21
Tecnología y Ciencias del Agua
, vol. VIII, núm. 2, marzo-abril de 2017, pp. 19-30
Fan
et al
.
, Effect of drip irrigation with saline water on the shelterbelts to soil and groundwater environment in the hinterland of Taklimakan Desert, China
ISSN 2007-2422
•
irrigation experiments with different water
treatments were set up in which water volume
decreased gradually, and the cross-sectional
distribution of water and salt for each treatment
and ultimate impact on the groundwater envi-
ronment were analyzed. Finally, an approach for
water conservation and the observed differences
between various treatments were described.
Experimental
Study area
The Taklimakan desert is the largest desert in
China, at the same time, is the world’s second-
largest drifting desert, and covers an area of
33.7 square kilometers (Sun & Liu, 2006). It is
located in the center of Tarim basin in northwest
China. This basin is a major area for producing
oil and gas resources in China. The Tarim Desert
Highway crosses the Taklimakan desert from
south to north. The shelterbelt forests were built
on both sides of the highway with the width of
72-78m. Due to the distance of the road across,
the drifting desert is the longest in the world
(Alles, 2012), so it is listed in the Guinness Book
of Records.
From north to south, Tarim Desert Highway
sequentially crosses five major geomorphic
units-compound transverse dune area, dome-
shaped dune area, high compound longitudinal
dune area, compound longitudinal dune area,
and compound transverse dune area (Lei
et
al
., 2008). The study area is located in a dome-
shaped dune area and the geomorphic unit has
a total length of about 20 km, and the ground-
water level is generally around 2 m. The water
supply for the shelterbelt is basically ground-
water with total dissolved solids (TDS) was
4.138 g/l and pH value is 7.21. The main pipe
was used to convey the water from the ground
while the branch pipe diverted the water with
drippers installed on the drip tube for irrigation.
The Aeolian sandy soil is fine sand, the soil bulk
density of peripheral plantations is 1.43 g/cm
3
,
and the soil porosity is 45.55%.
Test design
In order to effectively use the groundwater
characteristics of the regions with relatively rich
groundwater resources and to achieve water-
saving irrigation, three additional water supply
schemes for conservation of water resources
were proposed based on the original irrigation
system for shelterbelt project. As shown in
figure 1, the entire shelterbelt land irrigated by
well water was divided into four regions: region
I with the existing irrigation system and regions
II, III, and IV with modified irrigation systems
for the comparison with region I (table 1).
Since the Tarim Desert Highway Ecological
Shelterbelt Project completion in 2005, the an-
nual irrigation cycle fromMarch to October was
used for the shelterbelt. Under the condition of
sufficient water resources for the spring and
autumn irrigations, the above irrigation period
was elongated, so that plants were under water
stress compared to the original irrigation sys-
tem. The growth of plants in different regions
was monitored, in order to achieve effective wa-
ter conservation without affecting plant growth.
The specific experimental design is shown in
table 1.
The data in table 1 are calculated as follows:
Annual irrigation times (
W
IT
):
W
IT
=
90
W
IP
1
+
90
W
IP
2
+
60
W
IP
3
(1)
Irrigation water (
W
IW
):
W
IW
=
W
IT
6 3.5 10
3
(2)
Water conservation rate (
W
CR
). We set irrigation
treatment I’ for W
IW
=
W
IWCK
:
Then:
W
CR
=
W
IWCK
W
IW
_
n
W
IWCK
(3)
