Your search found 12 records
1 Swain, D. K.; Herath, S. 2004. Solar radiation stress assessment on rice production using CERES-rice model. In Herath, S.; Pathirana, A.; Weerakoon, S. B. (Eds.). Proceedings of the International Conference on Sustainable Water Resources Management in the Changing Environment of the Monsoon Region. Bandaranaika Memorial International Conference Hall, Colombo, Sri Lanka, 17-19 November 2004. Vol.1. Colombo, Sri Lanka: National Water Resources Secretariat. pp.110-122.
(Location: IWMI-HQ Call no: 333.91 G000 HER Record No: H039504)
2 Biggs, Trent; Scott, Christopher; Rajagopalan, Balaji; Turral, Hugh. 2007. Trends in solar radiation due to clouds and aerosols, Southern India, 1952-1997. International Journal of Climatology, 27(11): 1505–1518.
(Location: IWMI-HQ Call no: IWMI 551.5271 G635 BIG Record No: H039743)
Decadal trends in cloudiness are shown to affect incoming solar radiation (SW SFC) in the Krishna River basin (13–20°N, 72–82 °E), southern India, from 1952 to 1997. Annual average cloudiness at 14 meteorological stations across the basin decreased by 0.09% of the sky per year over 1952–1997. The decreased cloudiness partly balanced the effects of aerosols on incoming solar radiation (SW SFC), resulting in a small net increase in SW SFC in monsoon months (0.1–2.9 W m-2 per decade). During the non-monsoon, aerosol forcing dominated over trends in cloud forcing, resulting in a net decrease in SW SFC (-2.8 to -5.5 W m-2 per decade). Monthly satellite easurements from the International Satellite Cloud Climatology Project (ISCCP) covering 1983–1995 were used to screen the visual cloudiness measurements at 26 meteorological stations, which reduced the data set to 14 stations and extended the cloudiness record back to 1952. SW SFC measurements were available at only two stations, so the SW SFC record was extended in time and to the other stations using a combination of the Angstrom and Hargreaves-Supit equations. The Hargreaves-Supit estimates of SW SFC were then corrected for trends in aerosols using the literature values of aerosol forcing over India. Monthly values and trends in satellite measurements of SW SFC from National Aeronautics and Space Administration’s (NASA’s) surface radiation budget (SRB) matched the aerosol-corrected Hargreaves-Supit estimates over 1984–1994 (RMSE = 11.9 W m-2, 5.2%). We conclude that meteorological station measurements of cloudiness, quality checked with satellite imagery and calibrated to local measurements of incoming radiation, provide an opportunity to extend radiation measurements in space and time. Reports of decreased cloudiness in other parts of continental Asia suggest that the cloud-aerosol trade-off observed in the Krishna basin may be widespread, particularly during the rainy seasons when changes in clouds have large effects on incoming radiation compared with aerosol forcing.
3 Philibert, C. 2011. Solar energy perspectives. Paris, France: International Energy Agency; Paris, France: OECD. 228p. (Renewable Energy Technologies)
Solar energy ; Energy generation ; Energy technology ; Solar radiation ; Solar collectors ; Energy policies
(Location: IWMI HQ Call no: 621.471 G000 PHI Record No: H044628)
(0.49 MB)
In 90 minutes, enough sunlight strikes the earth to provide the entire planet's energy needs for one year. While solar energy is abundant, it represents a tiny fraction of the world’s current energy mix. But this is changing rapidly and is being driven by global action to improve energy access and supply security, and to mitigate climate change. Around the world, countries and companies are investing in solar generation capacity on an unprecedented scale, and, as a consequence, costs continue to fall and technologies improve. This publication gives an authoritative view of these technologies and market trends, in both advanced and developing economies, while providing examples of the best and most advanced practices. It also provides a unique guide for policy makers, industry representatives and concerned stakeholders on how best to use, combine and successfully promote the major categories of solar energy: solar heating and cooling, photovoltaic and solar thermal electricity, as well as solar fuels. Finally, in analysing the likely evolution of electricity and energy-consuming sectors – buildings, industry and transport – it explores the leading role solar energy could play in the long-term future of our energy system.
4 Petropoulos, G. P. 2014. Remote sensing of energy fluxes and soil moisture content. Boca Raton, FL, USA: CRC Press. 506p.
Remote sensing ; Energy balance ; Soil moisture ; Soil properties ; Hydrology ; Models ; Climate change ; Heat ; Flooding ; Agroecosystems ; Spatial distribution ; Evapotranspiration ; Radar ; Satellite observation ; Environmental factors ; Land use ; Vegetation ; Measurement ; Case studies ; Solar radiation ; Water balance / Brazil
(Location: IWMI HQ Call no: 551.52530287 G000 PET Record No: H046471)
(0.44 MB)
5 Gunawardena, J.; Muthuwatta, Lal; Fernando, M. J. J.; Rathnayake, S.; Rodrigo, T. M. A. S. K.; Gunawardena, A. (Eds.) 2015. Proceedings of the First International Symposium on Environment Management and Planning, Battaramulla, Sri Lanka, 23-24 February 2015. Colombo, Sri Lanka: Central Environmental Authority (CEA). 55p.
Environmental management ; Forest plantations ; Drug plants ; Tea ; Rubber industry ; Agroforestry ; Biodiversity ; Wildlife ; Freshwater ; Water quality ; Groundwater pollution ; Water deficit ; Land use ; Paddy fields ; Constructed wetlands ; Carbon ; Meteorology ; Models ; Satellite surveys ; GIS ; Remote sensing ; Maps ; Soil salinity ; Erosion ; Sand ; Solar radiation ; Watersheds ; Aquifers ; River basins ; Tanks ; Energy generation ; Bioremediation ; Waste management ; Performance evaluation ; Toxic substances ; Pollutant load ; Noise pollution ; Denitrification ; Leachates ; Biofertilizers ; Aquatic insects ; Food production ; Fishing ; Farmers ; Vegetable growing ; Vermicomposting ; Health hazards ; Malaria ; Case studies ; Arid zones ; Coastal area ; Coral reefs / Sri Lanka / India / Tangalle / Vavuniya / Jaffna / Killinochchi / Mullaitivu / Mannar / Kalpitiya / Colombo / Kalutara / Matara / Weligama / Badulla / Upper Mahaweli Catchment / Paraviwella Reef / Vairavapuliyankulam Tank / Kelani River / Himalayan Region
(Location: IWMI HQ Call no: IWMI Record No: H046899)
(1.32 MB)
6 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)
7 Zhao, W.; Duan, S.-B. 2020. Reconstruction of daytime land surface temperatures under cloud-covered conditions using integrated MODIS [Moderate Resolution Imaging Spectroradiometer]/terra land products and MSG [Meteosat Second Generation] geostationary satellite data. Remote Sensing of Environment, 247:111931. (Online first) [doi: https://doi.org/10.1016/j.rse.2020.111931]
Land cover ; Air temperature ; Satellite observation ; Geostationary satellite ; Moderate resolution imaging spectroradiometer ; Clouds ; Solar radiation ; Vegetation ; Regression analysis ; Models / Europe
(Location: IWMI HQ Call no: e-copy only Record No: H049904)
(5.29 MB)
There is considerable demand for satellite observations that can support spatiotemporally continuous mapping of land surface temperature (LST) because of its strong relationships with many surface processes. However, the frequent occurrence of cloud cover induces a large blank area in current thermal infrared-based LST products. To effectively fill this blank area, a new method for reconstructing the cloud-covered LSTs of Terra Moderate Resolution Imaging Spectroradiometer (MODIS) daytime observations is described using random forest (RF) regression approach. The high temporal resolution of the Meteosat Second Generation (MSG) LST product assisted in identifying the temporal variations in cloud cover. The cumulative downward shortwave radiation flux (DSSF) was estimated as the solar radiation factor for each MODIS pixel based on the MSG DSSF product to represent the impact from cloud cover on incident solar radiation. The RF approach was used to fit an LST linking model based on the datasets collected from clear-sky pixels that depicted the complicated relationship between LST and the predictor variables, including the surface vegetation index (the normalized difference vegetation index and the enhanced vegetation index), normalized difference water index, solar radiation factor, surface albedo, surface elevation, surface slope, and latitude. The fitted model was then used to reconstruct the LSTs of cloud-covered pixels. The proposed method was applied to the Terra/MODIS daytime LST product for four days in 2015, spanning different seasons in southwestern Europe. A visual inspection indicated that the reconstructed LSTs thoroughly captured the distribution of surface temperature associated with surface vegetation cover, solar radiation, and topography. The reconstructed LSTs showed similar spatial pattern according to the comparison with clear-sky LSTs from temporally adjacent days. In addition, evaluations against Global Land Data Assimilation System (GLDAS) NOAH 0.25° 3-h LST data and reference LST data derived based on in-situ air temperature measurements showed that the reconstructed LSTs presented a stable and reliable performance. The coefficients of determination derived with the GLDAS LST data were all above 0.59 on the four examined days. These results indicate that the proposed method has a strong potential for reconstructing LSTs under cloud-covered conditions and can also accurately depict the spatial patterns of LST.
8 Shafieiyoun, E.; Gheysari, M.; Khiadani, M.; Koupai, J. A.; Shojaei, P.; Moomkesh, M. 2020. Assessment of reference evapotranspiration across an arid urban environment having poor data monitoring system. Hydrological Processes, 34(20):4000-4016. (Online first) [doi: https://doi.org/10.1002/hyp.13851]
Evapotranspiration ; Assessment ; Arid zones ; Urban environment ; Weather data ; Monitoring ; Water requirements ; Remote sensing ; Air temperature ; Humidity ; Solar radiation ; Meteorological stations ; Models ; Sensitivity analysis / Iran Islamic Republic / Isfahan
(Location: IWMI HQ Call no: e-copy only Record No: H049952)
(23.80 MB)
Estimation of reference evapotranspiration (ET0) in urban areas is challenging but essential in arid urban climates. To evaluate ET0 in an urban environment and non-urban areas, air temperature and relative humidity were measured at five different sites across the arid city of Isfahan, Iran, over 4 years. Wind speed and sunshine hours were obtained from an urban surrounding weather station over the same period and used to estimate ET0. Calculated ET0 was compared with satellite-based ET0 retrieved from the MOD16A2 PET product. Although MODIS PET was strongly correlated with the Valiantzas equation, it overestimated ET0 and showed average accuracy (r = 0.93–0.94, RMSE = 1.18–1.28 mm/day, MBE = 0.73–0.84 mm/day). The highest ET0 differences between an urban green space and a non-urban area were 1.1 and 0.87 mm/day, which were estimated by ground measurements and MODIS PET, respectively. The sensitivity of ET0 to wind speed and sunshine hours indicated a significant effect on cumulative ET0 at urban sites compared to the non-urban site, which has a considerable impact on the amount of irrigation required in those areas. Although MODIS PET requires improvement to accurately reflect field level microclimate conditions affecting ET0, it is beneficial to hydrological applications and water resource managers especially in areas where data is limited. In addition, our results indicated that using limited data methods or meteorological data from regional weather stations, leads to incorrect estimation of ET0 in urban areas. Therefore, decision-makers and urban planners should consider the importance of precisely estimating ET0 to optimize management of urban green space irrigation, especially in arid and semi-arid climates such as the city of Isfahan.
9 Mechiche-Alami, A.; Abdi, A. M. 2020. Agricultural productivity in relation to climate and cropland management in West Africa. Scientific Reports, 10:3393. [doi: https://doi.org/10.1038/s41598-020-59943-y]
Agricultural productivity ; Farmland ; Land management ; Crop production ; Climate change ; Rain ; Temperature ; Land degradation ; Remote sensing ; Solar radiation ; Normalized difference vegetation index ; Trends ; Policies / West Africa / Nigeria / Burkina Faso / Mali / Niger / Benin / Gambia
(Location: IWMI HQ Call no: e-copy only Record No: H049962)
(3.33 MB) (3.33 MB)
The climate of West Africa is expected to become more arid due to increased temperature and uncertain rainfall regimes, while its population is expected to grow faster than the rest of the world. As such, increased demand for food will likely coincide with declines in agricultural production in a region where severe undernutrition already occurs. Here, we attempt to discriminate between the impacts of climate and other factors (e.g. land management/degradation) on crop production across West Africa using satellite remote sensing. We identify trends in the land surface phenology and climate of West African croplands between 2000 and 2018. Using the combination of a an attribution framework and residual trend anlaysis, we discriminate between climate and other impacts on crop productivity. The combined effect of rainfall, land surface temperature and solar radiation explains approximately 40% of the variation in cropland productivity over West Africa at the 95% significance level. The largest proportions of croplands with greening trends were observed in Mali, Niger and Burkina Faso, and the largest proportions with browning trends were in Nigeria, The Gambia and Benin. Climate was responsible for 52% of the greening trends and 25% of the browning trends. Within the other driving factors, changes in phenology explained 18% of the greening and 37% of the browning trends across the region, the use of inputs and irrigation explained 30% of the greening trends and land degradation 38% of the browning trends. These findings have implications for adaptation policies as we map out areas in need of improved land management practices and those where it has proven to be successful.
10 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.
11 Okakwu, I. K.; Alayande, A. S.; Akinyele, D. O.; Olabode. O. E.; Akinyemi, J. O. 2022. Effects of total system head and solar radiation on the techno-economics of PV [Photovoltaic] groundwater pumping irrigation system for sustainable agricultural production. Scientific African, 16:e01118. [doi: https://doi.org/10.1016/j.sciaf.2022.e01118]
Solar powered irrigation systems ; Groundwater ; Pumping ; Sustainable agriculture ; Agricultural production ; Solar radiation ; Photovoltaic systems ; Water supply ; Crop water use ; Water requirements ; Economic aspects ; Case studies / Nigeria / Sokoto
(Location: IWMI HQ Call no: e-copy only Record No: H051143)
https://www.sciencedirect.com/science/article/pii/S2468227622000278/pdfft?md5=cf901a952c9bf88ce6347fa1a856eb0d&pid=1-s2.0-S2468227622000278-main.pdf
https://vlibrary.iwmi.org/pdf/H051143.pdf
https://vlibrary.iwmi.org/pdf/H051143.pdf
(1.31 MB) (1.31 MB)
Several agricultural farms in Nigeria are found in off-grid locations where there is the lack of water supply despite the abundant groundwater resources possessed by the country. Since water is one of the key resources for agricultural production, majority of the farms only resort to the use of fossil fuel-powered generators to pump water for their operations in Nigeria. However, concerns about the frequent increase in fuel cost, the maintenance, and the environmental issues associated with running fossil-fuel generators have driven the need for a clean and sustainable energy source. The photovoltaic (PV)-pumping system is becoming more popular as an alternative energy source of water pumping for irrigation farming. This study presents the effects of total system head and solar radiation on the techno-economic design of PV-pumping system for groundwater irrigation of crop production in Nigeria. It also calculates the quantity of emissions avoided by the PV. The technical design is based on standard methodology to determine the PV capacity that can operate the pump to satisfy the daily water requirements for the crops, while the economic aspect involves the assessment of the life cycle cost and the cost of water per m3. The result reveals that the pump power ranges from 0.158 kW to 0.293 kW and the PV power ranges from 1.90 kW to 3.52 kW for a system head of 10 m and solar irradiation of 5.25 kWh/m2/day, respectively, while the unit cost of water ranges from $ 0.05/m3 to $ 0.054/m3, and the life cycle cost ranges from $ 7004 to $ 12331. This provides insights into the effects of varying the system head and the solar radiation, demonstrating that the PV-pumping system underperforms at higher system heads, but performs effectively at higher solar radiation. This is due to the decrease in the discharge rate and an increase in power output, respectively. The study will be useful for planning PV-based water pumping system for agricultural purposes.
12 Khamidov, M.; Ishchanov, J.; Hamidov, A.; Shermatov, E.; Gafurov, Zafar. 2023. Impact of soil surface temperature on changes in the groundwater level. Water, 15(21):3865. (Special issue: Climate and Water: Impacts of Climate Change on Hydrological Processes and Water Resources) [doi: https://doi.org/10.3390/w15213865]
Soil temperature ; Surface temperature ; Groundwater level ; Energy ; Foods ; Environmental factors ; Nexus approaches ; Regression analysis ; Precipitation ; Solar radiation ; Monitoring / Uzbekistan / Bukhara Region
(Location: IWMI HQ Call no: e-copy only Record No: H052401)
https://www.mdpi.com/2073-4441/15/21/3865/pdf?version=1699350450
https://vlibrary.iwmi.org/pdf/H052401.pdf
https://vlibrary.iwmi.org/pdf/H052401.pdf
(3.61 MB) (3.61 MB)
The relationship between the soil surface temperature and groundwater level is complex and influenced by various factors. As the soil surface temperature increases, water evaporates quickly from the soil, which can lead to a decrease in the groundwater level. In this study, we analyzed the impact of soil surface temperature on changes in the groundwater level in the Bukhara region of Uzbekistan using data from 1991 to 2020. The Bukhara region experiences regular water shortages, increased soil salinization, and inefficient energy in lift-irrigated areas, which is a typical constellation of challenges to the water–energy–food–environment (WEFE) nexus. The soil surface temperature data were collected from the Hydrometeorological Service Agency, whereas groundwater level data were obtained from the database of the Amelioration Expedition under the Amu-Bukhara Basin Irrigation Systems Authority. We used linear regression analysis and Analysis of Variance (ANOVA) tests to establish the significance of the relationship between the soil surface temperature and groundwater level, as well as the impact of the location of the groundwater level measurements. The results indicate that the model was a good fit to the data, and both the intercept and the soil surface temperature were significant factors that affected groundwater level. The results further suggest that the strength of the relationship between solar radiation and soil surface temperature is very high, with a correlation coefficient of 0.840. This means that when solar radiation increases, soil surface temperature also tends to increase. The analysis also showed that 53.5% of the changes in groundwater level were observed by the regression model, indicating a moderately correlated relationship between the groundwater level and soil surface temperature. Finally, higher solar radiation leads to higher soil surface temperature and higher evapotranspiration rates, which can lead to a decrease in groundwater level. As a result, we observe that the soil surface temperature determines changes in the groundwater level in the study region.
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