American Society of Civil Engineers.

Transactions of the American Society of Civil Engineers (Volume 81) online

. (page 21 of 167)
Online LibraryAmerican Society of Civil EngineersTransactions of the American Society of Civil Engineers (Volume 81) → online text (page 21 of 167)
Font size
QR-code for this ebook


tendency of the promoter, the investor, and in many cases the engineer,
to disregard the conditions under which the investment is to be re-
turned. Large expenditures have been made in order to deliver water
to land the character of which, except as regards surface appearance,
has been practically unknown.

Some of this land is impregnated so heavily with alkaline salts
that it cannot produce siifficient under irrigation to return interest
on the investment. Where the alkali shows on the surface in large
white patches, there is little danger of the land being included in an
irrigation scheme without provision being made for its reclamation.
The subsoil, however, may be very heavily impregnated and there may
be very slight indications, or none at all, on the surface, until after
the project is in operation, when the salts are brought to the surface
by the direct application of water or seepage from a near-by ditch. The
result is that the investor suddenly realizes that he will be obliged to
build an expensive drainage system, to wash out the alkali, or cut
out this land entirely from the project. In the latter case, in order
that the investment shall be returned, the remaining land must be
burdened with an additional tax, in proportion to the part excluded,
which possibly it is not able to stand.

No irrigation project should be built until a careful study of the
' soil conditions has been made, not only in regard to the topography



246



DISCUSSION OS CLASSIFICATION OF IRRIGABLE LANDS



SOIL INVESTIGATION FIELD NOTES

(a) Apparatus used in collecting. jywiA - -^Ufeji, li^-^y^^ yv/ b

(b) Approx. distance from Stream, Lake, or other water;a-2tru/*-S^'>vi^4«, i«.fv^Si^ixXjuji, Q>ixti^
(g) Irrigated Unirrigated

(h) If irrigated, the date of last application of water

(i) Date of last rainfall on the area: l'' - '''"-^ ^-^^^ /?///•.

(j) Are conditions where sample is taken average for the M section ?

f^r^ -«i .(U^ ^ j^^^^ j^^ ^2^

(k) Does white alkali appear on the surface? Ui^a j JiM^^o^^ Ji^^^L-^yoM^rvib .

(1) Has it affected the vegetation? Uj^; o^Luiaj- j,yyvu>JJi .JroJ\jt^ ..i-^avii.

(m) Remarks; W^>^ A/ft^^w ^^uj>j>> aA-^vk/wei A'yu, x«^4.(^. cH5A.tvn/,tijty, a,MvrJi t/ivp H-



Sample


Depth:


. _


Color.




from


to






A /t-/


0.0


0.4


-yy\,.


d^ix^A ^a^.


Cji'OiM, ix^wtt yOOTO/HA^,


B Ibf


oM


1.0


W.


Z-"-^*^.


Ctoj^ Z(r0^vn> .


c l(''^■


to


3.6"


X? 2^.


^-Vci-^ — xtf^Vinvw


otoj^ JUro^'Ws^


D ll'^f-


3.6'


fe.o


^y-.


'^jUUU^/^^,


>icx,avo6.


E





__


___






F














(n) Depth of the surface soil; O.y •^.
(o) Depths to which roots penetrate; 6.0 J^
(p) Depth to the water table; 6 b 'f^

Kemarks: Jt^An. ~ft.iZ ^i'"-^ at -^A/^ .^^ttttuvvx/- , a^b^/boAt^M-*;^^ '^«-<






ax


•-'COi-'


(t^tO


So


§5


J25


g


i?


oco


— to


to — to —


— to to


b

B

X
H


o


ooo

52^


§g


pp

CO to

toco


pp
coco
too


oo


p


o


oo

8k


oo

88


oooo

'to to CO —

oo*.-i


ooo

CO O CD

CO too


Total

precipitation in

period.


.!i


to


C«CT>-»


0^ to


coco


p-iCO


to I-'


>I-


.u


oto


oo


CO to toco


to — o


Number of

days on which

rain fell.


£?


o


OOO

0*B«1

IXifr.C.t


oo
coo


op

to^

too


oo
"co


oo

OOifr-


o

io

en


p


pp
b CO

o o


pp



pppp

— — to —
oaic-. o


ooo
tobb


Maximum for
one day.


^


OS


o


tocoS


128^


It^l-'
toco


to to — -'

*.0-J0


to CO to
■e. to oi


to

en


CO a

— CO


g


to — — to

i-i tO■

>

r

m


o


s


pop

1^00 CO


ppp
bsi-'co


oo


oooo


poo

io.lci to

o>(^*-


o


PP

C0 05


p

CO

o


ppop

CO CO — CO

eoo-jto


oo

Vo —
eo-'


en -5*.


to


en —


QC


O5eeco



Online LibraryAmerican Society of Civil EngineersTransactions of the American Society of Civil Engineers (Volume 81) → online text (page 21 of 167)