Monitoring Population Evolution in the Pearl River Delta From 2000 to 2010

Abstract

ABSTRACT:On behalf of more populous and developed regions in China, urban agglomerations have become important carries loading active economic activities and generous social benefits, and experienced sharper population increase, which results in great threat on local eco-environment construction. Therefore, exact and detailed population monitoring and analyzing, especially on the long sequence and multi frequency, is of great significance. The nighttime light time-series (NLT) products has been proven to be one of the most useful remotely sensed imagery to acquire persons at 1 km *1 km scales. However, the existed problems, such as light saturation and blooming, greatly limit the accuracy of estimated results. Furthermore, it's difficult to spatialize population at km 2 level due to the lack of basic data in non-census years. In order to solve all problems mentioned above, the populous Pearl River Delta was selected as the study area. A new residential extent extraction index (REEI) was proposed to solve light saturation and blooming problems. Population spatialization methods in census and non-census years were applied to acquire detailed population distribution from 2000 to 2010. Results showed the feasibility of the proposed methods in this work. During the decade, population was denser in the central PRD and sparser in the eastern, western and northern PRD. The speed of population increase was various in nine cities, but faster in

Microbial resistance and resilience in response to environmental changes under the higher intensity of human activities than global average level

“…Here, we are presenting a study about microbial resistance and resilience to different human activities in the second largest coastal ecosystem in the Pearl River Estuary (PRE) of China, where urbanization and agriculturalization (e.g., reclamation, and aquaculture) are recognized as the two major human disturbances driven by the rapid coastward migration of the population (Li, Bellerby, Craft, & Widney, ). In this region, the growth of coastal urban areas has been reported to be more than three times the national rate (McGranahan, Balk, & Anderson, ; Neumann, Vafeidis, Zimmermann, & Nicholls, ) with high population density of around 1,000–4,000 people/km 2 on average even in 2010 (Yu, Liu, & Zhang, ); this region is increasingly undergoing different environmental pressures related to human activities and disturbances. The primary objectives of this study were (a) to identify the changes in microbial communities within 1 year of different human disturbances in the field, the recovery in the structures of microbial communities and to identify the activities of these communities in microcosm experiments without human disturbances; (b) to evaluate the potential environmental factors driving the changes in microbial communities; and (c) to assess the importance of microbial abundance, diversity, and interactions to microbial functional resistance and resilience.…”