Co esponding au ho : Mamadou Bhoyi BALDÉ
Copy igh © 2025 Au ho (s) e ain he copy igh o his a icle. This a icle is published unde he e ms o he C ea i e Commons A ibu ion License 4.0.
Con ibu ion has he s udy o he Impac s o indus ial ac i i ies on he es ua ine
ecosys em o he Nunez Ri e , Case o clima ic pa ame e s
Mamadou Bhoyi BALDÉ 1, *, Mamadou Dioulde SOW 2, Abdoulaye BAH 3 and Mamadou Tanou DIALLO 4
1 PhD. Sc. En i onmen , Resea che a he Depa men o En i onmen al Geology, En i onmen al Labo a o y, Ma ine and
Coas al Resea ch Cen e o Guinea (CEREMAC-G) o me Scien i ic Resea ch Cen e o Conak y Rogbané (CERESCOR).
2 PhD. Sc. En i onmen , Resea che o he Depa men o Hyd obiology, Labo a o y o Ich hyology o he Ma ine and
Coas al Resea ch Cen e o Guinea (CEREMAC-G) o me Scien i ic Resea ch Cen e o Conak y Rogbané (CERESCOR).
3 PhD. Sc. En i onmen , Depa men o En i onmen al Geology, Scien i ic Sec e a y o he Doc o al School o he Ma ine
and Coas al Resea ch Cen e o Guinea (CEREMAC-G) o me Scien i ic Resea ch Cen e o Conak y Rognonné (CERESCOR).
4 Resea che om he Depa men o En i onmen al Geology, En i onmen al Labo a o y, o he Ma ine and Coas al
Resea ch Cen e o Guinea (CEREMAC-G) o me ly he Scien i ic Resea ch Cen e o Conak y Rogbané (CERESCOR).
Wo ld Jou nal o Ad anced Resea ch and Re iews, 2025, 27(02), 1247-1258
Publica ion his o y: Recei ed on 05 July 2025; e ised on 12 Augus 2025; accep ed on 14 Augus 2025
A icle DOI: h ps://doi.o g/10.30574/wja .2025.27.2.2834
Abs ac
Bauxi e mining is a ele an sou ce o economic and social de elopmen o coun ies ha ha e his na u al esou ce. I
eme ges om he indings and ex ensi e li e a u e e iews ha his exploi a ion has di ec impac s on es ua ine
ecosys ems h ough he es ablishmen o po s and mining indus ies, hence he oppo uni y o ou s udy en i led "
Con ibu ion has he s udy o he impac s o indus ial ac i i ies on he es ua ine ecosys em o he Nunez Ri e . The
ield obse a ion indica es ha despi e he e o s made by he au ho i ies h ough he compe en ins i u ions and
in es o s, he educ ion o en i onmen al impac s caused by his mining o en poses p oblems linked o a lack o
capaci y and means o deal wi h hem, as e ealed by ou s udy ca ied ou on he Nunez es ua y. The hypo hesis o ou
heme su icien ly p o es ha he nega i e e ec s o majo pollu an s in he Nunez Ri e es ua y due o he ins alla ion
o indus ial uni s, combined wi h he impac s linked o clima e change a ec ing he locali y, con ibu e o he
dys unc ion o he es ua y, and consequen ly, o he educ ion o oppo uni ies and ecosys em se ices o e ed by he
Nunez Ri e . In addi ion, nume ous s udies ha e been conduc ed on ai quali y, he measu emen o a ious
physicochemical pa ame e s ( empe a u e, pH, elec ical conduc i i y, salini y, u bidi y, dissol ed oxygen, ni a es,
ni i es, suspended ma e , dissol ed solids and phospha e) as well as he iden i ica ion and quan i ica ion o ace me al
elemen s (Cu, Cd, Ni, Pb, and Zn) in he wa e s o he Nunez Ri e . Howe e , gi en he high a iabili y o he eco ded
alues o hese physicochemical pa ame e s, he concen a ions and po en ial oxici y epo ed in he li e a u e o
hese elemen s, i seemed necessa y o s udy hem while add essing he clima ic con ex in which hese pollu ion
p ocesses ake place. The Eu opean Wa e F amewo k Di ec i e has se a moni o ing o me als such as cadmium, lead,
nickel and me cu y. Howe e , we ind i in e es ing o expand ou esea ch o he 5 mos lis ed me als in en i onmen al
s udies and he cha ac e is ic pa ame e s o wa e in gene al. Thus ou gene al objec i e is o s udy he le el o pollu ion
and i s impac on he unc ioning o he es ua ine ecosys em o he Nunez Ri e due o he ins alla ion and ope a ion o
indus ial uni s aking in o accoun he e olu ion o he clima ic cha ac e is ics o he s udy a ea. wi h he ollowing
speci ic objec i es: 1) E alua e he impac o pollu ion on he ecology o he Nunez es ua y aking in o accoun he
e olu ion o clima ic condi ions; 2) P opose mi iga ion and adap a ion measu es in acco dance wi h he le el o
pollu ion. ). Thus ele en sampling si es se ed as a s udy amewo k. These samples we e analyzed a he CERE / UGANC
labo a o y, and a he Guinéo Allemand analysis labo a o y in Land éah in Conak y. We used Wo ld Bank da a o he
analysis o clima e a iabili y in ou s udy a ea o he pe iod 1950-2020. The esul s o all hese de ailed analyses a e
p esen ed in Chap e 3. A summa y o he esul s, ope a ional pe spec i es and possible esea ch a e also men ioned.
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Keywo ds: Indus ial ac i i ies; Es ua ine ecosys ems; En i onmen al impac s; Pollu ion
1. In oduc ion
( Ch is ophe , 2011) d aws on he Ame ican expe ience o p o ide a con ibu ion o unde s anding he unc ioning o
in eg a ed coas al and ma ine zone managemen (ICMZ) and he ma i imiza ion p ocess, o which he no es a no able
ad ance eco ded by F ance. His e lec ion on ICMZ demons a es he impo ance o his ecological zone, which is
pa icula ly sensi i e o human ac i i ies. Acco ding o him, his zone con ains he majo i y o he plane 's biological
di e si y and mo e han 60% o he wo ld's popula ion is now li ing he e, which ep esen s app oxima ely 3.8 billion
indi iduals li ing in a s ip o land ha does no exceed 100 kilome e s om he sho eline. Acco ding o his au ho , by
ex apola ing he da a a ailable in he coun ies ha ha e made he calcula ion, i can be es ima ed ha he numbe o
kilome e s o na u al sho eline disappea ing in he wo ld due o de elopmen is on a e age be ween 5 and 10
kilome e s each day. The ma ine zone is inc easingly subjec o human ac ion e e y day. This e y ele an gene al
eali y is simila o ha o ou a ea which is an in eg al pa o he Guinean coas al zone.
Acco ding o Ch is ian Lé êque (2020), i was in 1960 ha he en i onmen al sensi i i y o he popula ion ook o in
iew o human ac i i ies ha ha e an impac on he en i onmen . Rachel Ca lson's book, "Silen Sp ing" (1962),
denounces he consequences o he use o pes icides, in pa icula DDT, which has become emblema ic. This posi ion is
o en conside ed one o he ounding ac s o en i onmen al hough . Bu kina Faso is a coun y whose economy has
always been ueled by he esou ces o ag icul u e as well as hose o li es ock, and his un il 2009. Nowadays, he
coun y is expe iencing an unp eceden ed mining boom. The in e na ional con ex , bu also he adop ion o i s new
mining code in 2003 (Law No. 031-2003/AN o May 8, 2003), mo e a o able o p i a e in es men , a e he main causes
o his p owess o he coun y in he mining sec o . Indeed, since 2009, gold has been Bu kina Faso's leading expo
p oduc ; and his aises a lo o hope bu also many conce ns abou he sus ainable managemen o his esou ce. In
such a con ex , he la ges mine Essakane SA loca ed in he a no h o he coun y, can se e as a mi o o add ess
hese a ious ques ions. The in e es in he con ex o ou s udy is pa icula ly ocused on he impac s ha mining
ac i i y could ha e on human and en i onmen al heal h .
Wes A ican coas al a eas in gene al, and Guinean coas al a eas in pa icula , a e home o majo indus ies, pa icula ly
in he mining, ag ibusiness and ou ism sec o s, as well as u ban and coas al esidences, which gene a e was e and
pollu ion. Many coas al a eas do no ha e adequa e was e and was ewa e ea men sys ems. As a esul , la ge olumes
o un ea ed was ewa e and was e a e discha ged in o he en i onmen , pollu ing he soil and wa e . In Kamsa and
i s su oundings, was ewa e discha ges a e la gely esponsible o he deg ada ion o he coas al en i onmen al
quali y. The immedia e nega i e e ec el in he sho e m is he poo heal h o con inen al and ma ine auna and lo a.
Fo ana (e al, 2019) .
Acco ding o Rachid A. (2011), 80% o ma ine pollu ion is a ibu able o human ac i i ies o land-based o igin,
na iga ion, and he in oduc ion o in asi e species (such as ce ain ma ine algae). O e exploi a ion o ishe ies
esou ces, deg ada ion, agmen a ion, and habi a loss a e all ac o s esponsible o he e osion o ma ine biodi e si y.
Exace ba ed by clima e change, his an h opiza ion h ea ens o des oy he agile balance o ma ine ecosys ems and
he biodi e si y hey con ain.
E ic D. M. ( 2019 ) eaches us ha Clima e change is ecognized by mos scien is s and leade s. Fa om being a simple
inc ease in a e age empe a u es, clima e change is an ala ming phenomenon. Among i s mos se ious consequences
a e wa e sho ages in ce ain egions, ising sea le els, changing p ecipi a ion pa e ns a ound he wo ld, ocean
acidi ica ion, and he eme gence o nume ous diseases. Fo una ely, he imbe indus y and o es ecosys ems a e he e
o s o e g eenhouse gases. Howe e , hese ecosys ems may be ulne able o clima e change. This is why i is necessa y
o implemen o he s a egies. Fo example, we should a o he mos esis an species and modi y p ac ices, e c. In
sho , we mus adap o clima e change. To mi iga e i , i would be p e e able o no longe eso o ossil uels ha use
oil, coal, and gas. Indeed, hei use no only causes he deple ion o esou ces, bu also esul s in signi ican CO2
emissions in o he a mosphe e, hus p omo ing global wa ming. In he ace o u u e global clima e change, he UNFCCC
(Uni ed Na ions F amewo k Con en ion on Clima e Change ) has p oposed o ocus on wo undamen al s a egies o
esponding o clima e change: mi iga ion and adap a ion (UNFCCC, 2006; Niasse e al. 2004). While mi iga ion seeks o
limi clima e change by educing g eenhouse gas (GHG) emissions, adap a ion aims o alle ia e ad e se impac s h ough
a wide ange o ac ions on speci ic sys ems (Füssel and Klein, 2002). F.Ma a (2010)
Fo es managemen and main aining soil quali y a e complemen a y. Sus ainable o es managemen is essen ial o
soils o con inue p oducing o ganic ma e o biomass. As a eminde , o ganic ma e in o es soil plays a cen al ole
in he igh agains clima e change because i s o es ca bon. Howe e , when i decomposes, his ca bon is eleased. I
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can also be said ha p ese ing soil quali y is essen ial o p e en ing heal h p oblems ha could a ec humans. Also
wi h a iew o adap ing o clima e change, ecosys em biodi e si y should be p o ec ed by implemen ing a ious
measu es. Co al ee s, i e s, s eams, and moun ains a e h ea ened by clima e change, acco ding o a publica ion om
he Sec e a ia o he Con en ion on Biological Di e si y. Because o his phenomenon, many species ha e also been
o ced o change hei mig a ion pa e ns o seasonal ac i i ies. Among he bigges en i onmen al challenges a e hose
ela ed o clima e change, soil quali y, and biodi e si y.
As o M . Diallo ( e al 2019) he Guinean coas line is cha ac e ized by he p esence o 300 km o coas line, mang o es,
ma ine p o ec ed a eas and signi ican ishe y biodi e si y. I is he si e o a ious socioeconomic ac i i ies, including
he exploi a ion o ishe y esou ces. Howe e , hese esou ces a e h ea ened by he cons uc ion o nume ous mine al
po s. This si ua ion isks causing se ious damage o ishe y biodi e si y in he absence o an adequa e impac
assessmen model o make an in o med choice o en i onmen ally iendly de elopmen scena io. La ge -scale mining
ope a ions ha e he po en ial o con ibu e signi ican ly o ai pollu ion, pa icula ly in he ope a ional phase.
US En i onmen al P o ec ion Agency, 2009- i le40- ol15 h p://www.gpo.go / dsys/ .
A he cu en s age o knowledge, he ques ion ha a ises is how, in a con ex o clima e change, indus ial ac i i ies
could con ibu e o he s uc u al and unc ional modi ica ion o he es ua ine ecosys em o he Nunez Ri e .
The nega i e e ec s o majo pollu an s in he Nunez Ri e es ua y due o he ins alla ion o indus ial uni s, combined
wi h he impac s o clima e change a ec ing he locali y, con ibu e o he dys unc ion o he es ua y, and consequen ly
o he educ ion o oppo uni ies and ecosys em se ices o e ed by he Nunez Ri e .
Goals Gene al objec i e
To s udy he le el o pollu ion and i s impac on he unc ioning o he es ua ine ecosys em o he Nunez Ri e due o
he ins alla ion and ope a ion o indus ial uni s, aking in o accoun he e olu ion o he clima ic cha ac e is ics o he
s udy a ea.
Speci ic objec i es
• E alua e he impac o pollu ion on he ecology o he Nunez es ua y, aking in o accoun changes in clima ic
condi ions.
• P opose mi iga ion and adap a ion measu es in acco dance wi h he le el o pollu ion.
1.1. P esen a ion o he s udy a ea:
The Republic o Guinea is loca ed in he wes e n pa o he A ican con inen . I is loca ed be ween he 8 h and 12 h
deg ees o no h la i ude) and be ween he 8 h and 15 h deg ees o wes longi ude. I is bo de ed o he no h by
Senegal, o he no hwes by Guinea-Bissau, o he wes by he A lan ic Ocean, o he sou h by Sie a Leone and Libe ia,
o he eas by I o y Coas and o he no heas by Mali. I s a ea is 245,857 km².
Ecologically subdi ided in o ou na u al egions (Lowe Guinea, Middle Guinea, Uppe Guinea and Fo es Guinea), i is
cha ac e ized by a wo-season clima e: a d y season and a ainy season, he du a ion and dis ibu ion o which a y
acco ding o he na u al egions om 3 mon hs (in he No h) o 9 mon hs (in he Sou heas ). Rain all a ies om 4,000
mm (Coas al Region) o 1,300 mm (Uppe Guinea); p ecipi a ion peaks e e ywhe e in July and Augus . Guinea is
cha ac e ized by he e ogeneous soils and an abundan hyd og aphic ne wo k. The nume ous i e s and s eams ha
o igina e he e wa e all he neighbo ing coun ies and make Guinea he wa e owe o he sub- egion. Today,
un o una ely, his wa e owe is h ea ened by he ex en o he d ough , which is he ha m ul consequence o human
ac ions o a ious o igins and clima e change.
Ou s udy ocuses on Lowe Guinea o Ma i ime Guinea, which is home o ou s udy a ea (Kamsa ) loca ed in he
adminis a i e egion o Boké), his egion co e s all o Guinea's ma ine and coas al ecosys ems. Ma i ime Guinea co e s
15% o he coun y's o al a ea (36,200 km 2 ) and includes a ma shy coas al a ea behind which ex ends a plain ising
slowly o he oo o he Fou ah-Djallon hills. I s cu en popula ion densi y is es ima ed a 29 inhabi an s / km 2 and i s
popula ion g ow h is es ima ed a 2.8%. ( e e o DNS da a] .
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Figu e 1 Map o he Republic o Guinea
Figu e 2 Sigh o he Nunez es ua ine wi h di e en collec on poin s
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Table 1 Geog aphic coo dina es o he sample collec ion poin s
No.
Sampling poin s
Geog aphic coo dina es
1
Po Nene
10407115 N / 14364304W
2
CBG GAC Te minal
10667914 N / 14607735W
3
Wi ness s a ion
10636136 N / 14638576W
4
Taidy
10734779 N / 14543816W
5
Tissaly
10694131N / 14633022W
6
Dahomey
10749705 N / 14556970W
7
Kan a andé
10826358 N / 14544165W
8
Legbane
10810252 N /14530271W
9
Diandiaya
10811442 N / 14531050W
10
Dougoula
10760490 N / 14554885W
11
Ta ensa po
10734779 N / 14573818 W
1.2. Physical con ex
The p esen s udy, which conce ns he ci y o Kamsa and i s su oundings, conce ns an a ea wi h clima ic, geological,
geomo phological and oceanological cha ac e is ics. I he e o e seems use ul o us, be o e app oaching he speci ic
analyses, o p esen he gene al physical amewo k in o de o ealize all he na u al condi ions o he a ea which could
unde go s uc u al and unc ional modi ica ions.
1.2.1. Clima e
The clima e o ou s udy a ea is ha o ma i ime Guinea, he e o e o he sub-Guinean ype
Ma i ime Guinea is cha ac e ized by a opical and humid clima e wi h wo seasons: The d y season (mid-Oc obe o
Ap il) is cha ac e ized by ho , d y winds ( he Ha ma an) blowing om he eas and no heas , ca ying ho ai and dus
om he Saha a Dese o he Gul o Guinea; and he ainy season (which las s he es o he yea ) which b ings hea y
monsoon ains, high humidi y, and sou hwes e ly winds. A e age daily empe a u es also a y only sligh ly h oughou
he yea . The e a e no long- e m clima e s a ions in he icini y o Kamsa o Sanga édi. Boké, loca ed abou 45 km
inland, no heas o Kamsa , and 70 km sou hwes o Sanga édi, has long- e m clima e da a. A summa y o s a is ics
based on da a collec ed by he Wo ld Me eo ological O ganiza ion is a ailable upon eques . De ailed his o ical da a on
wea he and clima e condi ions a e gene ally no a ailable o Kamsa o Sanga édi. (ESIA o he CBG Mine Ex ension
P ojec Chap e 2 Physical En i onmen S udy , 2014 p ojec numbe : 13ea0039).
1.3. Cha ac e iza ion o clima ic pa ame e s
1.3.1. Tempe a u e
A mosphe ic empe a u e is he deg ee o speci ic hea o he ai in a loca ion a a gi en ime. The empe a u e o he
a mosphe e depends on he amoun o sunshine o sola adia ion. ( h ps://www.aquapo ail.com/de ini ion-4925-
clima .h ml)
1.3.2. Da a and p ocessing me hods
In Sahelian A ica, majo en i onmen al and socio-economic p oblems a e mainly linked, di ec ly o indi ec ly, o soil
deg ada ion, de o es a ion o na u al habi a s, wa e sho ages, ecu ing d ough s, loods, po e y and lack o access
o essen ial se ices. To unde s and hese phenomena in he Nunez Ri e es ua y, we used, on he one hand,
me eo ological and hyd ological da a om he Boké Region collec ed by he Wo ld Bank. The analysis o hese da a was
ca ied ou using se e al me hods including s a is ical analysis echniques (Kendall a e).
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1.3.3. Desc ip ion o clima e da a
The clima e da a se ies we e p o ided by he Wo ld Bank. These p o ide o he pa ame e s such as minimum and
maximum empe a u es, ela i e humidi y and e apo a ion no a ailable om ain all s a ions. The clima e da a
analyzed co espond o daily ain all. The pe iods co e ed by he obse a ion se ies a e 70 yea s (Guinea and Boké)
and 30 yea s (Guinea and Boké). The analyses we e ca ied ou o e he pe iods 1950-2020 and 1991-2020.
The 1950-2020 clima e no mal was chosen as he e e ence o calcula ing anomalies. CCKP
(h ps://clima eknowledgepo al.wo ldbank.o g/coun y/guinea)
1.3.4. Me hods o p ocessing and analyzing clima e da a
Depending on he na u e o he da a, di e en s a is ical me hods and ools we e used o hei p ocessing and analysis.
Mul i a ia e analysis me hods using eg ession and co ela ion we e applied o he ime se ies o p ecipi a ion and
empe a u e in o de o calcula e ain all indices on he one hand and o cha ac e ize he ain all egime in ime and
space on he o he . De ini ion and calcula ion o p ecipi a ion and empe a u e indices among he conce ns ela ed o
clima e change, whe he in he Boké egion o in Guinea, he possible modi ica ion o he equency o ex eme e en s,
and no only g adual changes in he a e age cha ac e is ics o he clima e, a ouses majo in e es in he scien i ic
communi y, gi en hei an icipa ed e ec s on he na u al and human en i onmen . Despi e hei a i y, hese e en s
cons i u e impo an ac o s o ulne abili y o popula ions (Hough on e al. 2001), pa icula ly ex eme p ecipi a ion
e en s (o absence o p ecipi a ion, i.e. d ough ) in Guinea in gene al. To unde s and hese phenomena, he use o
indices de elopmen has been sugges ed as a ela i ely simple way o analyze changes in p ecipi a ion e en s
po en ially ha ing an e ec on he na u al and human en i onmen (Dubuisson and Moisselin, 2006; Gachon e al.
2005). Se e al in e na ional esea ch g oups ha e de eloped a s anda d me hodology o calcula e hese indices, such
as he ETCCDMI p ojec (Expe Team Clima e De ec ion Moni o ing and Indices), o he Eu opean STARDEX p ojec
(STA is ical and Regional dynamical Downscaling o EX emes o Eu opean egions). The CLIVAR CLIma e VARiabili y
and p edic abili y g oup (Ka l e al., 1996; Ka l e al., 1999; F ich e al., ( 2002) o he WCRP (Wo ld Clima e Resea ch
p og am) o he WMO (Wo ld Me eo ological O ganiza ion) p oposed a lis o di e en indices calcula ed om he daily
se ies o su ace a iables (p ecipi a ion and empe a u e). The use o hese indices made i possible in ou s udy o
highligh he links be ween luc ua ions in he in ensi y, equency and du a ion o we /d y sequences. F om he ime
se ies o daily p ecipi a ion and a mosphe ic empe a u e o Boké and Guinea, he in e annual luc ua ions in a e age
p ecipi a ion a e analyzed o e he pe iod 1950-2020 using he da a in he appendix: F om Table E2, he mo ing
a e age was calcula ed o e he same pe iod and g aphically supe imposed on he s anda dized in e annual anomalies
(Table E6). In a-seasonal dis ibu ion and a iabili y mon hly cumula i e p ecipi a ion. Fo analysis pu poses, ables
E1 and E3 con aining he ime se ies o mon hly a e age p ecipi a ion om Ap il o Oc obe we e used o cha ac e ize
he p ecipi a ion dis ibu ion pa e n o e he pe iod 1991-2020 on an analysis o mon hly a e age cumula i e
p ecipi a ion in o de o assess he a iabili y o hei con ibu ion compa ed o he clima e no mal
In o de o analyze he in e annual a iabili y o he indices and basic a iables ela i e o he e e ence pe iod o 1950-
2020, s anda dized anomalies we e calcula ed om he a ailable da a, using he ollowing o mula:
𝐴𝑗=(𝑋𝑦−𝑋𝑦
𝜎𝑦)……….(1)
Whe e X is he a iable conside ed
Y= yea
𝐴𝑗= anomaly o yea j
𝑋𝑦= a e age o he a iable in he yea conside ed
𝑋𝑦 = a e age o he index (pe iod conside ed, Ap il o Oc obe ) calcula ed o e he e e ence pe iod (1961 o 1990) o
(1950 o 2020)
𝜎𝑦 = in e annual s anda d de ia ion o he y index (Ap il-Oc obe pe iod) calcula ed o e he e e ence pe iod
The indices a e calcula ed o Guinea and Boké o each o he mon hs om Janua y o Decembe ( o each yea co e ing
he pe iod om 1950 o 2020). B
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P ecipi a ion: These a e all o ms o hyd ome eo om a mosphe ic wa e in he o m o clouds ha all o he ea h's
su ace h ough p ecipi a ion ( ain, snow, hail , e c.). h ps://www.aquapo ail.com/de ini ion-4925-clima .h ml
S anda dized P ecipi a ion Index (SPI):
The SPI is an index o measu ing me eo ological d ough . I is a p obabili y index based solely on p ecipi a ion. The
p obabili ies a e s anda dized so ha an SPI o 0 indica es a median p ecipi a ion amoun ( ela i e o a 30-yea a e age
e e ence clima ology). The index is nega i e o d ough s, and posi i e o we condi ions (Mc Kee e al . 1993).
The main ad an ages o SPI a e:
• I only equi es mon hly ain all;
• I can be compa ed o egions wi h di e en clima es;
• No maliza ion o he index makes i possible o de e mine he a i y o a d ough .
The use o his index is u he ecommended by he Wo ld Me eo ological O ganiza ion.
• SPI Values and Meaning:
• SPI > 0: mo e p ecipi a ion han no mal (we e );
• SPI < 0: less p ecipi a ion han no mal (d ie );
• -0.99 < SPI < +0.99: p ecipi a ion close o no mal;
• SPI < - 2.0: ex emely d y;
• SPI > 2.0: ex emely humid.
h p://www.d ias-clima . /accompagnemen /sec ions/183
2. Resul s, in e p e a ions and discussions
2.1. Cha ac e iza ion o clima ic pa ame e s
He e he clima ic pa ame e s a e analyzed aking in o accoun he clima ic no mal (1950-1990 o 1980-2020) which
a e mainly, empe a u e and ain all)
2.2. Tempe a u e
A mosphe ic empe a u e e e s o he speci ic hea con en o he ai a a gi en loca ion and ime. The empe a u e o
he a mosphe e depends on he amoun o sunshine o sola adia ion. h ps://www.aquapo ail.com/de ini ion-4925-
clima .h ml
2.3. The p ecipi a ion
Is any o m o hyd ome eo om a mosphe ic wa e in he o m o clouds ha all o he Ea h's su ace by p ecipi a ion
( ain, snow, hail , e c.). h ps://www.aquapo ail.com/de ini ion-4925-clima .h ml
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Figu e 3 Seasonal cycle o a e age empe a u e and p ecipi a ion in Guinea om 1991 o 2020
Figu e (3) shows he mon hly clima ology, o he a e age alues o a speci ic mon h o e a 30-yea pe iod. I allows us
o pu he seasons in o con ex o a gi en loca ion. As o he empe a u e cu e, i s a s wi h a minimum a e age o
24.06 o c in Janua y and eaches a maximum a e age o 28.79 o c in Ap il, be o e inally alling back o 23.88 o c in
Decembe . The coldes mon hs
a e Decembe and Janua y (23.04 o c). The ho es mon h is Ap il (28.80 o c) While o p ecipi a ion, i s a s om almos
00mm in Janua y (comple ely d y pe iod) o peak a a ound 450 mm in Augus . No e ha hese wo cu es a e opposi e.
When he empe a u e cu e is a i s highes poin , i coincides wi h he ela i ely d y pe iod (wi hou ain) and ice
e sa.
His o ically, Guinea has expe ienced he mos ain all in Augus wi h an a e age ain all o 438 mm and he lowes
ain all alue is eco ded in Decembe (5.36 mm). As shown in Figu e (4) Guinea is cha ac e ized by wo seasons. A d y
season ha begins om Decembe o Ap il and a ainy season ha uns om May o No embe .
Figu e 4 Seasonal cycle o minimum-mean-maximum empe a u e and a e age p ecipi a ion o Boké om 1991 o
2020
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Figu e 5 The seasonal e olu ion o empe a u e (minimum, a e age and maximum) and a e age ain all in Boké o
he pe iod 1991-2020 (29 yea s)
The clima ic no mal o p ecipi a ion indices and empe a u e o e he pe iod 1991-2020 om Janua y o Decembe o
he Boké egion. Rega ding he minimum empe a u e cu e, i s a s om 18.85 o c o Janua y, hen 24.57 o c in May
as he highes hen d ops o 23.05 o c in July, o ise o 24.46 o c in Augus , o inally g adually d op o 18.41 o c in
Decembe as he lowes o hese pe iods. As o he a e age empe a u e cu e and ha o he maximum empe a u e,
hey ha e p ac ically he same shape, only wi h he di e ence o he minimum, hey peak in Ap il (36.91 o c / 3040 o c)
o d op in Augus (29.50 o c / 26.95 o c) hen ise again; he lowes emains ha o Decembe 25.81 o c and hen ha o
Ap il 30.40 o c as being he highes . While o p ecipi a ion (blue ba s) i s a s om almos 0.08mm in Janua y
(comple ely d y pe iod) o peak a 581.43mm in Augus . No e ha hese h ee empe a u e cu es and he p ecipi a ion
ba s clea ly indica e he d y and cool pe iods o he yea s iden i ied . The obse ed his o ical clima e da a a e gene a ed
by housands o wea he s a ions a ound he wo ld, which collec empe a u e and p ecipi a ion da a con inuously.
These obse ed da a p esen he empe a u es (minimum, a e age and maximum) and p ecipi a ion. This annual and
seasonal clima e in o ma ion; Decembe -Janua y-Feb ua y, Ma ch-Ap il-May, June-July-Augus and Sep embe -
Oc obe -No embe a e a ailable and can be consul ed. These obse a ional da a come om he Clima ic Resea ch Uni
(CRU) a he Uni e si y o Eas Anglia.
Figu e (6) shows he s anda dized empe a u e anomaly o he Boké egion o he pe iod 1950-2020. I s a s om -
5.76 in 1950, ises sha ply o -2.14 in 1953, and hen alls back o -5.18 in 1954. No e ha his anomaly e ol es in a
saw oo h pa e n i egula below no mal o each -0.30 in 1990. Al hough i emains nega i e (cool pe iods) i has only
e ol ed in he posi i e di ec ion (inc easingly ho pe iods, wi h he announcemen o d ough ). F om 1998 (0.97) i has
e ol ed almos in he posi i e di ec ion, inc easingly highe un il eaching 2.33 in 2020, hus e lec ing he cu en s a e
o he clima e, cha ac e ized by his ema kable change in he a ia ion eco ded in hese clima ic pa ame e s.
