Study of the thermal and temperature conditions of flat and inclined lands tekis va qiyalik yerlarning issiqlik va temperatura rejimini o

 
Research object and methods 
 
Consider the movement of groundwater near a reservoir, in which the water level instantly 
increases from the initial value
to the value 
, 
the power of layer, 
he critical depth of groundwater standing, starting 
from which there is a noticeable consumption for evaporation; 
critical groundwater level 
corresponding to the critical depth 
. 
Let the reservoir have a horizontal aquiclude and there is no overflow of the non-gelling layer, 
and also evaporation occurs from the surface of the ground flow, depending on the depth of the 
groundwater and time according to the law 
where n-parameter, which can take values 0,1,2,3. 
Obviously, because of the dependence ε (y, t) by h (x, t) the motion area is divided into two 
zones, one of which has evaporation, and the other is not available. Section boundary we denote these 
two zones by 
. The value of the zone where evaporation from the surface of the soil flow 
occurs allows to determine the area where it is necessary to carry out reclamation measures to prevent 
the adverse consequences of a rise in the level of groundwater. By implementing separate 
Boussinesque linearize in equation for determining the ordinate of the free surface
and the 
curve 
, 
, we have the following problem: 
  (1) 
(2) 
(3) 
(4) 
(5) 

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* GULISTON DAVLAT UNIVERSITETI AXBOROTNOMASI,
Tabiiy va qishloq xo‘jaligi fanlari seriyasi. 2021. № 1
21 
где 
,
,
,
, 
k-filtration factor, 
и 
– некоторые средние значения
respectively from 
intervals
и 
. 
Let the intensity of evaporation from the soil surface 
change according to the law
then for the time value 
, where 
is a sufficiently large time value, we can take
i.e. 
, (6) 
Let us show that under the law of evaporation of the soil surface (6), problem (1) - (5) (motion) 
becomes self-similar. 
So, setting 
we pass to the self-similar variables. Indeed, assuming 
(7) 
Instead of (1) and (2), we have 
(8) 
(9) 
Obviously, in order for the movement to be self-similar, it is necessary to fulfill the conditions 
(10) 
Hence it is clear that for 
must be sought in the form
, (11) 
where 
is some constant. 
If formula (6) holds for 
, тthen equalities (10) and (11) will simultaneously 
hold for 
. 
Taking into account (7), (11), problem (1) - (5) in dimensionless form takes the form: 
(12) 
. (13)
(14)
(15)
(16)
where
.
The solution to 
the boundary value problem (14), (16) is sought in the form 
.
Satisfying condition (16), we find 
. 
Then the solution to problem (14), (16) has the form

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