**1. Introduction**

In September 2000, the United Nations (UN) presented Millennium Development Goals (MDGs) aimed at enhancing the quality of human life [1]. However, these MDGs set no concrete objectives for solving fundamental problems posed by factors hampering efforts to enhance quality of life. The 2012 UN Conference on Sustainable Development (UNCSD), "Rio + 20," produced the outcome document "The Future We Want" which set a new sustainable development agenda called Sustainable Development Goals (SDGs) [2]. In 2015, the UN adopted the "2030 Agenda for Sustainable Development" containing 17 SDGs and 169 targets [3]. The SDGs' primary goal is eradicating poverty, with a focus on balanced economic, social and environmental developments.

A broad range of forest-related issues, from forest managemen<sup>t</sup> to forest-added value, were considered in multiple SDGs including Goal 3 (Good Health and Well-being), Goal 6 (Clean Water and Sanitation), Goal 13 (Climate Action) and Goal 15 (Life on Land) [4]. Goal 15, "Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification and halt and reverse land degradation and halt biodiversity loss," is particularly associated with forestry; its targets emphasize the value of forests for biodiversity conservation along with marine and coastal areas [5].

In the Korean Peninsula, the area along the demilitarized zone between North and South Korea (DMZ) is valued as a treasure house of biodiversity together with the Baekdudaegan (Baekdu Mountains, the longest mountain chain running along the Korean Peninsula) and coastal islands. The DMZ was designated as one of the axes of the "Ecological Network of the Korean Peninsula" by the Ministry of Environment in 2002 [6]. The area is divided into the DMZ itself (about 4 km wide) and the Civilian Control Zone (CCZ), an area 5–20 km wide extending from the DMZ's Southern Limit Line to the Civilian Control Line further south. In the past, civilians were not allowed to enter the Civilian Control Zone (except during guarded tourist expeditions) and so its intact natural environment and ecosystems have been highly valued together with the DMZ [7]. However, as active government-led development programs are being implemented in the CCZ, its forests are exposed to increasing deforestation and forest degradation [8]. These processes degrade plant and animal habitats and disturb the ecological and environmental functions of the area, counteracting efforts to achieve the SDGs [9]. With increasing socioeconomic activities in the CCZ, the ongoing change from forest to non-forest land use is becoming increasingly complex [10]. The forests in the CCZ encompass a broad swath across the Korean Peninsula and proper understanding of forest land use and land cover (LULC) change factors is essential for integrated planning and managemen<sup>t</sup> [11–14].

LULC change does not take place independently of the surrounding environment; it is therefore important to consider associations and correlations with adjacent areas when analyzing its causes [15]. Jeong et al. [16] emphasized the importance of understanding the cluster and diffusion aspects of LULC distribution and identifying the underlying social, economic and environmental factors when setting up land-management plans. Of the various analytical approaches used to explore this topic, Hot spot analysis has been increasingly prioritized as an intuitive spatial-statistical analysis method compared to more complicated calculation methods [17]. This approach, developed by Ord and Getis [18], expresses the similarities and differences of spatial values measured and summarized for clustered locations [19]. For example, Lee [20] used remote sensing data to identify the relationship between LULC change and a vegetation index. Choi et al. [21] found that Hot spot analysis was useful for exploring the clustered factors related to LULC change and socioeconomic data but also noted the method's limitations with regards to determining the effects of individual factors. Analyzed various influential factors for LULC change and explored the differing effects of these factors [22].

On the other hand, structural equation modeling (SEM) is widely used in social humanities studies for its ability to compare correlations between various factors and to determine the inter-factor differences in impact [23–25]. For example, Jang and Kim [26] evaluated the impact of development density for various land types on the land's value and Asadi et al. [27] evaluated the impact of economic, social and environmental factors on cropland changes. To date, however, most related studies have used cross-sectional data rather than time-series data and hardly any studies have performed comprehensive spatial data analysis.

In this study, we have conducted studies forest managemen<sup>t</sup> and various factors influencing for DMZ forest, the only area in the world. We used Hot spot analysis to analyze patterns of forest LULC change and SEM to determine the effects of various factors influencing forest LULC change. Our results provide practical data for setting up comprehensive forest managemen<sup>t</sup> programs in the CCZ as part of ongoing efforts to achieve SDGs.

#### **2. Materials and Methods**

## *2.1. Study Site*

The CCZ was designated by Article 2(1) of the "Special Act on Management of Mountainous Districts North of The Civilian Control Line" and Article 5(2) of the "Protection of Military Bases and Installations Act" [28]. It extends over an area of ~120,000 ha, accounting for ~18% of the administrative divisions intersecting the DMZ area (Figure 1). The CCZ has a broad distribution of land use for military facilities due to its intrinsic nature but recent years have seen steady LULC changes related to the development of tourist attractions [29]. The Gyeonggi-do part of the CCZ is flat and low (<300 m above sea level) with intensive agricultural activities taking place on a residential or commuting basis. The Gangwon-do part of the CCZ is predominantly mountainous (≥1000 m above sea level) except for Cheorwon-gun [30].

**Figure 1.** Study Site: The Civilian Control Zone (CCZ)) south of the demilitarized zone separating North and South Korea.
