Precipitation trends in the main river headwaters of the southeastern Iberian Peninsula (1952–2021)
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Annual precipitation trends in the main river headwaters of the southeastern Iberian Peninsula using the Mann–Kendall test and the Sen’s slope estimator for the period 1952–2021 (70 years).
The analysis was conducted to identify statistically significant trends and quantify their magnitude, both in absolute and relative terms, at multiple meteorological stations.

Done in the framework of the project (PID2020-118797RB-I00 (Tool4Extreme)), funded by the Spanish Ministry of Science and Innovation and the Spanish State Research Agency (MCIN/AEI/10.13039/501100011033)).
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Methods:

Trends were evaluated following the methodology described in:

Estrela, M.J., Corell, D., Miró, J.J., Niclós, R. 2024. Analysis of Precipitation and Drought in the Main Southeastern Iberian River Headwaters (1952–2021). 
Atmosphere, 15(2):166. https://doi.org/10.3390/atmos15020166
The Mann–Kendall test was applied to detect the presence of significant monotonic trends, and the Sen’s slope estimator was used to quantify the rate of change.
All computations were performed at the station level for the complete period (1952–2021), and for stations with more than 40 years of observed data, as described in the paper.

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Technical information:

The dataset is provided in an Excel file containing the following variables for each meteorological station:

CodigoEst
    Identification code of the meteorological station.

Coord_Xutm
    UTM Easting coordinate (X), referenced to UTM zone 30N.

Coord_Yutm
    UTM Northing coordinate (Y), referenced to UTM zone 30N.

MannKendall_sig_pval_001
    Mann–Kendall trend test result at a 0.01 significance level (99.9%).
    Value 0 = non-significant; 1 or –1 = significant positive or negative trend.

MannKendall_sig_pval_005
    Mann–Kendall test result at a 0.05 significance level (95%).

MannKendall_sig_pval_010
    Mann–Kendall test result at a 0.10 significance level (90%).

Annual_Sen_slope
    Annual Sen’s slope of the precipitation trend (mm · year⁻¹).

Annual_Sen_slope_percent
    Annual Sen’s slope expressed as a percentage per year relative to mean annual precipitation.

Sen_total_periodo
    Total absolute change in annual precipitation over 1952–2021, derived from the Sen’s slope (mm).

Sen_percent_total_periodo
    Total relative change in annual precipitation over 1952–2021 (%).

Media_anual_mm
    Mean annual precipitation (mm) estimated from the Sen’s slope.

Media_inicial_mm
    Estimated precipitation for the first year (1952) of the series (mm).

Media_final_mm
    Estimated precipitation for the last year (2021) of the series (mm).

Stations with missing values correspond to cases where the Mann–Kendall test did not identify significant trends.

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References:

[1] Estrela, M.J., Corell, D., Miró, J.J., Niclós, R. 2024. Analysis of Precipitation and Drought in the Main Southeastern Iberian River Headwaters (1952–2021). 
Atmosphere, 15(2):166. https://doi.org/10.3390/atmos15020166

[2] Mann, H.B., 1945. Nonparametric test against trend. Econometrica 13 (3), 245–259.
https://doi.org/10.2307/1907187.

[3] Kendall, M.G., 1962. Rank Correlation Methods. Charles Griffin Book Series, London.

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Funding:
The study had the financial support of the projects Tool4Extreme PID2020-118797RB-I00 funded by MCIN/AEI/10.13039/501100011033 and PROMETEO/2021/016 funded by Generalitat Valenciana.

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Contact:
For any question contact the Principal Researcher of the project (PID2020-118797RB-I00 (Tool4Extreme)
funded by the Spanish Ministry of Science and Innovation and the Spanish State Research Agency (MCIN/AEI/10.13039/501100011033)): Raquel.niclos@uv.es
