1. Introduction
With the rise in carbon emissions (CEs), global climate change has already begun to pose a threat to human society [
1]. Therefore, enhancing urban resilience and effectively reducing and controlling CEs has become an important goal of environmental policies worldwide [
2,
3]. Meanwhile, LUC is a crucial driving factor in global climate change [
4,
5]. In 2020, the Chinese government proposed the “dual carbon” goals of CEs reaching their peak and achieving carbon neutrality [
6]. Achieving these ambitious goals requires a deep understanding of carbon emission dynamics at regional scales, where land-use decisions have immediate and profound impacts. While enhancing research on the patterns and mechanisms of land-use carbon emissions (LUCEs) can provide a basis for developing differentiated emission reduction policies, significant gaps remain. Existing studies on LUCEs, as reviewed, have extensively covered regional carbon cycles, terrestrial carbon sources/sinks, and the spatiotemporal evolution of emissions. However, many of these studies exhibit limitations: (1) They often focus on single aspects (e.g., either accounting or factor analysis) without integrating spatial evolution with a comprehensive driver decomposition, leading to an incomplete picture of the emission mechanism. (2) Research findings from national or developed regional scales may not be directly applicable to specific, rapidly urbanizing but economically developing regions like Jiangxi Province, due to distinct socioeconomic contexts and land-use transition patterns. (3) Furthermore, the dynamic relationship between economic growth and LUCEs in such contexts is not fully explored, limiting the formulation of targeted decoupling policies. To address these gaps, this study selects Jiangxi Province, a typical developing region in the Yangtze River Basin, as a case study. To construct a comprehensive analytical framework, we employ a suite of methodologies that includes land-use dynamic analysis, LUCE accounting, LMDI decomposition, and the Tapio decoupling (TD) model. This framework aims not only to quantify the spatiotemporal evolution of LUCEs but also to disentangle the complex contributions of various driving factors (e.g., LUCE intensity, land-use structure (LUS), economic level) and explicitly evaluate the decoupling state between economic growth and CEs. Enhancing research on the patterns and mechanisms of LUCEs can provide a basis for developing differentiated emission reduction policies and measures for different regions. As an important province in the Yangtze River Basin, significant efforts are being taken in Jiangxi Province to lower CEs. However, rapid changes in land-use methods, efficiency, and spatial structure have complicated regional research on LUCEs in this province. Therefore, exploring the characteristics of the Spatial–temporal evolution of LUCEs and their influencing factors in Jiangxi Province is highly necessary; indeed, it will prove crucial for high-quality national territorial spatial planning, formulating precise emission reduction policies, and achieving green, low-carbon sustainable development.
Domestic and international research on LUCEs has mainly focused on regional carbon cycling processes [
7,
8], carbon sources and sinks in terrestrial ecosystems [
9,
10,
11,
12], the relationship between land-use changes (LUCs) and carbon cycling [
13,
14,
15], the Spatial–temporal evolution of LUCEs and LUCE efficiency [
16,
17,
18], models for calculating LUCEs [
19,
20], analyses of carbon ecological footprints [
21,
22], the factors influencing LUCEs [
23,
24,
25], and studies on the intensity of LUCEs and ecological compensation for emissions [
25,
26]. Equally, research on LUCEs has mostly been conducted at national, provincial, municipal, and watershed scales [
23,
27,
28,
29,
30]. Its results indicate there are distinct differences in LUCEs between different regions. Widening gaps between the carbon sources and sinks within regions exist, with CEs from construction land constituting a major source of LUCEs and the carbon absorption capacity of forest land, grasslands, water areas, and unused land continuously decreasing at the same time. Thus, altering the patterns of LUCEs and promoting CE reduction efforts to reach lower levels in key areas have become crucial. Analyzing the factors that affect LUCEs is key to reducing excessive CEs and advancing carbon peak targets, and is a prerequisite for identifying the major contributing factors and implementing corresponding control measures [
31,
32]. To this end, methods such as factor decomposition [
33,
34], correlation analysis [
35,
36], gray relational analysis [
37,
38], and regression analysis [
39,
40] have often been employed, among others, including in studying multiple regions of China. Using the Logarithmic Mean Divisia Index (LMDI) [
41] is a particularly effective method. In considering the spatial effects between units, the target can be decomposed without leaving unexplained residuals, and relatively simple transformation expressions can be used for both additive and multiplicative decomposition, enhancing the interpretability of the results for studies on the factors influencing LUCEs [
42].
The levels of economic development in different regions of Jiangxi Province vary, with significant spatial and temporal differences in their LUCEs. Research on urban LUCEs can provide the basis for optimizing LUS, improving land-use efficiency (LUE), and reducing LUCEs in this region. On this premise, in this study, we analyze the changing patterns of land use in Jiangxi Province from 2000 to 2020 using data on LUC, models on the land-use dynamic degrees (LUDDs), and land-use transfer (LUT) matrices. Furthermore, by integrating the CE factors from the IPCC inventory methodology and its energy consumption and CE model with data on social, economic, and energy consumption variables, the net LUCEs, the intensity of LUCEs, and the intensity of LUCEs per capita in Jiangxi are calculated. The Spatial–temporal evolution of LUCEs is then analyzed further. Finally, an LMDI model and a TD model are applied to calculate and examine the contributions and degrees of the factors influencing LUCEs, elucidating the inherent driving relationships between these factors and net LUCEs, and between changes in LUCEs and economic growth. These findings will provide guidance for the “dual carbon” goals in Jiangxi Province, as well as offering crucial insights for low-carbon development in economically underdeveloped regions more generally.
3. Methods
In this study, LUCEs in Jiangxi Province are taken as the research object. The research content and influencing factors of LUCEs are qualitatively analyzed, followed by quantitative analysis. Based on the results of the analysis, effective policy recommendations are proposed. The research framework is shown in
Figure 2.
3.1. The LUDD Model
This study employs a series of complementary models to systematically analyze the spatiotemporal evolution and influencing factors of LUCEs in Jiangxi Province. The LUDD model is used to quantify the speed and extent of LUCs, providing a more intuitive reflection of trends than single indicators. The LUT matrix clearly displays the transition paths between different land types, revealing structural changes. The LUCE accounting model is based on IPCC standards, ensuring comparability and scientific rigor. The LMDI model decomposes influencing factors without residuals, yielding accurate and reliable results that effectively identify the contribution of each driver. The TD model is a widely used tool for assessing the relationship between economic growth and environmental pressure, helping to determine the decoupling status between CEs and economic development. Together, these models form a comprehensive analytical chain from description and accounting to attribution and evaluation.
LUDD refers to the changes in different land use types within a specific time frame. It can visually reflect the changes in the area and rate of a specific type of land-use during a given research period. It is calculated as follows [
43]:
where
K represents the LUDDs;
and
represent the land-use areas at the beginning and end of the research period; and
T is the duration of the research period. A higher value for
K indicates more drastic LUCs, while a lower value indicates a more stable situation.
The LUDD model provides an overall trend of LUCs, laying the foundation for subsequent LUT matrix and LUCE accounting.
3.2. A LUT Matrix
A LUT matrix is a tool used to describe and analyze changes and transitions between different land-use types. When studying changes in land use, land is typically divided into various use types. A LUT matrix is a commonly used tool in studies on LUCs that can help decision-makers and researchers understand the LUC process. It records the changes and transitions between various land-use types in different time periods, which are usually presented in the form of a row–column matrix. The calculation involved is expressed as follows [
44]:
where
represents the area of land type
x transitioning to land type
y, and
n represents the number of land-use types.
The LUT matrix complements the LUDD model by revealing specific transition paths between land-use types, providing a basis for understanding the spatial sources of CEs.
3.3. The LUCE Accounting Model
LUCEs are divided into direct and indirect LUCEs [
45]. Direct LUCEs refer to CEs caused by land use and are applicable to different land types [
31,
32], while indirect LUCEs refer to the CEs from production and life on various types of land represented by the amount of CO
2 produced by energy consumption and are applicable to accounting for construction land. In considering the findings of existing research [
29,
30,
31,
32] and the specific situation in Jiangxi Province, the coefficients for its direct LUCEs are confirmed, as shown in
Table 1. The direct LUCEs can then be obtained.
where
represents the total direct LUCEs, and
,
, and
represent the LUCEs, area, and LUCE coefficient for land-use type
i, respectively.
Fossil fuel consumption is one of the main sources of CEs in China [
46]. CEs are mainly related to energy production and consumption. Indirect estimation methods can be used to calculate them. This study calculates LUCEs for eight types of energy sources [
47], and the corresponding energy conversion coefficients are shown in
Table 2. The formula for calculating indirect LUCEs is as follows:
where
represents the LUCEs from construction land;
represents the CEs for energy type
i;
represents the consumption of energy type
i in daily life;
is the conversion coefficient for energy type
i to standard coal; and
represents the CE coefficient for energy type
i.
In summary, the formula for calculating the total LUCEs is as follows:
where
E represents the total LUCEs.
CE intensity is defined as the amount of CEs per unit of GDP output, which can reflect the level of low-carbon economic development. It is calculated using the following formula:
where
represents the CE intensity of energy consumption;
represents the net CEs;
represents the GDP of the research area; and
i represents the year in question.
Per capita LUCEs are defined as the total LUCEs divided by the total population, and they are calculated using the following formula:
where
represents the LUCEs per capita;
represents the net LUCEs; and
represents the resident population.
The LUCE accounting results provide direct CE data inputs for the LMDI decomposition and TD analysis.
3.4. The LMDI Model
There are no unexplained residuals in the decomposition results from the LMDI model, allowing relatively simple transformation expressions for additive and multiplicative decomposition to be obtained. Therefore, the driving factors behind LUCEs are commonly modeled this way. Referring to the Kaya identity [
48] and starting with five aspects—unit LUCE intensity, LUS, LUE, economic level, and population scale—an LMDI model of the factors affecting LUCEs in Jiangxi Province can be established. The LMDI decomposition process includes additive and multiplicative models. The calculation in the additive model uses the following formula:
where
C represents the total LUCEs;
represents the different types of LUCEs;
represents the areas of different land-use types;
L represents the total land area of the region;
G represents the GDP; and
P represents the permanent resident population. Let
The total regional LUCEs can be expressed as
where
represents the intensity of LUCEs;
represents the LUS;
l represents the LUE (land area per unit GDP);
g represents the economic level (per capita GDP); and
p represents the population scale.
The LMDI model can be used to decompose the contributions of the factors influencing LUCEs, where
is defined as the LUCEs at the beginning of the study period, and
is defined as the LUCEs at the end of the
t-th period; then, the change
in LUCEs can be expressed as
where
where
,
,
,
, and
represent the values for the contributions of the indicators
,
,
l,
g, and
p, respectively, and the expression
W is given by
.
The formula for the multiplication model calculation is
where
,
,
,
, and
represent the contribution rates of the indicators
,
,
l,
g, and
p, respectively, and
D represents the total contribution rate.
The LMDI model decomposes the contributions of various factors based on LUCE data and, together with the TD model, reveals the driving mechanisms and decoupling status of CEs.
3.5. The TD Model
The decoupling index is used to represent the relationship between the economic growth rate and the growth rate of resource consumption. When the economic growth rate is higher than the growth rate of resource consumption, this is called “decoupling”, which means that economic growth no longer depends on resource consumption. The decoupling index can be used to evaluate the sustainability of economic development patterns and guide the formulation of policy on environmental protection and resource utilization [
49]. This study utilizes the TD model to explore the interrelationship between economic growth and LUCEs in Jiangxi Province, and the calculation involved is expressed as follows:
where
represents the decoupling index for the
i-th year in Jiangxi Province;
represents the net growth in LUCEs;
C represents the initial net LUCEs at the beginning of the study period;
represents the increase in GDP; and
G represents the initial total GDP at the beginning of the study period.
The decoupling relationship between LUCEs and economic growth can be classified into eight types, as shown in
Table 3 and
Table 4. Strong decoupling is the optimal solution, indicating that the relationship between economic growth and LUCEs is weaker, and economic growth can be achieved without LUCEs increasing. Conversely, strong negative decoupling represents the worst situation, indicating that economic growth is in decline while LUCEs continue to increase. Neutral decoupling, weak decoupling, and other types reflect varying relationships between economic growth and LUCEs. In the process of pursuing low-carbon economic development, strong decoupling signifies a good level of decoupling between economic growth and LUCEs, which is desirable and holds significant importance for promoting sustainable development.
The TD model uses LUCE and economic growth data to assess the decoupling relationship, corroborating the LMDI results and forming a complete logical chain from description to policy evaluation.
The aforementioned models collectively serve the objectives of this study: to reveal the spatiotemporal evolution of LUCEs, identify key driving factors, and assess their decoupling relationship with economic growth. Through multi-model collaborative analysis, this study provides a scientific basis for Jiangxi Province to formulate differentiated emission reduction strategies, optimize territorial spatial planning, and support the achievement of the “dual carbon” goals.
3.6. Method Limitations and Assumptions
Data uncertainties: Energy consumption data from statistical yearbooks may have reporting biases or inconsistencies in statistical caliber.
Model assumptions: The LUCE coefficients are based on existing literature and may not fully reflect local characteristics of Jiangxi Province. The LMDI model assumes that influencing factors are independent, while interactions may exist in reality.
Unconsidered factors: Factors such as the impact of climate change on carbon sink capacity and the time-lag effects of policy interventions were not incorporated into the models, which may affect the comprehensiveness of the results.
Despite these limitations, this study strives to ensure scientific rigor and comparability by adopting internationally recognized methods and publicly available data, and provides directions for future research improvements.