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