Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability

The evolution of seasonal cycle and interannual rainfall, the number of rainy days and daily rainfall types, dry spells frequency of occurrence, onset/cessation/length of rainy season, sowing dates, and the duration of the cropping period, are investigated at local (individual sites) and sub-regiona...

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Main Authors: Salack, S., Muller, B., Gaye, A.T.
Format: Journal Article
Language:Inglés
Published: Springer 2011
Online Access:https://hdl.handle.net/10568/120215
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author Salack, S.
Muller, B.
Gaye, A.T.
author_browse Gaye, A.T.
Muller, B.
Salack, S.
author_facet Salack, S.
Muller, B.
Gaye, A.T.
author_sort Salack, S.
collection Repository of Agricultural Research Outputs (CGSpace)
description The evolution of seasonal cycle and interannual rainfall, the number of rainy days and daily rainfall types, dry spells frequency of occurrence, onset/cessation/length of rainy season, sowing dates, and the duration of the cropping period, are investigated at local (individual sites) and sub-regional scales (four different rainfall zones) using daily records of station data (83 sites) over Senegal. In the limits of a case study, these analyses complement and update previous studies conducted in the extreme Western Sahel (11–16° N and 20° W–10° E). The results unveil noticeable evolution of some of these rain-based factors in the recent periods as compared to the previous dry years. In the regions recording less than 800 mm/year (Sudan and Sahel sub-regions), the positive and statistically significant trends of rainfall amount are associated with new features of increasing frequency of short dry spell category, increasing number of some classes of extreme daily rainfall amounts and shifts in the peak number of rainy days. At sub-regional scales, the starting years (or change points) the magnitude and the signs of the new trends are unevenly distributed in the period post-1990. Earlier and higher amplitude changes are found at local scales and not less than one third of the sites in each sub-regional network are significantly affected. The extreme Southern sub-region exhibits no significant changes. Statistically significant trends are not observed on daily rain records ≤10 mm, onset/cessation dates, successful sowing dates, rainy season length, cropping period, medium and extreme dry spell categories. Rather, some of these factors such as the successful sowing date and the cropping season length exhibit significant variability. The onset (cessation) dates of the rainy season are followed (preceded) by extreme dry spell episodes. In the perspectives of climate impact assessments on the local agriculture a sub-regional periodic synopsis of the major rain-based factors of interest to agricultural applications are provided at the end the paper. They document some important internal variability patterns to reckon with in a multi-decadal work over the 1950–2008 period for this region.
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spelling CGSpace1202152025-01-27T15:00:52Z Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability Salack, S. Muller, B. Gaye, A.T. The evolution of seasonal cycle and interannual rainfall, the number of rainy days and daily rainfall types, dry spells frequency of occurrence, onset/cessation/length of rainy season, sowing dates, and the duration of the cropping period, are investigated at local (individual sites) and sub-regional scales (four different rainfall zones) using daily records of station data (83 sites) over Senegal. In the limits of a case study, these analyses complement and update previous studies conducted in the extreme Western Sahel (11–16° N and 20° W–10° E). The results unveil noticeable evolution of some of these rain-based factors in the recent periods as compared to the previous dry years. In the regions recording less than 800 mm/year (Sudan and Sahel sub-regions), the positive and statistically significant trends of rainfall amount are associated with new features of increasing frequency of short dry spell category, increasing number of some classes of extreme daily rainfall amounts and shifts in the peak number of rainy days. At sub-regional scales, the starting years (or change points) the magnitude and the signs of the new trends are unevenly distributed in the period post-1990. Earlier and higher amplitude changes are found at local scales and not less than one third of the sites in each sub-regional network are significantly affected. The extreme Southern sub-region exhibits no significant changes. Statistically significant trends are not observed on daily rain records ≤10 mm, onset/cessation dates, successful sowing dates, rainy season length, cropping period, medium and extreme dry spell categories. Rather, some of these factors such as the successful sowing date and the cropping season length exhibit significant variability. The onset (cessation) dates of the rainy season are followed (preceded) by extreme dry spell episodes. In the perspectives of climate impact assessments on the local agriculture a sub-regional periodic synopsis of the major rain-based factors of interest to agricultural applications are provided at the end the paper. They document some important internal variability patterns to reckon with in a multi-decadal work over the 1950–2008 period for this region. 2011-11 2022-07-20T06:45:37Z 2022-07-20T06:45:37Z Journal Article https://hdl.handle.net/10568/120215 en Limited Access Springer Salack, S. Muller, B. Gaye, A.T. Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability. Theoretical and Applied Climatology. 2011, Volume 106, Issue 1-2: 1–22.
spellingShingle Salack, S.
Muller, B.
Gaye, A.T.
Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability
title Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability
title_full Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability
title_fullStr Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability
title_full_unstemmed Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability
title_short Rain-based factors of high agricultural impacts over Senegal. Part I: integration of local to sub-regional trends and variability
title_sort rain based factors of high agricultural impacts over senegal part i integration of local to sub regional trends and variability
url https://hdl.handle.net/10568/120215
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