GRACE: Gravity Recovery and Climate Experiment long-term trend investigation over the Nile River Basin: Spatial variability drivers

2020 ◽  
Vol 586 ◽  
pp. 124870 ◽  
Author(s):  
Emad Hasan ◽  
Aondover Tarhule
2011 ◽  
Vol 400 (3-4) ◽  
pp. 333-340 ◽  
Author(s):  
Pavla Pekárová ◽  
Pavol Miklánek ◽  
Dana Halmová ◽  
Milan Onderka ◽  
Ján Pekár ◽  
...  

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1695
Author(s):  
Prashant K Srivastava ◽  
Rajani Kumar Pradhan ◽  
George P. Petropoulos ◽  
Varsha Pandey ◽  
Manika Gupta ◽  
...  

Analysis of spatial and temporal changes of long-term precipitation and extreme precipitation distribution at a local scale is very important for the prevention and mitigation of water-related disasters. In the present study, we have analyzed the long-term trend of 116 years (1901–2016) of precipitation and distribution of extreme precipitation index over the Kosi River Basin (KRB), which is one of the frequent flooding rivers of India, using the 0.25° × 0.25° resolution gridded precipitation datasets obtained from the Indian Meteorological Department (IMD), India. The non-parametric Mann–Kendall trend test together with Sen’s slope estimator was employed to determine the trend and the magnitude of the trend of the precipitation time series. The annual and monsoon seasons revealed decreasing trends with Sen’s slope values of −1.88 and −0.408, respectively. For the extreme indices viz. R10 and R20 days, a decreasing trend from the northeastern to the southwest part of the basin can be observed, whereas, in the case of highest one-day precipitation (RX1 day), no clear trend was found. The information provided through this study can be useful for policymakers and may play an important role in flood management, runoff, and understanding related to the hydrological process of the basin. This will contribute to a better understanding of the potential risk of changing rainfall patterns, especially the extreme rainfall events due to climatic variations.


2021 ◽  
Vol 13 (4) ◽  
pp. 651
Author(s):  
Zemede M. Nigatu ◽  
Dongming Fan ◽  
Wei You ◽  
Assefa M. Melesse

Hydroclimatic extremes such as droughts and floods triggered by human-induced climate change are causing severe damage in the Nile River Basin (NRB). These hydroclimatic extremes are not well studied in a holistic approach in NRB. In this study, the Gravity Recovery and Climate Experiment (GRACE) mission and its Follow on mission (GRACE-FO) derived indices and other standardized hydroclimatic indices are computed for developing monitoring and evaluation methods of flood and drought. We evaluated extreme hydroclimatic conditions by using GRACE/GRACE-FO derived indices such as water storage deficits Index (WSDI); and standardized hydroclimatic indices (i.e., Palmer Drought Severity Index (PDSI) and others). This study showed that during 1950–2019, eight major floods and ten droughts events were identified based on standardized-indices and GRACE/GRACE-FO-derived indices. Standardized-indices mostly underestimated the drought and flood severity level compared to GRACE/GRACE-FO derived indices. Among standardized indices PDSI show highest correlation (r2 = 0.72) with WSDI. GRACE-/GRACE-FO-derived indices can capture all major flood and drought events; hence, it may be an ideal substitute for data-scarce hydro-meteorological sites. Therefore, the proposed framework can serve as a useful tool for flood and drought monitoring and a better understanding of extreme hydroclimatic conditions in NRB and other similar climatic regions.


2001 ◽  
Vol 38 (3) ◽  
pp. 674-687 ◽  
Author(s):  
P. Stahl ◽  
J.M. Vandel ◽  
V. Herrenschmidt ◽  
P. Migot

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1400
Author(s):  
Isaac Kwesi Nooni ◽  
Guojie Wang ◽  
Daniel Fiifi T. Hagan ◽  
Jiao Lu ◽  
Waheed Ullah ◽  
...  

Actual evapotranspiration (ET) and its individual components’ contributions to the water–energy nexus provide insights into our hydrological cycle in a changing climate. Based on long-term satellite ET data assimilated by the Global Land Evaporation Amsterdam Model (GLEAM), we analyzed changes in ET and its components over the Nile River Basin from 1980 to 2014. The results show a multi-year mean ET of 518 mm·year–1. The long-term ET trend showed a decline at a rate of 18.8 mm·year–10. ET and its components showed strong seasonality and the ET components’ contribution to total ET varied in space and time. ET and its components decreased in humid regions, which was related to precipitation deficits. ET increases in arid-semiarid regions were due to water availability from crop irrigation fields in the Nile Plain. Precipitation was the dominant limiting driver of ET in the region. Vegetation transpiration (an average of 78.1% of total ET) dominated the basin’s water fluxes, suggesting biological fluxes play a role in the regional water cycle’s response to climate change. This analysis furthers our understanding of the water dynamics in the region and may significantly improve our knowledge of future hydrological modelling.


Author(s):  
Hisham Eldardiry ◽  
Faisal Hossain

AbstractTransboundary river basins are experiencing extensive dam development that challenges future water management, especially for downstream nations. Thus, adapting the operation of existing reservoirs is indispensable to cope with alterations in flow regime. We proposed a Forecast-based Adaptive Reservoir Operation (namely FARO) framework to evaluate the use of long-term climate forecasts in improving real-time reservoir operations. The FARO approach was applied to the High Aswan Dam (HAD) in the Nile river basin. Monthly precipitation and temperature forecasts at up to 12 months of lead time are used from a suite of eight North American Multimodel Ensemble (NMME) models. The value of NMME-based forecasts to reservoir operations was compared with perfect and climatology-based forecasts over an optimization horizon of 10 years from 1993 to 2002. Our results indicated that the forecast horizon for HAD operation ranges between 5- and 12-month lead time at low and high demand scenarios, respectively, beyond which the forecast information no longer improves the release decision. The forecast value to HAD operation is more pronounced in the months following the flooding season (October through December). During these months, the skill of streamflow forecasts using NMME forcings outperforms the climatology-based forecasts. When considering the operation of upstream Grand Ethiopian Renaissance Dam (GERD), using streamflow forecasts minimally helps to maintain current target objectives of HAD operation and therefore result in higher operation costs as opposed to current conditions without GERD. Our study underlined the importance of deriving a new adaptive operating policy for HAD to improve the value of available forecasts while considering GERD filling and operation phases.


Sign in / Sign up

Export Citation Format

Share Document