Modern Environmental Science and Engineering (ISSN 2333-2581) November 2019, Volume 5, No. 11, pp. 1009-1019 Doi: 10.15341/mese(2333-2581)/11.05.2019/004 Academic Star Publishing Company, 2019 www.academicstar.us
Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam
Lai Vinh Cam, Nguyen Van Hong, Vuong Hong Nhat, Nguyen Thi Thu Hien, Nguyen Phuong Thao, Tran Thi Nhung, and Le Ba Bien Institute of Geography, Vietnam Academy of Science and Technology, Vietnam
Abstract: This paper’s aim is concentrated on measuring the difference in landscape visual character as an indicator of landscape change. Seven landscape character indicators are used for calculating in a study area in Kon Tum province, Vietnam; concluding Landscape Shape Index, Aggregation Index, Number of Patches, Patch Density, Patch Cohesion Index, Perimeter - Area Ratio, Percentage of Landscape. This set of indicators proposed in previous research by McGarigal and Marks (1995) and calculated with GIS, Fragstats software. These indicators also express the attributes of the component maps which we used for main input data are land-use map, digital elevation map and soil map. These are the necessary mapping materials for calculating the indicators. In the method is used in this paper, a value for each indicator will be assigned for each observation to capture the character of the landscape. They will be compared with each other and considered changes in the forest, agricultural, artificial and others. This work is replicable and transparent, and constitutes a methodological step for landscape indication, since it adds a reference value for analyzing differences in landscape character. The difference among landscape units is then measured as an indicator of landscape change. The analysis of the difference is used to explain the manmade changes in the landscape. The results show that the difference in landscape character is mainly due to the loss of naturalness and the increase in landscape complexity brought about by agriculture and urban development.
Key words: indicators, landscape change, Kon Tum province
structure and function over time through their 1. Introduction interaction and mutual influences” [3]. Given this According to the European Landscape Convention circumstance, interdisciplinary landscape change (ELC), “Landscape means an area, as perceived by studies are focused on the causes and effects of people, whose character is the result of the action and land-use and landcover dynamics as well as the interaction of natural and/or human factors” [1]. ecological and social impacts of alternative design, Most of the studies are focused on landscape planning, policy, and management schemes on structure assessment and its quantification using landscapes and regions [3]. various spatial indices; there is also a great number of The landscape is often described as the prime sphere works dealing with the relations between landscape where the interactions of human beings, as well as the structure and biodiversity [2]. The surrounding environment, becomes evident and where the landscape has, especially in recent decades, undergone combined effects of nature, as well as society, becomes relatively dynamic and significant changes [2]. visible. Changes in the environment due to land use can Landscape change can be defined as “the alteration of negatively affect the functioning of the ecosystem These changes have been mainly driven by the
Corresponding author: Nguyen Van Hong, Doctor, expansion of agricultural activities and human Researcher; research area/interest: management of resource and settlements [4]. Understanding the impact of land-use environment. E-mail: [email protected].
1010 Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam change on the environment due to agricultural and requires a holistic approach that integrates both natural urban uses are important to inform government policy. and cultural information. However, it is less common Landscape change has attracted increasing interest to find works that assess changes in landscape because of its impact and close relation to climate character from a holistic point of view. Notable among change, sustainable development, and its impact on these are the Swiss Landscape Monitoring Program food security. There is consequently a pressing need to and the Living Landscapes approach. A set of understand the drivers and causes of landscape change. indicators for the Swiss Landscape Monitoring Driving forces are the forces that cause observed program is divided into physical landscape properties landscape change; processes that influence the and land-use indicators (general, recreational use, evolutionary trajectory of a landscape. The four major agriculture and forestry use), perception indicators driving forces of landscape change, are political, (evolutionarily determined landscape perception, cultural, socioeconomic, and natural or spatial driving culturally determined landscape perception), and forces [4]. indicators relating to legal aspects of landscape The European Landscape Convention ELC states conservation. An approach to LCA that introduces a that the landscape characteristics and the forces and spatial framework based on homogeneous landscape pressures that transform them should be analyzed by units is reflected differences in the natural and cultural noting the changes in the landscape. There is a whole dimensions of landscapes at different scales [11]. body of work on the assessment of landscape change In this paper, we focus on measuring indicators for detection, most of which focuses on land cover change. landscape changes. We compare the current landscape Changes in landscape structure patterns are assessed character and consider changes in the forest, using GIS map-based landscape metrics [5], satellite agricultural, artificial and others. This work provides a images [6,7,8] or a combination of both [6, 9, 10]. methodological step for landscape indication, since it Following A.M. Hersperger et al., on the paper adds a reference value to an existing LCA method to “Evaluating outcomes in planning: Indicators and analyse the differences, and can be used to explain reference values for Swiss landscapes”, a major landscape change. The set of landscape character challenge of landscape-planning evaluation is to select indicators based on GIS techniques, Fragstats sofware. relevant indicators that depict the outcomes of The research area in this paper is Kon Tum province landscape planning.In particular, the indicators have to which is located in the North of Central Highlands fulfil the following criteria: (1) show a clear link region, Vietnam. Kon Tum has common national between indicators and goals; (2) are easily measurable frontiers with Laos PDR, Cambodia (with 280.7 km and sensitive to external change; (3) can capture border length) and is contiguous with three other complex concepts such as landscape aesthetics, provinces in Vietnam. landscape quality and landscape; (4) are representative 2. Material and Methods for a specific geographic region. Unfortunately, constraints in time, money and personal resources often 2.1 Research Area lead to low sampling intensity, and therefore low Kon Tum is a mountainous province located in the informative value and long data series are seldom North of Central Highlands region, Vietnam. This one produced [1]. belongs to seven economic regions in Vietnam. In the It is necessary for natural resource management and western, Kon Tum has common national frontiers with spatial planning to monitor landscape changes over Laos PDR, Cambodia (with 280.7 km border length). time [11]. Landscape Character Assessment (LCA) Kon Tum is also is contiguous with three other
Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam 1011
Fig. 1 Map of the research area. provinces in Vietnam: Quang Nam rovince in the North, has two obvious seasons: rain season lasts from April Quang Ngai province in the East and Gia Lai province to Novermber, dry season lasts from December to in the South. March of next year. The annual average rainfall is The total area of Kon Tum is about 9.689,61 square about 2121 mm. kilometres, hold 3 percents of Vietnam’s area. Locating 2.2 Material and Methods in the T-junction of the Indochina, Kon Tum has enough conditions to create border gates and to enlarge The current landscape is characterized by a set of international cooperation to the West. Besides, Kom indicators proposed and calculated with GIS. Tum plays an important strategic position on national Landscape character is assessed by the following defence, ecological environment protection. That’s variables measured with a set of GIS indicators: why Kon Tum can be an economic connection between Landscape Shape Index (LSI), Aggregation Index (AI), the regions and the whole country. Almost parts of Kon Number of Patches (NP), Patch Density (PD), Patch Tum is in the western of Truong Son mountainous Cohesion Index (COHESION), Perimeter - Area Ratio range, its topography is low from the North to the (PARA), Percentage of landscape (PLAND). The South and from the East to the West. In which, hills mapping materials necessary to calculate the indicators are mountains hold about two-fifths of the whole are Digital Elevation Model (DEM), Soil Map and provincial area. The alleys are along Poko river which Land use/Land cover database. is low toward the South. The annual temperature in a The method involves assigning each observation year fluctuates in the period of 22○C to 23○C, the point value for each indicator to capture the character amplitude of temperature per day is 8○C-9○C. Kon Tum of the landscape (Fig. 2).
1012 Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam
Tabe 1 Indicators used for each landscape concept. Indicator Parameters Description
Landscape Shape Index - ei = total length of edge (or LSI equals the total length of edge (or perimeter) perimeter) of class i in terms of involving the corresponding class, given in a number ei LSI number of cell surfaces; includes all of cell surfaces, divided by the minimum length of min ei landscape boundary and background class edge (or perimeter) possible for a maximally edge segments involving class I aggregated class, also given in number of cell
- min ei = minimum total length of surfaces, which is achieved when the class is edge (or perimeter) of class i in terms maximally clumped into a single, compact patch. of cell surfaces
Aggregation Index (%) - gii = number of like adjacencies AI equals the number of like adjacencies involving the (joins) between pixels of patch type corresponding class, divided by the maximum possible gii AI (class) i based on the single count number of like adjacencies involving the max -gii method. corresponding class, which is achieved when the class - max-gii = maximum number of like is maximally clumped into a single, compact patch; adjacencies (joins) between pixels of multiplied by 100 (to convert to a percentage). patch type (class) i based on the single-count method. 2 Percentage of Landscape (%) Pi = proportion of the landscape PLAND equals the sum of the areas (m ) of all n occupied by patch type (class) i. patches of the corresponding patch type, divided by aij 2 2 aij = area (m ) of patch ij. total landscape area (m ), multiplied by 100 (to j1 2 PLAND Pi A = total landscape area (m ). convert to a percentage); in other words, PLAND A equals the percentage the landscape comprised of the corresponding patch type. Note, total landscape area (A) includes any internal background presen
Number of Patches NP = ni ni = number of patches in the NP equals the number of patches of the corresponding landscape of patch type (class). patch type (class) i.
Patch Density Number per 100 ni = number of patches in the PD equals the number of patches of the corresponding hectares landscape of patch type (class) i. patch type divided by total landscape area (m2), n A = total landscape area (m2). multiplied by 10,000 and 100 (to convert to 100 PD i (10,000) A hectares). Note, total landscape area (A) includes any internal background present.
Patch Cohesion Index pij = perimeter of patch ij in terms of COHESION equals 1 minus the sum of patch n number of cell surfaces. perimeter (in terms of number of cell surfaces) divided pij 1 j1 1 COHESION 1 1 aij = area of patch ij in terms of by the sum of patch perimeter times the square root of n paA number of cells. patch area (in terms of number of cells) for patches of ij ij j1 A = total number of cells in the the corresponding patch type, divided by 1 minus 1 landscape. over the square root of the total number of cells in the landscape, multiplied by 100 to convert to a percentage. Note, total landscape area (A) excludes any internal background present.
Perimeter - Area Ratio pij = perimeter (m) of patch ij. PARA equals the ratio of the patch perimeter (m) to 2 area (m2). Pij aij = area (m ) of patch ij. PARA aij
Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam 1013
Fig. 2 Outline of the methodology used to calculate the indicators.
3. Results and Discussion
3.1 The Components Creating Landscape
The case study which we use to apply proposed methodology is Kon Tum province — one of the provinces in the North of Central Highlands region, Vietnam. One of the components for creating the landscapes in Kon Tum province is elevation classification. This is also a landscape unit as one of the hard foundations for landscape. Almost parts of Kon Tum is located in South of Truong Son mountain range; its terrain is gradually low from the North to the South and the East from the West, its slope is very high in the North and low (about 2-5%) in the South.
The terrain here is diversified. Fig. 3 Landscape unit in the research area. The research area contains six landscape units: High Table 2 Area and scale of elevation classification. mountain which is concentrated on the North West of Landscape units Area (ha) Scale % Kon Tum province have attitude from 1200-2500 m Valleys 5271.10 0.55 with 22.5% total area, low mountain; the low Low hills (200-500 m) 114804.92 12.01 mountain is largest with 38.78% total area; hills also High hills (500-700 m) 245969.02 25.73 have a large area with 37.74% total area (Fig. 3). Valleys (among mountain) 3148.40 0.33 Another component of landscape in the research Low moutain (700-1200 m) 370727.29 38.78 area is soil map. Two of main soil units are held Average/high moutain 216085.12 22.60 almost area are acrisols (37% total area) and (1200-2500 m) Total 956005.85 100.00 ferralsols (59% total area). Fluvisols which hold a small ratio but has an important role in agriculture are Besides, landuse-landcover database is also located in valleys along the rivers. considered in this paper as a component of landscape The landscape units have been group for better in Kon Tum province. interpretation.
1014 Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam
Table 3 Area and scale of landuse landcover unit. LULC units Area Ratio (%) Closed canopy 320327.1 33.51 Open canopy 363486.2 38.02 Agricultural 134035.8 14.02 Shrubs 112649 11.78 Artificial 24210.87 2.53 Water surface 1296.896 0.14 Total 956005.85 100.00
Fig. 4 Soil unit in the research area.
In the research area, closed canopy and open canopy are held the almost area with ration 33.51% and 38.02 in turn. The landuse landcover units which are also held large area are agricultural (only hold 14.02% total area) and shrubs (held 11.78% total area). The research area has got twenty-five landscape units (Fig. 6) which created by overlaying three Fig. 6a Landscape map in Kon Tum province. landscape components (three input original data), consist of Digital Elevation Model (DEM), Soil unit, Landuse Landcover unit.
Fig. 6b Legend of landscape map in Kon Tum province.
3.2 Calculating Landscape Indicators
Landscape indicators which are proposed in this Fig. 5 Landuse landcover unit in the research area.
Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam 1015 paper calculated by applying ArcGis 10.5, Fragstats landscape units in Kon Tum province is range from 4 4.2 software. to 631. The NP of landscape units is also large Landscape shape index (LSI) provides a simple different. measure of class aggregation or clumpiness and, as Patch density (PD) is a limited, but fundamental, such, is very similar to the Aggregation index. The aspect of landscape pattern. Patch density has the differences lie in whether aggregation is measured same basic utility as number of patches as an index, via class edge (or perimeter) surfaces (as in LSI). The except that it expresses number of patches on a per result of LSI indicator is very different among the unit area basis that facilitates comparisons among landscape units in Kon Tum province. It’s range from landscapes of varying size. The result of NP indicator 3.3 to 41.53. of the landscape units in Kon Tum province is range Aggregation index (AI) is calculated from an from 0 to 0.07. The PD of landscape units are so adjacency matrix, which shows the frequency with close. which different pairs of patch types (including like Patch cohesion index (COHENSION) measures adjacencies between the same patch type) appear the physical connectedness of the corresponding side-by-side on the map. The result of AI indicator of patch type. Below the percolation threshold, patch the landscape units in Kon Tum province is range cohesion is sensitive to the aggregation of the focal from 77.74 to 98.58. class. Patch cohesion increases as the patch type
Percentage of landscape (PLAND) quantifies the Table 4 The results of calculating landscape indicator in proportional abundance of each patch type in the Kon Tum province (1). PLAND landscape. Like total class area, it is a measure of Landscape unit LSI AI (%) NP (%) landscape composition important in many ecological LC1 18.55 98.37 10.94 99.00 applications. However, because PLAND is a relative LC2 21.28 97.96 9.36 99.00 measure, it may be a more appropriate measure of LC3 21.32 89.79 0.38 96.00 landscape composition than a class area for LC4 23.33 95.00 1.89 224.00 comparing among landscapes of varying sizes. The LC5 3.33 91.38 0.01 4.00 LC6 29.64 97.58 13.16 173.00 result of PLAND indicator of the landscape units in LC7 34.24 97.54 17.20 231.00 Kon Tum province is range from 0.01 to 17.2. The LC8 41.53 91.40 2.10 391.00 range of this result is large differences among LC9 40.11 95.17 6.20 506.00 landscape units. LC10 21.66 83.25 0.15 208.00 Number of patches (NP) of a particular patch type LC11 7.23 96.13 0.25 5.00 LC12 6.88 88.66 0.03 9.00 is a simple measure of the extent of subdivision or LC13 26.59 96.07 4.01 157.00 fragmentation of the patch type. Although the LC14 33.71 95.63 5.29 270.00 number of patches in a class may be fundamentally LC15 37.88 96.60 11.12 195.00 important to a number of ecological processes, often LC16 38.14 93.60 3.19 355.00 it has limited interpretive value by itself because it LC17 39.18 91.81 2.06 631.00 conveys no information about area, distribution, or LC18 15.09 93.66 0.47 56.00 LC19 11.05 98.58 4.74 24.00 density of patches. Of course, if total landscape area LC20 13.56 98.49 6.54 20.00 and class area are held constant, then number of LC21 9.98 94.09 0.22 24.00 patches conveys the same information as patch LC22 20.52 77.74 0.07 164.00 density or mean patch size and may be a useful index LC23 12.81 94.83 0.50 10.00 to interpret. The result of NP indicator of the LC24 9.27 82.04 0.02 5.00 LC25 10.41 91.48 0.12 109.00
1016 Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam
Table 4 The results of calculating landscape indicator in The results of landscape indicators have been Kon Tum province (2). treated, classified and used for creating maps through Landscape unit PD(*) PARA COHESION ArcGis 10.5. LC1 0.01 306.49 99.70 LC2 0.01 222.57 99.53 The LSI indicator is very different among LC3 0.01 342.75 96.67 landscape units which show that the landscape LC4 0.02 431.48 98.11 units in Kon Tum have been separated powerfully. LC5 0.00 165.74 93.20 This influence happened on hills or low mountains LC6 0.02 235.16 99.50 (Fig. 7). LC7 0.02 198.92 99.52 The AI indicator is closely related to the LC8 0.04 303.33 97.90 LC9 0.05 437.76 98.72 Landscape Shape Index (LSI), only the latter is based LC10 0.02 898.58 94.30 on perimeter surfaces as opposed in internal like LC11 0.00 84.05 99.11 adjacencies. Almost AI value in the research area is LC12 0.00 218.90 95.23 more than 95% means the landscape units are nearby LC13 0.02 154.78 99.09 maximally aggregated into a single, compact patch LC14 0.03 263.34 99.43 LC15 0.02 440.49 99.87 (Fig. 8). LC16 0.04 282.04 98.23 The PLAND indicator is different among LC17 0.07 965.84 99.27 landscape units with its range from 0.01 to 17.2. That LC18 0.01 247.32 98.08 means all landscape units of the corresponding LC19 0.00 158.05 99.71 landscape type are small and becomes increasingly LC20 0.00 230.51 99.86 rare. It is a measure of landscape composition LC21 0.00 141.90 98.43 LC22 0.02 1151.33 95.79 important in many ecological applications (Fig. 9). LC23 0.00 179.37 99.41 The NP indicator values in Kon Tum is very LC24 0.00 413.23 95.85 different means the landscape units corresponding LC25 0.01 1074.00 97.36 landscape type have fragmentation is happened *Unit of PD: Number per 100 hectares strongly. The strongest extent of subdivisions are becomes more clumped or aggregated in its landscapes which lie on the high mountains, with NP distribution; hence, more physically connected. equals more than 500 (Fig. 10). Above the percolation threshold, patch cohesion does not appear to be sensitive to patch configuration. The result of COHESION indicator is very different among the landscape units in Kon Tum province. It’s range from 93.20 to 99.86. Perimeter-area ratio (PARA) is a simple measure of shape complexity but without standardization to a simple Euclidean shape (e.g., square). A problem with this metric as a shape index is that it varies with the size of the patch. The result of LSI indicator is very different among the landscape units in Kon Tum province. It’s range from 84.05 to 1151.33. The PARA of landscape units is so different.
Fig. 7 Map of LSI indicator in Kon Tum province.
Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam 1017
Fig. 8 Map of AI indicator in Kon Tum province. Fig. 10 Map of NP indicator in Kon Tum province.
Fig. 9 Map of PLAND indicator in Kon Tum province. Fig. 11 Map of PD indicator in Kon Tum province.
PD indicator values among landscape units in the aggregation of the focal landscape or identical inside whole research area are also different but small every landscape (Fig. 12). values. That means there is different separation The PARA indicator values in Kon Tum is very among landscape types but not among landscape different means landscape shape complexity is huge. units corresponding landscape type (Fig. 11). This causes the differences of zoning for usage, Almost landscape units hold COHESION indicator management of resource and environment (Fig. 13). units more than 99. That means the proportion of the landscape comprised of the focal class increases and becomes decreasingly subdivided and more physically connected. This is also sensitive to the
1018 Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam
Percentage of landscape (PLAND). These indicators are calculated by GIS, Fragstats sofware. Seven GIS map-based indicators are combined, allowing us to simplify the complexity of the visual landscape. Our approach was shown to be applicable to Kon Tum province, Vietnam containing twenty-five landscape units created by three input data (land-use map, digital elevation map and soil map). The methodological step for these landscape indicators is proposed and the results should be replicable and transparent. It is recognized that the values of five indicators (LSI, PLAND, NP, PD, PARA) are different among landscape units. These indicators can be used for assessing landscape for the unique
Fig. 12 Map of COHESION indicator in Kon Tum purpose such as land-use planning, function zoning…. province. It is recognized that the possible correlations between indicators need to study. It is necessary to concern about the interrelationships and possible overlaps in landscape character concepts, so future research should include a study of the correlation between the indicators.
Acknowledgement
The authors would like to acknowledge the project: “Research, propose the model of stable usage natural resource go through the frontier of three countries Laos - Vietnam – Cambodia (consist of the provinces of Kon Tum, Quang Nam, Da Nang, Ratanakiri, Atapeu)”, belonged to the national science and technology program in the period of Fig. 13 Map of PARA indicator in Kon Tum province. 2016-2020 “Science and technology for social-economic development the Central Highlands 4. Conclusion in associated regions and international integration” (the Central Highlands program 2016-2020); the The main aim of this study is calculating seven project’s code: TN18/T09. indicators of landscape which is made by overlaying three main its components, including elevation References classification, soil and land-use landcover data. [1] A.M. Hersperger, G. Mueller, M. Knöpfel, A. Siegfried, These indicators are Landscape Shape Index (LSI), F. Kienast, Evaluating outcomes in planning: Indicators Aggregation Index (AI), Number of Patches (NP), and reference values forSwiss landscapes, Ecological Indicators 77 (2017) 96-104. Patch Density (PD), Patch Cohesion Index [2] K. Krováková, S. Semerádová, M. Mudrochová, J. (COHENSION), Perimeter - Area Ratio (PARA), Skaloš, Landscape functions and their change — A
Measuring Indicators for Landscape Change in Kon Tum Province, Vietnam 1019
review on methodological approaches, Ecological heterogeneous landscape in West Africa: Loss of Engineering 75 (2015) 378-383. forestlands and capacity building opportunities, Earth [3] L. Musacchio, E. Ozdenerolb, M. Bryant, T. Evans, Obs Geoinformation 63 (2017) 15-23. Changing landscapes, changing disciplines: seeking to [8] C. Wohlfart, B. Mack, G. Liu, C. Kuenzer, Multi-faceted understand interdisciplinarity in landscape ecological land cover and land-use change analyses in the Yellow change research, Landscape and Urban Planning 73 River Basin based on dense Landsat time series: (2005) 326-338. Exemplary analysis in mining, agriculture, forest, and [4] W. Musakwa, S.Wang, Landscape change and its urban areas, Applied Geography 85 (2017) 73-88. drivers: A Southern African perspective, Environmental [9] Q. Fan and S. Ding, Landscape pattern changes at a Sustainability33 (2018) 80-86. county scale: a case study in Fengqiu, Henan Province, [5] V. Amici, S. Maccherini, E. Santi, D. Torri, F. Vergari China from 1990 to 2013, Catena 137 (2016) 152-160. and M. D. Monte, Long-term patterns of change in a [10] V. V. Eetvelde and M. Antrop, Indicators for assessing vanishing cultural landscape: a GIS-based assessment, changing landscape character of cultural landscapes in Ecology Informatics 37 (2017) 38-51. Flanders (Belgium), Land Policy 26 (2009) 901-910. [6] B. Martín, E. Ortega, P. Martino and I. Otero, [11] F. Kienast, J. Frick, M. J. V. Strien and M. Hunziker. Integrating economic landscape valuation into The swiss landscape monitoring program — A Mediterranean territorial planning, Ecological comprehensive indicator set to measure landscape Indicators 90 (2018) 584-593. change, Ecological Modelling 295 (2015) 136-150. [7] H. M. Badjana, P. Olofsson, C. E. Woodcock, J. [12] T. Liu and X. Yang, Monitoring land changes in an Helmschrot, K. Wala and K. Akpagana, Mapping and urban area using satellite imagery, GIS and landscape estimating land change between 2001 and 2013 in a metrics, Applied Geography 56 (2015) 42-54.