Your search found 7 records
1 Bharati, Luna; Smakhtin, Vladimir; Gurung, Pabitra; Lacombe, Guillaume; Amarasinghe, Upali A.; Sapkota, Pratibha; Hoanh, Chu Thai. 2012. Environmentally sustainable water resources management in the Upper Ganga Basin under changing climate conditions. [Project report prepared by IWMI for World Wide Fund for Nature, India under the project "Environmentally Sustainable Water Resources Management in the Upper Ganga Basin"]. Kathmandu, Nepal: International Water Management Institute (IWMI). 51p.
Water resources ; Water management ; River basins ; Hydrology ; Simulation models ; Climate change ; Rain ; Temperature ; Relative humidity ; Wind speed ; Water balance ; Water allocation ; Water availability ; Water use ; Canal irrigation ; Environmental flows / India / Upper Ganga Basin
(Location: IWMI HQ Call no: e-copy only Record No: H045053)
(2.50 MB)
2 Luo, Y.; Jiang, Y.; Peng, S.; Khan, S.; Cai, Xueliang; Wang, W.; Jiao, X. 2012. Urban weather data to estimate reference evapotranspiration for rural irrigation management. Journal of Irrigation and Drainage Engineering, 138(9):837-842. [doi: https://doi.org/10.1061/(ASCE)IR.1943-4774.0000470]
Irrigation management ; Irrigation requirements ; Weather data ; Temperature ; Humidity ; Wind speed ; Evapotranspiration ; Rural areas / China / Kaifeng Station / Huibei Station
(Location: IWMI HQ Call no: PER Record No: H045719)
(0.94 MB)
Weather data measured in urban areas are generally more easily available than those in rural areas. If the urban weather data are used to calculate the reference crop evapotranspiration (ET0) for rural irrigation management or spatial and temporal trend analysis, the results may be biased because of the differences in weather variables. We collected daily data for mean, maximum, and minimum temperatures; relative humidity; average wind speed; and sunshine duration from two stations: Kaifeng Station in the City of Kaifeng and Huibei Station in the nearby irrigation scheme for 1984–2009. ET0 for both stations were calculated using the FAO-56 Penman-Monteith method and then compared. The results indicated that the difference in daily ET0 was remarkable [with relative error (RE) of 52.6%], the difference between monthly average ET0 increased gradually during the last three decades and the temporal trends in annual average daily ET0 were opposite. There were significant differences in ETC (with RE of 31.1%) and irrigation requirements (with RE of 24.3%) between the two stations. Even though the distance between the two stations is only 20 km, the urban weather cannot be used to estimate ET0 for rural irrigation management.
3 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)
Climate change ; Water requirements ; Weather ; Meteorological stations ; Crop production ; Evapotranspiration ; Winter wheat ; Precipitation ; Solar radiation ; Wind speed ; Relative humidity ; Temperature / China / Huang-Huai-Hai Plain
(Location: IWMI HQ Call no: IWMI Record No: H047371)
(740 KB)
4 Hamidi, M. 2020. The key role of water resources management in the Middle East dust events. Catena, 187:104337. (Online first) [doi: https://doi.org/10.1016/j.catena.2019.104337]
Water resources ; Water management ; Dust storms ; Water scarcity ; Precipitation ; Temperature ; Wind speed ; Vegetation ; Rivers ; Flow discharge / Middle East / Iraq / Iran Islamic Republic / Tigris River / Euphrates River
(Location: IWMI HQ Call no: e-copy only Record No: H049543)
(0.79 MB)
Dust events in the Middle East have resulted in serious environmental problems in many countries in the area. The dust activities in the Middle East were intensified in recent years due to many factors including climate change, drought, and poor water management strategies. This paper investigates the dust activity during 1980–2010 in the Lower Mesopotamia and southwestern Iran and demonstrates that the dust activity in the study area has increased after 1999. This study investigates the role of surface temperature, precipitation, water resources, vegetation, and surface wind velocity on the development of dust events during the study period. This investigation is performed using the correlation analysis of the normalized value of the 5 and 10 year moving average of the mentioned parameters to evaluate the role of each parameter on the increase of dust activity in the last decade of the study period. The correlation analysis demonstrates that the dust activity has the highest correlation and relationship to the water resources of the Tigris and Euphrates rivers and indicates the key role of water resources management on the dust activity in the study area. It is shown, The large scarcity of the Tigris and Euphrates rivers water resources has occurred when there was not a sharp reduction in the average precipitation in the study area. Hence, the excessive water withdrawal through the dam construction projects could be considered as the main reason of large reduction of the Tigris and Euphrates rivers water resources and high dust activity in the Middle East during the last decades.
5 Maza, M.; Bandyopadhyay, A.; Bhadra, A. 2020. Development of GIS toolbar to estimate reference evapotranspiration and net irrigation requirement on raster based approach. Agricultural Engineering International: CIGR Journal, 22(3):27-42.
Irrigation requirements ; Evapotranspiration ; Geographical information systems ; Remote sensing ; Estimation ; Rain ; Crop water use ; Solar radiation ; Temperature ; Humidity ; Wind speed / India
(Location: IWMI HQ Call no: e-copy only Record No: H050037)
https://cigrjournal.org/index.php/Ejounral/article/download/5765/3359
https://vlibrary.iwmi.org/pdf/H050037.pdf
https://vlibrary.iwmi.org/pdf/H050037.pdf
(2.92 MB) (2.92 MB)
An ArcGIS toolbar was developed with the help of ArcObjects within ArcGIS environment to estimate evapotranspiration (ET) and net irrigation requirement (NIR) on raster based approach. The toolbar can estimate ET on a daily or monthly basis either with Hargreaves and Samani method or FAO56-PM method and calculate the corresponding NIR on a monthly basis. The toolbar was tested using normal monthly meteorological data (maximum temperature, minimum temperature, relative humidity, wind speed, solar radiation and rainfall) collected from 133 India Meteorological Department (IMD) stations covering 19 agro-ecological regions from 1971–2000. These point meteorological data were interpolated using ordinary kriging method and resampled at 1 km spatial resolution to generate the input rasters. Crop coefficient (kc) raster for each month was prepared by analysing the cropping pattern of the country. Using the developed toolbar, reference evapotranspiration (ETo) was estimated using both the methods on a monthly basis and NIR was estimated using the ETo of FAO56-PM method and comparison was made between the two ETo estimates. Verification of ETo and NIR estimates made by the toolbar was performed by comparing the toolbar estimated monthly ETo and NIR with manually calculated ones at ten evenly distributed locations and was found that the toolbar can generate accurate ETo and NIR rasters.
6 Cai, Y.; Breon, F.-M. 2021. Wind power potential and intermittency issues in the context of climate change. Energy Conversion and Management, 240:114276. (Online first) [doi: https://doi.org/10.1016/j.enconman.2021.114276]
Wind power ; Renewable energy ; Energy generation ; Electricity ; Climate change ; Wind farms ; Technology ; Wind speed ; Models ; Evaluation / France / Germany
(Location: IWMI HQ Call no: e-copy only Record No: H050420)
https://www.sciencedirect.com/science/article/pii/S0196890421004520/pdfft?md5=1cae745d768584e38659488011be79cd&pid=1-s2.0-S0196890421004520-main.pdf
https://vlibrary.iwmi.org/pdf/H050420.pdf
https://vlibrary.iwmi.org/pdf/H050420.pdf
(8.71 MB) (8.71 MB)
Wind power is developing rapidly because of its potential to provide renewable electricity and the large reduction in installation costs during the past decade. However, the high temporal variability of the wind power source is an obstacle to a high penetration in the electricity mix as it makes difficult to balance electricity supply and demand. There is therefore a need to quantify the variability of wind power and also to analyze how this variability decreases through spatial aggregation. In the context of climate change, it is also necessary to analyze how the wind power potential and its variability may change in the future. One difficulty for such objective is the large biases in the modeled winds, and the difficulty to derive a reliable power curve. In this paper, we propose an Empirical Parametric Power Curve Function (EPPCF) model to calibrate a power curve function for a realistic estimate of wind power from weather and climate model data at the regional or national scale. We use this model to analyze the wind power potential, with France as an example, considering the future wind turbine evolution, both onshore and offshore, with a focus on the production intermittency and the impact of spatial de-correlations. We also analyze the impact of climate change.
We show that the biases in the modeled wind vary from region to region, and must be corrected for a valid evaluation of the wind power potential. For onshore wind, we quantify the potential increase of the load factor linked to the wind turbine evolution (from a current 23% to 30% under optimistic hypothesis). For offshore, our estimate of the load factor is smaller for the French coast than is currently observed for installed wind farms that are further north (around 35% versus 39%). However, the estimates vary significantly with the atmospheric model used, with a large spatial gradient with the distance from the coast. The improvement potential appears smaller than over land. The temporal variability of wind power is large, with variations of 100% of the average within 3–10 h at the regional scale and 14 h at the national scale. A better spatial distribution of the wind farms could further reduce the temporal variability by around 20% at the national scale, although it would remain high with respect to that of the demand. The impact of climate change on the wind power resource is insignificant (from +2.7% to -8.4% for national annual mean load factor) and even its direction varies among models.
We show that the biases in the modeled wind vary from region to region, and must be corrected for a valid evaluation of the wind power potential. For onshore wind, we quantify the potential increase of the load factor linked to the wind turbine evolution (from a current 23% to 30% under optimistic hypothesis). For offshore, our estimate of the load factor is smaller for the French coast than is currently observed for installed wind farms that are further north (around 35% versus 39%). However, the estimates vary significantly with the atmospheric model used, with a large spatial gradient with the distance from the coast. The improvement potential appears smaller than over land. The temporal variability of wind power is large, with variations of 100% of the average within 3–10 h at the regional scale and 14 h at the national scale. A better spatial distribution of the wind farms could further reduce the temporal variability by around 20% at the national scale, although it would remain high with respect to that of the demand. The impact of climate change on the wind power resource is insignificant (from +2.7% to -8.4% for national annual mean load factor) and even its direction varies among models.
7 Acharya, P.; Barik, G.; Gayen, B. K.; Bar, S.; Maiti, A.; Sarkar, A.; Ghosh, Surajit; De, S. K.; Sreekesh, S. 2021. Revisiting the levels of aerosol optical depth in South-Southeast Asia, Europe and USA amid the COVID-19 pandemic using satellite observations. Environmental Research, 193:110514. [doi: https://doi.org/10.1016/j.envres.2020.110514]
Air pollution ; Air quality ; Aerosols ; COVID-19 ; Nitrogen dioxide ; Sulphur dioxide ; Emission ; Weather data ; Wind speed ; Humidity ; Satellite observation ; Moderate resolution imaging spectroradiometer / South Asia / South East Asia / Europe / USA
(Location: IWMI HQ Call no: e-copy only Record No: H050797)
(12.20 MB)
The countries around the world are dealing with air quality issues for decades due to their mode of production and energy usages. The outbreak of COVID-19 as a pandemic and consequent global economic shutdown, for the first time, provided a base for the real-time experiment of the effect of reduced emissions across the globe in abetting the air pollution issue. The present study dealt with the changes in Aerosol Optical Depth (AOD), a marker of air pollution, because of global economic shutdown due to the coronavirus pandemic. The study considered the countries in south and south-east Asia (SSEA), Europe and the USA for their extended period of lockdown due to coronavirus pandemic. Daily Aerosol Optical Depth (AOD) from Moderate-resolution imaging spectroradiometer (MODIS) and tropospheric column density of NO2 and SO2 from Ozone monitoring instrument (OMI) sensors, including meteorological data such as wind speed (WS) and relative humidity (RH) were analyzed during the pre-lockdown (2017–2019) and lockdown periods (2020). The average AOD, NO2 and SO2 during the lockdown period were statistically compared with their pre-lockdown average using Wilcoxon-signed-paired-rank test. The accuracy of the MODIS-derived AOD, including the changing pattern of AOD due to lockdown was estimated using AERONET data. The weekly anomaly of AOD, NO2 and SO2 was used for analyzing the space-time variation of aerosol load as restrictions were imposed by the concerned countries at the different points of time. Additionally, a random forest-based regression (RF) model was used to examine the effects of meteorological and emission parameters on the spatial variation of AOD. A significant reduction of AOD (- 20%) was obtained for majority of the areas in SSEA, Europe and USA during the lockdown period. Yet, the clusters of increased AOD (30–60%) was obtained in the south-east part of SSEA, the western part of Europe and US regions. NO2 reductions were measured up to 20–40%, while SO2 emission increased up to 30% for a majority of areas in these regions. A notable space-time variation was observed in weekly anomaly. We found the evidence of the formation of new particles for causing high AOD under high RH and low WS, aided by the downward vertical wind flow. The RF model showed a distinguishable relative importance of emission and meteorological factors among these regions to account for the spatial variability of AOD. Our findings suggest that the continued lockdown might provide a temporary solution to air pollution; however, to combat persistent air quality issues, it needs switching over to the cleaner mode of production and energy. The findings of this study, thus, advocated for alternative energy policy at the global scale.
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