An aridity index (AI) is a numerical indicator of the degree of dryness of the climate at a given location. A number of aridity indices have been proposed (see below); these indicators serve to identify, locate or delimit regions that suffer from a deficit of available water, a condition that can severely affect the effective use of the land for such activities as agriculture or stock-farming.
Historical background and indices
At the turn of the 20th century, Wladimir Köppen and Rudolf Geiger developed the concept of a climate classification where arid regions were defined as those places where the annual rainfall accumulation (in centimetres) is less than , where:
if rainfall occurs mainly in the cold season,
if rainfall is evenly distributed throughout the year, and
if rainfall occurs mainly in the hot season.
where is the mean annual temperature in Celsius.
This was one of the first attempts at defining an aridity index, one that reflects the effects of the thermal regime and the amount and distribution of precipitation in determining the native vegetation possible in an area. It recognizes the significance of temperature in allowing colder places such as northern Canada to be seen as humid with the same level of precipitation as some tropical deserts because of lower levels of potential evapotranspiration in colder places. In the subtropics, the allowance for the distribution of rainfall between warm and cold seasons recognizes that winter rainfall is more effective for plant growth that can flourish in the winter and go dormant in the summer than the same amount of summer rainfall during a warm-to-hot season. Thus a place like Athens, Greece that gets most of its rainfall in winter can be considered to have a humid climate (as attested in lush foliage) with roughly the same amount of rainfall that imposes semi-desert conditions in Midland, Texas, where rainfall largely occurs in the summer.
Regional and global aridity trends and future projections, was launched at the 16th conference of UNCCD’s nearly 200 parties in Saudi Arabia (COP16) ...Global aridity index (AI) data track these conditions and reveal widespread change over the decades.
The vision. The old tree spoke. ... the “summer heat-moisture index,” to capture the increasing aridity of Northwest summers, and the “mean coldest month,” a key consideration because Douglas firs need a to grow come spring ... Left... .
The five highest heat index in Naples so far in 2024 ...HeatIndex (F)Date ... The body actually feels cooler in arid conditions.There is a direct relationship between the air temperature and relative humidity and the heat index.
The five highest heat index in Fort Myers so far in 2024 ...HeatIndex (F)DATE ... The body actually feels cooler in arid conditions.There is a direct relationship between the air temperature and relative humidity and the heat index.
Thursday, warning that the heat index could reach 108 or higher across much of southwest and central Florida because of high temperatures and humidity ... The body actually feels cooler in arid conditions.".
The heat index, or “feels like” temperature in Sarasota-Bradenton last Wednesday topped out at 105, just one notch below the record set for July 10 in 2020 ... The record heat index mark for July in Sarasota-Bradenton is 115, set last year.
The team learned that the temporal stability of plant communities decreased more rapidly in more arid areas when the threshold level of aridity index 0.2 is crossed.
Measuring soil carbon, however, is a painstaking, expensive process ... While climate was the most common predictor of soil organic carbon across most of the regions, the vegetation index tended to be more important in the arid areas of the southwest.
...Index (NDVI) in the context of climate, topography, and soil conditions ... The research highlighted how climatic responses varied with aridity index, soil category, stand age, and topographical factors.
The role of socio-economics and climate were incorporated through the Human DevelopmentIndex (HDI) and the aridity index ... and the NorthMediterranean are net receivers despite their aridity.
Our index allows the detection of areas with suitable conditions to hold pGDV where vegetation behavior also indicates groundwater use ... The index is initially designed for the Mediterranean biome, but is ideally adaptable to other semi-arid climates.
... types and along aridity gradients ... The impact of the heat wave on the diurnal cycle of photosynthesis is predominantly observed in arid and semiarid regions with an aridity index (AI) below 0.6.
On Monday morning, the oil minister and the mining minister were arrested, the party charged ... The arid landlocked state, which frequently ranks at the bottom of the UN’s Human DevelopmentIndex, is struggling with two jihadist campaigns. ....
, where:
if rainfall occurs mainly in the cold season,
if rainfall is evenly distributed throughout the year, and
if rainfall occurs mainly in the hot season.
is the mean annual temperature in Celsius.
Oelwein Daily Register
09 Dec 2024
Oelwein Daily Register
09 Dec 2024