植被对水土流失和水源涵养的影响

第十四届中国国际水务高峰论坛暨北京生态修复学会年会
植被对水土流失和水源涵养的影响
2019年11月5日
国家科技重大专项（水体污染控制与治理）--冬奥会核心区生态修复与水源涵养功能提升技术与示范
ØVertical vegetation structures;
ØPlant diversity ;ØVegetation spatial distribution
Multidimensional analysis of the effects of vegetation on
runoff and soil loss
(Crockford and Richardson, 2000; Li et al., 2014; Quinton et al., 1997; Janssens et al., 1998; Martin et al., 2010;Puigdefabregas, 2005; Bochet et al., 1998; Feng et al., 2012; Lu et al., 2012;
Liu et al., 2018; )
üAbsorbs
the
energy
of
falling rain;
üRemoves water from soil and transpires it into the air;üRoots hold surface soil and stabilize bank materials;üHelps the ground to absorb water;
üSlows the runoff velocity and traps sediment.
EFFECTS OF VEGETATION IN
MINIMIZING EROSION
Questions discussed in this research :
1.How does the vegetation coverage and
litter coverage influence soil erosion process?What is the dynamic process of soil water infiltration during rainfall?
2.The regulation mechanism of vegetation
coverage on soil erosion?
Methods
Measuring experimental indexes
Precondition of experiment Vegetation coverage/Litter coverage Grass: Carex Shrub: Twigs of the CHASTE Tree Rainfall simulation experiment
Runoff bucket
Rainfall intensity: 60mm/h Duration of rainfall: 60min Slope ：15
°
Vegetation Coverage: 0, 25%, 50%, 75%,100%; Litter Coverage: 0, 50, 100, 150，200, 250g/m
2
Control condition
Methods
0200400600800100012000
10
20
30
40
50
60S u r f a c e r u n o f f r a t e (m L /m i n )Time
025%50%75%100%
Fig. 1Dynamic changes of surface runoff rate and sediment
rate under different vegetation coverage conditions
Slope Runoff and Sediment Process
0.00
2.004.006.008.0010.0012.0014.0016.0018.0020.000
10
20
30
40
50
60
S e d i m e n t r a t e (g /m i n )
Time
025%50%75%
100%
100200300400500600700800900100011000
5
101520253035404550556065
S u r f a c e R u n o f f (m l /m i n )
Time/min
0g 50g 100g 150g 200g 250g Fig. 2Dynamic changes of surface runoff rate and sediment
rate under different Litter coverage conditions
0.00
0.200.400.600.801.001.20
10
203040
5060
I n f i l t r a t i o n r a t e (m m /m i n )
Duration of rainfall(min)
25%
50%
75%
100%
Fig. 3Dynamic changes of Soil moisture increment and soil infiltration rate under different vegetation coverage conditions 024*********
10
20
30
40
50
60
70
8090S o i l m o i s t u r e i n c r e m e n t Time(min)
25%
50%
75%
100%
Slope Soil Infiltration Process
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.0010.000
10
20
30
40
50
60
70
8090
S o i l m o i s t u r e i n c r e m e n t
Time/min
0g
50g
100g
150g
200g
250g
0.00
0.200.400.600.801.00
10
20
30
40
50
60
I n f i l t r a t i o n r a t e (m m /m i n )
Time (min)
0g 50g 100g 150g 200g 250g
Fig. 4Dynamic changes of Soil moisture increment and soil infiltration rate under different Litter coverage conditions
ØWith the increment of vegetation and litter coverage,soil moisture increased and the surface runoff rate decreased.
ØIt shows that more water was used for infiltration,and thus increased soil moisture with the increment of vegetation and litter coverage.
ØVegetation and litter coverage can achieve good water storage effect.。