Cooling air using vegetation

Spekboom could cool the ground in dry areas and enhance rainfall. Sand has air between the grains and this causes sand to act as an insulator concentrating the solar energy in the top few cm of dry sandy soil. So sand gets very hot and heats the air above it by contact and infrared radiation. While sand could reach a temperatures of 60 deg C or so I think Spekboom would be a lot cooler. Leaves of trees and Spekboom, etc, act like "convection machines" because there is a large leaf area at the top of trees, etc, (where leaves are heated in the sun) in contact with the air. So the tree is air-cooled.
If you cool the ground you cool the air above it and the lifted condensation level (LCL) is reduced making rain more likely when the air is lifted by blowing up mountains, etc. The equation is LCL=125(Tair-Tdew) where LCL is in m, Tair is the air temperature in deg C and Tdew is the dew point temperature in deg C.
If you just heat or cool air the dew point temperature remains the same, so cooling air reduces the LCL (height to which air must be lifted for clouds to form). The dew point temperature depends only on the water vapour pressure in the air. Since the atmospheric pressure remains the same and the mole fraction of water vapour remains the same when air is heated or cooled and vapour pressure in the air is (mole fraction of water vapour)x(atmospheric pressure), the dew point remains the same.
If you cool air the vapour pressure deficit decreases.

Townsville Australia 10 Sept 2019 at 13:00

Weather report for Townsville QLD Australia for 10 Sept 2019 at 13:00:
T=27 deg C, RH=15%
Calculation: For all the following calculations the atmospheric pressure is assumed to be 101.325 kPa and the efficiency of evaporative cooling is 30%:
With evaporative cooling of 30% efficiency the air will be cooled 4.22 deg C to 22.78 deg C. 

Volumetric heat capacity of air before cooling is 1.185 kJ/(m^3.degC)

The mass of water required to do the evaporative cooling is 2035 tonnes per cubic km.
RH after evaporative cooling will be 29.38%. 

Danger of fire. The greater the Chandler Burning Index the greater the danger of fire:
Before evaporative cooling: Chandler burning index is 124.9 (extreme danger of fire)
After evaporative cooling: Chandler burning index is 60.6 (moderate risk of fire)

Dew Point:
Dew point before evaporative cooling is -1.82 deg C
Dew point after evaporative cooling is 4.02 deg C
Using Espy's equation for lifted condensation (height air must rise for clouds to start forming):

Lifted condensation level  (LCL) before evaporative cooling is 3603 m
Lifted condensation level after evaporative cooling is 2345 m.
Vapour pressure deficit (VPD). Usually VPD should be between 0.45 kPa and 1.25 kPa: Danger zones are VPD is less than 0.4 kPa and VPD is greater than 1.6 kPa
Before evaporative cooling VPD is 3.03 kPa
After evaporative cooling VPD is 1.96 kPa