Your search found 10 records
1 Finch, J. W.; Gash, J. H. C. 2002. Application of a simple finite difference model for estimating evaporation from open water. Journal of Hydrology, 255:253-259.
(Location: IWMI HQ Call no: P 7820 Record No: H039910)
(Location: IWMI HQ Call no: P 7836 Record No: H039938)
3 Helmuth, B.; Hofmann, G. E. 2001. Microhabitats, thermal heterogeneity, and patterns of physiological stress in the rocky intertidal zone. Biological Bulletin, 201:374-384.
(Location: IWMI HQ Call no: P 7837 Record No: H039939)
(Location: IWMI HQ Call no: P 7943 Record No: H040310)
(0.30 MB)
5 McCartney, Matthew; Sally, Hilmy. 2007. Managing the environmental impact of dams. In Ranade, P. S. (Ed.). Rivers, dams and development: Issues and Dilemmas. Punjagutta, Hyderabad, India: Icfai University Press. pp.88-104.
(Location: IWMI HQ Call no: IWMI 627.8 G000 MCC Record No: H040455)
6 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)
(Location: IWMI HQ Call no: 577.22 G000 WAG Record No: H046622)
(0.44 MB)
(Location: IWMI HQ Call no: 621.3678 G000 CAR Record No: H046804)
(0.76 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H048083)
(4.00 MB) (4.00 MB)
Recent droughts and heatwaves showed the vulnerability of the electricity sector to surface water constraints with reduced potentials for thermoelectric power and hydropower generation in different regions. Here we use a global hydrological-electricity modelling framework to quantify the impacts of recent drought and warm years on hydropower and thermoelectric power usable capacity worldwide. Our coupled modelling framework consists of a hydrological model, stream temperature model, hydropower and thermoelectric power models, and was applied with data of a large selection of hydropower and thermoelectric power plants worldwide. Our results show that hydropower utilisation rates were on average reduced by 5.2% and thermoelectric power by 3.8% during the drought years compared to the long-term average for 1981–2010. Statistically significant (p < 0.01) impacts on both hydropower and thermoelectric power usable capacity were found during major drought years, e.g. 2003 in Europe (-6.6% in hydropower and -4.7% in thermoelectric power) and 2007 in Eastern North America (-6.1% in hydropower and -9.0% in thermoelectric power). Our hydrological-electricity modelling framework has potential for studying the linkages between water and electricity supply under climate variability and change, contributing to the quantification of the 'water-energy nexus'.
(Location: IWMI HQ Call no: e-copy only Record No: H049295)
(2.02 MB)
Uncertainty in capturing the effects of riparian tree shade for assessment of algal growth rates and water temperature hinders the predictive capability of models applied for river basin management. Using photogrammetry-derived tree canopy data, we quantified hourly shade along the River Thames (UK) and used it to estimate the reduction in the amount of direct radiation reaching the water surface. In addition we tested the suitability of freely-available LIDAR data to map ground elevation. Following removal of buildings and objects other than trees from the LIDAR dataset, results revealed considerable differences between photogrammetry- and LIDAR-derived methods in variables including mean canopy height (10.5 m and 4.0 m respectively), percentage occupancy of riparian zones by trees (45% and 16% respectively) and mid-summer fractional penetration of direct radiation (65% and 76% respectively). The generated data on daily direct radiation for 2010 were used as input to a river network water quality model (QUESTOR). Impacts of tree shading were assessed in terms of upper quartile levels, revealing substantial differences in indicators such as biochemical oxygen demand (BOD) (1.58–2.19 mg L-1 respectively) and water temperature (20.1 and 21.2 °C respectively) between ‘shaded’ and ‘non-shaded’ radiation inputs. Whilst the differences in canopy height and extent derived by the two methods are appreciable they only make small differences to water quality in the Thames. However such differences may prove more critical in smaller rivers. We highlight the importance of accurate estimation of shading in water quality modelling and recommend use of high resolution remotely sensed spatial data to characterise riparian canopies. Our paper illustrates how it is now possible to make better reach scale estimates of shade and make aggregations of these for use at river basin scale. This will allow provision of more effective guidance for riparian management programmes than currently possible. This is important to support adaptation to future warming and maintenance of water quality standards
(Location: IWMI HQ Call no: e-copy only Record No: H051845)
(10.90 MB)
Evaporation from water bodies (Ew) is a critical component of the global water cycle. However, existing evaporation products that include Ew often suffer from drawbacks such as coarse resolution, short time span, and high uncertainty. This study developed a 60-year (1960–2019) high-resolution (0.05º×0.05º) evaporation dataset for small shallow water bodies in China based on the Penman model. Two key factors affecting the accuracy of the Penman model were considered: the uncertainty of the empirical wind function and changes in heat storage in the water body. Specifically, we used large-size (20 or 100 m2) pan evaporation (Epan) observations from 21 sites as a benchmark to correct the wind function of the Penman model. A data-driven model was then developed to map the spatial distribution of the wind function coefficients across China. The corrected wind function significantly improved the accuracy of Epan estimates compared to the original wind function, with the Kling-Gupta efficiency (KGE) increased by 0.05~0.10. To model the effect of heat storage changes on evaporation, an equilibrium temperature method was used. We also introduced an area-dependent scaling factor into the wind function to account for the effect of water body's size on Ew estimation. The reliability of the Ew algorithm was tested on two lakes using eddy-covariance flux observations, and simulations showed good agreement with observations. The Epan (20 m2 pan) dataset and its two components calculated from the radiative and aerodynamic terms of the Penman model can be accessed at https://osf.io/qd28m/. Users can utilize the two Epan components and the area-dependent scaling factor to estimate evaporation for water bodies of varying sizes. However, caution is needed when applying this dataset to deep water bodies, as it is designed for shallow water bodies.
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