113
Tecnología y Ciencias del Agua
, vol. VIII, núm. 2, marzo-abril de 2017, pp. 105-115
Wang
et al
.,
Research on the hydrologic cycle characteristics using stable isotopes of oxygen and hydrogen in the Jinxiuchuan Basin
ISSN 2007-2422
•
The
δ
18
O values of groundwater and river
water have a high degree of fitting, and the
δ
18
O
values of groundwater are mainly distributed
among the
δ
18
O values of precipitation, as shown
in figure 6. The results showed that there are
close relationships in different water bodies. The
soil thickness is small and the average of about
20 cm, and a rigid top slab of the impermeable
floor. However, karren, slot, dissolving fissure
develop extraordinary in the Jinxiuchuan Basin,
so as to the more frequent hydraulic contact
between groundwater and precipitation.
In the Jinxiuchuan Basin, the river is sup-
plied by precipitation in the form of overland
flow, and soil water and groundwater from in-
filtration of precipitation. Groundwater exposes
on the surface and supplies river by spring.
River evaporates in the process of flow and then
returns into the atmosphere. The water cycle
is completed between different water bodies
finally. According to equation (6) and take
δ
18
O
for example,
δ
M
is the value of precipitation,
δ
18
O
= -7.9713‰;
δ
N
is the value of groundwater,
δ
18
O
= -8.8895‰;
δ
sample
is the value of river water,
δ
18
O = -8.4877‰. After calculation, precipitation
accounts for 43.76% in river water. In the same
way, precipitation accounts for 21.91% in soil
water and 6.84% in groundwater, as shown in
table 2. The
δ
D and
δ
18
O of river water increase
from valley to outlet because of the weak evapo-
ration, and the river is supplied by groundwater.
It is confirmed by field investigation that three
springs expose to supply surface water, which
makes groundwater convert into surface water.
So the proportion of river water transformed
by soil water and groundwater is 28.75%. The
total supply ratio is 72.51%, and the remaining
is 27.49%. The remaining water consumed by
surface evaporation and plants intercept, which
can be understand as the soil water and river
water reverse supplemental atmospheric water.
Based on the relevant data of the Jinan’s
hydrological bureau, the above conclusions
are verified by the water balance method.
Taking precipitation and river as an example,
the conversion relationship between rainfall
and river water are analyzed based on the
precipitation of August 25, 2011. There are five
precipitation monitoring sites, and the average
precipitation is 55.2 mm. The watershed total
rainfall is calculated by the Thiessen polygon
method, and the value is 2976.66×10
4
m
3
. River
runoff is calculated based on the data of river
level before and after this precipitation, and it is
1254.36×10
4
m
3
. The river section is downstream
in the Jinxiuchuan Basin. The ratio of between
rainfall and river water is 42.14%. The results
showed that the precipitation accounts for
42.14% in river water, and the results obtained
from two methods are close to each other.
Meanwhile, it indicated that the previous con-
clusion which obtained from the stable isotopes
method is scientific and rational.
Atmospheric precipitation is absorbed or
becomes surface runoff, which gradually flows
into rivers. Surface water partly evaporates and
infiltrates into the soil to recharge groundwater.
The atmospheric precipitation converts into sur-
face runoff and underground runoff eventually
through a series of processes, and groundwater
changes into surface water. From table 2, the
conversion rate of groundwater is high in the
slope runoff area of the Jinxiuchuan Basin. The
study area has strong ability to intercept and
store water, because it has higher vegetation
coverage. Karren, slot and dissolving fissure
well developed, which leads to increase the
number of infiltration recharge to groundwater
in the slope zone.
Table 2. Supply ratio of atmospheric precipitation.
Water
type
δ
value
Supply ratio
δ
D/‰
δ
18
O/‰
of atmospheric precipitation /%
Soil water
-72.3637
-8.9569
21.91
Groundwater
-74.9468
-8.8895
6.84
River
-56.5361
-8.4877
43.76
