Monitoring rangeland degradation using a novel Local NPP Scaling based scheme on the “Three-Rivers Headwaters” region, the hinterland of the Qinghai-Tibetan Plateau

the “Three-River Headwaters” region (TRHR) rangeland ecosystem is extremely sensitive and fragile, and in recent years has undergone continuous degradation. The vast area and severe nature conditions inhibit data acquisition and field experiments, resulting in different understandings about the spatial characteristics and dynamics of rangeland degradation in the region. Therefore, reliable monitoring method of rangeland degradation is urgently needed for the rangeland protection and management. In this paper, a novel rangeland degradation monitoring scheme based on Local NPP Scaling (LNS) was suggested; A suitable partition program of rangeland productivity unit was set up by using Analytical Hierarchy Process (AHP); And the spatio-temporal pattern of degradation in 1990 and 2004 were revealed and validated by multiple data sets including field measured data, land use and land cover maps and the discoveries of other researches. This research provides basis in the avoidance of intensive field work and labor costs for visual interpretation of remote sensing image as used before. The results show that the percentage of rangeland degradation is 32.86% in 1990 and 36.7% in 2004, indicating increased 3.84% over 15 years. The eastern part of the study area, consisting of Banma, Gadê, Henan, Jigzhi, Tongde and Zêkog, had minimal deterioration. The most severely degraded area is Qumarlêb. The deteriorated rangeland accounted for 63.33% of the total area in 1990 and increased to 77.47% in 2004. The sum of degradation percentage at Madoi and Chindu is more than 40%. It is found that the results on the spatio-temporal distribution of the rangeland degradation at TRHR are reasonable through various verification,, and the approach we suggested is effective in rangeland degradation monitoring in inaccessible region with severe environment. According to the author, similar research reports are not accessible yet.