. CMIP5 GCMs were used for climate change detection, change point estimation, and attribution studies. Support Vector Machine (SVM) regression method was adopted to downscale GCM variables at the local scale. Monte-Carlo simulation approach was used to detect changes in different seasons. The climate change ‘signals’ were detectable after the year 1980 using Signal to Noise ratio (SNR) method in the majority of central and north-western regions. The change point was detectable only in annual monsoon precipitation at the basin level. Attribution analysis indicated >50% contribution of anthropogenic activities (GHGs) to annual monsoon precipitation changes. So, there is high confidence that monsoon precipitation in GBM has significantly changed due to anthropogenic activities. Different mitigation and adaption measures are also suggested, which may be adopted to manage the growing demand and water availability in the basin.
5 Larbi, I.; Hountondji, F. C. C.; Dotse, S.-Q.; Mama, D.; Nyamekye, C.; Adeyeri, O. E.; Koubodana, H. D.; Odoom, P. R. E.; Asare, Y. M. 2021. Local climate change projections and impact on the surface hydrology in the Vea Catchment, West Africa. Hydrology Research, 16p. (Online first) [doi: https://doi.org/10.2166/nh.2021.096]
Climate change ; Forecasting ; Surface runoff ; Hydrology ; Climatology ; Catchment areas ; Water balance ; Water resources ; River basins ; Land use ; Precipitation ; Rain ; Evapotranspiration ; Models ; Uncertainty / West Africa / Ghana / Burkina Faso / White Volta River Basin / Vea Catchment
(Location: IWMI HQ Call no: e-copy only Record No: H050593)
https://iwaponline.com/hr/article-pdf/doi/10.2166/nh.2021.096/931645/nh2021096.pdf
https://vlibrary.iwmi.org/pdf/H050593.pdf
https://vlibrary.iwmi.org/pdf/H050593.pdf
(0.91 MB) (932 KB)
Water security has been a major challenge in the semi-arid area of West Africa including Northern Ghana, where climate change is projected to increase if appropriate measures are not taken. This study assessed rainfall and temperature projections and its impact on the water resources in the Vea catchment using an ensemble mean of four bias-corrected Regional Climate Models and Statistical Downscaling Model-Decision Centric (SDSM-DC) simulations. The ensemble mean of the bias-corrected climate simulations was used as input to an already calibrated and validated Soil and Water Assessment Tool (SWAT) model, to assess the impact of climate change on actual evapotranspiration (ET), surface runoff and water yield, relative to the baseline (1990–2017) period. The results showed that the mean annual temperature and actual ET would increase by 1.3 °C and 8.3%, respectively, for the period 2020–2049 under the medium CO2 emission (RCP4.5) scenario, indicating a trend towards a dryer climate. The surface runoff and water yield are projected to decrease by 42.7 and 38.7%, respectively. The projected decrease in water yield requires better planning and management of the water resources in the catchment.
6 Mekonnen, Kirubel; Velpuri, Naga Manohar; Leh, Mansoor; Akpoti, Komlavi; Owusu, Afua; Tinonetsana, Primrose; Hamouda, T.; Ghansah, B.; Paranamana, Thilina Prabhath; Munzimi, Y. 2023. Accuracy of satellite and reanalysis rainfall estimates over Africa: a multi-scale assessment of eight products for continental applications. Journal of Hydrology: Regional Studies, 49:101514. [doi: https://doi.org/10.1016/j.ejrh.2023.101514]
Rainfall ; Estimation ; Satellites ; Datasets ; Models ; Performance assessment ; Evaluation ; Climatology ; River basins ; Climatic zones ; Rain gauges ; Observation / Africa
(Location: IWMI HQ Call no: e-copy only Record No: H052164)
https://www.sciencedirect.com/science/article/pii/S221458182300201X/pdfft?md5=eeafc6b121eec039f2a2cd37cb0c7e67&pid=1-s2.0-S221458182300201X-main.pdf
https://vlibrary.iwmi.org/pdf/H052164.pdf
https://vlibrary.iwmi.org/pdf/H052164.pdf
(14.00 MB) (14.0 MB)
Study Region: Continental Africa
Study Focus: This study evaluates the accuracy of eight gauge-corrected rainfall products across Africa through direct comparisons with in situ observations for the period 2001–2020. The effect of validation datasets on the performance of the rainfall products was also quantified in ten African countries. Four categorical and five continuous metrics were estimated at multiple spatial and temporal scales as part of the evaluation.
New hydrological insights for the Region: Results indicate that the performance of the rainfall products varied in space and time. Evaluation at temporal scales revealed that, on average, most rainfall products showed poor results (KGE < 0.35) at the daily timescale. In contrast, RFE v2.0, ARC v2.0, and MSWEP v2.8 were reliable (KGE > 0.75) at the monthly and annual timescales. Among the rainfall products, the performance of TAMSATv3.1, PERSIANN-CDR, and ERA 5 was relatively poor in capturing in situ observations. Evaluation at various spatial scales revealed mixed results. The ARC v2.0 and CHIRPS v2.0 rainfall products were reliable in detecting no rains (< 1 mm/day) for all 19 spatial scales, indicating a high level of confidence for drought studies. IMERG-F v6B and RFE v2.0 were reliable in detecting heavy and high-intensity rainfall events for all spatial scales. Using the KGE performance metrics at the regional level, MSWEP v2.8 in the Northern Africa region, RFE v2.0 in the Western and Southern Africa regions, ARC v2.0 in Central Africa, and CHIRPS v2.0 in the Eastern Africa region showed better performances at monthly timescale. Moreover, the performance of the gauge-corrected rainfall datasets was reduced when compared with independent validation data (gauge data not used by rainfall products) than dependent validation data. This study provides several new insights into choosing a rainfall product for continental to regional applications and identifies the need for bias correction.
Study Focus: This study evaluates the accuracy of eight gauge-corrected rainfall products across Africa through direct comparisons with in situ observations for the period 2001–2020. The effect of validation datasets on the performance of the rainfall products was also quantified in ten African countries. Four categorical and five continuous metrics were estimated at multiple spatial and temporal scales as part of the evaluation.
New hydrological insights for the Region: Results indicate that the performance of the rainfall products varied in space and time. Evaluation at temporal scales revealed that, on average, most rainfall products showed poor results (KGE < 0.35) at the daily timescale. In contrast, RFE v2.0, ARC v2.0, and MSWEP v2.8 were reliable (KGE > 0.75) at the monthly and annual timescales. Among the rainfall products, the performance of TAMSATv3.1, PERSIANN-CDR, and ERA 5 was relatively poor in capturing in situ observations. Evaluation at various spatial scales revealed mixed results. The ARC v2.0 and CHIRPS v2.0 rainfall products were reliable in detecting no rains (< 1 mm/day) for all 19 spatial scales, indicating a high level of confidence for drought studies. IMERG-F v6B and RFE v2.0 were reliable in detecting heavy and high-intensity rainfall events for all spatial scales. Using the KGE performance metrics at the regional level, MSWEP v2.8 in the Northern Africa region, RFE v2.0 in the Western and Southern Africa regions, ARC v2.0 in Central Africa, and CHIRPS v2.0 in the Eastern Africa region showed better performances at monthly timescale. Moreover, the performance of the gauge-corrected rainfall datasets was reduced when compared with independent validation data (gauge data not used by rainfall products) than dependent validation data. This study provides several new insights into choosing a rainfall product for continental to regional applications and identifies the need for bias correction.
7 Wang, L.; Gu, X.; Slater, L. J.; Lai, Y.; Zheng, Y.; Gong, J.; Dembele, Moctar; Tosunoglu, F.; Liu, J.; Zhang, X.; Kong, D.; Li, J. 2023. Attribution of the record-breaking extreme precipitation events in July 2021 over central and eastern China to anthropogenic climate change. Earth's Future, 11(9):e2023EF003613. [doi: https://doi.org/10.1029/2023EF003613]
Precipitation ; Anthropogenic climate change ; Extreme weather events ; Climate prediction ; Forecasting ; Climatology ; Climate models ; Time series analysis ; Greenhouse gas emissions / China
(Location: IWMI HQ Call no: e-copy only Record No: H052231)
https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2023EF003613
https://vlibrary.iwmi.org/pdf/H052231.pdf
https://vlibrary.iwmi.org/pdf/H052231.pdf
(13.70 MB) (13.7 MB)
In July 2021, Typhoon In-Fa produced record-breaking extreme precipitation events (hereafter referred to as the 2021 EPEs) in central and eastern China, and caused serious socioeconomic losses and casualties. However, it is still unknown whether the 2021 EPEs can be attributed to anthropogenic climate change (ACC) and how the occurrence probabilities of precipitation events of a similar magnitude might evolve in the future. The 2021 EPEs in central (eastern) China occurred in the context of no linear trend (a significantly increasing trend at a rate of 4.44%/decade) in the region-averaged Rx5day (summer maximum 5-day accumulated precipitation) percentage precipitation anomaly (PPA), indicating that global warming might have no impact on the 2021 EPE in central China but might have impacted the 2021 EPE in eastern China by increasing the long-term trend of EPEs. Using the scaled generalized extreme value distribution, we detected a slightly negative (significantly positive) association of the Rx5day PPA time series in central (eastern) China with the global mean temperature anomaly, suggesting that global warming might have no (a detectable) contribution to the changes in occurrence probability of precipitation extremes like the 2021 EPEs in central (eastern) China. Historical attributions (1961–2020) showed that the likelihood of the 2021 EPE in central/eastern China decreased/increased by approximately +47% (-23% to +89%)/+55% (-45% to +201%) due to ACC. By the end of the 21st century, the likelihood of precipitation extremes similar to the 2021 EPE in central/eastern China under SSP585 is 14 (9–19)/15 (9–20) times higher than under historical climate conditions.
8 Aniley, E.; Gashaw, T.; Abraham, T.; Demessie, S. F.; Bayabil, H. K.; Worqlul, A. W.; van Oel, P. R.; Dile, Y. T.; Chukalla, A. D.; Haileslassie, Amare; Wubaye, G. B. 2023. Evaluating the performances of gridded satellite/reanalysis products in representing the rainfall climatology of Ethiopia. Geocarto International, 38(1):2278329. [doi: https://doi.org/10.1080/10106049.2023.2278329]
Rainfall ; Datasets ; Weather data ; Performance assessment ; Climatology ; Satellite observation ; Agroecological zones ; Precipitation / Ethiopia
(Location: IWMI HQ Call no: e-copy only Record No: H052402)
https://www.tandfonline.com/doi/epdf/10.1080/10106049.2023.2278329?needAccess=true
https://vlibrary.iwmi.org/pdf/H052402.pdf
https://vlibrary.iwmi.org/pdf/H052402.pdf
(3.33 MB) (3.33 MB)
This study evaluated performances of the Climate Hazard Group Infrared Precipitation with stations version 2.0 (CHIRPS v2.0) and Multi-Source Weighted-Ensemble Precipitation version 2.8 (MSWEP v2.8) products against observed data. Rainfall climatology was simulated for different agro-ecological zones (AEZs) of Ethiopia during 1991–2020 at different temporal scales. Performance evaluations were made using continuous and statistical performance measures as well as Probability Density Function (PDF). CHIRPS v2.0 for estimating monthly, seasonal, and annual rainfall totals, and MSWEP v2.8 for daily rainfall have shown better performance over all AEZs. The two products display comparable performance for detecting daily rainfall occurrences over alpine AEZ, but MSWEP v2.8 is superior in the rest four AEZs. CHIRPS v2.0 outperforms MSWEP v2.8 for detecting most of the daily rainfall intensity classes over all AEZs. The findings will play a noteworthy role to improve the quality of hydro-climate studies in Ethiopia.
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