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    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>A clustering optimization approach for disaster relief delivery: A case study in Lima-Per u´</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Jorge Vargas-Florez</string-name>
          <email>jorge.vargas@pucp.edu.pe</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Rosario Medina-Rodr´ıguez</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Rafael Alva-Cabrera</string-name>
          <email>rafael.alva@pucp.pe</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>Pontificia Universidad Cat o ́lica del Per u ́</institution>
        </aff>
      </contrib-group>
      <fpage>122</fpage>
      <lpage>129</lpage>
      <abstract>
        <p>During the last decade, funds to face humanitarian operations have increased approximately ten times. According to the Global Humanitarian Assistance Report, in 2013 the humanitarian funding requirement was by US$ 22 billion, which represents 27.2% more than the requested in 2012. Furthermore, the transportation cost represents between one third to twothirds from the total logistics cost. Therefore, a frequent problem in a disaster relief is to reduce the transportation cost by keeping an acceptable distribution service. The latter depends on a reliable delivery route design, which is not evident considering a post-disaster environment. In this case, the infrastructures and sources could be inexistent, unavailable or inoperative. This paper tackles this problem, regarding the constraints, to relief delivery in a post-disaster environment (like an eight degree earthquake) in the capital of Peru´. The routes found by the hierarchical ascending clustering approach, which has been solved with a heuristic model, achieved the best result.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>-</title>
      <p>
        1 Introduction
Humanitarian response recognizes two phases
after a disaster: the life-saving and the
lifesustaining actions
        <xref ref-type="bibr" rid="ref16">(Thevenaz and Resodihardjo,
2010)</xref>
        . The first one, consists in carrying
activities that aim to preserve life, like removal debris
and rescue victims. The second one, involves the
provision of aid kits and services such as: food,
water, temporary shelter, medical care, and
protection
        <xref ref-type="bibr" rid="ref1">(Assessment and Coordination, 2006)</xref>
        . As
it was mentioned in
        <xref ref-type="bibr" rid="ref5">(Hall, 2012)</xref>
        , the initial relief
dispatch is more oriented to beneficiary
communities in a timely manner, while waiting for the
initial disaster assessment to be completed. Klibi and
Martel (2012), described that under a state of
disaster the depots network is not expected to respond
adequately, because its storage and distribution
capacity loses its nominal operability.
      </p>
      <p>
        Moreover, Martinez et al. (2011) confirms
that transport is the second largest general
budget of humanitarian organizations, after staff.
Thus, planning transportation routes (VRP,
Vehicle Routing Problem) is one of the most
important problems of combinatorial optimization
and it is widely studied with many applications
in the real world, like distribution logistics and
transport
        <xref ref-type="bibr" rid="ref17">(Toth and Vigo, 2002)</xref>
        . The
humanitarian delivery in disasters cases are concerned to
optimize; maximizing unsatisfied demand,
minimizing travel time and minimizing total
delivery delay
        <xref ref-type="bibr" rid="ref2">(Beamon and Balcik, 2008)</xref>
        . There are
three basic approaches for modeling the problem:
(i) the vehicle route is represented by a binary
variable of multiple indexes, that define the
vehicle and route identification; (ii) the
construction of a dynamic network flow model whose
outputs are the vehicle and material flows, that
have to be parsed in order to construct vehicle
routes and loads and; (iii) to enumerate all
feasible routes between all pairs of supply and
demand nodes
        <xref ref-type="bibr" rid="ref11 ref7">(O¨ zdamar and Demir, 2012)</xref>
        . The
latter open a data analysis utilization based on pattern
mining, data mining or clustering to optimize
delivery routes. For our purposes, we decided to use
the last mentioned approach.
      </p>
      <p>
        In literature, numerous works have been
proposed to deal with the problem of spatial
clustering on data associated to natural disasters. Early
papers attacked the problem of emergency
evacuation, for exa
        <xref ref-type="bibr" rid="ref12">mple, Pidd et al. (1996</xref>
        ) presented
a spatial decision support system to emergency
planning. Their approach, based on Geographical
Information System (GIS) software, evaluated two
issues: (i) static, processing the data from a
mathematical, statistical and logical point of view and;
(ii) dynamic, establish the terrain for evacuation
under certain assumptions and with some
specified policies. Then, in
        <xref ref-type="bibr" rid="ref4">(Gong and Batta, 2007)</xref>
        , an
ambulance allocation to improve the rescue
process of victims, was proposed. The authors used a
spatial clustering combined with fuzzy logic in
order to allocate the correct number of ambulances
to each spatial objects grouped into a cluster after
an earthquake.
      </p>
      <p>
        Later, Tai et al. (2010) described a method to
evacuate Shin-Hua city, Taiwan, after an
earthquake. They analyze the spatial correlation
between objects taking into account six indexes
associated to route characteristics. Moreover,
O¨ zdamar and Demir (2012), proposed a
hierarchical cluster and route procedure (HOGCR) for
coordinating vehicle routing in large-scale
postdisaster distribution and evacuation activities.
Recently, M
        <xref ref-type="bibr" rid="ref10">atthew et al. (2015</xref>
        ) evaluated the
survival Kobe-1995-earthquake manufacturing plants
and their post-earthquake economic performance.
They used a geographical clustering technique
combined with a micro-econometric approach.
      </p>
      <p>In Peru´, from 1582 to 2007, occurred 47
earthquakes with magnitudes between 6.0 to 8.6 on
the Richter scale. At least 10 were greater than
8.0 and 100% of them occurred between the
center and the south coast area of Peru´; where
Lima is located. Leseure et al. (2010), presented
the 7.9 earthquake in Pisco-Peru´ in 2007, which
killed more than 500 people and affected more
than 655 thousand people; who demanded water,
food, shelter, clothes, etc. The assistance for
victims was distributed through multiple civil defense
committees, leaded by the Instituto de Defensa
Civil (INDECI).</p>
      <p>Despite the efforts, they could not manage a
proper relief delivery, however the authors stand
out the following conclusions: (i) humanitarian
donations reception and transport were
improvised; (ii) humanitarian aid was distributed
haphazardly; (iii) duplication of supplies in some
closer areas, while the more isolated ones,
received partial support and; (vi) distribution of
inappropriate aid relief and unfit food for
consumption (rotten food, expired date drugs, etc.).</p>
      <p>From these statements, three points can be
highlighted: (1) the high risk that would suffer the
Peruvian capital in a potential major earthquake due
to its sociodemographic and seismic location; (2)
the failed National delivery relief case described
before and; (3) the importance of supplies
transportation to humanitarian operations. Therefore,
it is necessary to provide an optimal, efficient and
resilient route design regarding the constraints of
a post-disaster environment. For this purpose, we
propose an approach based on the hierarchical
ascending classification that seems the best option
considering the expected bad conditions of the
roads in a post disaster environment.</p>
      <p>Following this brief introduction and review,
the paper is organized as follows: Section 2,
describes the followed methodology. Then,
Section 3, exposes the medical aid relief delivery to
Lima and Callao in an eventual earthquake,
analyzing the Hierarchical Ascending Classification
approach for humanitarian distribution. At the
end, we conclude with an analysis of the solution
with the lowest travel time and also some future
research works are described.
2</p>
      <p>Methodology
In order to find an approximate solution to the
process of delivery humanitarian relief in Lima, we
propose an efficient and resilient approach. The
efficiency is related to the ability to provide the
service with fewer resources, while resilience
condition is related to the ability to retain the
operation in time, even whether infrastructures and
sources are inexistent. Our methodology is
composed by the following stages:
1. Obtain the information about the actual
Peruvian humanitarian system from government
entities (i.e. INDECI).
2. Perform an analysis about cartography in the
territory of study, to identify the most
vulnerable, exposed and threatened areas.
3. Carry out a study about available models to
solve the vehicle routing problem.
4. Identify the costs following a
clustering approach (Hierarchical Ascending
Classification-HAC).</p>
      <p>
        Our goal is to identify the routes to be used
for the distribution of humanitarian aid. Whereas
these routes be comprised by pre-positioned by
INDECI warehouses which are: the Medical
Supplies (AM, “Almace´n de Insumos Me´dicos”, in
spanish) and Central Warehouses (AC, “Almace´n
Central”, in spanish); both located in Lima and
pre-defined by INDECI. We follow a heuristic
called “cluster-first route-second”, which
determines clusters of customers compatible with
vehicle capacity and solves a traveling salesman
problem for each cluster
        <xref ref-type="bibr" rid="ref13">(Prins et al., 2014)</xref>
        . Thus, for
this proposal we apply the Hierarchical Ascending
Classification, forming clusters using the total
adjusted travel time for each route instead of the
Euclidean distance as a proximity measure. In order
to correct this time, we use as criterion “how
critical is the condition of the affected region”, which
is based on measures of vulnerability,
accessibility, exposure and proximity for each district of
Lima, where each AM is located.
3
      </p>
      <p>
        Results and Discussion
The HAC analysis performed by using
dendrograms
        <xref ref-type="bibr" rid="ref18">(Villardo´n, 2007)</xref>
        , is as an efficient tool
for the cluster identification task which combines
many features. For instance, it is possible to
separate the population into homogeneous clusters
(low within-variability and high between
variability). In this proposal, we have considered five
features that describe vulnerabilities: (i) seismic
location; (ii) socioeconomic state; (iii) access to
delivery point; (iv) exposure to hazards and; (v)
proximity to the central depot (AC).
      </p>
      <p>
        Step 1: we use an advanced statistical analysis
tool (XLSTAT 2013.6.03) and the vulnerability
scales were obtained from the INDECI
categorization criteria (see Table 1). Then, based on this
criteria, we obtained a summary of the value
associated with each type of vulnerability and the district
where they belong to, as can be seen in Table 2.
However, in order to apply the HAC approach, it is
necessary to standardize our values, so there is an
existent correlation (see Table 3). For this purpose,
we used the method of the “maximum magnitude
of 1”
        <xref ref-type="bibr" rid="ref6">(Justel, 2008)</xref>
        . This means, the division of
the value of each variable by its maximum value,
obtaining values between 0 and 1.
      </p>
      <p>Step 2: we apply the HAC method on the new
standardized data, choosing which Central
Warehouses (ACs) will supply store whose Medical
Supplies Warehouses (AMs). This choice was
based on the shortest distance from AC to AM; for
instance, if the distance between AC1 and AM1 is
less than the distance between AC2 and AM1, then
it will supply AC1. The result can be observed in
the dendrograms shown in Fig 1, where the
horizontal dotted line divides the collection of points
in three clusters set by AMs.
Step 3: then, we apply the algorithm proposed
by Clarke and Wright (1964), looking for routes
with lower cost, linking each AM to clusters. The
final result shows each AM supplied by each AC,
as can be seen in Table 4.
3.1</p>
      <p>Distances Evaluation
Here, we present an analysis about post disaster
distances to be covered by routes. At the
beginning, Euclidean ideal distances have been
considered however they must be corrected by a
“Correction Factor” in order to represent realistic post
disaster conditions; for example streets with debris,
transport infrastructures collapsed like bridges.
According to the Peruvian Ministry of Transport
and Communications, the poor accessibility post
disaster can cause variations up to 30 minutes
(corresponding to 50% of the average transport time).</p>
      <p>Also, reviewing historical events recorded by
INDECI, it realizes that poor accessibility in
affected areas increases between 25% to 100%, due
to collapsed infrastructure or debris. For instance,
to evaluate AM1 distance, due to correction
factors, it will be increased in 65% (correction
factor 165% or 1.65). Because its location has a 4
level accessibility then, corresponds to 25% and
its seismic zoning characteristics corresponds to
40% (according to INDECI), hence 25% + 40% =
65%. Whether it is applied this criterion in
Table 6, the corrected and covered distance (based
on Table 5 percentages) for this application case is
250.32 Km.</p>
      <p>
        Distribution Expenses Evaluation
Once we already have obtained the routes and its
associated distance, it is necessary to know the
type of transportation that will be used, in
order to estimate the required resources. According
to
        <xref ref-type="bibr" rid="ref9">(Martinez et al., 2011)</xref>
        , the best vehicles to be
used in the humanitarian distribution due to its
capacity and potency are the pick-up (4 ⇥ 4), whose
main characteristics are shown in Table 7.
      </p>
      <p>According to INDECI, each medicine
packaging unit (emergency backpack) should be able to
supply at least two people. It is recommended an
average weight of 8 Kg, corresponding to a
backpack with a capacity of 20 to 40L. Thus, for
practical calculations, we consider an intermediate value
of 30L. Then, considering 1 vehicle, we can
calculate the number of backpacks to carry and how
many people they would help. For instance,
every trip that makes one transport, will attend 200
people.</p>
      <p>Backpacks = volume occupied by medicines in
one vehicle; 3m3 = 3000L.</p>
    </sec>
    <sec id="sec-2">
      <title>1Backpack</title>
      <p>3000L ⇥ = 100Backpacks
30L
People = attention capacity for backpack ⇥
quantity of backpacks in one pick up</p>
    </sec>
    <sec id="sec-3">
      <title>2 people</title>
      <p>Backpack ⇥ 100 Backpacks = 200 people
Furthermore, we proceeded to group the
provinces of Lima and Callao in four main
sectors: North-Lima, South-Lima, Lima-Center,
East-Lima and Callao; it will allow us to estimate
the amount of affected people to assist (see
Table 8). Lima and Callao have 49 districts, and
some of them do not have points of medical
supplies depots, meanwhile other ones have more than
one depot. For this reason, we consider that each
depot will support the victims by the sector where
they belong to (see Table 9); regardless districts
which are part of it. The support must be done
proportionally to victims’ amount in each district.</p>
      <p>In Table 10, we indicate the total amount of
victims to be supported for each route (each
clusDistrict
Ate
Callao
Carabayllo
Chorrillos
Comas
Lima
Lurigancho
Lurin
Pachacamac
Puente Piedra
S. J. de Lurigancho
S. J. de Miraflores
Ventanilla
Villa el Salvador
Villa Maria del Triunfo
tering became to one route), considering the
corrected distance according to the correction factor.
Moreover, we describe the cost of fuel used to
support all the victims considering the least distance
covered; which is S /.160, 520.62 approximately.
We can also provide valuable additional
information, for instance, the amount of trips required to
support all the victims considering the number of
vehicles used.</p>
      <p>For instance, in Table 11, we obtained the
number of vehicles needed to complete the route in an
acceptable number of days (8.26 days), using 600
vehicles. It would support 120 000 people with 18
trips (number of trips is needed in each identified
route until complete the requested demand).
Finally, as an expected result, we can see in Fig 2,
that the number of supported people will increase
with more assigned vehicles.
4</p>
      <p>Conclusions and Future works
In this study, we propose an approach to
optimize aid distribution kits in an eventual disaster
in Lima. Previous research works consider the
existence of infrastructure, transport, capacity,
availability of public services, among others; as a
postdisaster state. However, a solution should be
suitable to manage an uncertain lack of resources,
lost of capacity and infrastructure. Thus, our
approach using the corrected distances representing
the vulnerability of a location, uses minimal
reNorth-Lima
South-Lima
Center-Lima
East-Lima</p>
      <p>Callao
sources (time to complete routes) and it is reliable
(routes made under post-disaster conditions). Our
results, suggests that the method of Hierarchical
Ascendant Classification (HAC), allow us to find
an approximate route solution, considering a
postdisaster environment.</p>
      <p>We found a sufficient and satisfactory
humanitarian relief distribution, the searching solution
criterion was the shortest time route with the
lowest cost, under a spatial configuration which
represents a post-disaster state, considering a
Correction Factor (CF) to nominal times. This CF was
calculated considering a previous HAC analysis,
based on vulnerabilities assessment expressed by
urbanistic layouts, forecast victims, seismic
hazard maps, in Lima and Callao districts. For
future research activities we consider to perform an
evaluation adding a correction factor which use
resilience assessment and; to evaluate the impact
of non-considered costs as man power,
maintenance, resources loading/downloading and
security. In addition, to carry out a sensitivity analysis
to choose particulars trucks, timetables and
outsourcing service.</p>
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