for land resource and environment management [6; 14; 15]. In addition, remote sensing makes the LULC change detection possible by the supplying of multi-temporal and historical data [6; 15]. Since LULC change detection and monitoring by remote sensing involves the use of several multi-date images, the degree of success depends mainly upon the accuracy of image classification [16]; thus, an adequate understanding of landscape features, eco-environment characteristics and image processing systems is necessary [17]. The pixel-based post-classification comparison methodology is the most common approach and makes a successful change detection possible, with the ability to use images acquired from diverse sources with different spatial and spectral resolutions [6; 18]. The post-classification comparison goes beyond simple change detection and provides \"from-to\" change information quantitatively [14; 16; 19]. However, this technique requires high classification accuracy for every image and a heavy workload. The Three-River Headwaters Region (TRHR), which is known as the \"Chinese Water Tower,\" is the source region of the Yangtze River, Yellow River and Lancang River and of key importance to the ecological security of China and Southeastern Asia (Figure 1). However, owing to the high altitude and harsh natural condition, the eco-environment in the TRHR is highly fragile and sensitive to climate change. Recently, the structure and functions of the ecosystem in this area have undergone severe degradation owing to the impact of rapid climate change and intense human activities, which posed a serious threat to the ecological security of regions downstream from the TRHR [20]. With these considerations, the State Council approved _the Ecological Protection and Construction Master Plan of Qinghai Sanjiangyuan Nature Reserve_ in 2005, including 22 projects such as forbidding grazing, combating desertification, and human-induced rainfall. International and domestic researchers have conducted many studies at both the regional and local scales on LULC change in the TRHR. [PERSON] _et al._[21] analyzed the land-use dynamic degree in the TRHR, and found that the spatial patterns of ecosystem change have been stable and rather slow during the last 30 years compared to other places in China. [PERSON] _et al._[22; 23] reported that, after the implementation of the ecological projects, the ecosystem degradation in the TRHR has basically been contained, and the conditions have been partially meliorated. [PERSON] _et al._[24] found that the vegetation coverage in the TRHR displayed an upward trend under the combined effects of climate change and the projects based on the analysis of the NDVI dataset from 2000 to 2011. [PERSON] _et al._[25] indicated that, comparing before and after 2004, the area of grassland deterioration increased slightly, while the  
Figure 1: Location of the Three-River Headwaters Region and study areas. grassland coverage showed significant increase. However, these researchers focused mainly on single LULC type, specifically grassland and wetland [26], or performed their studies on regional or local scales; few works have involved contrastive analyses of different headwater regions that could show the spatial heterogeneity in LULC change in the TRHR more efficiently. Meanwhile, LULC types have different impacts on ecosystems and their services [15], and LULC change detection have increasingly been recognized as one of the most effective tools for natural resource management [18]. However, many previous works only focused on the characteristics of LULC change, and further discussion of ecosystem situations and their service changes was lacking, or simulated using a mass of data and complicated models. Under this consideration, we defined the LULC change index to evaluate the change of macro-ecological situation in a simple and convenient manner, despite the complicated calculations of different ecosystems services.