Your search found 27 records
1 Ward, R. C. 1967. Principles of hydrology. 2nd ed. Boston, UK: McGraw-Hill. 367p.
Hydrological cycle ; Precipitation ; Storms ; Rainfall patterns ; Snow ; Interception ; Vegetation ; Woodlands ; Grasses ; Crops ; Water balance ; Water quality ; Evaporation ; Meteorological factors ; Radiation ; Temperature ; Humidity ; Winds ; Soil moisture ; Evapotranspiration ; Infiltration water ; Groundwater ; Water storage ; Groundwater ; Groundwater recharge ; Flow discharge ; Chemical composition ; Runoff ; Drainage
(Location: IWMI HQ Call no: 551.48 G000 WAR Record No: H045969)
(0.58 MB)
2 Ahmad, Waqas; Fatima, A.; Awan, U. K.; Anwar, Arif. 2014. Analysis of long term meteorological trends in the middle and lower Indus Basin of Pakistan: a non-parametric statistical approach. Global and Planetary Change, 122:282-291. [doi: https://doi.org/10.1016/j.gloplacha.2014.09.007]
Climate change ; Rain ; Air temperature ; River basins ; Meteorological factors ; Parametric programming ; Case studies / Pakistan / Indus Basin
(Location: IWMI HQ Call no: e-copy only Record No: H046663)
(1.09 MB)
The Indus basin of Pakistan is vulnerable to climate change which would directly affect the livelihoods of poor people engaged in irrigated agriculture. The situation could be worse in middle and lower part of this basin which occupies 90% of the irrigated area. The objective of this research is to analyze the long term meteorological trends in the middle and lower parts of Indus basin of Pakistan. We used monthly data from 1971 to 2010 and applied non-parametric seasonal Kendal test for trend detection in combination with seasonal Kendall slope estimator to quantify the magnitude of trends. The meteorological parameters considered were mean maximum and mean minimum air temperature, and rainfall from 12 meteorological stations located in the study region. We examined the reliability and spatial integrity of data by mass-curve analysis and spatial correlation matrices, respectively. Analysis was performed for four seasons (spring—March to May, summer—June to August, fall—September to November and winter—December to February). The results show that max. temperature has an average increasing trend of magnitude +0.16, +0.03, 0.0 and +0.04 °C/decade during all the four seasons, respectively. The average trend of min. temperature during the four seasons also increases with magnitude of +0.29, +0.12, +0.36 and +0.36 °C/decade, respectively. Persistence of the increasing trend is more pronounced in the min. temperature as compared to the max. temperature on annual basis. Analysis of rainfall data has not shown any noteworthy trend during winter, fall and on annual basis. However during spring and summer season, the rainfall trends vary from -1.15 to +0.93 and -3.86 to +2.46 mm/decade, respectively. It is further revealed that rainfall trends during all seasons are statistically non-significant. Overall the study area is under a significant warming trend with no changes in rainfall.
3 Khandu; Forootan, E.; Schumacher, M.; Awange, J. L.; Schmied, H. M. 2016. Exploring the influence of precipitation extremes and human water use on total water storage (TWS) changes in the Ganges-Brahmaputra-Meghna River Basin. Water Resources Research, 52(3):2240-2258. [doi: https://doi.org/10.1002/2015WR018113]
Water storage ; Water use ; Climate change ; Precipitation ; Surface water ; Groundwater extraction ; Rain ; Drought ; Meteorological factors ; Soil moisture ; River basins ; Satellite observation ; Models ; Human behaviour / India / Nepal / Bangladesh / Bhutan / China / Ganges River Basin / Brahmaputra River Basin / Meghna River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H047761)
(8.17 MB)
Climate extremes such as droughts and intense rainfall events are expected to strongly influence global/regional water resources in addition to the growing demands for freshwater. This study examines the impacts of precipitation extremes and human water usage on total water storage (TWS) over the Ganges-Brahmaputra-Meghna (GBM) River Basin in South Asia. Monthly TWS changes derived from the Gravity Recovery And Climate Experiment (GRACE) (2002–2014) and soil moisture from three reanalyses (1979–2014) are used to estimate new extreme indices. These indices are applied in conjunction with standardized precipitation indices (SPI) to explore the impacts of precipitation extremes on TWS in the region. The results indicate that although long-term precipitation do not indicate any significant trends over the two subbasins (Ganges and Brahmaputra-Meghna), there is significant decline in rainfall (9.0 6 4.0 mm/decade) over the Brahmaputra-Meghna River Basin from 1998 to 2014. Both river basins exhibit a rapid decline of TWS from 2002 to 2014 (Ganges: 12.2 6 3.4 km3 /yr and Brahmaputra-Meghna: 9.1 6 2.7 km3 /yr). While the Ganges River Basin has been regaining TWS (5.4 6 2.2 km3 /yr) from 2010 onward, the Brahmaputra Meghna River Basin exhibits a further decline (13.0 6 3.2 km3 /yr) in TWS from 2011 onward. The impact of human water consumption on TWS appears to be considerably higher in Ganges compared to Brahmaputra-Meghna, where it is mainly concentrated over Bangladesh. The interannual water storage dynamics are found to be strongly associated with meteorological forcing data such as precipitation. In particular, extreme drought conditions, such as those of 2006 and 2009, had profound negative impacts on the TWS, where groundwater resources are already being unsustainably exploited.
4 Anarbekov, Oyture; Gaipnazarov, Norboy; Akramov, Isomiddin; Djumaboev, Kakhramon; Gafurov, Zafar; Solieva, Umida; Khodjaev, Shovkat; Eltazarov, Sarvarbek; Tashmatova, Mukhtabar. 2018. Overview of existing river basins in Uzbekistan and the selection of pilot basins. [Project Report of the Sustainable Management of Water Resources in Rural Areas in Uzbekistan. Component 1: National policy framework for water governance and integrated water resources management and supply part] Colombo, Sri Lanka: International Water Management Institute (IWMI) 89p. [doi: https://doi.org/10.5337/2018.203]
Integrated management ; Water resources ; Water management ; Water governance ; Water supply ; Water use ; International waters ; Sustainability ; Rural areas ; Climatic factors ; Meteorological factors ; Hydrometeorology ; Irrigation systems ; Irrigated land ; Land resources ; Land use ; River basin management ; Streams ; Pumps ; Assessment ; Population density ; Population growth ; Soil salinity ; Agricultural production / Uzbekistan
(Location: IWMI HQ Call no: e-copy only Record No: H048491)
(6 MB)
5 Fyffe, C. L.; Brock, B. W.; Kirkbride, M. P.; Black, A. R.; Smiraglia, C.; Diolaiuti, G. 2019. The impact of supraglacial debris on proglacial runoff and water chemistry. Journal of Hydrology, 576:41-57. [doi: https://doi.org/10.1016/j.jhydrol.2019.06.023]
Glaciers ; Snow ; Meltwater ; Discharges ; Runoff ; Sediment ; Hydrology ; Hydrography ; Meteorological factors ; Mountains ; Lakes ; Ponds ; Streams ; Catchment areas / Europe / Miage Glacier
(Location: IWMI HQ Call no: e-copy only Record No: H049320)
https://www.sciencedirect.com/science/article/pii/S0022169419305694/pdfft?md5=a1156d40dae0d41bc6aa3d58ec5cc7d5&pid=1-s2.0-S0022169419305694-main.pdf
https://vlibrary.iwmi.org/pdf/H049320.pdf
https://vlibrary.iwmi.org/pdf/H049320.pdf
(3.63 MB) (3.63 MB)
Debris is known to influence the ablation, topography and hydrological systems of glaciers. This paper determines for the first time how these influences impact on bulk water routing and the proglacial runoff signal, using analyses of supraglacial and proglacial water chemistry and proglacial discharge at Miage Glacier, Italian Alps. Debris does influence the supraglacial water chemistry, but the inefficient subglacial system beneath the debris-covered zone also plays a role in increasing the ion contribution to the proglacial stream. Daily hydrographs had a lower amplitude and later discharge peak compared to clean glaciers and fewer diurnal hydrographs were found compared to similar analysis for Haut Glacier d’Arolla. We attribute these observations to the attenuating effect of the debris on ablation, smaller input streams on the debris-covered area, a less efficient subglacial system, and possible leakage into a raised sediment bed beneath the glacier. Strongly diurnal hydrographs are constrained to periods with warmer than average conditions. ‘Average’ weather conditions result in a hydrograph with reverse asymmetry. Conductivity and discharge commonly show anti-clockwise hysteresis, suggesting the more dilute, rapidly-routed melt component from the mid-glacier peaks before the discharge peak, with components from higher up-glacier and the debris-covered areas arriving later at the proglacial stream. The results of this study could lead to a greater understanding of the hydrological structure of other debris-covered glaciers, with findings highlighting the need to include the influence of the debris cover within future models of debris-covered glacier runoff.
6 Dubey, S. K.; Sharma, D.; Babel, M. S.; Mundetia, N. 2020. Application of hydrological model for assessment of water security using multi-model ensemble of CORDEX-South Asia experiments in a semi-arid river basin of India. Ecological Engineering, 143:105641. [doi: https://doi.org/10.1016/j.ecoleng.2019.105641]
Water security ; Hydrology ; Models ; Semiarid zones ; Water resources ; River basins ; Climate change ; Water availability ; Water yield ; Precipitation ; Evapotranspiration ; Soils ; Meteorological factors / India / Rajasthan / Banas River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049554)
(4.73 MB)
This study analyses the impacts of climate change on water resources in the Banas River Basin, which is located in a semi-arid part of the state of Rajasthan in India. A bias-corrected ensemble mean of three CORDEX-SA driving GCM experiments (CNRM-CM5, CCSM4, and MPI-ESM-LR) was used with the Soil Water Assessment Tool (SWAT) to predict water yield and evapotranspiration for three future periods (2011–2040, 2041–2070, and 2071–2099) under two representative concentration pathway scenarios (RCP4.5 and RCP8.5), and the results were compared with the data of a historical period (1979–2008). The SUFI-2 method was used for the calibration and validation of the SWAT model. The model was calibrated for the period of five years (1982–1986) and validated for the next five years (1987–1991). The values of R2, NSE, bR2, PBIAS, and RSR were, respectively, 0.78, 0.77, 0.61, 47.4 and 0.48 during the calibration period, and 0.71, 0.65, 0.60, 72.1 and 0.59 during the validation period. Trend analysis was also performed for annual future predicted flows using the Sen Slope method. From the results, it can be predicted that precipitation, evapotranspiration, and water yield will increase in all the three future periods under both RCP4.5 and RCP8.5. Water availability in the future in the basin (zone wise) was identified using appropriate indicators. Per-capita water availability and meteorological variation were used to calculate future water availability and, considering these indicators, it can be concluded that zone 3 will better than the other zones. Zone 3 exhibits high values of per capita water availability and meteorological variation. This study will be useful in understanding the impacts of climate change on the water availability of the river basin and may help in overall water management in the present and the future.
7 Wu, P.-Y.; You, G. J.-Y.; Chan, M.-H. 2020. Drought analysis framework based on copula and poisson process with nonstationarity. Journal of Hydrology, 588:125022. (Online first) [doi: https://doi.org/10.1016/j.jhydrol.2020.125022]
Drought ; Water resources ; Water reservoirs ; Watersheds ; Stream flow ; Water supply ; Meteorological factors ; Hydrology ; Precipitation ; Models ; Case studies / Taiwan / Zengwen Reservoir / Shihmen Reservoir
(Location: IWMI HQ Call no: IWMI HQ Record No: H049757)
(2.50 MB)
Droughts have been occurring with increased frequency and bringing with them considerable losses. Due to its nature, the best approach to monitoring and assessing droughts is in terms of stochastic theories. As a consequence, this study applied SPI in the hydrological drought detection, and examine/interpret drought-related phenomena. The 3-month SPI is used to decide the drought development and terminate phases based on the coincidence of hydrological drought and anomalies in precipitation.
Four primary characteristics were determined to clarify the descriptions of drought magnitude and occurrence: duration, deficit, occurrence time and recurrence year. A stochastic process of drought is established to take account these characteristics using the copula function and a Poisson process as well as non-stationarity. Case study on the Shihmen and Zengwen reservoir watersheds in Taiwan revealed that hydrological drought events often coincide with meteorological drought, but some inconsistencies due to unusual hydrological hysteresis in rainfall and runoff. Our analysis raised several issues, including the choice of drought identification parameters and SPI time scale/ threshold, which should take into account anthropogenic activity and hydrological characteristics. A positive correlation between drought duration and drought deficit and a negative correlation between them and occurrence time were identified. It was also observed that subsequent drought event may be more severe due to the partial recovery of hydrological condition. In terms of non-stationarity, our results do not show strong evidence of long-term trend for drought characteristics. Some limitations could be due to the percentile-to-percentile basis of copula. This issue may need to be examined using non-stationary copula analysis or time-variant correlation-covariance models. In the end, we demonstrated that this framework can apply in forecasting drought conditions and generating synthetic droughts for use in the formulation of water resources management strategies and the development of drought preparedness plans.
Four primary characteristics were determined to clarify the descriptions of drought magnitude and occurrence: duration, deficit, occurrence time and recurrence year. A stochastic process of drought is established to take account these characteristics using the copula function and a Poisson process as well as non-stationarity. Case study on the Shihmen and Zengwen reservoir watersheds in Taiwan revealed that hydrological drought events often coincide with meteorological drought, but some inconsistencies due to unusual hydrological hysteresis in rainfall and runoff. Our analysis raised several issues, including the choice of drought identification parameters and SPI time scale/ threshold, which should take into account anthropogenic activity and hydrological characteristics. A positive correlation between drought duration and drought deficit and a negative correlation between them and occurrence time were identified. It was also observed that subsequent drought event may be more severe due to the partial recovery of hydrological condition. In terms of non-stationarity, our results do not show strong evidence of long-term trend for drought characteristics. Some limitations could be due to the percentile-to-percentile basis of copula. This issue may need to be examined using non-stationary copula analysis or time-variant correlation-covariance models. In the end, we demonstrated that this framework can apply in forecasting drought conditions and generating synthetic droughts for use in the formulation of water resources management strategies and the development of drought preparedness plans.
8 Arsenault, K. R.; Shukla, S.; Hazra, A.; Getirana, A.; McNally, A.; Kumar, S. V.; Koster, R. D.; Peters-Lidard, C. D.; Zaitchik, B. F.; Badr, H.; Jung, H. C.; Narapusetty, B.; Navari, M.; Wang, S.; Mocko, D. M.; Funk, C.; Harrison, L.; Husak, G. J.; Adoum, A.; Galu, G.; Magadzire, T.; Roningen, J.; Shaw, M.; Eylander, J.; Bergaoui, K.; McDonnell, Rachael A.; Verdin, J. P. 2020. The NASA hydrological forecast system for food and water security applications. Bulletin of the American Meteorological Society (BAMS), 101(7):E1007-E1025. [doi: https://doi.org/10.1175/BAMS-D-18-0264.1]
Hydrology ; Forecasting ; Early warning systems ; Food security ; Water security ; Drought ; Flooding ; Precipitation ; Groundwater ; Water storage ; Soil water content ; Stream flow ; Monitoring ; Land area ; Meteorological factors ; Satellite observation ; Modelling / Africa / Middle East
(Location: IWMI HQ Call no: e-copy only Record No: H049803)
https://journals.ametsoc.org/bams/article-pdf/101/7/E1007/4981535/bamsd180264.pdf
https://vlibrary.iwmi.org/pdf/H049803.pdf
https://vlibrary.iwmi.org/pdf/H049803.pdf
(8.47 MB) (8.47 MB)
Many regions in Africa and the Middle East are vulnerable to drought and to water and food insecurity, motivating agency efforts such as the U.S. Agency for International Development’s (USAID) Famine Early Warning Systems Network (FEWS NET) to provide early warning of drought events in the region. Each year these warnings guide life-saving assistance that reaches millions of people. A new NASA multimodel, remote sensing–based hydrological forecasting and analysis system, NHyFAS, has been developed to support such efforts by improving the FEWS NET’s current early warning capabilities. NHyFAS derives its skill from two sources: (i) accurate initial conditions, as produced by an offline land modeling system through the application and/or assimilation of various satellite data (precipitation, soil moisture, and terrestrial water storage), and (ii) meteorological forcing data during the forecast period as produced by a state-of-the-art ocean–land–atmosphere forecast system. The land modeling framework used is the Land Information System (LIS), which employs a suite of land surface models, allowing multimodel ensembles and multiple data assimilation strategies to better estimate land surface conditions. An evaluation of NHyFAS shows that its 1–5-month hindcasts successfully capture known historic drought events, and it has improved skill over benchmark-type hindcasts. The system also benefits from strong collaboration with end-user partners in Africa and the Middle East, who provide insights on strategies to formulate and communicate early warning indicators to water and food security communities. The additional lead time provided by this system will increase the speed, accuracy, and efficacy of humanitarian disaster relief, helping to save lives and livelihoods.
9 Donmez, C.; Berberoglu, S.; Cilek, A.; Krause, P. 2020. Basin-wide hydrological system assessment under climate change scenarios through conceptual modelling. International Journal of Digital Earth, 13(8):915-938. [doi: https://doi.org/10.1080/17538947.2019.1597188]
Hydrology ; Assessment ; River basins ; Climate change ; Modelling ; Water resources ; Precipitation ; Rain ; Temperature ; Meteorological factors ; Forecasting ; Watersheds ; Runoff ; Evapotranspiration ; Case studies / Turkey / Goksu Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049880)
(5.68 MB)
Mediterranean region is identified as a primary hot-spot for climate change due to the expected temperature and rainfall changes. Understanding the potential impacts of climate change on the hydrology in these regions is an important task to develop long-term water management strategies. The aim of this study was to quantify the potential impacts of the climate changes on local hydrological quantities at the Goksu Watershed at the Eastern Mediterranean, Turkey as a case study. A set of Representative Concentration Pathways (RCP) scenarios were used as drivers for the conceptual hydrological model J2000 to investigate how the hydrological system and the underlying processes would respond to projected future climate conditions. The model was implemented to simulate daily hydrological quantities including runoff generation, Actual Evapotranspiration (AET) and soil-water balance for present (2005–2015) and future (up to 2100). The results indicated an increase of both precipitation and runoff throughout the region from January to March. The region showed a strong seasonally dependent runoff regime with higher flows during winter and spring and lower flows in summer and fall. The study provides a comparative methodology to include meteorological-hydrological modelling integration that can be feasible to assess the climate change impacts in mountainous regions.
10 Brouziyne, Y.; Abouabdillah, A.; Chehbouni, A.; Hanich, L.; Bergaoui, Karim; McDonnell, Rachael; Benaabidate, L. 2020. Assessing hydrological vulnerability to future droughts in a Mediterranean watershed: combined indices-based and distributed modeling approaches. Water, 12(9):2333. (Special issue: Modeling Global Change Impacts on Water Resources: Selected Papers from the 2019/2020 SWAT International Conferences) [doi: https://doi.org/10.3390/w12092333]
Climate change ; Drought ; Vulnerability ; Hydrological factors ; Weather forecasting ; Modelling ; Water resources ; Watersheds ; Water yield ; Meteorological factors ; Risk management ; Precipitation ; Rain ; Temperature ; Land use ; Runoff ; Evapotranspiration / Mediterranean Region / Morocco / Bouregreg Watershed
(Location: IWMI HQ Call no: e-copy only Record No: H049879)
(6.58 MB) (6.58 MB)
Understanding the spatiotemporal distribution of future droughts is essential for effective water resource management, especially in the Mediterranean region where water resources are expected to be scarcer in the future. In this study, we combined meteorological and hydrological drought indices with the Soil and Water Assessment Tool (SWAT) model to predict future dry years during two periods (2035–2050and 2085–2100) in a typical Mediterranean watershed in Northern Morocco, namely, Bouregreg watershed. The developed methodology was then used to evaluate drought impact on annual water yields and to identify the most vulnerable sub-basins within the study watershed. Two emission scenarios (RCP4.5 and RCP8.5) of a downscaled global circulation model were used to force the calibrated SWAT model. Results indicated that Bouregreg watershed will experience several dry years with higher frequency especially at the end of current century. Significant decreases of annual water yields were simulated during dry years, ranging from -45.6% to -76.7% under RCP4.5, and from -66.7% to -95.6% under RCP8.5, compared to baseline. Overall, hydrologic systems in sub-basins under the ocean or high-altitude influence appear to be more resilient to drought. The combination of drought indices and the semi-distributed model offer a comprehensive tool to understand potential future droughts in Bouregreg watershed.
11 Zhu, X.; Jin, X.; Zhang, X.; Zhang, J. 2020. Regional analysis of evapotranspiration changes in an arid river basin using satellite observations. Arid Land Research and Management, 26p. (Online first) [doi: https://doi.org/10.1080/15324982.2020.1853279]
River basins ; Evapotranspiration ; Trends ; Satellite observation ; Arid zones ; Water use ; Groundwater ; Climate change ; Soil moisture ; Land cover change ; Energy balance ; Human activity ; Meteorological factors ; Precipitation ; Rain ; Vegetation ; Farmland ; Remote sensing / China / Golmud River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050140)
(3.70 MB)
This study employed the Surface Energy Balance System (SEBS) algorithm to determine the actual evapotranspiration (ET) trends of the piedmont plain region of the Golmud River Basin between 2001 and 2016 and the effects of climate change and human activities on ET. The results indicate that the regional ET increased in the study area from 2001 to 2016. However, ET trends exhibited no change in most parts (68.58%) of the study area over the 16 years, but increased significantly in saline ponds and areas with vegetation cover, whereas no significant trends were observed in saline marshes or the piedmont Gobi gravel plain. The ET trend was closely related to the land-cover changes caused by human activities in the Golmud River Basin. During the study period, saline pond areas expanded from 50.57 to 257.85 km2 due to potash fertilizer production, and the area of farmland increased from 28.71 to 62.91 km2 and these changes contributed greatly to ET changes. Also, groundwater exploitation for potash fertilizer production and irrigation were correlated with ET.
12 Maru, H.; Haileslassie, Amare; Zeleke, T.; Esayas, B. 2022. Agroecology-based analysis of meteorological drought and mapping its hotspot areas in Awash Basin, Ethiopia. Modeling Earth Systems and Environment, 8(1):339-360. [doi: https://doi.org/10.1007/s40808-021-01101-y]
Drought ; Mapping ; Agroecological zones ; Meteorological factors ; Precipitation ; Evapotranspiration ; Rain ; Temperature ; Risk management ; Disaster preparedness ; Adaptation ; Arid zones ; Highlands ; Lowland / Ethiopia / Awash Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050179)
(11.30 MB)
Drought-related risk is among the major global challenges of our time. It negatively impacts food security and ecosystem health. It is becoming a persistent problem in many parts of sub-Saharan Africa and specifically in Ethiopia. Information on its intensity and spatiotemporal distribution is critical to contextualize interventions and build agroecosystem and community resilience. This study aims at analyzing spatiotemporal characteristics of meteorological drought over eight Agroecological Zones (AEZs) of the Awash Basin, Ethiopia. Annual gridded temperature and precipitation dataset obtained from the National Meteorological Agency of Ethiopia for the period 1983–2016, covering 1655 grid points, were used. The study applied the Standard Precipitation and Evapotranspiration Index (SPEI) and Standard Precipitation Index (SPI) methods to characterize the meteorological droughts. The study applied Arc GIS 10.5 to map the drought hotspots. From the result, the value of SPEI and SPI methods was divergent in characterizing the magnitude and spatial occurrence of drought episodes. SPEI has more advantages in detecting dry months and a small advantage in detecting dry seasons compared to the SPI. Temporally, wet and dry years dominated the 1990s and 2010s, respectively. Drought dominated 1980s and normal years dominated the 2000s. The spatial context of drought hotspot showed that AEZs in the upper and lower parts of the Awash Basin were hit by severe to extreme drought while the escarpments and middle parts of the basin experienced mild to moderate drought. This contrasts with the common perception that the hot to warm arid lowlands AEZs are the only hotspot areas to drought. Moreover, previously none frequent drought AEZs, such as tepid to cool humid mid-highlands were identified as drought hotspots in the basin. This information could help policymakers to target AEZs and implement context-specific and informed drought risk management decisions and adaptation measures.
13 Zhou, Y.; Zaitchik, B. F.; Kumar, S. V.; Arsenault, K. R.; Matin, M. A.; Qamer, F. M.; Zamora, R. A.; Shakya, K. 2021. Developing a hydrological monitoring and sub-seasonal to seasonal forecasting system for South and Southeast Asian river basins. Hydrology and Earth System Sciences, 25(1):41-61. [doi: https://doi.org/10.5194/hess-25-41-2021]
Hydrology ; Monitoring ; Forecasting ; River basins ; Precipitation ; Drought ; Indicators ; Soil moisture ; Estimation ; Meteorological factors ; Satellite observation ; Models / South Asia / Southeast Asia / Helmand Basin / Indus Basin / Ganges Basin / Brahmaputra Basin / Mekong Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050187)
https://hess.copernicus.org/articles/25/41/2021/hess-25-41-2021.pdf
https://vlibrary.iwmi.org/pdf/H050187.pdf
https://vlibrary.iwmi.org/pdf/H050187.pdf
(4.23 MB) (4.23 MB)
South and Southeast Asia is subject to significant hydrometeorological extremes, including drought. Under rising temperatures, growing populations, and an apparent weakening of the South Asian monsoon in recent decades, concerns regarding drought and its potential impacts on water and food security are on the rise. Reliable sub-seasonal to seasonal (S2S) hydrological forecasts could, in principle, help governments and international organizations to better assess risk and act in the face of an oncoming drought. Here, we leverage recent improvements in S2S meteorological forecasts and the growing power of Earth observations to provide more accurate monitoring of hydrological states for forecast initialization. Information from both sources is merged in a South and Southeast Asia sub-seasonal to seasonal hydrological forecasting system (SAHFS-S2S), developed collaboratively with the NASA SERVIR program and end users across the region. This system applies the Noah-Multiparameterization (NoahMP) Land Surface Model (LSM) in the NASA Land Information System (LIS), driven by downscaled meteorological fields from the Global Data Assimilation System (GDAS) and Climate Hazards InfraRed Precipitation products (CHIRP and CHIRPS) to optimize initial conditions. The NASA Goddard Earth Observing System Model sub-seasonal to seasonal (GEOS-S2S) forecasts, downscaled using the National Center for Atmospheric Research (NCAR) General Analog Regression Downscaling (GARD) tool and quantile mapping, are then applied to drive 5 km resolution hydrological forecasts to a 9-month forecast time horizon. Results show that the skillful predictions of root zone soil moisture can be made 1 to 2 months in advance for forecasts initialized in rainy seasons and up to 8 months when initialized in dry seasons. The memory of accurate initial conditions can positively contribute to forecast skills throughout the entire 9-month prediction period in areas with limited precipitation. This SAHFS-S2S has been operationalized at the International Centre for Integrated Mountain Development (ICIMOD) to support drought monitoring and warning needs in the region.
14 Mishra, V.; Aadhar, S.; Mahto, S. S. 2021. Anthropogenic warming and intraseasonal summer monsoon variability amplify the risk of future flash droughts in India. npj Climate and Atmospheric Science, 4:1. [doi: https://doi.org/10.1038/s41612-020-00158-3]
Drought ; Risk ; Anthropogenic factors ; Monsoon climate ; Climate change ; Precipitation ; Rain ; Soil moisture ; Air temperature ; Greenhouse gas emissions ; Aerosols ; Land use change ; Land cover change ; Meteorological factors ; Forecasting ; Models / India
(Location: IWMI HQ Call no: e-copy only Record No: H050274)
(2.36 MB) (2.36 MB)
Flash droughts cause rapid depletion in root-zone soil moisture and severely affect crop health and irrigation water demands. However, their occurrence and impacts in the current and future climate in India remain unknown. Here we use observations and model simulations from the large ensemble of Community Earth System Model to quantify the risk of flash droughts in India. Root-zone soil moisture simulations conducted using Variable Infiltration Capacity model show that flash droughts predominantly occur during the summer monsoon season (June–September) and driven by the intraseasonal variability of monsoon rainfall. Positive temperature anomalies during the monsoon break rapidly deplete soil moisture, which is further exacerbated by the land-atmospheric feedback. The worst flash drought in the observed (1951–2016) climate occurred in 1979, affecting more than 40% of the country. The frequency of concurrent hot and dry extremes is projected to rise by about five-fold, causing approximately seven-fold increase in flash droughts like 1979 by the end of the 21st century. The increased risk of flash droughts in the future is attributed to intraseasonal variability of the summer monsoon rainfall and anthropogenic warming, which can have deleterious implications for crop production, irrigation demands, and groundwater abstraction in India.
15 Qi, P.; Xia, Z.; Zhang,G.; Zhang, W.; Chang, Z. 2021. Effects of climate change on agricultural water resource carrying capacity in a high-latitude basin. Journal of Hydrology, 597:126328. (Online first) [doi: https://doi.org/10.1016/j.jhydrol.2021.126328]
Agriculture ; Water resources ; Carrying capacity ; Climate change ; Climatic factors ; Precipitation ; Temperature ; Drought ; Meteorological factors ; Evapotranspiration ; Crop production ; Wheat ; Soybeans ; Rice ; Maize ; Food safety ; River basins / China / Nenjiang River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050363)
(15.50 MB)
The agricultural water resource carrying capacity (AWRCC) is affected by climate change now as never before. However, it is still unclear how the AWRCC in high latitudes responses to climate change. In this study, spatiotemporal changes in climatic factors and AWRCC during the crop growing season from 1961 to 2014 in the Nenjiang River Basin (NRB), a high-latitude basin in China, were identified via multivariate statistical analysis. Meanwhile, the impact of climatic factors on AWRCC was analyzed by using cross-wavelet approaches and Pearson correlational analysis. The results showed that temperature has followed an increasing trend, especially the lowest temperature during crop growing season, with a trend of 0.57 /10a in the local region. There was no obvious change trend for precipitation, but the interannual change was large. The drought index increased first and then decreased, which was consistent with the trend of the ET0. Different spatial distributions of water resource carrying for all crops in a region were shown with a variation range of 0.22–0.76 kg/m2 in the NRB. It is worth noting that AWRCC showed an increasing trend, especially in the past decade. Precipitation, ET0, and meteorological drought were all key driving factors affecting AWRCC. The correlation was significant between the crop planting proportion and AWRCC under climate change. Moreover, adjusting the planting proportion of wheat, soybean and rice, and increasing that of maize, would be conducive to improving the AWRCC and facilitating the synergistic development of agriculture and wetlands in NRB.
16 Shi, W.; Huang, S.; Liu, D.; Huang, Q.; Han, Z.; Leng, G.; Wang, H.; Liang, H.; Li, P.; Wei, X. 2021. Drought-flood abrupt alternation dynamics and their potential driving forces in a changing environment. Journal of Hydrology, 597:126179. [doi: https://doi.org/10.1016/j.jhydrol.2021.126179]
Drought ; Flooding ; Climate change ; Precipitation ; Meteorological factors ; Water vapour ; River basins ; Spatial distribution ; Time series analysis / China / Wei River Basin / Jing River Basin / Beiluo River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050405)
(8.36 MB)
Compared with a single drought or flood, drought-flood abrupt alternation (DFAA) may have more adverse impact on water resources management, crop production, and food security. However, existing studies have paid seldom attention on the evolution characteristics of DFAA in northern China, and their driving factors have not yet been fully revealed. To this end, DFAA events such as drought to flood (DTF) and flood to drought (FTD) are examined from 1960 to 2010 in the Wei River basin (WRB) located in northern China, which is the largest tributary of the Yellow River Basin. Firstly, the long-cycle drought-flood abrupt transition index (LDFAI) is defined to identify DFAA events during the flood season of WRB. Secondly, the spatiotemporal evolution characteristics and future trend variability of DFAA events are explored based on LDFAI. Finally, the driving factors of DFAA events are comprehensively evaluated using qualitative and quantitative combination framework. Results indicate that (1) the frequency of DTF events in the WRB presents a “less-more-less” variation pattern from southwest to northeast and shows a significant spatial difference. However, the FDT events are vice versa; (2) the flood season is dominated by FTD events in the WRB, and the upstream of the WRB and Jing River basin (JRB) are dominated by the DTF events before mutation point; (3) the four sub-regions of the WRB show oscillation changes of “DTF-FDT” with 35-year period, and are prone to DTF events after 2010 years; and (4) average water vapor pressure is the dominant factor of DFAA events in the WRB compared with other meteorological factors, whereas Arctic Oscillation among multiple teleconnection factors exerts strong impacts on DFAA dynamics. The findings may be significant to the early warning and prevention of flood and drought disasters in the WRB under the challenge of future climate change.
17 Han, Z.; Huang, S.; Huang, Q.; Leng, G.; Liu. Y.; Bai, Q.; He, P.; Liang, H.; Shi, W. 2021. GRACE-based high-resolution propagation threshold from meteorological to groundwater drought. Agricultural and Forest Meteorology, 307:108476. (Online first) [doi: https://doi.org/10.1016/j.agrformet.2021.108476]
Groundwater ; Drought ; Meteorological factors ; River basins ; Water storage ; Precipitation ; Vegetation ; Soil moisture ; Satellites ; Observation ; Models / China / Xijiang River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050424)
(11.50 MB)
Groundwater drought could cause tremendous damage to the social-economy via land subsidence, seawater intrusion and permanent loss of aquifer storage capacity, and often show strong association with meteorological drought. To date, the threshold for meteorological drought triggering groundwater drought and its dominant factors have been not clarified, which inhibits the effective groundwater drought risk management based on preceding meteorological drought information. In this study, we used the Standardized precipitation index (SPI) and the drought severity index of groundwater storage anomalies (GWSA-DSI) to characterize meteorological and groundwater droughts in the Xijiang River Basin (XRB) of China, respectively. A probabilistic framework is proposed to identify the high-resolution propagation thresholds from meteorological to groundwater drought on 0.25° grid. Results show that GWSA-DSI can reliably identify groundwater drought events, and the propagation time from meteorological to groundwater drought ranges from 8 to 42 months. Although the XRB is located in a humid region with abundant precipitation, the probability of groundwater drought occurrence reached 43.8%, 54.8%, 61.2%, and 64.2% under a light, moderate, severe and extreme meteorological drought event, respectively. The propagation threshold triggering light groundwater drought is mainly dominated by moderate and severe meteorological droughts, which showed an increasing trend from central to southeast of XRB. Soil evaporation and watershed elevation are the main influencing factors on the propagation threshold. It is worth noting that anthropogenic overexploitation of groundwater not only destroy the dynamic balance of regional groundwater system, but also interfere with the propagation processes of meteorological to groundwater drought. The results have great implications for more reliably monitoring and predicting the dynamics of groundwater systems under drought stress, and our proposed framework can also be extended to other regions.
18 Pandey, B. K.; Khare, D.; Kawasaki, A.; Meshesha, T. W. 2021. Integrated approach to simulate hydrological responses to land use dynamics and climate change scenarios employing scoring method in Upper Narmada Basin, India. Journal of Hydrology, 598:126429. [doi: https://doi.org/10.1016/j.jhydrol.2021.126429]
Climate change ; Land use change ; Land cover ; Hydrological modelling ; River basins ; Water availability ; Water balance ; Evapotranspiration ; Precipitation ; Temperature ; Meteorological factors ; Forecasting ; Discharges ; Vegetation ; Uncertainty / India / Narmada Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050469)
(11.20 MB)
Accurate spatial and temporal measurement of water budget play a crucial role in achieving the sustainable planning and management of water resources. This paper presents a comprehensive integrated approach to simulate hydrological responses under dynamics of land use land cover (LULC) and climate change scenarios over Upper Narmada Basin, India. In order to select the representative climate models, scoring method was applied at regional scale. Best five performing climate models (MIROC5, CNRM-CM5, MPI-ESM-LR, GFDL-ESM2G and IPSL-CM5A-MR) were coupled with semi-distributed hydrological model to simulate the hydrological responses. Considering the heterogeneity of the large basin, multi-site calibration and parameters sensitivity analysis were performed using Sequential Uncertainty Fitting (SUFI-2) algorithm. To compute the hydrological sensitivity against land use change, calibrated model was coupled with historical and futuristic land use scenarios (1990, 2000, 2010 and 2030). The results indicate intensified precipitation towards the late 21st century, whereas annual mean temperature could be raised by 1.79 °C and 3.57 °C under mid and high emission scenarios respectively, at the end of century. Annual and monsoon flow in the basin likely to increase during the 2050 s (2041–2070) and 2080 s (2071–2100). Moreover, the relation between climate variables and water budget components were identified to analyse the hydrological sensitivity of the basin under changing climate.
19 Poonia, V.; Goyal, M. K.; Gupta, B. B.; Gupta, A. K.; Jha, S.; Das, J. 2021. Drought occurrence in different river basins of India and blockchain technology based framework for disaster management. Journal of Cleaner Production, 312:127737. (Online first) [doi: https://doi.org/10.1016/j.jclepro.2021.127737]
Drought ; River basins ; Blockchain technology ; Disaster risk management ; Climate change ; Meteorological factors ; Hydrological factors ; Precipitation ; Rain ; Soil moisture ; Vegetation / India
(Location: IWMI HQ Call no: e-copy only Record No: H050475)
(7.94 MB)
Drought assessment is crucial to mitigate its adverse impact, especially in India, where risk is more due to an increase in population and climate change. However, most of the studies deal with one or a couple of droughts and lack the interrelationship between all major drought types. The study investigates the spatio-temporal distribution of multiple drought types, individually and concurrently in India. Further drought trend analysis is performed based on their mean duration, mean spatial extent, and frequency. Moreover, the drought evolution process which explains the evolution of drought type into another type is also examined. Finally, a blockchain-based framework is proposed to improve the current drought risk management system to facilitate the drought fatalities to get their help and aid as soon as possible. Results demonstrate that hydrological and soil moisture droughts are observed to be more influential as compared to the other two drought types in most of the river basins of India. Further, it was found that 82% of concurrent droughts involve soil moisture drought in 16 out of 25 river basins. The present study facilitates a novel method to investigate drought from several perspectives over India, thus helps to provide important information for drought mitigation and adaptation strategies.
20 Kimwatu, D. M.; Mundia, C. N.; Makokha, G. O. 2021. Monitoring environmental water stress in the Upper Ewaso Ngiro River Basin, Kenya. Journal of Arid Environments, 191:104533. [doi: https://doi.org/10.1016/j.jaridenv.2021.104533]
Water stress ; Environmental factors ; Drought ; Monitoring ; River basins ; Ecosystems ; Meteorological factors ; Land use ; Land cover ; Evapotranspiration ; Precipitation ; Vegetation ; Infiltration ; Stochastic processes ; Socioeconomic aspects / Kenya / Upper Ewaso Ngiro River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H050476)
(14.90 MB)
This study provides a new methodology for simulating environmental water stress index (EWSI) that addresses environmental droughts' stochastic nature at regional and local scales. The current research used a case study of the Upper Ewaso Ngiro river basin in Kenya that possesses regional disparities attributed to climatic, biophysical, and anthropogenic variables. A stochastic modelling approach that ensembled 4D Euclidean feature space algorithm, least-squares adjustment, and iterations integrated the four environmental droughts indicators (meteorological, agricultural, socio-economic, and hydrological) into a single multivariate index called EWSI. The correlation between the simulated EWSI and initial reconnaissance drought index ) produced a correlation coefficient (r) of -0.93 and a p-value < 0.02. The correlation between EWSI and river discharge had a correlation coefficient of -0.89 and a p-value < 0.02. The assessment of severity revealed that 67–100% of the basin exhibited moderate to extreme environmental water stresses conditions between 1986 and 2018.
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