Your search found 8 records
1 Masih, Ilyas; Uhlenbrook, S.; Ahmad, M. D.; Maskey, S. 2008. Regionalization of a conceptual rainfall runoff model based on similarity of the flow duration curve: a case study from Karkheh River Basin, Iran. [Abstract only]. Geophysical Research Abstracts, 10. 2p.
(Location: IWMI HQ Call no: e-copy only Record No: H041238)
Streamflow data is a prerequisite for planning and management of water resources. However, in many cases, observed streamflow data are not available or the records are too short or of insufficient quality. This undermines the informed planning and management of water resources at a specific site and as well as at the river basin scale. The study examines the possibility of simulating time series of streamflows for ungauged catchments based on hydrological similarity, using the mountainous, semiarid Karkheh river basin (55,000 km2, Iran) as an example. The main research question examined in this paper is whether or not the parameters of a hydrological model applied to gauged catchments can be successfully transferred for simulating streamflows in hydrologically similar ungauged catchments. In this study, the HBV model is applied to simulate daily streamflow with parameters transferred from gauged basin counterparts. Different similarity measures were reviewed and finally the approach based on the shape of the flow duration curve (FDC) was used. FDCs are frequently used for comparing the response of gauged catchments and for estimating hydrological indices for ungauged catchments, but their potential use for the regionalization of conceptual rainfall runoff models to ungauged catchments needs to be explored and is a subject of this paper. FDCs for ungauged basins are defined using developed regional regression relationships between the parameters of a logarithmic FDC model and physiographic catchment characteristics of eleven gauged catchments. The results suggest that the proposed method could be successfully applied for the estimation of ungauged streamflows in the mountainous parts of the Karkheh river basin. Then the estimated ungauged streamflows were used as an input to conduct water balance analysis of main river reaches of Karkheh river system. The utility of this information is demonstrated in closing the water balance, scenario analysis for surface water allocation and identification of river reaches where further hydrological investigations are crucial.
2 Masih, Ilyas; Uhlenbrook, S.; Maskey, S.; Ahmad, M. D.. 2010. Regionalization of a conceptual rainfall-runoff model based on similarity of the flow duration curve: a case study from the semi-arid Karkheh Basin, Iran. Journal of Hydrology, 391(1-2):188–201. [doi: https://doi.org/10.1016/j.jhydrol.2010.07.018]
River basins ; Rainfall-runoff relationships ; Hydrology ; Simulation models ; Stream flow ; Time series analysis ; Catchment areas ; Case studies / Iran / Karkheh River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H043079)
(1.14 MB)
The study examines the possibility of simulating time series of streamflows for poorly gauged catchments based on hydrological similarity. The data of 11 gauged catchments (475–2522 km2), located in the mountainous semi-arid Karkheh river basin of Iran, is used to develop the procedure. The well-known HBV model is applied to simulate daily streamflow with parameters transferred from gauged catchment counterparts. Hydrological similarity is defined based on four similarity measures: drainage area, spatial proximity, catchment characteristics and flow duration curve (FDC). The study shows that transferring HBV model parameters based on the FDC similarity criterion produces better runoff simulation compared to the other three methods. Furthermore, it is demonstrated that the FDC based regionalization of HBV model parameters works reasonably well for streamflow simulations in the data limited catchments in the mountainous parts of the Karkheh river basin. In addition, it could be demonstrated that the parameter uncertainty of the model has little impact on the FDC based regionalization approach. The methodology presented in this paper is easy to replicate in other river basins of the world, particularly those facing decline in streamflow monitoring networks and with a limited number of gauged catchments.
3 Ahmad, M. D.; Giordano, Mark. 2012. The Karkheh River Basin: the food basket of Iran under pressure. In Fisher, M.; Cook, Simon (Eds.). Water, food and poverty in river basins: defining the limits. London, UK: Routledge. pp.59-81.
River basins ; Water resources ; Water productivity ; Food security ; Farmers ; Poverty ; Crop production ; Yields ; Irrigated farming ; Rainfed farming ; Water use ; Water consumption ; Evapotranspiration ; Precipitation ; Flow discharge ; Economic aspects ; Institutions ; Policy / Iran / Karkheh River Basin
(Location: IWMI HQ Call no: IWMI Record No: H044839)
(4.83 MB)
4 Cai, Xueliang; Molden, David; Mainuddin, M.; Sharma, Bharat; Ahmad, M. D.; Karimi, Poolad. 2012. Producing more food with less water in a changing world: assessment of water productivity in 10 major river basins. In Fisher, M.; Cook, Simon (Eds.). Water, food and poverty in river basins: defining the limits. London, UK: Routledge. pp.280-300.
Water management ; Water productivity ; Water consumption ; Water use ; River basins ; Crop production ; Food security ; Assessment ; Sustainable development ; Socioeconomic development ; Livestock ; Fisheries ; Climate change ; Evapotranspiration ; Irrigation / China / Southeast Asia / South Asia / Iran / Africa / Yellow River Basin / Mekong River Basin / Indus River Basin / Ganges River Basin / Karkheh River Basin / Nile River Basin / Limpopo River Basin / Niger River Basin / Volta River Basin / Andes River Basins
(Location: IWMI HQ Call no: IWMI Record No: H044848)
(1.64 MB)
5 Mulligan, M.; Fisher, M.; Sharma, Bharat; Xu, Z. X.; Ringler, C.; Mahe, G.; Jarvis, A.; Ramirez, J.; Clanet, J.-C.; Ogilvie, A.; Ahmad, M. D.. 2012. The nature and impact of climate change in the Challenge Program on Water and Food (CPWF) basins. In Fisher, M.; Cook, Simon (Eds.). Water, food and poverty in river basins: defining the limits. London, UK: Routledge. pp.334-362.
Climate change ; Temperature ; Precipitation ; Seasonality ; River basins ; Food security ; Flow discharge ; Water balance ; Agriculture ; Poverty ; Social aspects ; Living conditions ; Rain / Africa / Asia / South America / Limpopo River Basin / Niger River Basin / Nile River Basin / Volta River Basin / Ganges River Basin / Karkeheh River Basin / Mekong River Basin / Yellow River Basin / Andes River Basins
(Location: IWMI HQ Call no: IWMI Record No: H044850)
(2.13 MB)
6 Ahmad, M. D.; Masih, I.; Giordano, Mark. 2014. Constraints and opportunities for water savings and increasing productivity through Resource Conservation Technologies in Pakistan. Agriculture, Ecosystems and Environment, 187:106-115. [doi: https://doi.org/10.1016/j.agee.2013.07.003]
Water saving ; Water productivity ; Resource conservation ; Technology ; Cropping systems ; Rice ; Wheat ; Tillage ; Groundwater irrigation ; Water use ; Water balance / Pakistan
(Location: IWMI HQ Call no: e-copy only Record No: H046050)
(1.91 MB)
Increasing the productivity of rice–wheat cropping systems is critical for meeting food demand in rapidly growing South Asia. But this must be done with increasingly scarce water resources, bringing greater attention to Resource Conservation Technologies (RCTs) such as zero tillage, laser land leveling and furrow bed planting. While the impacts of RCTs on yields are easy to measure and explain, impacts on water savings are not well understood beyond the field scale because of the complex movement of water. This paper uses both physical measurements and farmer survey data from the rice–wheat cropping system of Punjab, Pakistan to explain the main drivers of RCT adoption and their impacts on land and water productivity and water savings across scales. The primary drivers for RCT adoption (zero tillage wheat and laser land leveling) were reduced costs of production and labor requirements, reduced field scale irrigation water application, and higher yield. While the large proportion of farmers benefiting from RCTs explains overall increases in RCT adoption, a considerable proportion (30% of zero tillage adopters for wheat cultivation) reported yield loss, highlighting the need for further technological refinement and enhancing farmers’ ability to implement RCT. The study also indicates that the field scale reduction in irrigation application did not always translate into real water savings or reductions in water use at farm, cropping system and catchment scales, especially in areas where deep percolation from the root zone could be reused as groundwater irrigation. Finally, the evidence shows that medium and large farmers tended to use the field scale irrigation savings to increase their cropped area. This finding suggests that without regulations and policies to regulate the use of “saved” water, adoption of RCTs can result in overall increased water use with implications for the long-term sustainability of irrigated agriculture.
7 Ahmad, M. D.; Kirby, J. M.; Cheema, M. J. M. 2019. Impact of agricultural development on evapotranspiration trends in the irrigated districts of Pakistan: evidence from 1981 to 2012. Water International, 44(1):51-73. [doi: https://doi.org/10.1080/02508060.2019.1575110]
Agricultural development ; Irrigation management ; Evapotranspiration ; Irrigated farming ; Crops ; Water use ; Estimation ; Water accounting ; Groundwater ; Remote sensing ; Uncertainty / Pakistan / Indus Basin / Punjab / Balochistan / Sindh
(Location: IWMI HQ Call no: e-copy only Record No: H049118)
(3.49 MB)
Understanding time-series evapotranspiration trends is critical for water-balance assessments and sustainable water management in arid regions. In this paper, an approach is presented to understand time-series evapotranspiration trends by combining remote sensing-based evapotranspiration and agricultural statistics data and applying them to understand district-level water-use trends in the Indus basin irrigation system of Pakistan. The evapotranspiration of most districts in the Punjab increased over the period, whereas in Sindh it generally remained about the same or decreased. The trends in Punjab suggests that the already unsustainable groundwater use in some areas may become more unsustainable.
8 Pena-Arancibia, J. L.; Mainuddin, M.; Ahmad, M. D.; Hodgson, G.; Murad, K. F. I; Ticehurst, C.; Maniruzzaman, M.; Mahboob, M. G.; Kirby, J. M. 2020. Groundwater use and rapid irrigation expansion in a changing climate: hydrological drivers in one of the world’s food bowls. Journal of Hydrology, 581:124300. [doi: https://doi.org/10.1016/j.jhydrol.2019.124300]
Water use ; Groundwater table ; Irrigated farming ; Climate change ; Groundwater extraction ; Water balance ; Soil water ; Surface water ; Hydrology ; Remote sensing ; Evapotranspiration ; Rice ; Dry season ; Wet season ; Rain ; Models / Bangladesh
(Location: IWMI HQ Call no: e-copy only Record No: H049556)
(6.34 MB)
In recent decades, increased groundwater use enabled a large areal increase in irrigated dry season crops in northwest Bangladesh. Concurrent declining groundwater levels across the region are of great concern for food security. A water balance model approach that considered changes in irrigated agriculture was implemented to assess changes over the long-term to three five-year evaluation periods (1985–1989, 1998–2002 and 2011–2015) and seasonally (annual, dry season and wet season). The model used two different methods that explicitly capture changes in irrigation to compute and compare actual evapotranspiration (ETa). The first method used MODIS satellite data to estimate a crop coefficient based on vegetation indices (at 500 m spatial resolution) scaled by reference crop evapotranspiration (ETref). The second method used a crop coefficient approach based on survey data of crop areas at the district level and subsequently scaled by ETref. Both methods yielded very similar results at the district level, with correlation coefficients between 0.75 and 0.89. The maximum difference between the monthly averages was only of 5.4%. Notwithstanding the observed overall increase in irrigated areas, estimated overall mean annual ETa is similar through the analysis (ca. 1100 mm) and district-level trends were mixed (some increasing and some decreasing) showing in some districts a weak association between ETa and the related declining groundwater level. From the water balance, it is inferred that both the groundwater extraction (by pumping for irrigation and capillary rise to supply roots) and the groundwater recharge reduced from 1998–2002 to 2011–2015, and with deeper groundwater in later years, much of the irrigation water supply is by soil water storage rather than by groundwater. As highlighted in this paper, there are other factors aside crop expansion that may have contributed to the groundwater decline, thus a single policy or management change such as restricting groundwater extraction for irrigation may alone be inadequate to reverse declining groundwater trends.
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