A GIS Application in Optimizing the Collection and Transportation Route of Domestic Solid Waste in Hue City, Vietnam45232

This article with the title of GIS application in optimizing the route of collecting and transporting domestic solid waste in Hue city aims to shorten the maximum distance of waste colle

A GIS Application in Optimizing the Collection and Transportation Route of Domestic Solid Waste in

Hue City, Vietnam

Chan Van Mai (1)(2) , Son Hoang Nguyen (1)* , Cham Dinh Dao (3)(4) , Tin Van Le (1) , Hang Anh Phan (5)

(1) University of Education, Hue University, Thua Thien Hue, Vietnam

(2) The College of Environment and Planning of Henan University, Kaifeng city, Henan Province, China (3) VAST Institute of Geography, Hanoi, Vietnam

(4) VAST Graduate University of Science and Technology, Hanoi, Vietnam

(5) University of Science, Hue University, Thua Thien Hue, Vietnam

* Correspondence: nguyenhoangson@dhsphue.edu.vn

Abstract: The collection and transportation of domestic solid waste in Hue city in particular and other

cities in Vietnam generally are still manually implemented, which requires a lot of manpower, costly operation but gets low economic efficiency and management difficulties in return This article with the title of GIS application in optimizing the route of collecting and transporting domestic solid waste

in Hue city aims to shorten the maximum distance of waste collection and transportation in order to reduce the number of waste trucks From the research results, the number of daily trucks reduces by

7 from 20 trucks to 13 ones, which contributes to the dramatic reduction of collection and transportation operation cost, saves manpower, and minimizes potential environmental issues

Keywords: GIS; location allocation; vehicle routing problem; routing optimization; solid waste

1 Introduction

Along with the fast-growing national economy, the management system of urban solid waste has been comprehensively improved Besides, science and technologies have been gradually applied in many cities to quickly and efficiently sort, collect, transport and dispose waste However, outdated facilities and equipment, limited techniques in solving issues of collecting, transporting and disposing waste lead to manpower consuming, high cost of transportation, under-expected economic and environmental results (Han and Ponce-Cueto 2015; MONRE 2018; HPC 2018)

In many cities in Vietnam in general and Hue city in particular, collecting and transporting solid waste from transfer stations to landfills are still being manually operated Specifically, the amount of daily waste is calculated, waste collecting workers are assigned

to collect at fixed gathering points along the roads into bigger waste containers or transport

to waste transfer stations, then waste trucks are sent to collect and transport to landfills The schedule of waste trucks is completely done manually without applying software or algorithms to optimize the route According to the statistics from Hue urban and environmental company, around 220 tons of domestic waste are daily discharged in Hue city and 20 trucks are needed from 6pm to 2 am the next morning to collect and transport all of this quantity (HEPCO 2018), which can be inferred that the ability to collect and transport waste of the city is still limited and weak

This paper suggests applying GIS into optimizing the route of collecting and transporting urban domestic waste to minimize the distance of collection and

transportation, then accordingly reducing the number of waste trucks and the operation cost

2 Methodology

2.1 Data collecting method

Primary data includes detailed data on road traffic of Hue city; location of garbage bins; location of transfer station; the average daily waste volume of the city; the daily number of trucks used in collecting and transporting waste, and etc

Secondary data includes data from relevant research results in Hue city and data from Hue Urban Environment and Public Works State Company like annual assessment reports on the environmental impacts of waste collecting and transporting activities in Hue city, results of provincial scientific and technological studies on GIS application in management of drainage system infrastructure and means of waste transportation in Hue city (Nguyen 2014)

2.2 Analyzing method

To optimize the route of collecting and transporting domestic waste in Hue city, the authors analyze and process the data as the following steps:

- Prepare a complete database and create Network Data in Catalog to analyze data system

- Use the analysis function of location allocation in the Network Analyst toolbar of ArcGIS 10.3 software to establish parameters to analyze and adjust the location of waste transfer stations in the city

- Use the function of analyzing Vehicle Routing Problem in Network Analyst toolbar

of ArcGIS 10.3 software to set up parameters to run the model of waste collecting and transporting route

3 Results

3.1 Subsection

3.1 Current situation of collecting and transporting domestic waste in Hue city

Collection and transportation of domestic waste in Hue city can be summarized as follows (Nguyen 2014):

Domestic waste of households is collected by handcarts, the waste can be put into plastic bags or garbage bins which can be put in front of the house or delivered to the nearest public waste containers Every day, the workers will push handcarts through residential areas and collect them to the nearest transfer station

Waste from institutions, schools, production and business establishments is stored

in public garbage bins, when the cans are full, they will be transported to landfills

Waste at markets and on streets is swept and collected by workers at where it is, then delivered to transfer station to get transported to landfills by trucks

Waste in hospitals is only collected if it is domestic waste contained in 600-liter cans which are transferred by handcarts to transfer stations Other types of waste will be handled

by hospitals themselves

Non-hazardous industrial waste is taken to transfer station, then transported to landfills by specialized trucks

Means of transportation used for waste collection are as follows:

Handcarts are used to collect domestic waste from households in small lanes, streets, markets and roads After these handcarts are full, they will be moved to hubs to transfer waste to specialized trucks The working shift is from 6pm to 2am the next morning

Specialized trucks are daily driven to fixed routes collecting waste on streets and in hubs and transferring to landfills The working shift is from 6pm to 2am the next morning

Currently, Hue city system of solid waste collection and transportation does not use facilities like containers, container trucks, waste transfer stations etc The process of collection and transportation can be summarized as below (Figure 1)

Figure 1 The process of collecting and transporting domestic solid waste in Hue city (Le 2012)

3.1.2 GIS application to analyze and select the location of transfer station

Derived from the fact that the trucks to collect and transport waste daily go through fixed roads and areas to collect waste at transfer stations and in roadside garbage bins, which is time-consuming and low efficient The authors suggest that all of waste in garbage bins should be moved to the nearest transfer station by cleaning workers and handcart workers Waste trucks will only go to transfer stations to collect waste and needn’t collect at different points on roadside, which can reduce quite a number of trucks and save a huge amount of time (Xiao 2018; Zhu 2018)

From the current data, there are 1755 locations of garbage bin and 92 transfer stations, the authors use Location_Allocation tool to analyze the minimum distance from the location of each garbage bin to the nearest transfer station The analysis is taken by the below steps:

Network Analyst / New Location_Allocation

Right click Facilities/ Load Locations, uploading the data of current transfer stations (92 stations)

Right click Demand points/ Load Locations, uploading the data of current garbage bin locations (1755 locations)

Layer Properties/ Analysis Settings/ Impedance/ Length (Meters)

Layer Properties/ Analysis Settings/ U-Turns at Junctions/ Allowed

Layer Properties/ Analysis Settings/ Ouput Shape Type/ Straight Line

Layer Properties/ Advanced Setting/ Problem Type/ Maximize Caverage

Layer Properties/ Advanced Setting/ Facilities to Choose: Fill in the current number

of transfer stations (92 in this case)

Layer Properties/ Advanced Setting/ Impedance Cutoff: Choose a suitable distance

to ensure all garbage bins connected to the nearest transfer station (5000m is chosen in this case)

Click Done to confirm the completion of data setup

Finally click Slove of Network Analyst toolbar to run the analysis (Figure 2)

Figure 2 The correlation between locations of current garbage bins and transfer stations

In Figure 2, the green spots are the locations of 1755 garbage bins, the blue points are the locations of 92 transfer stations, the purple lines are 1755 lines connecting garbage bins

to the nearest transfer station

Realizing that this result is still inadequate, the central area of the transfer stations is too dense while it is too sparse in the suburb area, making the distance between garbage bins and transfer stations too far When locations from garbage bins to transfer stations is too far, it will take more time and effort to collect waste from garbage bins to transfer stations, leading to low efficiency

The authors have analyzed, adjusted and added a number of transfer stations (this process always complies with the principle of selecting transfer station locations) The result

is 16 stations adjusted and 18 stations added, increasing the total number of transfer stations from 92 to 110

Continue using the Location_Allocation tool to perform the analysis steps as mentioned above and get the results (Figure 3)

Figure 3 The correlation between locations of garbage bins and transfer stations after adjustment

3.1.3 GIS application in optimizing the route of collecting and transporting domestic solid waste in Hue city

Scheduling and arranging for waste collecting trucks to go along fixed routes is mainly done manually, which cannot suggest the best optimal route, leading to far and even overlapping travel routes, longer collection and transportation time and many vehicles needed as a result, increasing the total cost of the operating system

In order to optimize the route of collecting and transporting domestic waste in Hue City, the authors have chosen to use the New Vehicle Routing Problem in Network Analyst toolbar of ArcGIS 10.3 software The analysis process is done as follows:

Network Analyst/ New Vehicle Routing problem

Vehicle Routing problem, right click Orders/ Load Locations to upload the data of transfer stations after added and supplemented

Use Geometry/ Search Tolerance to fill 5000 (This is the longest distance to the transfer station, meter unit, other parameters defaulted)

Vehicle Routing problem, right click to choose Deports/ Load Locations, add the starting point and ending point of waste trucks In this article, the starting point is the parking lot at Huong So ward, the ending point is Thuy Phuong landfill However, the distance from Hue City to Thuy Phuong landfill is quite far while the map and transport layer to build Network Data are located in Hue city, so the ending point will be located in Hue city for easier analysis The final result of each route will be added with the distance from this ending point to Thuy Phuong landfill

- Vehicle Routing problem / Router to set up parameters for routes, including starting time; ending time; starting point; ending point; maximum reaching transfer stations; maximum load of each truck; the longest possibly moving distance

Set up parameters in Layer Properties like below:

- Layer Properties/ Analysis Setting/ Time Attribute/ Travel_time (Minutes)

- Layer Properties/ Analysis Setting/ Distance Attribute/ Length (Meters)

- Layer Properties/ Analysis Setting/ Capacity Count/ 1

- Layer Properties/ Analysis Setting/ Time Field Units/ Minutes

+ Layer Properties/ Analysis Setting/ Distance Field Units/ Meters

+ Layer Properties/ Analysis Setting/ U-Turns at Juntions/ Allowed

+ Layer Properties/ Analysis Setting/ Output Shape Type/ True Shape with Measures + Layer Properties/ Analysis Setting/ Distance Units/ Meters…

Finally click (Directions) in Network Analyst to analyze the result (Figure 4)

Figure 4 Optimizing Hue city waste collection and transportation route

A total of 110 transfer stations were collected with 39 trucks Each truck can go for

03 turns in one shift, so the minimum number of needed trucks is 13 (reducing by 7 compared to actual operation)

From Table 1, the result is shortened like Table 2

Therefore, from the results in Figure 4, Table 1 and 2, it is totally possible to make schedule for 13 trucks to travel along the analyzed route and collect waste at transfer stations shown in Table 1, control time and volume that each truck can handle (Nayati 2008; Mariagrazia 2017; Aremu 2011; Faccio 2011; Katusiimeh 2012; Thelma 2016; Han 2015; Malandraki 1992)

Table 1 Result of analyzing the route of waste collection and transportation in Hue city

(min）

5 Truck 2 turn 2 146 6000 45-42-40-41

Table 2 Result of analyzing of waste collection and transportation route in Hue city

5 Truck 5 326 17000

4 Conclusions and discussion

Applying Network Analyst in ArcGIS 10.3 software to analyze and select the locations of waste transfer stations and optimize the route of solid waste collection and transportation in Hue city brings about favorable results shown by the fact that the number

of trucks to collect waste is reduced from 20 to 13 A big reduction of waste trucks and time

of collection and transportation will help to reduce the total operating cost of the city's waste collection and treatment system

This model of optimizing the route of waste collection should be quickly applied and replicated in other cities throughout the country, contributing to save manpower, operating costs and minimize environmental issues

References

Aremu, A.S.，Mihelcic, J.R.，Sule, B.F (2011) Trip time model for municipal solid waste collection applicable to developing countries Environmental Technology, 32(15): 1749-1754

Faccio, M.，Persona, A., Zanin, G (2011) Waste collection multi-objective model with real time traceability data Waste Management 31(12): 2391-2405

Han, H., E Ponce-Cueto (2015) Waste Collection Vehicle Routing Problem: Literature Review, Promet - Traffic&Transportation, 27(4), 345-358

HEPCO (Hue Urban Environment and Public Works State Company R) (2018) A summary report on planning to collect waste in Hue city in 2018 Thua Thien Hue province

HPC (Hue People’s Committee) (2018) Report on the current environmental situation of Hue 2018, Thua Thien Hue province, 132 pages

Katusiimeh, M.W., Mol A.J.，Burger, K (2012) The operations and effectiveness of public and private provision of solid waste collection services in Kampala Habitat International，36(2): 247-252

Le, V.D (2012) Apply GIS (Geography Information System) into management of domestic solid waste in central districts of Thai Nguyen city, Thai Nguyen province Code: 60.44.03.01 Thai Nguyen University