Your search found 63 records
(Location: IWMI HQ Call no: e-copy only Record No: H045070)
(0.35 MB)
Wetlands in the coastal catchments adjacent to the Great Barrier Reef lagoon play an important role in local hydrological processes and provide important ecological habitats for terrestrial and aquatic species. Although many wetlands have been removed or degraded by agricultural expansion, there is now great interest in their protection and restoration as important aquatic ecosystems and potential filters of pollutant runoff. However, the filtering capacity of tropical wetlands is largely unknown, so the current study was established to quantify the water, sediment and nutrient balance of a natural riverine wetland in tropical north Queensland. Surface and groundwater fluxes of water, sediment and nutrients into and out of the wetland were monitored for a 3-year period. This paper focuses on the water balance of this natural wetland and a companion paper presents its sediment and nutrient balance and estimates of water quality filtering. Wetland inflows and outflows were dominated by surface flows which varied by 3–4 orders of magnitude through the course of the year, with 90% of the annual flow occurring during the period January to March. Although groundwater inputs to the wetland were only 5% of the annual water balance, they are very important to sustaining the wetland during the dry season, when they can be the largest input of water (up to 90%). Water retention times in this type of wetland are very short, particularly when most of the flow and any associated materials are passing through it (i.e. 1–2 h), so there is little time to filter most of the annual flux of water through this wetland. Longer retention times occur at the end of the dry season (up to 8Ð5 days); but this is when the lowest fluxes of water pass through the wetland.
2 Chemin, Yann. 2012. Wavelet-based spatio-temporal fusion of observed rainfall with NDVI in Sri Lanka. Paper presented at the 33rd Asian Conference on Remote Sensing, Pattaya, Thailand, 26-30 November 2012. 11p.
(Location: IWMI HQ Call no: e-copy only Record No: H045585)
(0.38 MB)
Availability of rainfall time-series is limited in many parts of the World, and the continuity of such records is variable. This research endeavors to extend actual daily rainfall observations to ungauged areas, taking into account events of rainfall as well as cumulative total daily rainfall, over a period of 11 years. Results show that rainfall events histograms can be reconstructed, and that total cumulative rainfall is estimated with 85% accuracy, using a surrounding network of rain gauges at 30-50 Km of distance from the point of study. This research can strengthen various types of research and applications such as ungauged basins research, regional climate modeling, food security early warning systems, agricultural insurance systems, etc.
3 Ochoa, C. G.; Fernald, A. G.; Guldan, S. J. 2011. Deep percolation from surface irrigation: measurement and modelling Using the RZWQM [Root Zone Water Quality Model] In Shukla, M. K. (Ed.) Soil hydrology, land use and agriculture: measurement and modelling. Wallingford, UK: CABI. pp.231-252.
(Location: IWMI HQ Call no: e-copy SF Record No: H045782)
4 Bleiweiss, M. P.; Bawazir, A. S. 2011. Climate data for hydrological and agronomic modelling. In Shukla, M. K. (Ed.) Soil hydrology, land use and agriculture: measurement and modelling. Wallingford, UK: CABI. pp.329-349.
(Location: IWMI HQ Call no: e-copy SF Record No: H045787)
5 Sene, K. 2010. Hydrometeorology: forecasting and applications. London, UK: Springer. 355p.
(Location: IWMI HQ Call no: 551.57 G000 SEN Record No: H046312)
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(Location: IWMI HQ Call no: e-copy only Record No: H046345)
(3.51 MB)
Accurate daily reference evapotranspiration (ET0) forecasting is necessary for real-time irrigation forecasting. We proposed a method for short-term forecasting of ET0 using the locally calibrated Hargreaves–Samani model and temperature forecasts. Daily meteorological data from four stations in China for the period 2001–2013 were collected to calibrate and validate the Hargreaves–Samani (HS) model against the Penman–Monteith (PM) model, and the temperature forecasts for a 7-day horizonin 2012–2013 were collected and entered into the calibrated HS model to forecast the ET0. The pro-posed method was tested through comparisons between ET0 forecasts and ET0calculated from observed meteorological data and the PM model. The correlation coefficients between observed and forecasted temperatures for all stations were all greater than 0.94, and the accuracy of the minimum temperature forecast (error within ±2 C) ranged from 60.48% to 76.29% and the accuracy of the maximum tempera-ture forecast ranged from 50.18% to 62.94%. The accuracy of the ET0 forecast (error within ±1.5 mm day-1) ranged from 77.43% to 90.81%, the average values of the mean absolute error ranged from 0.64 to1.02 mm day-1, the average values of the root mean square error ranged from 0.87 to 1.36 mm day-1,and the average values of the correlation coefficient ranged from 0.64 to 0.86. The sources of errors were the error in the temperature forecasts and the fact that the effects of wind speed and relative humidity were not considered in the HS model. The applications illustrated that the proposed method could provide daily ET0forecasts with a certain degree of accuracy for real-time irrigation forecasts.
(Location: IWMI HQ Call no: IWMI Record No: H046390)
(1 MB)
Participatory research is increasingly recognized as being useful for conducting multiple activities in research for development projects. The co-learning environment created in participatory research helps to identify existing social and technological gaps, and develop possible solutions to improve the livelihoods of rural communities. This report describes a participatory approach used in the establishment and implementation of hydrometeorological monitoring networks in the Blue Nile River Basin of Ethiopia. The networks were established with the involvement of rural communities and other stakeholders to gain insights into the hydrological processes of the watersheds, in order to improve rainwater management strategies. Local people were involved in the day-to-day management and maintenance of the networks. The participatory approach proved beneficial for several reasons, not least, because it instilled trust and goodwill amongst the communities.
8 Muthuwatta, Lal; Liyanage, P. K. N. C. 2013. Impact of rainfall change on the agro-ecological regions of Sri Lanka. In Gunasena, H. P. M.; Gunathilake, H. A. J.; Everard, J. M. D. T.; Ranasinghe, C. S.; Nainanayake, A. D. (Eds.). Proceedings of the International Conference on Climate Change Impacts and Adaptations for Food and Environment Security on Sustaining Agriculture Under Changing Climate. Colombo, Sri Lanka, 30-31 July 2013. Lunuwila, Sri Lanka: Coconut Research Institute; Colombo, Sri Lanka: Ministry of Environment and Renewable Energy; New Delhi, India: World Agroforestry Center Regional Office. pp.59-66.
(Location: IWMI HQ Call no: e-copy only Record No: H046672)
(6.87 MB)
Changes in future rainfall distribution for the agro-ecological regions of Sri Lanka were analyzed. The baseline period to compare future predictions was taken as 1970 to 2000. Downscaled climate change prediction grids were extracted from the UK Hadley Centre for Climate Prediction and Research Model (HadCM3). These grids were extracted for 2050. In the baseline period 76 stations of147 showed decreasing trends in annual rainfall and 71 increasing trends. Thirty six of the 76 stations showing a decrease were in the wet zone. In the intermediate zone 17 stations showed increasing trends and in the dry zone 34 stations indicated increasing trends. Mean annual rainfall (MAR) for the baseline period for the whole country was 2094 mm/year while the projected value for 2050 is 2249 mm/year. The increase of MAR over Sri Lanka by 2050 compared to the baseline period is about 7%. The comparison of rainfall between the baseline period and 2050 showed that some areas of the dry zone will receive MAR of more than 1750 mm and could be classified and included into the intermediate zone by 2050. Further, the increase of MAR for 11 agroecological regions goes beyond the variability observed in the baseline data set.
(Location: IWMI HQ Call no: e-copy only Record No: H046709)
(4.13 MB)
A large proportion of Pakistan's irrigation water supply is taken from the Upper Indus River Basin (UIB) in the Himalaya–Karakoram–Hindukush range. More than half of the annual flow in the UIB is contributed by five of its snow and glacier-fed sub-basins including the Astore (Western Himalaya — south latitude of the UIB) and Hunza (Central Karakoram — north latitude of the UIB) River basins. Studying the snow cover, its spatiotemporal change and the hydrological response of these sub-basins is important so as to better managewater resources. This paper compares new data from the Astore River basin (mean catchment elevation, 4100 m above sea level; m asl afterwards), obtained using MODIS satellite snow cover images, with data from a previouslystudied high-altitude basin, the Hunza (mean catchment elevation, 4650 m asl). The hydrological regime of this sub-catchment was analyzed using the hydrological and climate data available at different altitudes from the basin area. The results suggest that the UIB is a region undergoing a stable or slightly increasing trend of snow cover in the southern (Western Himalayas) and northern (Central Karakoram) parts. Discharge from the UIB is a combination of snow and glacier melt with rainfall-runoff at southern part, but snow and glacier melt are dominant at the northern part of the catchment. Similar snow cover trends (stable or slightly increasing) but different river flow trends (increasing in Astore and decreasing in Hunza) suggest a sub-catchment level study of the UIB to understand thoroughly its hydrological behavior for better flood forecasting and water resources management.
10 Chemin, Yann; Sanjaya, Niroshan; Liyanage, Panni Kankanamlage Nirosha Chandani. 2014. An open source hardware and software online raingauge for real-time monitoring of rainwater harvesting in Sri Lanka. In Lanka Rain Water Harvesting Forum. Proceedings of the 11th Symposium on Mainstreaming Rainwater Harvesting as a Water Supply Option, Colombo, Sri Lanka, 5 September 2014. Colombo, Sri Lanka: Lanka Rain Water Harvesting Forum. pp.13-19.
(Location: IWMI HQ Call no: e-copy only Record No: H046858)
(0.32 MB)
11 Fenta, A. A.; Rientjes, T.; Haile, Alemseged Tamiru; Reggiani, P. 2014. Satellite rainfall products and their reliability in the Blue Nile Basin. In Melesse, A. M.; Abtew, W.; Setegn, S. G. (Eds.). Nile river basin: ecohydrological challenges, climate change and hydropolitics. Dordrecht, Netherlands: Springer. pp.51-67.
(Location: IWMI HQ Call no: e-copy only Record No: H046898)
(0.37 MB)
In the Upper Blue Nile (UBN) basin, there is very sparse and uneven distribution of ground-based meteorological stations which constrain assessments on rainfall distributions and representation. To assess the diurnal cycle of rainfall across the UBN basin, satellite observations from Tropical Rainfall Measuring Mission (TRMM) were used in this study. Data of 7 years (2002–2008) of Precipitation Radar (PR) and TRMM Microwave Imager (TMI) were processed, with analyses based on geographic information system (GIS) operations, statistical techniques, and harmonic analysis. Diurnal cycle patterns of rainfall occurrence and rain rate from three in-situ weather stations are well represented by the satellite observations. Harmonic analysis depicts large differences in the mean of the diurnal cycle, amplitude, and time of the amplitude across the study area. Diurnal cycle of rainfall occurrence has a single peak in Lake Tana, Gilgel Abbay, and Jemma subbasins and double peaks in Belles, Dabus, and Muger subbasins. Maximum rain rate occurs in the morning (Gilgel Abbay, Dabus, and Jemma), afternoon (Belles, Beshilo, and Muger), and evening (Lake Tana and along the river gorges). Results of this study indicate that satellite observations provide an alternative source of data to characterize diurnal cycle of rainfall in data-scarce regions. We noticed, however, that there are a number of constraints to the use of satellite observations. For more accurate assessments, satellite products require validation by a network of well-distributed ground stations. Also, we advocate bias correction.
(Location: IWMI HQ Call no: IWMI Record No: H047091)
(1 MB)
13 Bharati, Luna; Chinnasamy, Pennan; Khadka,Ambika; Okwany, Romulus. 2015. Watershed hydrology impact monitoring research. Inception Report. [Project report of the Building Climate Resilient Watersheds in Mountain Eco-Regions (BCRWME)] Kathmandu: Nepal: International Water Management Institute (IWMI). 73p.
(Location: IWMI HQ Call no: e-copy only Record No: H047153)
(2.94 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H047334)
(0.92 MB)
The Soil and Water Assessment Tool (SWAT) was used to simulate water balances in different cropping patterns under current and future climates in West Seti river Sub-basin, which is located in the far western region of Nepal. The results show that total precipitation over rice, maize, millet, wheat and barley fields were 1002, 818, 788, 186 and 169 mm respectively, whereas total simulated actual evapo transpiration (ET) are 534, 452, 322, 138 and 177 mm respectively under current climate. Actual ET will change by-1.9% in rice, -1.1% in maize, -2.0% in millet, +6.7% in wheat and +5.4% in barley under future climate projections. Results show that yield of maize and millet will decrease by 5.9% and 8.0% whereas yield of rice, wheat and barley will increase by 1.2%, 6.6% and 7.0% respectively. Therefore, the impact of climate change shows that summer crop yields will decrease except of rice and winter crop yields will increase. In general, a result of watersheds interventions shows that the crop yields will increase after the watershed interventions.
15 Liu, Q.; Yan, C.; Yang, J.; Mei, X.; Hao, W.; Ju, H. 2015. Impacts of climate change on crop water requirements in Huang-Huai-Hai Plain, China. In Hoanh, Chu Thai; Johnston, Robyn; Smakhtin, Vladimir. Climate change and agricultural water management in developing countries. Wallingford, UK: CABI. pp.48-62. (CABI Climate Change Series 8)
(Location: IWMI HQ Call no: IWMI Record No: H047371)
(740 KB)
(Location: IWMI HQ Call no: IWMI Record No: H047367)
(0.35 MB)
(Location: IWMI HQ Call no: e-copy only Record No: H047525)
(0.62 MB)
The Ilisu Dam and HEPP Project, on the Tigris River in the South-Eastern Anatolia Region of Turkey, has been under debate for more than half a century due to its possible adverse effects on the environment. In particular, the proposed inundation of the archaeological sites around Hasankeyf has prompted strong criticism from national and international organizations. The primary reason for the administration’s insistence on construction of the dam is its energy production capacity. The present study is an assessment of an alternative solution that not only saves Hasankeyf with its countless ancient monuments from inundation but also supplies the projected energy production of Ilisu Dam.
18 Tesemma, Z. K. 2009. Long term hydrologic trends in the Nile Basin. Thesis submitted to the Presented to the Faculty of the Graduate School of Cornell University in Partial Fulfillment of the Requirements for the Degree of Master of Professional Studies. 96p.
(Location: IWMI HQ Call no: e-copy only Record No: H047674)
(Location: IWMI HQ Call no: IWMI Record No: H047737)
(2 MB)
20 Chapungu, L.; Nhamo, Luxon. 2016. An assessment of the impact of climate change on plant species richness through an analysis of the normalised difference water index (NDWI) in Mutirikwi Sub-catchment, Zimbabwe. South African Journal of Geomatics, 5(2):244-268.
(Location: IWMI HQ Call no: e-copy only Record No: H047746)
This study assesses the effects of climate change on vegetative species diversity exploring the usefulness of the Normalised Difference Water Index (NDWI) in predicting spatio-temporal diversity variations. The relationship between species richness and climatic variables of rainfall and temperature is explored based on species data collected from the field over a 3 year period and climate data collected from four local weather stations. Relationship between NDWI and species diversity indices is examined to confirm the usefulness of Remote Sensing in predicting vegetative diversity. The resultant predictive model was used to estimate changes in species richness over a 27 year period (1987-2014). The species diversity data was then regressed with climatic data for the same period. The results show a significant (P<0.05) correlation between species diversity and the two climatic variables. The results also indicate that there is a significant positive (P=0.0001; a=0.05; R2=0.565) relationship between species richness and NDWI. This implies that the NDWI is essential when assessing changes in species diversity over time. The Mann Kendall test revealed a decrease, though not statistically significant, in the rainfall received within the catchment over the period and significant variability. The minimum and maximum temperatures over the period were significantly increasing. These changes in climate variables were matched with a decrease in species richness. Some species tend to be succumbing to the environmental changes influenced by climate change resulting in their changes in phenology, abundance and distribution.
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