###### Abstract  
Land degradation and development (LDD) is one of the important ecological issues in coastal China. This study analyzed the temporal and spatial changes of the LDD process in coastal China from 1982 to 2015 using the LDD index constructed from normalized NDVI and GPP data. The study also quantitatively evaluated the relative contributions of climate and human factors to LDD and explored their impact on LDD. The study's findings indicate that coastal regions in China experienced a marked increase in land development during the study period, with 62.47% of the regions displaying a growth trend and only 7.03% exhibiting signs of land degradation. The impact of climate change on the change in LDD processes was limited, while human activities were the main driving force, with their impact becoming increasingly apparent over time. Human activities were the dominant contributor to the change in LDD in most regions, accounting for over 60% of the change. Fast urbanization led to a notable decrease in cropland, wetland, shrub, and grassland, with a substantial proportion of the affected cropland transformed into impervious surfaces, accounting for 91.31% of the total cropland conversion. These findings deepen our understanding of the LDD process and its driving factors in coastal China, providing valuable insights for developing effective policy interventions and implementing successful land restoration plans in the region. land degradation and development; coastal China; human activities; climate change 202315249.12.  
coastal regions, particularly coastal wetlands, significantly impairing their roles as carbon and nitrogen sinks [17; 18]. In addition to the human impact, climate variables such as temperature, precipitation, and soil moisture are also frequently regarded as key driving factors in the LDD processes [19; 20]. The coastal regions of China span across tropical, subtropical, and temperate zones, encompassing approximately 13.6% of China's total land area and being the regions with the highest economic development and population density [21]. Since the reform and opening in 1978, coastal China's social and economic development has been huge in world history with unprecedented speed and scale. However, fast industrialization and urbanization, excessive land reclamation, and unreasonable natural resource development have brought huge pressure to coastal China regarding soil, biological resources, natural environment, and ecological systems. In recent decades, China's coastal region have experienced fast and less-regulated development, with widespread land reclamation activities leading to land degradation, which has become a major environmental concern restricting the eco-friendly development of the coastal areas [22]. From 1979 to 2014, the area of coastal wetlands reclamation reached 11,163 km\({}^{2}\), causing massive coastline changes [23; 24]. During this process, LDD has caused serious disturbances in the coastal environment and ecological system, degrading many coastal wetland ecological functions [23; 25] To support the rapid financial growth and urban expansion, a significant portion of high-quality agricultural land and city water bodies have been converted into urban construction land [26; 27]. Many studies have evaluated the LDD in specific areas based on observations and remote sensing products, although often using a single normalized vegetation index [19; 28]. However, the Normalized Difference Vegetation Index (NDVI) has limitations and may not accurately capture substantial changes in vegetation [29]. Thus, a single NDVI index may not fully reflect the dynamic changes in biological mass and ecological power in a specific area, leading to strong uncertainty in evaluating LDD dynamics. To address this issue, some studies have attempted to combine NDVI with other parameters (such as gross primary productivity, sun-induced chlorophyll fluorescence, and net primary productivity) to construct new composite indices for evaluating LDD [12; 29; 30; 31].