Your search found 15 records
1 Rientjes, T. H. M.. 2004. Inverse modelling of the rainfall-runoff relation: a multi objective model calibration approach. Delft, Netherlands: Delft University Press. DUP Science. xxxvi, 371p.
Rainfall-runoff relationships ; Evaporation ; Models ; Calibration ; Catchment areas ; Case studies ; Groundwater ; Soil moisture
(Location: IWMI-HQ Call no: 551.577 G000 RIE Record No: H038655)
2 Muthuwatta, Lal P.; Ahmad, Mobin-ud-Din; Bos, M. G.; Rientjes, T. H. M.. 2008. Surface energy balance modeling to track water consumption by heterogeneous land uses in the Karkheh River Basin, Iran. In Humphreys, E.; Bayot, R. S.; van Brakel, M.; Gichuki, F.; Svendsen, M.; Wester, P.; Huber-Lee, A.; Cook, S. Douthwaite, B.; Hoanh, Chu Thai; Johnson, N.; Nguyen-Khoa, Sophie; Vidal, A.; MacIntyre, I.; MacIntyre, R. (Eds.). Fighting poverty through sustainable water use: proceedings of the CGIAR Challenge Program on Water and Food, 2nd International Forum on Water and Food, Addis Ababa, Ethiopia, 10-14 November 2008. Vol.1. Keynotes; Cross-cutting topics. Colombo, Sri Lanka: CGIAR Challenge Program on Water and Food. pp.101-104.
River basin management ; Models ; Remote sensing ; Satellite surveys ; Evapotranspiration ; Water balance ; Precipitation ; Water productivity / Iran / Karkheh River Basin
(Location: IWMI HQ Call no: IWMI 333.91 G000 HUM Record No: H041784)
http://ifwf2.org/addons/download_presentation.php?fid=1044
https://vlibrary.iwmi.org/pdf/H041784.pdf
https://vlibrary.iwmi.org/pdf/H041784.pdf
3 Muthuwatta, Lal P.; Ahmad, Mobin-ud-Din; Bos, M. G.; Rientjes, T. H. M.. 2010. Assessment of water availability and consumption in the Karkheh River Basin, Iran using remote sensing and geo-statistics. Water Resources Management, 24(3):459-484. [doi: https://doi.org/10.1007/s11269-009-9455-9]
Water availability ; Evapotranspiration ; Precipitation ; River Basins ; Remote sensing ; Water balance ; Irrigated farming ; Rainfed farming ; Land use / Iran / Karkheh River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H042158)
(0.91 MB)
This study was conducted to assess water availability and consumption in the Karkheh River Basin in Iran using secondary data and freely available satellite data. Precipitation was estimated using geo-statistical techniques while a Surface Energy Balance approach was selected for evapotranspiration estimation. The spatial distribution of actual evapotranspiration (ETa) for the Karkheh Basin has been estimated by use of 19 cloud free Moderate Resolution Imaging Spectroradiometer (MODIS) images, which cover a complete cropping year from November 2002 to October 2003. ETa estimates were compared to potential crop evapotranspiration (ETp) estimates for two predominantly irrigated wheat areas in Upper and Lower Karkheh. Differences were found to be 12.5% and 11.7% respectively. Results of the ETa and precipitation estimates reveal that for the study period, the Karkheh Basin received 18,507 × 106m3 as precipitation while ETa is estimated at 16,680 × 106m3. Estimated outflow from the basin for the study period only is 7.8% of the precipitation and indicates that water is a very scarce resource in the Karkheh basin. The basin has been divided in sub-basins to allow for more detailed analysis and results indicate that water balance closure at sub-basin scale ranges from 7.2% to 0.6% of the precipitation. This suggests that the water balance is sufficiently understood for policy and decision making.
4 Muthuwatta, Lal P.; Booij, M. J.; Rientjes, T. H. M.; Bos, M. G.; Gieske, A. S. M.; Ahmad, Mobin-ud-Din. 2009. Calibration of a semi-distributed hydrological model using discharge and remote sensing data. In Yilmaz, K. K.; Yucel, I.; Gupta, H. V.; Wagener, T.; Yang, D.; Savenije, H.; Neale, C.; Kunstmann, H.; Pomeroy, J. (Eds.). New approaches to hydrological prediction in data-sparse regions: proceedings of Symposium HS.2 at the Joint Convention of the International Association of Hydrological Sciences (IAHS) and the International Association of Hydrogeologists (IAH), Hyderabad, India, 6–12 September 2009. Wallingford, UK: International Association of Hydrological Sciences (IAHS). pp.52-58. (IAHS Publication 333)
Hydrology ; Models ; Calibration ; Stream flow ; Evapotranspiration ; Simulation ; Discharges ; Remote sensing ; Rivers ; Catchment areas ; Time series analysis / Iran / Karkheh River Basin / Hoor-Al-Azim swamp
(Location: IWMI HQ Call no: 551.48 G000 YIL Record No: H042296)
(0.12 MB)
The objective of this study is to present an approach to calibrate a semi-distributed hydrological model using observed streamflow data and actual evapotranspiration time series estimates based on remote sensing data. First, daily actual evapotranspiration is estimated using available MODIS satellite data, routinely collected meteorological data and applying the SEBS algorithm. Second, the semi-distributed hydrological model HBV is calibrated and validated using the estimated evapotranspiration and observed discharge. This is done for multiple sub-basins of the Karkheh River basin in Iran. The Nash-Sutcliffe coefficient (NS) is calculated for each sub-basin. Maximum and minimum NS values for the calibration using observed discharge are 0.81 and 0.23, respectively, and using estimated evapotranspiration 0.61 and 0.46, respectively. The comparison of model simulations with multiple observed variables increases the probability of selecting a parameter set that represents the actual hydrological situation of the basin. The new calibration approach can be useful for further applications especially in data sparse river basins.
5 Muthuwatta, Lal P.; Ahmad, Mobin-ud-Din; Rientjes, T. H. M.; Bos, M. G. 2010. Estimating the spatial variability of water consumption in the Karkheh River Basin, Iran - using MODIS data. AQUA mundi, Am02015:115-122. [doi: https://doi.org/10.4409/Am-016-10-0015]
River basins ; Water use ; Evapotranspiration ; Estimation ; Water balance ; Irrigated land ; Remote sensing / Iran / Karkheh River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H043551)
(1.00 MB)
Spatially distributed actual evapotranspiration (ETa) values were estimated based on satellite data and the Surface Energy Balance System (SEBS) approach for the Karkheh River Basin, Iran. Nineteen cloud free MODIS (Moderate Resolution Imaging Spectroradiometer) images, representing a complete cropping year from November 2002 to October 2003 were acquired and processed. Estimated ETa values were verified using sub-catchment scale water balance analysis. The results revealed that during the study period ETa was estimated at 16680x106m3 and that the water balance closure terms at sub-basin scale ranged from 0.6% to 7.2% of precipitation. This implies that water balance is sufficiently understood. Estimated outflow from the basin was 7.8% of precipitation and indicates that water is a very scarce resource in the Karkheh. Rain fed areas consume about 3720 x106 m3/year and are mainly located in the subcatchments of the upper Karkheh while irrigated areas consume 2680x 106 m3/year and are mainly located in the lower areas in the basin. Total water consumption by forest is about 2070×106 m3/year, mainly in the middle parts of the basin. The range lands are scattered mainly all over the Upper Karkheh and together with areas in the Lower Karkheh consume about 3360×106 m3/year. ETa from other land uses is 4110×106 m3/year, of which ETa from open water surfaces is the main contributor. The Karkheh Dam evaporates 80×106 m3/ year while wetlands located in the lower area of the basin evaporate 660×106 m3/year. Satellite data along with the SEBS algorithm and geo-statistical techniques are effective to estimate spatial patterns of water consumption and availability. These facilitate the introduction of diverse management interventions to different areas in the basin based on the real ground situation.
6 Rientjes, T. H. M.; Perera, B. U. J.; Haile, A. T.; Reggiani, P.; Muthuwatta, Lal P. 2011. Regionalisation for lake level simulation - the case of Lake Tana in the Upper Blue Nile, Ethiopia. Hydrology and Earth System Sciences, 15(4):1167-1183. [doi: https://doi.org/10.5194/hess-15-1167-2011]
Lakes ; Water balance ; Catchment areas ; Rainfall-runoff relationships ; Simulation models ; Regression analysis ; Calibrations / Ethiopia / Blue Nile River / Lake Tana
(Location: IWMI HQ Call no: e-copy only Record No: H043860)
http://www.hydrol-earth-syst-sci.net/15/1167/2011/hess-15-1167-2011.pdf
https://vlibrary.iwmi.org/pdf/H043860.pdf
https://vlibrary.iwmi.org/pdf/H043860.pdf
(1.82 MB) (1.81MB)
In this study lake levels of Lake Tana are simulated at daily time step by solving the water balance for all inflow and outflow processes. Since nearly 62% of the Lake Tana basin area is ungauged a regionalisation procedure is applied to estimate lake inflows from ungauged catchments. The procedure combines automated multi-objective calibration of a simple conceptual model and multiple regression analyses to establish relations between model parameters and catchment characteristics. A relatively small number of studies are presented on Lake Tana’s water balance. In most studies the water balance is solved at monthly time step and the water balance is simply closed by runoff contributions from ungauged catchments. Studies partly relied on simple ad-hoc procedures of area comparison to estimate runoff from ungauged catchments. In this study a regional model is developed that relies on principles of similarity of catchments characteristics. For runoff modelling the HBV-96 model is selected while multiobjective model calibration is by a Monte Carlo procedure. We aim to assess the closure term of Lake Tana’s water balance, to assess model parameter uncertainty and to evaluate effectiveness of a multi-objective model calibration approach to make hydrological modeling results more plausible. For the gauged catchments, model performance is assessed by the Nash-Sutcliffe coefficient and Relative Volumetric Error and resulted in satisfactory to good performance for six, large catchments. The regional model is validated and indicated satisfactory to good performance in most cases. Results show that runoff from ungauged catchments is as large as 527mm per year for the simulation period and amounts to approximately 30% of Lake Tana stream inflow. Results of daily lake level simulation over the simulation period 1994–2003 show a water balance closure term of 85mm per year that accounts to 2.7% of the total lake inflow. Lake level simulations are assessed by Nash Sutcliffe (0.91) and Relative Volume Error (2.71%) performance measures.
7 Rientjes, T. H. M.; Perera, J. B. U.; Haile, A. T.; Gieske, A. S. M.; Booij, M. J.; Reggiani, P. 2011. Hydrological balance of Lake Tana, Upper Blue Nile Basin, Ethiopia. In Melesse, A. M. (Ed.). Nile River Basin: hydrology, climate and water use. Dordrecht, Netherlands: Springer. pp.69-89.
Hydrology ; Water balance ; Lakes ; River basins ; Models ; Calibration ; Regression analysis ; Runoff / Ethiopia / Lake Tana / Upper Blue Nile River Basin
(Location: IWMI HQ Call no: 551.483 G136 MEL Record No: H044023)
8 Rientjes, T. H. M.; Haile, A. T.; Gieske, A. S. M.; Maathuis, B. H. P.; Habib, E. 2011. Satellite based cloud detection and rainfall estimation in the Upper Blue Nile Basin. In Melesse, A. M. (Ed.). Nile River Basin: hydrology, climate and water use. Dordrecht, Netherlands: Springer. pp.93-107.
Remote sensing ; Satellite observation ; Clouds ; Rain ; Estimation ; River basins / Ethiopia / Lake Tana / Upper Blue Nile River Basin
(Location: IWMI HQ Call no: 551.483 G136 MEL Record No: H044024)
9 Abdo, K. S.; Rientjes, T. H. M.; Gieske, A. S. M. 2008. Assessment of climate change impacts on the hydrology of Gilgel Abbay Catchment in Lake Tana Basin, Ethiopia. In Abtew, W.; Melesse, A. M. (Eds.). Proceedings of the Workshop on Hydrology and Ecology of the Nile River Basin under Extreme Conditions, Addis Ababa, Ethiopia, 16-19 June 2008. Sandy, UT, USA: Aardvark Global Publishing. pp.39-56.
Climate change ; Hydrology ; Catchment areas ; Lakes ; Models ; Calibration ; Sensitivity analysis / Ethiopia / Gilgel Abbay Catchment / Lake Tana Basin
(Location: IWMI HQ Call no: 551.48 G136 ABT Record No: H044316)
(1.14 MB)
10 Wale, A.; Rientjes, T. H. M.; Dost, R. J. J.; Gieske, A. 2008. Hydrological balance of Lake Tana, Upper Blue Nile Basin, Ethiopia. In Abtew, W.; Melesse, A. M. (Eds.). Proceedings of the Workshop on Hydrology and Ecology of the Nile River Basin under Extreme Conditions, Addis Ababa, Ethiopia, 16-19 June 2008. Sandy, UT, USA: Aardvark Global Publishing. pp.160-181.
Hydrology ; Lakes ; River basins ; Flow ; Regionalization ; Water balance ; Runoff ; Simulation models ; Calibration ; Sensitivity analysis / Ethiopia / Upper Blue Nile Basin / Lake Tana
(Location: IWMI HQ Call no: 551.48 G136 ABT Record No: H044321)
(1.30 MB)
11 Fiseha, B. M.; Alemseged, T. H.; Rientjes, T. H. M.; Gieske, A. S. M. 2008. Rainfall estimation using satellite remote sensing and ground truth for hydrologic modelling over the Upper Blue Nile region. In Abtew, W.; Melesse, A. M. (Eds.). Proceedings of the Workshop on Hydrology and Ecology of the Nile River Basin under Extreme Conditions, Addis Ababa, Ethiopia, 16-19 June 2008. Sandy, UT, USA: Aardvark Global Publishing. pp.229-249.
Rain ; Estimation ; Satellite surveys ; Remote sensing ; Hydrology ; Models ; Temperature / Ethiopia / Upper Blue Nile
(Location: IWMI HQ Call no: 551.48 G136 ABT Record No: H044325)
(1.39 MB)
12 Muthuwatta, Lal; Rientjes, T. H. M.; Bos, M. G. 2013. Strategies to increase wheat production in the water scarce Karkheh River Basin, Iran. Agricultural Water Management, 124:1-10. [doi: https://doi.org/10.1016/j.agwat.2013.03.013]
Irrigated farming ; Rainfed farming ; Wheat ; River basins ; Water productivity ; Water consumption ; Evapotranspiration ; Remote sensing ; Satellite surveys ; Rangelands ; Land use ; Land suitability / Iran / Karkheh River Basin
(Location: IWMI HQ Call no: PER Record No: H045834)
(2.15 MB)
Two strategies are assessed to increase wheat production in the water-scarce Karkheh River Basin (KRB) in Iran to meet targets by the year 2025. The strategies proposed are (a) to increase yields in the current irrigated and rainfed wheat areas and (b) to increase the area under rainfed wheat through land conversion. Crop water consumption, based on satellite remote sensing and crop yield data, was used to estimate crop water productivity (CWP) in irrigated and rainfed wheat areas in five sub-basins. CWP for wheat ranges from 0.5–1.63 kg m-3 in irrigated areas to 0.37–0.62 kg m-3 in rainfed areas. Conditions indicating water-stress in wheat areas were assessed by relative evapotranspiration (ETa/ETp) and showed that water-stress only had a minimal effect for about 154,000 ha of irrigated wheat (57%). Land suitability analysis showed that about 71,000 ha of rangelands can be converted into rainfed wheat areas without harming the current water balance in the basin. Statistical analyses showed that more than 70% of the variation in irrigated and rainfed wheat yield at plot level can be explained by water, fertilizer and seed rates. This suggests that wheat production can be increased by improving inputs other than water. Results from this study indicate that it is possible to meet approximately 85% of the wheat production targets in the year 2025 when strategies are combined.
13 Rientjes, T. H. M.; Muthuwatta, Lal P.; Bos, M. G.; Booij, M. J.; Bhatti, H. A. 2013. Multi-variable calibration of a semi-distributed hydrological model using streamflow data and satellite-based evapotranspiration. Journal of Hydrology, 505:276-290. [doi: https://doi.org/10.1016/j.jhydrol.2013.10.006]
Hydrology ; Models ; Calibration ; Stream flow ; Data ; Evapotranspiration ; River basins ; Water balance ; Catchment areas / Iran / Karkheh River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H046218)
(1.69 MB)
In this study, streamflow (Qs) and satellite-based actual evapotranspiration (ETa) are used in a multi-variable calibration framework to reproduce the catchment water balance. The application is for the HBV rainfall–runoff model at daily time-step for the Karkheh River Basin (51,000 km2) in Iran. Monte Carlo Simulation serves to estimate parameter values and to assess uncertainty for three calibration cases. In case one streamflow is used as the calibration target. In case two satellite-based ETa is used as calibration target. For both cases model performance is evaluated for the second variable that closes the water balance. In case three a preference-based multi-variable objective function is applied which is weighted for Qs and satellite-based ETa. For cloudy days a procedure is developed to complete the daily time series of satellite-based ETa that cover 4 years. Results on multi-variable calibration indicated satisfying results for both water balance terms. Results are compared against field observations and results of single-variable calibration. For cases one and two the second variable only is poorly simulated and resulted in poor reproduction of the water balance. The most important contribution of this work is that the catchment water balance is best reproduced when both Qs and satellite-based ETa serve as calibration target.
14 Gumindoga, W.; Rientjes, T. H. M.; Haile, Alemseged Tamiru; Makurira, H.; Reggiani, P. 2019. Performance of bias-correction schemes for CMORPH rainfall estimates in the Zambezi River Basin. Hydrology and Earth System Sciences, 23(7):2915-2938. [doi: https://doi.org/10.5194/hess-23-2915-2019]
Rainfall patterns ; Precipitation ; Estimation ; Satellite observation ; Performance evaluation ; River basins ; Water resources ; Weather forecasting ; Meteorological stations ; Rain gauges / Botswana / Malawi / Mozambique / Zambia / Zimbabwe / Zambezi River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049387)
https://www.hydrol-earth-syst-sci.net/23/2915/2019/hess-23-2915-2019.pdf
https://vlibrary.iwmi.org/pdf/H049387.pdf
https://vlibrary.iwmi.org/pdf/H049387.pdf
(4.60 MB) (4.60 MB)
Satellite rainfall estimates (SREs) are prone to bias as they are indirect derivatives of the visible, infrared, and/or microwave cloud properties, and hence SREs need correction. We evaluate the influence of elevation and distance from large-scale open water bodies on bias for Climate Prediction Center-MORPHing (CMORPH) rainfall estimates in the Zambezi basin. The effectiveness of five linear/non-linear and time–space-variant/-invariant bias-correction schemes was evaluated for daily rainfall estimates and climatic seasonality. The schemes used are spatio-temporal bias (STB), elevation zone bias (EZ), power transform (PT), distribution transformation (DT), and quantile mapping based on an empirical distribution (QME). We used daily time series (1998–2013) from 60 gauge stations and CMORPH SREs for the Zambezi basin. To evaluate the effectiveness of the bias-correction schemes spatial and temporal crossvalidation was applied based on eight stations and on the 1998–1999 CMORPH time series, respectively. For correction, STB and EZ schemes proved to be more effective in removing bias. STB improved the correlation coefficient and Nash–Sutcliffe efficiency by 50 % and 53 %, respectively, and reduced the root mean squared difference and relative bias by 25 % and 33 %, respectively. Paired t tests showed that there is no significant difference (p- q) plots. The spatial cross-validation approach revealed that most bias-correction schemes removed bias by >28 %. The temporal cross-validation approach showed effectiveness of the bias-correction schemes. Taylor diagrams show that station elevation has an influence on CMORPH performance. Effects of distance >10 km from large-scale open water bodies are minimal, whereas effects at shorter distances are indicated but are not conclusive for a lack of rain gauges. Findings of this study show the importance of applying bias correction to SREs.
15 Gumindoga, W.; Rientjes, T. H. M.; Haile, Alemseged Tamiru; Makurira, H.; Reggiani, P. 2019. Performance evaluation of CMORPH satellite precipitation product in the Zambezi Basin. International Journal of Remote Sensing, 40(20):7730-7749. [doi: https://doi.org/10.1080/01431161.2019.1602791]
Rain ; Precipitation ; Satellites ; Weather forecasting ; Performance evaluation ; River basins ; Meteorological stations ; Observation ; Hydrology ; Deltas / Botswana / Mozambique / Malawi / Zimbabwe / Zambia / Zambezi River Basin
(Location: IWMI HQ Call no: e-copy only Record No: H049388)
(2.28 MB)
For evaluation of the Climate Prediction Center-MORPHing (CMORPH) satellite rainfall product in the Zambezi Basin, daily time series (1998–2013) of 60 rain gauge stations are used. Evaluations for occurrence and rain rate are at sub-basin scale and at daily, weekly, and seasonal timescale by means of probability of detection (POD), false alarm ratio (FAR), critical success index (CSI) and frequency bias (FBS). CMORPH predicts 60% of the rainfall occurrences. Rainfall detection is better for the wet season than for the dry season. Best detection is shown for rainfall rates smaller than 2.5 mm/day. Findings on error decomposition revealed sources of Hit, Missed and False rainfall bias. CMORPH performance (detection of rainfall occurrences and estimations for rainfall depth) at sub-basin scale increases when daily estimates are accumulated to weekly estimates. Findings suggest that for the Zambezi Basin, errors in CMORPH rainfall should be corrected before the product can serve applications such as in hydrological modelling that largely rely on reliable and accurate rainfall inputs.
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