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Testing
the accuracy of rainfall forecast for its usability in planning smart
agricultural practices and its user response
A.N. Islam1*,
R.L. Deka2, K. Medhi2 and K. Sarmah2
1Department
of Natural Resource Management, College of Horticulture and Farming System
Research (Assam Agricultural University), Nalbari-781 336, India
2Department
of Agricultural Meteorology, College of Agriculture (Assam Agricultural
University), Jorhat-785 013, India
Received: 30 June
2025 Revised: 22 February 2026 Accepted:
16 April 2026
*Corresponding Author Email: athar.islam@aau.ac.in
*ORCiD: https://orcid.org/0009-0001-7712-1682
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Abstract
Aim: Compute the
accuracy of district level rainfall forecast issued during last five years
and compare its accuracy with the block level forecast and evaluate its
usability by farmers.
Methodology: 5-years rainfall
forecasts were verified qualitatively by using Ratio Score (RS) and
quantitatively by using statistical technique like RMSE. The error structures
for verification of quantitative precipitation were also followed to
discriminate between probability of success and failure forecasts. 5-Day
Block level forecasted rainfall was also verified for three blocks viz.,
Kaliapani, Jorhat and Titabor, and the accuracy was compared with the
district level forecasted data for assessing its practical utility. Further,
based on the agromet advisory bulletins (AABs) disseminated, feedback were
collected from 700 respondents regarding the field level usability of the
AABs and the weather forecasts issued during the study period.
Results: Qualitative
verification of district level rainfall forecasts from 2018-19 to 2022-23
showed that, Ratio Score (RS) had a good acceptability with a mean score of
72% on annual basis and 80%, 76%, 67% and 66% during winter, post-monsoon,
monsoon and pre-monsoon seasons, respectively. Quantitatively, 65% rainfall
forecasts were found correct and usable on an annual basis with highest
probability of success during winter (96%; i.e., highly accurate) and lowest
during monsoon (30%). Probability of success along with the RS of the block
level rainfall forecasts were somewhat fair when compared with the district
level forecast. Further, feedback analysis from 700 respondents revealed that
86% of the farmers followed the agromet advisories and out of the total sample,
81% were satisfied with the rainfall forecast and 17% farmers were partially
satisfied.
Interpretation: District level
rainfall forecast had a good acceptability with fair quantitative and
qualitative forecast accuracy. Though the qualitative acceptability of
rainfall forecast during monsoon was satisfactory, there was a lag in
forecast of the exact quantum of rainfall occurred, which resulted in reduced
probability of success with high RMSE values for the season. Further, Block
level forecast accuracy showed slightly better results in most of the cases
and therefore it can be effectively utilized over district level rainfall
forecast for formulation and dissemination of micro level smart weather-based
advisories.
Key
words:
Accuracy, Agromet Advisory Bulletins, Block level, District level,
Qualitative, Quantitative, Rainfall forecast
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