GIS Application for Forest Territories Providing Water Ecosystem

Services

ADELINA ALEKSIEVA-PETROVA1, NEVENA SHULEVA2

1Department of Computer Systems, Technical University of Sofia, Sofia, BULGARIA

2Faculty of Agronomy, University of Forestry, Sofia, BULGARIA

Abstract: - Protecting forests and maintaining their water conservation function has proven to be the most

effective approach to generating and maintaining water quantity from the source to the end user. The water

conservation and water regulating properties of forest ecosystems that are inherent in forested areas are an

undervalued resource at the current stage. To turn this property into a source of income, it needs to be

institutionalized as a production function of forest owners. This also defines the main aim of this research,

namely to design and implement a system for mapping the territorial distribution and characteristics of sanitary

protection zones in Bulgaria, which will help assess the condition and determine the value of ecosystems and

ecosystem services. In this regard, this paper presents the approaches used to integrate and design the spatial

data of the sanitary protection zones and the database of the forests in Bulgaria in a repository and the system

created to visualize these data through different approaches.

Key-Words: - ecosystem service, forest, GIS, Sanitary Protection Zones, water

Received: October 23, 2022. Revised: February 27, 2023. Accepted: March 22, 2023. Published: April 21, 2023.

1 Introduction

In Bulgaria, the forests are divided into two main

groups depending on their purpose: forests with

economic importance and forests with a special

purpose. The protected forests are a subgroup of

forests with special purposes where the forests with

water protection functions belong, [1]. The sanitary

protection zones (SPZs) around water sources and

drinking and domestic water supply facilities are

defined, [2], and the conditions and procedures for

their study, design, approval, and exploitation are

established by the regulation of the Ministry of

Environment and Water, the Ministry of Health and

the Ministry of Regional Development and Public

Works.

The sanitary protection zones consist of three

belts according to the adaptive methodology. The

inner belt (SPZ-I) includes the territory around the

water source which is highly secure and strictly

guarded against human activities that may damage

the water used. The middle belt (SPZ-II) protects

the water source from pollution by chemical,

biological, and rapidly decaying substances and

activities leading to the reduction or degradation of

the quality of the water resources. The outer belt

(SPZ-III) includes additional protection of the water

source against pollution from slowly degrading and

difficult-to-degrade substances.

The forests in Bulgaria and their water protection

function in particular are an important part of

valuing the water ecosystem service which provides

economic value. According to [3], data availability

for ecosystem service valuation stands out as one of

the main problems because different sources are

used for data transfer, such as regional, national, and

global statistics.

Our research is related to the water ecosystem

service which is provided by forest ecosystems and

is one of the 9 paid benefits of forest areas for which

users are intended to make payments.

To determine the value of the water ecosystem

service, it is necessary to determine the economic

value of the productive forest capital. This

necessitates the difficult task of studying the

territorial distribution and characteristics of the

forest areas falling within the scope of SPZs in

Bulgaria.

The diversity of data sources and the amount of

data to be processed complicate the process of

assessing water ecosystem services that are provided

by forests. Therefore, it is of particular importance

to be able to summarize, visualize and appropriately

filter these data to be able to make the necessary

decisions.

Therefore, the main objective of the paper is to

integrate spatial data on sanitary protection zones

and a database on forests in Bulgaria into a

repository and to design and create a GIS

application that supports the visualization and

analysis of these data using different views. To

WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT

DOI: 10.37394/232015.2023.19.33

Adelina Aleksieva-Petrova, Nevena Shuleva

E-ISSN: 2224-3496

369

Volume 19, 2023

achieve this goal, the following research problems

that require a solution have been defined:

 to propose a method for data processing and

data aggregation into a repository;

 to propose a GIS architecture for data

processing and visualization;

 to implement an experimental prototype

based on the proposed data processing

method and architecture to validate them.

The paper has been structured as follows. In

Section 2 similar works have been discussed. In

Section 3, a method for processing spatial data on

the sanitary protection zones and a database of

forests in Bulgaria has been considered. Section 4

describes the architecture of the WEB GIS

application. The main results and data visualization

have been provided in Section 4 and Section 5 is the

conclusion.

2 Related Works

Ecosystem services are the benefits that people

receive from nature, and therefore valuing these

services is an important challenge. Therefore,

various studies have been conducted that present

and discuss a regional ecosystem service assessment

and have created their ecosystem map, such as a

case study from Romania, [4].

Our research focused on studies that propose the

use of a Geographic Information System (GIS) to

map territories that are involved in ecosystem

service assessment.GIS is used for visualizing,

managing, creating, and analyzing geographic data,

[5]. Thus, that application will help us to see the

linkage and identify patterns in new ways. For

example, a web-based GIS/spatial visualization tool

provides the ability to view the data in an online

map and visually explore the data in a web browser

without the need for additional software, [6].

Moreover, in another study, the GIS application

adopts a raster format to offer a simple data

structure and has high spatial variability

representation for easy and efficient overlay

analysis, and unified grid cells for several attributes,

[7].

The different GIS-based tools help to analyze

some priority ecosystem services, [8]. For example,

in [9], the authors have created a spatial model,

based on GISs, capable of quantifying the potential

amount of woody biomass from the forest sector.

Even a public participation GIS is used to assess the

cultural ecosystem services based on geo-located,

passively crowdsourced data from social media

through a large amount of available data, [10].

An interesting approach in the use of GIS is the

Multi-Criteria Decision Analysis developed to

determine forest areas for soil protection function

based on erosion risk factors, [11]. The GIS method

with an assessment of stakeholders’ perceptions is

used to measure environmental change, while still

considering spatial variation, [12].

A GIS-based approach was designed to collect

data, perform spatial analysis, and map the

economic values of ecosystem services which is

implemented for three key steps of spatial valuation

- agricultural products, forest products, and tourism

services, [13].

On the other hand, the heterogeneity of data that

is being used for service assessment is also

challenging. Consequently, the following research

proposes a method for applying the standards of

interoperability using data provenance between the

processing steps in each transition to ensure

cohesive workflows across models and platforms,

[14].

3 Data Processing

A method is proposed to process spatial data for the

SPZs and a database of forests in Bulgaria. The

spatial data for the SPZs are provided as three ESRI

shape files for each of the three categories. The

second data are Excel tables that contain

information about the regions, districts, forest

groups, year class, SPZs, area, etc. The method

contains two main stages as shown in Fig. 1.

Fig. 1: Data Processing

The first stage is implemented in two steps: the

initial processing of the source data and the database

design on forests in the SPZs.

In the initial processing of the source data,

topological processing of the spatial data for the

SPZs was performed. Overlaps were found both

between individual layers and between polygons

included in each layer. The topological rules "Must

Not Overlap with" to detect overlaps between layers

and "Must Not Overlap" to detect overlaps between

polygons within a layer were used. The following

WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT

DOI: 10.37394/232015.2023.19.33

Adelina Aleksieva-Petrova, Nevena Shuleva

E-ISSN: 2224-3496

370

Volume 19, 2023

algorithm was applied to remove the detected

overlaps:

1) In an ArcGIS environment, territories from

SPZ-II and SPZ-III that fell within SPZ-I

were sequentially removed; and

subsequently, territories from SPZ-III that

fell within SPZ-II were removed.

2) Overlaps within each layer were removed.

3) Three generalized layers were created for the

individual zone categories.

4) Sections were created between the

generalized layers for the SPZs as well as a

spatial layer including the boundaries of the

municipalities in the country.

The database of forests in the SPZ was created and

the following algorithm was used:

1) The cross sections between the national

forest layer and the layers obtained as a

result of points 3 and 4 of the proposed

algorithm using the INTERSECT procedure

were created. The execution of the

INTERSECT procedure with small objects

usually produces parasitic cross sections

(SLIVER POLYGONS) - these are polygons

with minimal areas and most often have the

appearance of long linear objects. The

resulting layers were considered based on the

Area/Perimeter ratio as a criterion for the

removal of such polygons.

Empirically, for the present data it was found

that when the Area/Perimeter ratio is less

than 0.3, polygons are subject to removal.

Subsequently, polygons with an area of less

than 100 sq. m from the

dSOZ2_mun_DLESO and

dSOZ3_mun_DLESO layers were also

excluded from further analyses. Polygons

from dSOZ1_mun_DLESO (SPZ-I) were

retained regardless of the cross-sectional area

due to the fact that there were polygons with

an area of less than 10 sq. m in the source

database.

2) Selection of database records containing

information on the taxonomic characteristics

of sub-plots (or parts of sub-plots) falling

into the three SPZ categories. These data

according to the structure of the forest

database are contained in the WOODTYPE

table. Three tables were created

corresponding to the three SPZ categories

obtained from the general forest database

and the national parks.

3) The required data contained in a table

obtained from the common forest database

were added to the six tables.

The second stage of Data Processing is creating a

database in a PostgreSQL/PostGIS environment.

The database includes source (base) spatial layers

and data in the form of three tables that contain the

boundaries of the sanitary protection zones for belt1,

2, and 3. The tables have an identical structure and

contain the following fields: service identifier, site

identifier according to the Ministry of Environment

and Water of Bulgaria (MoEW) database, permit

number according to the MoEW database, site name

according to the MoEW database, Latin name

according to the MoEW database, belt, which

contains the numeric value 1, 2 or 3 depending on

the relevant belt, total stock in cubic meters of

woody vegetation present on the site, weighted

average increment of the woody species present on

the site, site perimeter in linear meters, site area in

square meters and a service field.

Three tables were created with information at the

subdivision level and by tree species, i.e. the three

belts contain attribute type data for the forests in the

respective sites. These tables include calculations in

terms of average growth, stock, forest groups, etc.

Each table has a correlation to the spatial data type

table (polygons) for the boundaries of the sanitary

protection zones for the respective belt.

The additional tables contained in the DB have

type spatial data (polygons) and content as follows:

 x_dgp – boundaries of state forest

enterprises.

 x_dgs - boundaries of the State Forests/LFS.

 x_municipalities - boundaries of planning

regions.

 x_nuts2 - boundaries of planning regions.

 x_regions - borders of districts.

 x_rfb - boundaries of regional forestry

directorates.

The SQL queries are created to reference the

materialized views and the data is returned directly

like from a table. In order to obtain summary

information from the above-mentioned tables,

similar SQL queries are generated which include the

following fields: 'Identifier', 'Permit', 'Name',

'Tree_species', 'Age', 'Age_class', 'Forest_group',

'Bonite', 'Completeness', 'Area_ha', 'Stock_cube_m',

'District', 'Average_growth', 'Municipality'.

Three MATERIALIZED VIEWS were created

as an extract from the respective SPZ boundary

tables and information on: geometry, "Identifier",

"Permit", "Name", "Total_stock_cubic_m",

"Area_ha" and "Average_growth" was obtained

WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT

DOI: 10.37394/232015.2023.19.33

Adelina Aleksieva-Petrova, Nevena Shuleva

E-ISSN: 2224-3496

371

Volume 19, 2023

using similar SQL queries. The resulting

MATERIALIZED VIEWS were converted to tables

with the same fields, which were then published to a

GeoServer environment for subsequent use in a

MapStore environment.

3 Design GIS Application

Open Source software products, compatible with

Open Geospatial Consortium (OGC) standards for

geospatial information interoperability were used to

create the web GIS application.

Fig. 2 shows the architecture of the designed web

GIS application. Three main layers have been

implemented: Database Layer, Server Layer, and

Presentation Layer. PostgreSQL has been used as

the database management system, along with its

spatial data extension PostGIS. The source

databases used were spatial data on sanitary

protection zones for each of the three belts and the

Bulgarian forest database as of December 2019.

Fig. 2: GIS Application Architecture

The Server Layer contains two servers –

GeoServer and Apache Tomcat. The last one works

with the forest database and was used for data

filtering of the regions, districts, forest groups, year

class, SPZs, and area. Geoserver was used to

publish the spatial data in a web environment and

the MapStore application was used as the end-user

interface which is in Presentation Layer. The two

software applications, GeoServer and MapStore, are

products of the Italian company GeoSolutions.

4 Data Visualization

To visualize the data a Dashboard was created in

MapStore to provide a set of information suitably

collected to show aggregated data in one view.

Geospatial data are displayed on a map along with

different widgets, such as tables, charts, and others,

which are used to show different kinds of

information and details relating to a specific context

(Fig. 3).

Fig. 3: GIS application home screen with all filters

and statistics

to The system allows users to interact with

published dashboards by editing, adding, arranging,

resizing, or deleting the widgets inside a dashboard.

The system provides a function that helps users

to select which type of widget they want. The

process of working with widgets is almost the same

for the supported five widget types: chart, text,

table, counter, and map (Fig. 4). The process

includes the following main three steps: selecting a

vector layer, configuring data and saving and adding

to the dashboard.

Fig. 4: Widgets in the GIS application

For example, the user can use the chart widget to

show and aggregate data, having the option to

choose what type of chart they want to use for

visualisation – pie, line, or bar charts.

The new interactive map on the dashboard adds

more than one map with the ability to connect other

WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT

DOI: 10.37394/232015.2023.19.33

Adelina Aleksieva-Petrova, Nevena Shuleva

E-ISSN: 2224-3496

372

Volume 19, 2023

widgets to them. After saving the first map, the

legend widget will be added to the list. The Legend

Widget will show a legend related to the connected

map.

5 Results and Discussion

The implemented GIS system fulfills its intended

purpose, is user-friendly, and integrates the data

from sources to represent the water ecosystem

service in Bulgaria. Fig. 5 shows a screenshot of the

system when filtering data for a specific SPZ with

ID 7245, which is visualized on the map, calculating

and displaying the average values of age, health,

completeness, growth, total area, and total forest

stocks.

Fig. 5: GIS application - data calculation and

visualization

The implemented system enables the generation

of detailed reports on forest territories within SPZs

by economic region, district, and municipality.

The territory of Bulgaria is divided into 6

economic regions: North-East, North-Central,

North-West, South-West, South-Central, and South-

East. Each region includes 5 or 6 districts. There are

28 districts altogether, and they are divided into a

total of 266 municipalities.

Fig. 6 shows reference data for Sofia City and

Sofia District:

 in tabular form on the distribution of forest

territories in the 3 SPZs by area, forest type,

and age class and

 in graphical form on the distribution of the

growth in the 3 SPZs by age class.

To be able to assess the state of ecosystems and

ecosystem services and determine their value, we

offer concrete practical steps for the implementation

of a GIS system for mapping the territorial

distribution and characteristics of sanitary protection

zones:

Fig. 6: Reports for Sofia City and Sofia District

1. Generalized layers for the three SPZ belts by

applying the DISSOLVE procedure.

2. Intersections between the generalized layers for

the SPZs and a spatial layer including municipal

boundaries by means of the INTERSECT

procedure.

3. Intersections between the national forest layer and

the layers obtained as a result of the previous two

steps by means of the INTERSECT procedure.

4. Creation of a database containing information on

the taxation characteristics of the subdivisions (or

parts of subdivisions) falling into the three SPZs.

6 Conclusion

The paper proposes a method for integration of the

spatial data of the sanitary protection zones and the

database of the forests in Bulgaria in a repository. A

GIS system has been designed and implemented to

help visualize territorial divisions, water protection

forests, and water resources in Bulgaria. This helps

to determine the territorial distribution and

characteristics of forest areas falling in SPZs in

Bulgaria, which have a total area of 576,117 ha and

49.837 million cubic meters of total growing stock.

The reports generated by the system contain data

on the distribution of the area, stock, and growth per

1 ha of forest territory by forest group and main tree

species.

The results will be used to determine the values

of "natural capital" forests and the water ecosystem

service. They are crucial for the development of

national ecosystem accounts and for assessing the

costs and benefits associated with national and

regional strategies and plans.

WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT

DOI: 10.37394/232015.2023.19.33

Adelina Aleksieva-Petrova, Nevena Shuleva

E-ISSN: 2224-3496

373

Volume 19, 2023

Acknowledgement:

Thе rеsеarch lеading to thеsе rеsults rеcеivеd

funding from thе Bulgarian Sciеncе Fund – project:

“Assessment of the water ecosystem service

provided by forest areas with water protection

functions in Bulgaria”, Contract No. КП-06-ОПР

03/7.

References:

[1] (text in Bulgarian) Forest Act, promulgated in

State Gazette issue 89/1958; amended in issue

26/1968, abolished in issue 125/1997.

[2] (text in Bulgarian) Regulation No. 2 on

sanitary protection zones around water sources

and drinking and domestic water supply

facilities, promulgated in State Gazette issue 68

of 1/1989, abolished in issue 88/2000;

Regulation on sanitary protection zones around

water sources and water supply facilities,

promulgated in State Gazette issue 24/1974.

[3] Koulov, Boian, et al. "GIS-based valuation of

ecosystem services in mountain regions: A case

study of the Karlovo municipality in Bulgaria."

One Ecosystem 2 (2017): e14062.

[4] Czúcz, Bálint, et al., How to design a

transdisciplinary regional ecosystem service

assessment: a case study from Romania,

Eastern Europe, One Ecosystem 3 (2018):

e26363.

[5] Numbere, Aroloye O., Application of GIS and

remote sensing towards forest resource

management in mangrove forest of Niger Delta,

Natural Resources Conservation and Advances

for Sustainability. Elsevier, 2022. 433-459.

[6] Botha, Tarryn Lee, et al., Development of a

GIS-based knowledge hub for contaminants of

emerging concern in South African water

resources using open-source software: Lessons

learnt. Heliyon, 2023, e13007.

[7] Siraj, G., Khan, H. H., and Khan, A., Dynamics

of surface water and groundwater quality using

water quality indices and GIS in river Tamsa

(Tons), Jalalpur, India. HydroResearch, 2023,

6, 89-107.

[8] Sieber, J., and Pons, M., Assessment of urban

ecosystem services using ecosystem services

reviews and GIS-based tools. Procedia

Engineering, 2015, 115, 53-60.

[9] Sacchelli, Sandro, Isabella De Meo, and

Alessandro Paletto, Bioenergy production and

forest multifunctionality: a trade-off analysis

using multiscale GIS model in a case study in

Italy, Applied Energy 104 (2013): 10-20.

[10] Depietri, Yaella, et al., Public participation GIS

versus geolocated social media data to assess

urban cultural ecosystem services: Instances of

complementarity. Ecosystem Services 50, 2021.

101277.

[11] Bozali, Nuri. Assessment of the soil protection

function of forest ecosystems using GIS-based

Multi-Criteria Decision Analysis: A case study

in Adıyaman, Turkey. Global Ecology and

Conservation, 2020, 24: e01271.

[12] Hinojosa, L., & Hennermann, K., A GIS

approach to ecosystem services and rural

territorial dynamics applied to the case of the

gas industry in Bolivia. Applied Geography,

2012, 34, 487-497.

[13] Chen, N., Li, H., & Wang, L., A GIS-based

approach for mapping direct use value of

ecosystem services at a county scale:

Management implications. Ecological

economics, 2009, 68(11), 2768-2776.

[14] Lacayo, M., Rodila, D., Giuliani, G., and

Lehmann, A., A framework for ecosystem

service assessment using GIS interoperability

standards. Computers & Geosciences, 2021,

154, 104821.

Contribution of Individual Authors to the

Creation of a Scientific Article (Ghostwriting

Policy)

The authors equally contributed in the present

research, at all stages from the formulation of the

problem to the final findings and solution.

Sources of Funding for Research Presented in a

Scientific Article or Scientific Article Itself

Thе rеsеarch rеcеivеd funding from thе Bulgarian

Sciеncе Fund – project: “Assessment of the water

ecosystem service provided by forest areas with

water protection functions in Bulgaria”, Contract

No. КП-06-ОПР 03/7.

Conflict of Interest

The authors have no conflict of interest to declare.

Creative Commons Attribution License 4.0

(Attribution 4.0 International, CC BY 4.0)

This article is published under the terms of the

Creative Commons Attribution License 4.0

https://creativecommons.org/licenses/by/4.0/deed.en

_US

WSEAS TRANSACTIONS on ENVIRONMENT and DEVELOPMENT

DOI: 10.37394/232015.2023.19.33

Adelina Aleksieva-Petrova, Nevena Shuleva

E-ISSN: 2224-3496

374

Volume 19, 2023