August 24th, 2022

In May-June 2022, 130 people died in landslides and floods caused by heavy rainin the Metropolitan Region of Recife, northeastern Brazil – Short report.
Prof. Masato Kobiyama(Hydraulic Research Institute, Federal University of Rio Grande do Sul, Brazil)
Recommended reference to cite this report: Kobiyama, M. (2022) In May-June 2022, 130people died in landslides and floods caused by heavy rain in the Metropolitan Region of Recife,
northeastern Brazil – short report. In: GADRI News, Kyoto, Global Alliance of Disaster
Research Institutes (GADRI), 9p.

1. General description
Recife (8° 04' 03'' S and 34° 55' 00'' W) is the capital of the state of Pernambuco, located in
the Northeast Region of Brazil. This city is located on an alluvial plain along the Atlantic Ocean
coast, with many islands, peninsulas and mangroves, and its mean altitude above sea level is 4 m.
According to Leão et al. (2021), having four rivers and more than 70 artificial drainage channels,
this city is known as “Brazilian Venice”. Hence, the geomorphic features of the city are generally
favorable to floods. During the early Portuguese colonization of Brazil, Recife was founded in 1537
and its population is 1,661,017 in 2021, which makes this city the sixth oldest city and the ninth
largest city in the country. The city's Carnival is very famous both nationally and internationally.
Thus, this capital of Pernambuco state plays a central role historically, culturally and economicallyin Brazil, especially in the northeast region. Furthermore, it should be emphasized that in Brazil
Recife is one of the most vulnerable cities, precisely because of the whole geographical concerns: avery low altitude, a very high population density, and socio-economic inequality.
Nearly three weeks of heavy rainfall since the end of May 2022 caused landslide and flood
disasters that left 130 dead, 9134 homeless, and 119,523 temporarily-displaced people in theMetropolitan Region of Recife. The most significant damage occurred on May 28th. This
metropolitan region consists of 14 municipalities whose geographical characteristics are shown in
Table 1.
Table 1 – Characteristics of 14 municipalities of the Metropolitan Region of Recife.
Municipality
Area (km2) Population (2021) GDP per capita (2017)
Abreu e Lima
126.193
100,698
20164
Araçoiaba
96.381
20,936
4986
Cabo de Santo Agostinho
448.735
210,79648689
Camaragibe
51.257
159,94511238
Igarassu
305.56
119,69021483
Ilha de Itamaracá
66.68427,0769283
Ipojuca
527.107
99,101
115089Itapissuma
74.23527,144
53089
Jaboatão dos Guararapes
258.694
711,330
19463
Moreno196.072
63,792
10989
Olinda41.681
393,734
13918
Paulista
97.312336,91912240
Recife218.435
1,661,017
31743
São Lourenço da Mata
262.106
114,9109878
Total
2,770.452
4,047,088
Obs.: Municipalities marked in red are those that have lost human lives in this disaster.

August 24th, 2022

Table 2 shows the number of human deaths and monthly rainfall in May and June of themunicipalities that lost human lives. The municipality of Jaboatão dos Guararapes had the highest
number of human deaths followed by Recife. Therefore, it is clearly noted that the border between
these two municipalities, which is characterized by hills and cliffs, was more severely affected.
Figure 1 shows the locality of the Metropolitan Region of Recife and its 14 municipalities.

Table 2 – Numbers of human deaths and monthly rainfall of May and June for each municipality.
No. Monthly rain in May (mm)Monthly rain in June (mm)deathMunicipality
2022
Average
2022
Average
Camaragibe
7684.5
294.6
393.5
339.1
Jaboatão dos Guararapes
64675.0
310.1
436.0
352.5
Olinda
6
496.1
325.8
508.9
384.7
Paulita
1
653.5
310.1
447.7
363.0
Recife
50
686.4
328.9
449.2
389.6
Bom Conselho*
1
114.0
86.0
240.8
95.6
Limoeiro*
1
316.7
135.6
190.7
186.5
* The municipalities of Bom Consello and Limoeiro are not part of the Metropolitan Region ofRecife and are 233.41 km and 64.75 km respectively from Recife.

Figure 1 – Locality of the Metropolitan Region of Recife and its 14 municipalities. Fivemunicipalities marked in pink color are those that have lost human lives in the disaster.

August 24th, 2022

Based on information presented by Aguiar (2022) that examined public data from various
public agencies, the breakdown of fatalities data by category is briefly demonstrated in Table 3. It isclearly observed that this disaster in Recife in 2022 was predominantly characterized with shallow
landslides which caused 121 deaths. Figure 2 shows the typical scene of shallow landslide (hillslopefailure) which occurred at the border between the municipalities of Recife and Jaboatão dos
Guararapes and many people were buried alive.
Table 3 – Categorical characteristics of fatalities caused by the disaster.
CategorySexHazard type
Age

Description• Male58• Female 72• Shallow landslide• Flood• 0-12 years old• 13-17 years old• 18-30 years old• 31-65 years old• > 65 years old1219258246310Figure 2 – Shallow landslide at the border between the municipalities of Recife and Jaboatão dos
Guararape, Brazil, in May 2022 (Source: Alves, 2022)

August 24th, 2022

2. Rainfall characteristics
The rainy season of the Metropolitan Region of Recife usually runs from April to July, withJune and July being the rainiest months in the region. Accumulation of heavy rain during this period
is natural. In other words, the rainy season had already started in this region at the moment thedisaster struck. In addition to the onset of the rainy season, there were three other factors
contributing to the intensification of the storm.
(i)

(ii)

(iii)

The La Niña phenomenon: The anomalous cooling of the waters of the equatorial
Pacific causes the intensification of the trade winds and, consequently, intensifies therains in the Northeast region in 2022.
Easterly Waves (EWs): They form on the African coast, reach the Brazilian
Northeast coast and meet warm waters. This meeting serves as if it were fuel tointensify these rain waves which are even more charged. It is considered as one of
the most important weather systems to the total rainfall over many tropical regions.
They can be defined as synoptic disturbances associated with troughs and warm sea
surface temperature (Machado et al., 2012; Cheng et al., 2019; Silva et al., 2020;
Enyew and Mekonnen, 2022). The EWs generate Eastern Wave Disturbances that
advance through the tropical region of the African continent towards the Americas,often giving rise to tropical storms and hurricanes in the North Atlantic. According
to Sias (2022), however, in the case of Northeast Brazil, the EWs do not bringhurricanes, but a lot of rain. These waves form in the area of influence of the tradewinds, close to the equator, especially in the autumn and winter months of theSouthern Hemisphere.
The warming of the Atlantic Ocean in front of the Brazilian Northeast coast: In
2022, this warming is up to 1°C above average.

Each of these three phenomena can be said to occur naturally. However, when they occur
simultaneously, they cause anomalous energy input in the physical spatial system and sometimes
exceptional rainfall events.
Based on daily rainfall monitoring data as Rainfall Bulletin (Boletim Pluviométrico),
available at the Pernambuco Water and Climate State Agency (Agência Pernambucana de Águas e
Clima – APAC) (https://www.apac.pe.gov.br/boletins), daily rainfall values obtained in Recife
during the period May 17th to June 14th, 2022, were summarized in Table 4. In case of Recife,
most of May's monthly rainfall began on May 22nd. In addition, it should be emphasized that theevent lasted for 22 days (May 22nd to June 12th), with a total amount of 926.4 mm and an average
daily precipitation of 42.1 mm during this period. The highest amount of rainfall occurred on May
28th. For comparison, the average annual rainfall for Recife is about 2155 mm.
According to Madeiro (2022), the Brazilian Center for Monitoring and Early Warnings ofNatural Disasters (Centro Nacional de Monitoramento e Alertas de Desastres Naturais –CEMADEN) issued a geo-hydrological bulletin on May 25th, warning of the "high risk" of heavy
rains and landslides in the Metropolitan Region of Recife. Even with this alert, just on May 27th(Friday) when the APAC issued another statement informing the heavy rain forecast for theweekend, the Recife City Hall finally activated the contingency plan. After the APAC alert wasissued, the Civil Defense Agency of Recife acted immediately in the late morning of May 27th,

August 24th, 2022

summoning more than 3,000 municipal civil servants to work on duty from the same day. Inaddition, this Agency sent the alert to over 32,000 families living in at-risk areas via Short Message
Service (SMS). On the other hand, Madeiro (2022) reported the comments of community leaders:
Local residents were not informed that they would need to leave the area, nor were they receiving
assistance, such as vehicles, to move them to safer shelters. Therefore, it will be necessary to findout what kind of communication actually occurred (or whether it did not occur) between the Civil
Defense Agency and local residents.
Table 4 – Daily rainfall in Recife during the period May 17th to June 14th, 2022.
May date
17th
18th
19th
20th
21st
22nd
23rd
24th
25th
26th
27th
28th
29th
30th
31st

Daily rainfall (mm)
0.0
0.0
0.0
0.0
0.0
10.2
1.8
69.0
137.4
33.2
13.2
190.0
85.2
19.2
35.2

June date
1st
2nd
3rd
4th5th
6th
7th
8th
9th
10th
11th
12th
13th
14th
15th

Daily rainfall (mm)
15.2
18.0
9.2
81.5
38.0
0.3
101.4
12.0
5.2
4.0
26.2
21.0
0.0
0.0
0.0

3. Historical views of disasters in Recife.
The population of Recife, one of the major cities in northeastern Brazil, has been growing
rapidly (Figure 3). The current situation of the city, which plays an important role culturally andeconomically, encourages an influx of people to Recife from within the state, from outside the state,and even from outside the country.

Figure 3 - Population trends in Recife during the period 1890-2020 (Source: Leão et al. 2021)

August 24th, 2022

At first, poorer people generally began to live in vulnerable areas, especially in coastal,wetlands and mangrove areas. These areas are naturally susceptible to (coastal) flood. Through sucha population settlement history, inhabitants in Recife frequently suffered from large and strong
floods. Two largest flood disasters occurred in 1966 and 1975 (Table 5). Alves (2022) reported that,in the past, poor people lived in wetlands or floodplains and many of them were evacuated andtransported to hillslopes and cliffs. Carrying out interviews with various experts in Recife, thisauthor emphasized the housing deficit and urgent establishment of adequate housing policies. Insummary, it can be said that the greater population density towards the hillslopes and cliffs of thecity contributed to the social problems, i.e., sediment-related disasters.

Table 5 – Three main disasters occurred in (Metropolitan Region of) Recife
Year
1966

Locality
RecifeDateMay 30hNo. deaths
175

1975

RecifeJuly 17-18107

2022

Metropolitan
region of Recife

May 22 - June 130
12 (May 28)

Characteristics
Predominantly flood. River Capibaride
overflowed. In many places the water
was more than 2-m deep. There wasno problem with cliffs.
Predominantly flood. River Capibaride
overflowed. 80% of the city wasflooded. 350,000 people became
temporarily homeless. At one moment,
more than 50% of the houses in thecity lost power. There was no problem
with cliffs.
Predominantly shallow landslide.
More than 100 people were buried
alive in slope failures and died.

Furthermore, with interviews and available data analysis, Lins et al. (2022) mentioned that
600 thousand people (about 36% of Recife’s population) are living at hillslopes and cliffs which areconsidered as high hazard area, and concluded that the social inequality can be the principal factor
for disasters in Recife.
Thus, it is easily thought that there is a growing tendency of landslide disasters in Recife.
Lins et al. (2022) investigated citizens’ calls for landslides, registered by the Civil Defense Agencyof Recife during the period 2014 to May 2022, and reported the total of 7340 calls. Table 6 showsthis data.

Table 6 – Number of calls for landslides in Recife during the period 2014 to May 2022.

Year2014

2015

2016

2017

2018

2019

2020

2021

2022

Calls

486

1043

1124

710

639

1064

253

1145

876

Obs.: The number of calls in 2022 is just until May 2022.

August 24th, 2022

Figure 4 shows that many unstable houses were built on the top and bottom of cliffs and on
steep hillslopes which are all dangerous places. This situation certainly caused the landslidedisasters in May-June 2022.

Figure 4 – Several landslide-related disasters in the Metropolitan Region of Recife, Brazil(Sources: Diego Nigro/AFP/METSUL-Meteorologia in Sias (2022))

4. Final remarks
An evolution of hydrological disasters in a city, from flood disaster (water-related disaster)
to mass movement disaster (sediment-related disaster) through the city’s development history canbe observed in various cases over the world (Figure 5). Kobiyama et al. (2010) explained that a city
settlement normally starts with flood-plain occupation. Then after occupying this area, hillslope
areas will be occupied. Therefore, the numbers of occurrences of flood and mass movement as
natural phenomena can be constant through the city’s history meanwhile those numbers as natural
disasters will be probably changed, especially with a drastic increase of sediment-related disasters.
Thus, people just feel that they have suffered formerly from flood and now from mass movements(landslides, debris flow, etc.). This is the hydrological disasters’ evolution associated to landoccupation history in a city. Recife is not an exception and has been certainly performing such anevolution.
Investigating the inequality in Brazilian metropolis, Salata and Ribeiro (2022) concluded
that the Metropolitan Region of Recife is in the worst situation in Brazil. The authors also reported
that 13% of the population of the region live in extreme poverty (with an income of less than
US$32/month) and that 39.7% live in poverty (US$91/month). This means that, in case of theAugust 24th, 2022

Metropolitan Region of Recife, more than half of the people (52.7%) live in poverty. These poor
people used to live in coastal areas or swamps at altitudes near sea level. As a result of sufferingfrom frequent flood disasters, they were relocated by public policy to cliffs or hillslopes which haveanother type of natural hazard.

?

?
?

0hi
lls

ide

flo
od
plainSe
dim

Disasters occurence

ent-r
ela
ted
ate
disr-r
ela
ast
ers
ted
dis
astersTime

City settlement
Dominance ofwater-related
disasters

W

Area of occupation

100%

Time
Present
Dominance of
sediment-related
disasters

Figure 5 – Hydrological disasters evolution due to the land occupation change. (Source: Kobiyamaet al., 2010).

Indeed, Recife has been playing an important role in climate change and greenhouse gas
emission issues, and showing its leadership nationally and internationally (Leão et al., 2021).
Though these actions are certainly useful in improving the lives of local residents and should behighly evaluated, the reality is that the results have not reached the poor people adequately.
UN (2015) presented 17 Sustainable Development Goals and 169 targets, among which theGoal 10 is “Reduce inequality within and among countries”. Landslide-dominated disasters in theMetropolitan Region of Recife in 2022 gave many lessons to people and public agencies. The fact isthat the achievement of the Goal 10 should be considered the best action for disaster risk reductionin this region as well as the other places in Brazil.

August 24th, 2022

References
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