Afforestation For Valley Urban Air Pollution Control

Transcription

1 International Symposium on Clean Environment. Cheonan, Korea, November 2003 Afforestation For Valley Urban Air Pollution Control Peter C Chu, Naval Postgraduate School Yuchun Chen and Shihua Lu, Institute of Cold & Arid Environment & Engineering, Chinese Academy of Sciences

2 Central China Geography and isobaths o N o N 42 o N 40 o N 38 o N 36 o N T I A N Terim Basin Urumqi S A N Dunhuang Jiuquan Qinghaiu QILIAN SAN o+ Zhangye o+ Lanzhou River Yellow Yellow River o N QING ZANG PLATEAU Yangtse River o N 30 o N 28 o N Lhasa Yangtse River o E 85 o E 90 o E 95 o E 100 o E 105 o E 110 o E 115 o E 500

3 Topography around Langzhou

4 Lanzhou One of the Most Polluted Cites in China In the past two decades, the air pollution problem has been improved.

5 Total Dustfall Trend in Lanzhou (Wang et al. 2001) Total Dustfall (ton km -2 mon -1 )

6 SO 2 Trend in Lanzhou (Wang et al., 2001) SO 2 Concentration (mg/m 3 ) Bold solid curve - the observed data Thin solid curve main period, dashed line - trend

7 CO Trend in Lanzhou (Wang et al., 2001) CO Concentration (mg/m3) Bold solid curve - the observed data Thin solid curve main period, dashed line - trend

8 TSP Trend in Lanzhou (Wang et al., 2001) TSP Concentration (mg/m3) Bold solid curve - the observed data Thin solid curve main period, dashed line - trend

9 NO x Trend in Lanzhou (Wang et al., 2001) NO x Concentration (mg/m3) Bold solid curve - the observed data Thin solid curve main period, dashed line - trend

10 Factors Affecting Air Quality Meteorological Conditions Stable stratification especially Inversion Low Winds Pollution Sources

11 Mountain-Valley Wind (at Night)

12 Three Major Tasks in Controlling Air Pollution Change Meteorological Conditions (Weakening the Inversion) Create Pollutant-Sinks Reduce the Pollutant Source-Level

13 Weakening of the Inversion Mountain-slope forestation weakens the mountain-valley circulation and in turn weakens the inversion.

14 Mountain Slope Afforestation Weakens the Inversion Creates Pollutant-Sinks

15 Model Simulation Effect of Mountain Slope Forestation Using Regional Atmospheric Modeling System (RAMS)

16 Model Description Nonhydrostatic Multi-grid System: 9 km, 3 km, 1 km 23 vertical levels, to 50 hpa 30 - Topography data Assimilation of observational data Land surface model Integration area: 720 km (E-W),540 km (N-S) Centered at o E, 36.1 o N

17 Multi-Grid System

18 Model Integration Control Run Winter Simulation (Dec 5 7, 2000) Initial Time: 08 BT, Dec 5, 2000 Initial Conditions (NCEP Reanalysis) Lateral Boundary for the Largest Area (Every Six ours, NCEP Reanalysis) Δt: 60 s, 30 s, 10 s

19 Simulated Wind and Temperature Fields at 800 hpa on: (a) 08, (b)14, (c) 20, (d) 02 BT

20 Simulated (v, w) and T in the north-south cross-section section across the GaoLanShan Mountain on: (a) 08, (b)14, (c) 20, (d) 02 BT

21 Three Types of Afforestation Green-A: All area above 2100 m Green-B: Northern Mountain (below 1800 m) and Valley Green-C: Northern and Southern Mountains (below 2200 m) with 40 km (E-W) x 26 km (N-S) and centered at Lanzhou

22 USGS Vegetation 25-Category 1 Urban 2 Drylnd Crop. Past. 3 Irrg.. Crop. Past. 4 Mix. Dry/Irrg Irrg.. C.P. 5 Crop/Grs Grs.. Mosaic 6 Crop./Wood Mosc 7 Grassland 8 Shrubland 9 Mix. Shrb./Grs. 10 Savanna.

23 Green-A

24 Green-B 南北 方向 格点 数

25 Green-C

26 Reduction of Inversion Strength Cont r ol Gr een_a Inversion Strength (unit: o C/m) 逆温强度 (Unit: /m) Gr een_b Gr een_c 时间 Time (BT)

27 Reduction of Stability (Lapse Rate) ( o C/m) Green-A A minus Control

28 Reduction of Stability (Lapse Rate) ( o C/m) Green-B B minus Control

29 Reduction of Stability (Lapse Rate) ( o C/m) Green-C C minus Control

30 Coupled RAMS-NYPACT NCEP/EC Data DPREP Module Model ISAN Module Source Initializati on Topography Land Surface RAMS YPACT Grads NCAR V5D REVU Graphic Module

31 Lagrange Method t w w w t Z t t Z t v v t Y t t Y t u u t X t t X p Δ = Δ + Δ + + = Δ + Δ + + = Δ + ) ' ( ) ( ) ( ) ' ( ) ( ) ( ) ' ( ) ( ) ( (u,v, w) on Grid (u,v, w ) on Subgrid (Turbulence) w p Vertical Velocity caused by external forcing

32 Topography and TSP Sources in 2000 (1000 kg) in Lanzhou (a Valley City) o N o N o N o N o N o N o N (a) III L L IV II L A 2 1 L 1496 I L 1478 (a) Seven Stations (six-angle star) (b) TSP Sources o N o N (b) o N o N o N o N o N o N o N o N o E o E o E o E o E o E o E o E o E 104 o E _ _ _ _ 6 27 _ _ _ _ _ _ 1159 _ _ _ _ _ _ _ _ _ _ _ _ _ _ o E o E o E o E o E o E o E o E L Industrial Residential

33 SO Sources in 2000 (1000kg) 2 Topography and isobaths (m), SO 2 Source in 2000(1000kg) o N o N o N o N o N o N o N o N _ _ 17 _ _ _ _ 5 25_ 19 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ o E o E o E o E o E o E o E o E _ 6 _ Industrial Residential

34 NO x Sources in 2000 ( 1000 kg) o N o N o N o N o N o N o N o N _ 45_ _ _ _ 6 1 _ _ _ The NOx in 2000(1000kg) _ 11 1 _ _ _ _ _ _ _ _ _ 2 12 _ _ _ _ o N o E o E o E o E o E o E o E o E Industrial Residential

35 36.16 o N o N o N o N o N o N o N o N o N Dust Sources (1000 kg) _ The Yan Chen in 2000(1000kg) _ _ _ _ 1 7 _ 4 10 _ _ _ _ _ _ _ _ _ _ _ 79 2_ 98 _ o E o E o E o E o E o E o E o E _ _ Industrial Residential

36 CO Sources (1000 kg) o N o N o N o N o N o N o N o N _ _ The CO in 2000(1000kg) _ _ 2 0 _ _ 0 2 _ 2 6 8_ _ _ _ 11 9 _ _ _ _ _ _ _ 53 1 _ _ _ o E o E o E o E o E o E o E o E _ 0 _ _ _ 6 2 _ 1800 Industrial Residential

37 SO Simulated and Observed Concentration (mg/m 3 ) on December 25, 2000 观测值 模拟值 1# 2# 3# 4# 6# 7# 8# Simulated ( ),( Observed ( )(

38 TSP Concentration at Two Stations Simulated (dashed), Observed (Solid)

39 SO 2 Time-Latitude Cross- Section (Dec 17-19, 2000)

40 SO 2 Time-Latitude Cross- Section (December 28-29, 2000)

41 SO 2 (y, z) Cross-Section

42 07h Dec 11, 2000 NO x

43 13 h, Dec 11, 2000 NO x

44 22h, Dec 11, 2000 NO x

45 07h, Dec 12, 2000 NO x

46 13h, Dec 11, 2000 TSP

47 01h, Dec 12, 2000 TSP

48 22h, Dec 16, 2000 TSP

49 Conclusions Afforestation improves the air quality through destabilizing the atmosphere and providing sinks for pollutants. RAMS-YPACT has capability to simulate and predict the transport of the pollutants.