DESERTS DESERTS Geography concept analysis *Agnieszka * Denise * Teshome * Thore*

Ambiguities and Modes of Classification desert != dry land : e.g. volcano deserts dry/hot deserts ice deserts salt desert 2 Geographic concept analysis - deserts

deserted = uninhabited places; the term does not describe the lack of water (arid place) and deserts may be quite heavily populated in military terminology, desertion is the abandonment of a "duty" or post without permission from one's Government or superior. Geographic concept analysis - deserts 3 Ambiguities and Modes of Classification

Relevant Objective Primitives windspeed temperature precipitation evapotranspiration Geographic concept analysis - deserts 4 vegetation material (rock, sand, ice, salt) characteristic landforms (dunes) human inhibitions

Predication Criteria (a)Individuation : check the relevant objective primitives ( precipitation, evapotranspiration) (b)Demarcation: sudden change in physical paramters (c) Identity : one connected place of sand, ice … Geographic concept analysis - deserts 5

Predication Criteria Example Sahara typical turning circle desert cloud free sky no vegetation arid high temperature changes windy Ground inversion animals and plants: Fennec Fox, Rose of Jericho Geographic concept analysis - deserts 6

Predication Criteria Example : Antarctica whole continent desert borders of the continent (floating ice/underlying rock) extreme changes over time in the year Geographic concept analysis - deserts 7

Parameters of variability temperature is not always high (->ice desert) the changes of temperature can be huge - daily amplitudes up to 40°C for many years no drop of water can fall but in the following year a huge amount can fall different continents have different values of maximum precipitation for land called desert air in the desert is not always dry - it can have up to 70% humidity Geographic concept analysis - deserts 8

Parameters of variability different landforms depending on many factors in some deserts there are specialized animals close to sea does not mean humid -> Namib Desert the cover of the desert can be very different depending on the type of the desert (snow, sand, stones, rocks, etc.) the origin can vary (natural processes as climate changes after glacial period to anthropological reasons like deforestation) Geographic concept analysis - deserts 9

Definitions average annual precipitation of less than 250 millimeters per year more water is lost by evapotranspiration than falls as precipitation vegetation cover is sparse to almost nonexistent sand, rocky, ice Geographic concept analysis - deserts 10

Geographic concept analysis - deserts 11 Definitions/ Characteristics

Axioms Expressing Relations to other Geographic Concepts region(Sahara). region(Antarctica). region(Great Salt Lake Desert). all x (region(x) & precipitation(x) desert(x)). Geographic concept analysis - deserts 12

Axioms Expressing Relations to other Geographic Concepts all x (region(x) & hightempdiffsdaynight(x) -> applicableTemperature(x)). all x (region(x) & (vegetation(x)=sparse | vegetation(x)=no) - > applicableVegetation(x)). all x (region(x) & (material(x)=rock | material(x)=sand | material(x)=ice | material(x)=salt) -> applicableMaterial(x)). all x (applicableTemperature(x) & applicableVegetation(x) & applicableMaterial(x) -> mostlikelyDesert(x)). Geographic concept analysis - deserts 13

Axioms Expressing Relations to other Geographic Concepts all x (region(x) & (desert(x) | mostlikelyDesert(x)) & (material(x)=sand | material=rock) & temperature(x)>20 -> hotDesert(x)). all x (region(x) & (desert(x) | mostlikelyDesert(x)) & material(x)=salt -> saltDesert(x)). all x (region(x) & (desert(x) | mostlikelyDesert(x)) & temperature(x) iceDesert(x)). all x (iceDesert(x) -> smaller(x, Antarctica)). all x (hotDesert(x) -> smaller(x, Sahara)). all x (saltDesert(x) -> smaller(x, Great Salt Lake Desert)). Geographic concept analysis - deserts 14

Thank you for your attention! Meerkats in Kalahari desert