关键词: 渗滤湿地, 污水处理, 垂直流, 人工土壤, 设计

Abstract: In this paper, the 2001-2010 time-series TERRA/MODIS EVI dataset of northern Tibetan Plateau was reconstructed by asymmetric Guassian function fitting method, and the yearly key vegetation phenological parameters including the maximum EVI (EVI_max) in growth season, growth season length, green-up date, and wilting date of typical grassland plants in the region in 2001-2010 were extracted with dynamic threshold method. On these bases, the spatial distribution patterns of the vegetation phenology in northern Tibetan Plateau were analyzed. For the typical grassland plants in the region, their EVI_max in growth season, growth season length, and green-up date all showed the spatial distribution of horizontal transition from southeast to northwest and vertical zonation in southeastern Nagqu mountain topography, and the three phenological parameters all decreased in the order of mixed agriculture-forestry zone > forest and shrub > meadow > steppe > desert steppe. As for the wilting date, it was obviously later in mixed agriculture-forestry zone than in other vegetation cover types. Considering for different climatic zones, the EVI_max in growth season, growth season length, and green-up date all performed the order of sub-humid area > semi-arid zone > arid zone. Besides, with the increase of altitude, the EVI_max in growth season became smaller, growth season length became shorter, and green-up date postponed.

Key words: Infiltration wetland, Wastewater treatment, Vertical-flow, Artificial soil, Design