Your search found 9 records
1 Smakhtin, Vladimir U.; Revenga, C.; Doll, P. 2004. Taking into account environmental water requirements in global-scale water resources assessments. Colombo, Sri Lanka: International Water Management Institute (IWMI), Comprehensive Assessment Secretariat. v, 24p. (Comprehensive Assessment of Water Management in Agriculture Research Report 002) [doi: https://doi.org/10.3910/2009.391]
Environmental effects ; Water requirements ; Assessment ; Water availability ; water stress ; Water scarcity ; Hydrology ; Water allocation ; Environmental effects
(Location: IWMI-HQ Call no: IWMI 631.7.5 G000 SMA Record No: H031758)
(1.10 MB)
2 Smakhtin, Vladimir U.; Piyankarage, Sujeewa C.; Stanzel, P.; Boelee, Eline. 2004. Simulating the hydrology of small coastal ecosystems in conditions of limited data. Colombo, Sri Lanka: International Water Management Institute (IWMI). v, 28p. (IWMI Research Report 077) [doi: https://doi.org/10.3910/2009.079]
Hydrology ; Simulation ; Ecosystems ; Lagoons ; Estuaries ; Irrigation effects / Sri Lanka / South Africa / Karagan Lagoon / Bundala Lagoon
(Location: IWMI-HQ Call no: IWMI 631.7.5 G000 SMA Record No: H034783)
(822KB)
The impacts of water resources and irrigation development need to be quantified in order to understand the environmental costs of such development activities. Complex data-intensive simulation methods are normally used for this purpose in the developed world. However, lack of reliable data prohibits the use of such models in developing countries where it is more practical to apply models with less data requirements. The report illustrates three applications of simple and pragmatic simulation models to small coastal water bodies in Sri Lanka and South Africa.
3 Thenkabail, Prasad Srinivas; Gamage, M. S. D. Nilantha; Smakhtin, Vladimir U.. 2004. The use of remote sensing data for drought assessment and monitoring in southwest Asia. Colombo, Sri Lanka: International Water Management Institute (IWMI). v, 25p. (IWMI Research Report 085) [doi: https://doi.org/10.3910/2009.086]
(Location: IWMI-HQ Call no: IWMI 338.14 G570 THE Record No: H035615)
(833KB)
This report describes the development of the near real-time drought monitoring and reporting system for the region, which currently includes Afghanistan, Pakistan and western parts of India. The system is based on drought-related indices derived from high-resolution remote-sensing data (MODIS). The unique feature of the study is the development of regression relationships between drought-related indices obtained from MODIS and AVHRR data, which have different pixel-resolution and optical characteristics. The goal is to make the system available, via Internet, to all stakeholders in the region.
4 Smakhtin, Vladimir U.; Hughes, D. A. 2004. Review, automated estimation and analyses of drought indices in South Asia. Colombo, Sri Lanka: International Water Management Institute (IWMI) v, 24p. (IWMI Working Paper 083: Drought series paper 1) [doi: https://doi.org/10.3910/2009.255]
Drought ; Estimation ; Analysis ; Automation ; Models ; Computer software ; Soil moisture ; Precipitation ; Water supply ; Rain / South Asia
(Location: IWMI-HQ Call no: IWMI 338.14 G570 SMA Record No: H035616)
(1037 KB)
5 Smakhtin, Vladimir U.. 2004. Simulating the hydrology and mouth conditions of small, temporarily closed/open estuaries. Wetlands, 24(1):123-132.
(Location: IWMI-HQ Call no: IWMI 574.5 G 178 SMA Record No: H036242)
(1.00 MB)
Many small estuaries and coastal lagoons in different parts of the world may be classified as temporarily closed/open ecosystems. They are blocked off from the sea for varying lengths of time by a sand bar, which forms at the estuarine mouth. The lengths of the closed and open phases, which are determined primarily by the interaction of river inflow and the sea in the mouth region, affect the structure and functioning of the estuarine biotic community. Freshwater inflow to such estuaries is normally not measured, and observations on the duration of estuarine mouth openings/closures are very scarce. As a result, relevant management decisions are often made on the basis of general experience and intuitive judgment. This paper describes an innovative approach for linking hydrologic data to mouth state in ungauged estuaries. A key characteristic in the method is the stream/river flow duration curve. It is first established for a daily index, which reflects the upstream catchment wetness and is calculated using rainfall information from the nearest rain gauge(s). This duration curve is then used to convert the current precipitation index time series into a continuous daily inflow time series at the ungauged estuarine mouth location. The conversion is based on the assumption that precipitation index values in a small catchment, and daily inflows to the estuarine mouth correspond to similar probabilities on their respective duration curves. The paper further illustrates how the generated inflow data could be used for the simulation of a continuous time series of estuary mouth openings/closures. Inflows are routed through a reservoir model, and the estuary mouth is considered open on days when the spillage from an estuarine “reservoir” occurs. The approach is illustrated using limited observed data on estuary mouth conditions from the South African coastline.
6 Smakhtin, Vladimir U.; Schipper, E. Lisa F. 2008. Droughts: the impact of semantics and perceptions. Water Policy, 10: 131-143.
(Location: IWMI HQ Call no: IWMI 333.714 G000 SMA Record No: H040990)
7 Smakhtin, Vladimir U.; Eriyagama, Nishadi. 2008. Developing a software package for global desktop assessment of environmental flows. Environmental Modelling and Software, 23(12):1396-1406. [doi: https://doi.org/10.1016/j.envsoft.2008.04.002]
River basins ; Ecology ; Ecosystems ; Time series ; Simulation ; Computer software ; Hydrology ; Environmental protection
(Location: IWMI HQ Call no: IWMI 551.483 G000 SMA Record No: H041447)
The paper describes a method and software package for desktop assessment of environmental flows - a hydrological regime designed to maintain a river in some agreed ecological condition. The method uses monthly flow data and is built around a flow duration curve, which ensures that elements of natural flow variability are preserved in the estimated environmental flow time series. The curve is calculated for several categories of aquatic ecosystem protection - from ‘largely natural’ to ‘severely modified’. The corresponding environmental flows progressively reduce with the decreasing level of ecosystem protection. A non-linear data transformation procedure subsequently converts the calculated environmental flow duration curve into a continuous time series of environmental flows. The software has facilities to zoom on a river basin, calculate a variety of hydrological characteristics, define or select any category of ecosystem protection, calculate the associated environmental flow duration curves and time series and display both. The analyses can be carried out either using default (simulated) global flow data, with a spatial resolution of 0.5 degree, or a user- defined file. The package is seen as a training tool for water practitioners, policymakers and students, and as a tool for rapid preliminary environmental flow assessment.
8 Kim, U.; Kaluarachchi, Jagath J.; Smakhtin, Vladimir U.. 2008. Climate change impacts on hydrology and water resources of the Upper Blue Nile River Basin, Ethiopia. Colombo, Sri Lanka: International Water Management Institute (IWMI). 21p. (IWMI Research Report 126) [doi: https://doi.org/10.3910/2009.126]
Climate change ; Hydrology ; River basins ; Runoff ; Precipitation ; Models ; Dams ; Operating policies ; Water power ; Drought ; Analysis / Africa / Ethiopia / Egypt / Sudan / Upper Blue Nile River Basin
(Location: IWMI HQ Call no: IWMI 333.9162 G100 KIM Record No: H041713)
(404 KB)
The report evaluates the impacts of climate change on the hydrological regime and water resources of the Blue Nile River Basin in Ethiopia. It starts from the construction of the climate change scenarios based on the outcomes of several general circulation models (GCMs), uses a simple hydrological model to convert theses scenarios into runoff, and examines the impacts by means of a set of indices. The results, however uncertain with existing accuracy of climate models, suggest that the region is likely to have the future potential to produce hydropower, increase flow duration, and increase water storage capacity without affecting outflows to the riparian countries in the 2050s.
9 Smakhtin, Vladimir U.. 2002. Some early Russian studies of subsurface storm-flow processes. Hydrological Processes, 16(13):2613-2620. [doi: https://doi.org/10.1002/hyp.1016]
(Location: IWMI HQ Call no: e-copy only Record No: H044257)
(0.13 MB)
Subsurface flow is an important component of the catchment hydrological cycle. Various mechanisms of this process and their role in storm-flow generation attracted the attention of many researchers throughout the twentieth century. The results of most of these studies are well documented. However, similar studies conducted in the past by many Russian hydrologists have never been made available to the English speaking hydrological community. This paper attempts to fill this gap and briefly review some of these investigations, focusing on their main results. It starts with the review of the early experimental studies (after 1930s–1950s), which allow the main characteristics of subsurface storm flow to be established. This is followed by a review of the research conducted in 1960s, which resulted in some conceptualization of the subsurface flow mechanisms. The paper also draws some parallels between this, mostly unknown, subsurface flow research in Russia and the better-known contemporary studies of this process.
Powered by DB/Text WebPublisher, from
