ABSTRACT Vitcos was occupied by the Incas of Vilcabamba in the sixteenth century, which included ... more ABSTRACT Vitcos was occupied by the Incas of Vilcabamba in the sixteenth century, which included about 20 ha of agricultural fields with crops such as maize, potato, quinoa, amaranth and beans. The current study assessed water management for agriculture on this site. Desk research included relating past climatic data to a parallel study on modern climate, evapotranspiration, crop schedules, crop water requirements and capillary rise estimates; additionally, field studies comprised soil sample collection and analysis, watercourse flow measurements and hydrological interpretation, GIS mapping of crop fields, and the reconstruction of crops with palynology techniques and radiocarbon dating. Results indicate that irrigation requirements for crops sown once a year occurred only in May, for potato (15.3mm) and quinoa (3.5 mm), but rainfed irrigation was feasible if capillary rise is considered. Finally, the Inca population of Vitcos was estimated in relation to food production, considering dietary habits, crop field area, crop yields, nutrition value of crops and calorie requirements, reaching 365 people, taking into account that crops were sown once a year and meat supply represented 10% of the diet. This estimate matches with the number of people that could have been accommodated in Vitcos Inca dwellings.
ABSTRACT We present a new vertical coordinate system for cross-scale applications. Dubbed LSC2 (L... more ABSTRACT We present a new vertical coordinate system for cross-scale applications. Dubbed LSC2 (Localized Sigma Coordinates with Shaved Cell), the new system allows each node of the grid to have its own vertical grid, while still maintaining reasonable smoothness across horizontal and vertical dimensions. Furthermore, the staircase created by the mismatch of vertical levels at adjacent nodes is eliminated with a simple shaved-cell like approach using the concept of degenerate prisms. The new system is demonstrated to have the benefits of both terrain-following and Z-coordinate systems, while minimizing their adverse effects. We implement LSC2 in a 3D unstructured-grid model (SELFE) and demonstrate its superior performance with test cases on lake and ocean stratification.
ABSTRACT Vitcos was occupied by the Incas of Vilcabamba in the sixteenth century, which included ... more ABSTRACT Vitcos was occupied by the Incas of Vilcabamba in the sixteenth century, which included about 20 ha of agricultural fields with crops such as maize, potato, quinoa, amaranth and beans. The current study assessed water management for agriculture on this site. Desk research included relating past climatic data to a parallel study on modern climate, evapotranspiration, crop schedules, crop water requirements and capillary rise estimates; additionally, field studies comprised soil sample collection and analysis, watercourse flow measurements and hydrological interpretation, GIS mapping of crop fields, and the reconstruction of crops with palynology techniques and radiocarbon dating. Results indicate that irrigation requirements for crops sown once a year occurred only in May, for potato (15.3mm) and quinoa (3.5 mm), but rainfed irrigation was feasible if capillary rise is considered. Finally, the Inca population of Vitcos was estimated in relation to food production, considering dietary habits, crop field area, crop yields, nutrition value of crops and calorie requirements, reaching 365 people, taking into account that crops were sown once a year and meat supply represented 10% of the diet. This estimate matches with the number of people that could have been accommodated in Vitcos Inca dwellings.
ABSTRACT We present a new vertical coordinate system for cross-scale applications. Dubbed LSC2 (L... more ABSTRACT We present a new vertical coordinate system for cross-scale applications. Dubbed LSC2 (Localized Sigma Coordinates with Shaved Cell), the new system allows each node of the grid to have its own vertical grid, while still maintaining reasonable smoothness across horizontal and vertical dimensions. Furthermore, the staircase created by the mismatch of vertical levels at adjacent nodes is eliminated with a simple shaved-cell like approach using the concept of degenerate prisms. The new system is demonstrated to have the benefits of both terrain-following and Z-coordinate systems, while minimizing their adverse effects. We implement LSC2 in a 3D unstructured-grid model (SELFE) and demonstrate its superior performance with test cases on lake and ocean stratification.
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Papers by Jason Yu