Rainfall is an extremely variable parameter in both space and time. Rain gauge density is very crucial in order to quantify the rainfall amount over a region. The level of rainfall accuracy is highly dependent on density and distribution of rain gauge stations over a region. Indian Space Research Organisation (ISRO) have installed a number of Automatic Weather Station (AWS) rain gauges over Indian region to study rainfall. In this paper, the effect of rain gauge density over daily accumulated rainfall is analyzed using ISRO AWS gauge observations. A region of 50 km × 50 km box over southern part of Indian region (Bangalore) with good density of rain gauges is identified for this purpose. Rain gauge numbers are varied from 1-8 in 50 km box to study the variation in the daily accumulated rainfall. Rainfall rates from the neighbouring stations are also compared in this study. Change in the rainfall as a function of gauge spacing is studied. Use of gauge calibrated satellite observations to fill the gauge station value is also studied. It is found that correlation coefficients (CC) decrease from 82% to 21% as gauge spacing increases from 5 km to 40 km while root mean square error (RMSE) increases from 8.29 mm to 51.27 mm with increase in gauge spacing from 5 km to 40 km. Considering 8 rain gauges as a standard representative of rainfall over the region, absolute error increases from 15% to 64% as gauge numbers are decreased from 7 to 1. Small errors are reported while considering 4 to 7 rain gauges to represent 50 km area. However, reduction to 3 or less rain gauges resulted in significant error. It is also observed that use of gauge calibrated satellite observations significantly improved the rainfall estimation over the region with very few rain gauge observations.
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http://dx.doi.org/10.1186/2193-1801-2-311 | DOI Listing |
Health Phys
January 2025
Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109-2104.
Combining a traditional weather station with radiation monitors draws the public's attention to the magnitude of background radiation and its typical variation while providing early indications of unplanned radiological releases, such as nuclear power plant accidents or terrorist acts. Several networks of combined weather and radiation monitoring sensors exist, but these fail to be affordable for broad distribution. This work involves creating an affordable system to accumulate data from multiple locations into a single open-source database.
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November 2024
Department of Civil, Environmental, and Geomatics Engineering, Florida Atlantic University, Boca Raton, FL, 33431, USA.
Glob Chang Biol
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Environmental Defense Fund, Boulder, Colorado, USA.
Methane emissions by global wetlands are anticipated to increase due to climate warming. The increase in methane represents a sizable emissions source (32-68 Tg CH year greater in 2099 than 2010, for RCP2.6-4.
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October 2024
Laboratory of Environmental Monitoring and Modelling for the Sustainable Development (LaMMA), 50019 Florence, Italy.
Accurate precipitation measurement is critical for managing flood and drought risks. Traditional meteorological tools, such as rain gauges and remote sensors, have limitations in resolution, coverage, and cost-effectiveness. Recently, the opportunistic use of microwave communication signals has been explored to improve precipitation estimation.
View Article and Find Full Text PDFThe distinct spatiotemporal characteristics of the hourly intense precipitation (HIP) over the Pearl River Delta (PRD) and the impact of urbanization before and after the monsoon onset from 1972 to 2021 have been investigated using the hourly rain gauge data, nighttime lights data, and land use data. The results show a significant decreasing trend of HIP during the pre-monsoon onset period and a notable increasing trend during the post-monsoon onset period over the past five decades. However, compared to rural areas, rapid urbanization in the PRD after the mid-1990s weakens the HIP reduction, especially in the inland cities of PRD before the onset of the monsoon and enhances the HIP increase, particularly in the southeast inland and west coast cities after the onset of the monsoon.
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