TerraClim

Figure 1: Hourly temperature for the last 24 hours

Figure 2: Mean hours above 35C for Summer

Figure 3: Mean hours below 5C for Winter

Figure 4: Mean daily temperture for the last 2 months

Figure 5: Mean daily temperature for Summer

Figure 6: Mean daily temperature for Winter

Figure 7: Mean monthly temperature for 2019

Figure 7: Long-term mean monthly temperature (2015-2019)

Variable summary

Elevation

Elevation (altitude) is the elevation above mean sea level. Air temperature generally decreases with an increase in elevation at a mean lapse rate of approximately 0.65 per 100 m increase in altitude. The coolest localities during the nights are at the bottom of south facing slopes where cultivars that needs cold temperatures forgood colour development needs to be planted.

Slope Gradient

Slope (percentage steepness) highlights the maximum rate of change from a cell to its neighbors, indicating the steepness of terrain. Although steeper slopes are more difficult to manage, these slopes produce some of the best wines in the world. Slope is important in all aspects of farming, determines row direction for adequate drainage, mechanization and labour intensity.

Slope Aspect

Aspect is the direction in which a slope faces. Aspect has a big influence on solar interception and exposure to prevailing winds. South facing slopes are cooler than north facing slopes in the southern hemisphere at the same altitude. East facing slopes are exposed to the morning sun and west facing slopes are exposed to afternoon sun

Topographic Wetness Index

Topographic (or Terrain) Wetness Index (TWI), quantifies topographic controls of basic hydrological processes displayed as a dimensionless linear color gradient, with starting and ending point colors based on the minimum and maximum flowpath intensities unique to each catchment. TWI is one the most important factors that indicates the potential of runoff generation. High values of TWI means the high potential of runoff generation and vice versa.

Variable Maps

Variable summary

HI

Pierre Huglin developed a bioclimatic heat index for vineyards, the Huglin heat sum index in which the temperature sum over the temperature threshold of 10 °C is calculated and then summed for all days from beginning of April to end of September.

GDD

Growing degree days (GDD) are calculated for each day on a basis of daily average temperature and base temperature set to 10’C for grapevines. Daily seasonal summations from 1 September to 31 March. Higher GDD for the season is expected to advance grapevine phenological stages. This was adapted from the Winkler index (Amerine & Winkler, 1944) by Le Roux (1974).

Variable maps