کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4579728 1630124 2007 18 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stochastic modelling of rainfall from satellite data
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
پیش نمایش صفحه اول مقاله
Stochastic modelling of rainfall from satellite data
چکیده انگلیسی

SummarySatellite-based rainfall monitoring is widely used for climatological studies because of its full global coverage but it is also of great importance for operational purposes especially in areas such as Africa where there is a lack of ground-based rainfall data. Satellite rainfall estimates have enormous potential benefits as input to hydrological and agricultural models because of their real time availability, low cost and full spatial coverage. One issue that needs to be addressed is the uncertainty on these estimates. This is particularly important in assessing the likely errors on the output from non-linear models (rainfall-runoff or crop yield) which make use of the rainfall estimates, aggregated over an area, as input. Correct assessment of the uncertainty on the rainfall is non-trivial as it must take account of
• the difference in spatial support of the satellite information and independent data used for calibration
• uncertainties on the independent calibration data
• the non-Gaussian distribution of rainfall amount
• the spatial intermittency of rainfall
• the spatial correlation of the rainfall fieldThis paper describes a method for estimating the uncertainty on satellite-based rainfall values taking account of these factors. The method involves firstly a stochastic calibration which completely describes the probability of rainfall occurrence and the pdf of rainfall amount for a given satellite value, and secondly the generation of ensemble of rainfall fields based on the stochastic calibration but with the correct spatial correlation structure within each ensemble member. This is achieved by the use of geostatistical sequential simulation. The ensemble generated in this way may be used to estimate uncertainty at larger spatial scales. A case study of daily rainfall monitoring in the Gambia, west Africa for the purpose of crop yield forecasting is presented to illustrate the method.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hydrology - Volume 346, Issues 1–2, 15 November 2007, Pages 33–50
نویسندگان
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