Advanced Very High Resolution Radiometer (AVHRR) satellite data were acquired and composited into twice-a-month periods from 1 May 1991 to 15 October 1991 in order to map vegetation characteristics of the Alaskan landscape. Unique spatial and temporal qualities of the AVHRR data provide information that leads to a better understanding of regional biophysical characteristics of vegetation communities and patterns. These data provided synoptic views of the landscape and depicted phenological diversity, temporal vegetation phenology (green-up, peak of green, and senescence), photosynthetic activity, and regional landscape patterns. Products generated from the data included a phenological class map, phenological composite maps (onset, peak, and duration), and photosynthetic activity maps (mean and maximum greenness). The time-series data provide opportunities to study phenological processes at small landscape scales over time periods of weeks, months, and years. Regional patterns identified on some of the maps are unique to specific areas; others correspond to biophysical or ecoregional boundaries. The data provide new insights to landscape processes, ecology, and landscape physiognomy that allow scientists to look at landscapes in ways that were previously difficult to achieve.

Characteristics of vegetation phenology over the Alaskan landscape using AVHRR time-series data

The results of integrated landscape mapping at different levels and scales (global, regional, local) are presented. The relationships between physical environment, land use practice, and degree of landscape modification were studied for various arid regions. A hierarchical concept for the organization and mapping of land units, developed at Moscow University, is applied to particular land use mapping problems of arid lands, e.g., of environmental destruction in the Aral Sea region, monitoring landscape changes in Iran.

A. V. Kushlin

Papers

Landscape mapping and assessment at global and regional scales