THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA 697
RURAL DYNAMICS: A STUDY ON THE EXPLOITION AND PROTECTION OF
THE RURAL RESOURCES IN A SOUTHERN PROVINCE OF CHINA
Wu Jianzhong: Wu Gang
Shanghai Jiaotong University, China Fu Dan University, China
7 ABSTRACT
In this Paper we use system dynamics‘approach to build a policy lab.
focusing on the exploition and protection of the rural resources in
a southern province of china at.first. Then we proceed, after
validating the model thoroughly, model-based policy analyses.
THE - BACKGROUND
Since the end of 1985, we have been engaging a research on the
_exploition and protection of the rural resources in a southern
province of china. The main problem we confront is that the quality
of the rural ecosystem was deteriorating a lot while the agricuture
production was in a low lev The percentage of forest cover was
decreasing from 55Zin 1950s to 40% in 1980s. The area of soil
erosion was increasing from 2000 kmu before the cultural revolution
to 8000 kmu today. On the one hand the average annual income per
capita is only about 150 yuan in the rural area, on the other this
area is very rich in natural resources. After reading a lot of
references, carrying on investigations on-the-spot and talking with
the people canceraed many times, we think it necessary to build a
model for policy analyses. According to the following reasons, we
utilise specially system dynamics approach.
= The exploitiun and protection of the rural resources involves
various problems with different term.
- A wide range of society, economy and ecology must be
considered in the model. ;
- @ lot of relations between variables is nonlinear.
698 THE. 1987 INTERNATIONAL ‘CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA
MODEL ING
Model purpose
In this paper, we want to build a policy lab. focusing on the
following problems, mainly.
- How to develop the agriculture Production while the quality of
rural ecosystem won‘t deteriorate any more but shows some
improvements.
- How to utilise the limited capital and workforce to coordinate
the development among agriculture,rural enterprises and rural
infrastructure.
- Attempt to find a reasonable structure among farming, forestry,
animal husbandry, fishery and side-occupations.
Then we can evalute various plans comprehensively on the model. All
variables related to the exploition and protection of the rural
resources must be involved in the model interactly. To identify the
variables which are concerned in the model and the interacts between
the different variables, we have to first draw out the boundary of
the model.
System boundar y
Owing ito the fact that the problem we confront is relavant to
natural resources, especially the agriculture resources, our
_attention is concentrated on rural area here only. In this paper we
probe into, as figure 1 shows, the level of workforce, capital and
rural infrastructure.
he problem we confront!
pre structure of rural economy and the utilising structure of rural
i
Merk torce, capital and rural: infrastructure
resources
THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA 699
Next the variables of interest and the interacts between them can be
defined as figure 2:
Shortage rate of rural domestic energy.
Protection The percentage of forest cover.
é
variables
The area of soil erasion and controled
‘soil erosion.
Variables of
interest : The area of farmland, grasstand,
forest-land and aquatic breed.
Dutput value of farming, forestry,
animal husbandry, side-occupations and
Exploition } rural enterprises.
variables
Rural infrastructure such as water
conservancy, energy and transportation.
\Population, capital.
pMoney interacts.
Workforce interacts.
The interacts betwepgn farming and animal husbandry.
Interacts The interacts between farming and rural infrastructure
The interacts between forestry and the quality of
rural ecosystem
The interacts between soil erosion and the shortage
‘rate of rural domestic energy
700 THE 1987 INTERNATIONAL CONFERENCE OF THE.SYSTEM DYNAMICS SOCITY. CHINA
Causal-loop diagram
Figure 3 shows the causal-loop diagram of the madel focusing on
problem concerned. After that ,in the light of the data situation
the causal-loop diagram will be translated to the flow diagram, and
computer equations finally step by step. The variables. hare are
relatively aggregated. The variables and arrows in the diagram will
be realised by detailed structure of physical flow and information
flow.
“shortage rate of
workforce
workforce denand for
workforce derand production ¢ control soil cae
for agriculture © in agriculture
production
Living Consume
of single / per-capita
forast-land grqssland area
area
anount of energy supptivs
i pig ange z fron straws
or fogls fL \,
output of crops wortage rate of
rural donestl
energy ~
ener manure of
supplies fron dotegtic anieal ]
uk fofage grass
'shorthge rate ri of
of water for ant a
i amount’ Expectancy
irrigation Byes
J i
ergy supplies
from methane
A 4
biological éner
supplies
Feakal national
figure 3
py aanbry
FARMING
fla fo fpe fwd
FORESTRY
ANIMAL. HUSBANDRY
ahm ahpc ahwd aho
fa frpc trad fro
Z ¥
POPULATION
SIDE-OCCUPATION
so
find
FISHERY
fipe fio
WATER
WSR = CONSERVANC:
wi oOWHD
gla pafe sea
ECOLOBY ntsc
wdfsc
CAPITAL
srole efs,efw ef
TRANSPORTATION &
ENERGY
rwd orfci ro
RURAL ENTERPRISES
Tapow ay} so aunqonsys peueag
04 VNIHO “ALIOOS SOIWWNAG WHLSAS SHL JO FONAYTANOD IVNOILYNYAINI L861 HL
702 THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA.
FLA ---farmland area.
FO ---farming output value.
FPC ~--farming production cost.
FWD ---farming workforce demand.
FA ---forest-land area.
FRPC---forestry production cost.
forest workforce demand.
FRO ---forestry output value,
AHM -~--manure of animal husbandry,
AHPC---animal husbandry production cost.
AHWD---animal husbandry workforce demand.
AHD ---animal husbandry output value.
SO ---side-occupations output value.
FIPC---fishery production cost.
FIWD---fishery workforce demand.
FIO —
fishery output value. 1
water demand for crops.
WSR ---shortage rate of water for irrigation.
WI ---investment in water conservancy.
WWD ---workforce demand for water conservancy construction.
GEA ---grassland area.
PAFC---percentage of forest cover.
SEA --~soil erosion area.
SROL-~-shortage rate of domestic ennergy.
EFS —
EFW
EFM
RWD —
RFCI--~annual investments in rural enterprises.
energy supplies from straws.
energy supplies from fire-woods.
energy supplies from methane.
workforce demand of rural enterprises.
RCO ~--output value of rural enterprises.
MODEL VALIDITY
Sensitivity analyses
THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA 703
The basic assumption of system dynamics approach is that the system
behavior comes from the feedback structure of the system, So it is
very important to judge whether the structure of model is catched’
proply or not. Sensitivity analyses, although without sufficiency,
may be after all be one way of structure validity. Here,the
sensitivity ffom some coupling variables is analysed.
A.Multiple crop index
ORIGINAL TFZI=2.9565/2. 0800/2. 0738/2. 0220/2.0142/1. 9853
PRESENT TFZI=2. 1000/2. 0000/1. 9700/2. 0000/2, 0600/1, 9000
obs FLZ200 FLZOP FLZOS Faoo. FAROP Faos.
1981 476.8100 486.5700 0.999700 899.6000. 509.4000. 0.672000
1gs2 522.2400 502.1600. 0.999700 ° 969.7000 $45,.6000 0O.646200
1983 559.9600 531.9300 1.000100 1012.100.. 978.4000 o.ceszoa
1984 588.3800 561.9700 1,001300 1121.6090: 1113. 300: 0.680100
1985, 630.6300 44,9700 1.000000. 1200.000 121e.300. 0.670700
1986 616.2500 589.7700 1.000100 1255.900 1221.100 0.644900
1987 612.3300 600.0800 1.000300 1379,000 .1361.400:°.0.63e16¢
Baeicic} 632.3300 619.6800 1.000300 .1403,700 1386.200°.. 0.623376
1989, 652.5500 639.5000. 1.000000 1430.000 1412.500° 0.611911
1930 656.7800 643.6500 0.999600 1475.400 1457.500 0.606638
1991 661.2400 648.0200 0.999600 1527.300 1509.000 0.599120
1992 662.9600 649.7000 1.000100. .1571.200 1552.900 0.582377
1993 664.4600 651.1700 1.000100 1622.600 1604.300 0.563928
1934 S63.8600 650.5600 1.000200 1681.100 i662.900 0.541331
1935, 663.2400 649.9800 0.999600 1752.100 17353.900 0.519395
iss6 661.0200 647.8000 1.000000 1845.200 1626.900 0.495898
1997 658.7900 645.6100 -O000300 1955.400 1937,100 0.467954
1333, 651.5700 638.5400
2000 647.7700 634.8100
2001 643.9500 631.0700
~999900 2245.000 2226.700 0.407589
-000400 2440.900 2422,600 0.374872
000100
figure S
1
a
1938 655.1900 642.0800 1.000400 2085.500 2067.200 0.458761
is}
1
1
2663.900 0.341151
TFZ1 ---multiple crop index
FLZ00-—-criginal output value of food crops
FLZOP---present output value of food crops
FA0O +--criginal output value of agriculture
FAOP ---present output value of agriculture
FLZ0S---sensitivity of food,.ccops cutput value
FAS —“sensitivoty of agriculture output value
704 THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA
B.Multiplier from animal husbandry to food crops
ORIGINAL TYXI=0.0900/1.0000/1.0200/1.1000/1. 1500
PRESENT TYXI=0.0950/1,0000/1.0500/1.0800/1. 1000
YLZOP. YLZOS _ ¥Aaoo YAOP YAOS:
oooooo
1981 478.8100 476.8100 0.000000 699,6000 999.6000 3G.
1982 522.2400 521.7900. 0.023745 967.7000 969.3000 —0. 045560
1983 559.9600 559.5700 0.019195 1012.100 1011.300 6.021761
1984 588.3800 567.1800 9.056201 1121.600 1120.400 a. 025481
1985 630.6300 628.0500 0.112736 1200.000 1197.400 9.059704
1986, 616.2500 612.7600 0.156057 1255.990 1252.400 0.076794
1587 600.0800 597.1000 0.136845 1361.400 1358.400 0.060722
198s 619.6800 616.9400 0.121842 1366.200 1363.400. 0.055659
1989 639.5000 636.6600 0.122376 1412°500 1409.700 0.054625
13930 643.6500 640.5700 0.131861 1457.500 1454.400 oO, 058609
1991 648.0200 644.4800 0.150534 1509.000 1505.500 0.063914
1992 649.7000 645.8100 0.164968 1552.900 1549.000 0.069205
1333 651.1700 647.0000 0.176463 1604.300 1600.100 0.072142
1994 650.5800 646.1300 0.188484 1662.900 1656.400 0.074569
1995 649.9800 645.2300 0.201376. 1733.900 1729.200 0.074696
1936 447.8000 642.7700 0.213963 1926.900 1821.900 0.075417
1997 645.6100 640.3000 0.226641 1937..100 1931.700 0.076817
1iss8 642.0800 636.5000 0.239475 2067.200 2061.600 0.074646
1999 638.5400 632.7000 0.252021 2226.700 2220.900 0.071777
2000 634.8100 628.7408 O.2634e8 2422.600 2416.600 0.068247
2o001 631.0700 7e00 0.274654 2657,600 0.065166
Figure &
TYXI ---multiplier
YLZ00--=original output value of food crops
YLZOP---present output value of food crops
YLZ0S---sensitivity of food crops output value
YAOO ---original output value of agriculture
YAOP ---present output value of agriculture
YADS --- sensitivity of agriculture output value
THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA 705
C.The ratio bftween forage and fuel
ORIGINAL TCNR=1. 0000/0. 4500/0. 3200/0. 2000/0. 1000/0. 0000
PRESENT TCNR=1.0000/0. 4250/0. 3000/0. 2100/0. 1050/0. 0000
NYDOBO NYDGBP NYDOBS: ocLo
OcLs
.203820 0.186450 1.362908 373.6000 373.6000 0.000000
.194400 0.190900 0.332696 395.0000 380.0000 0.141567
-201690 0.196790 0.459088 393.5000 389.9000 0.165348
-214160. 0.205670 0.716487 412.4000 408.6000 0.166534
.220500 0.212400 0.663920 438.4000 434.1000 0.177270
233320 0.226180 0.953077 478.2000 473.8000 0.166297
.1S4230 0.196900 0.682067 S26é.4000 S04.2000 a. 762214
174540 0.1713e0 0.327214 S¢2.2000 547.7000 0.466140
.166040 0.162140 0.424514 630.7000 618.3000 0.355336
.157930 0.154170 0.430291 685.9000 673.4000 0.329373
-150520 0.146920 0.432263 727.6000 715.5000 0.300560
-140040 O.144570 0.423633 757.5000 745.e@000 0.275153
.143970 0.140610 0.421800 772.8000 761.5000 0.264271
133460 0.136220 6.419690 782.6000 771.6000 0.254034
-134220 0.151120 0.417431 730.4000 779.7000 0.244668
-126010 0.125070 0.415090 797.5000 787.3000 0.231153
.0ee760 0.086350 0.490726 616.7000 e09.6000 a. 200650
.059660 0.057930 0.524085 889.5000 .ee2.9000 0.134102
-031810 0.030740 0.607938 371.3000 367.1000 0.078151
-0043560 0.003950 1.699562 1052.200 1050.000 0.037788
. 022680 ~0.022440 0.191253 11351.200 11350.900 0o.004792
figure 7
TCNR -~-ratio between forage and fuel
original shortage rate of rural domestic energy
NYDOBP-~—~present shortage rate of rural domestic energy
OCLO ---original amount of ox
OCLP ---present amount of ox
NYDOBS-—-sensitivity of rural domestic energy shortage rate
OCLS .---sensitivity of ox amount
706 THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA
D.Expected amount of pig and domestic fowls supported by! ‘eh output
value of food crops per capita
ORIGINAL EPCLP=10. 478E03 EJQCLP=42. 758E03 .
PRESENT EPCLP=10, 178E03 EJ@CLP=41.758E03
PCLO PCLP. PS JGCLG JaCLP Jas
. 955443 4490.900 4390
.81S196 4587.700 44986. 900
.5es2e8 4695.100 45e9. 300
O71500 S022.100 4900.100
141562 5727.200 SsS9e, 700
e25704 7095.000 6950.900
943716 7327.300 7167. 800
goS2e80 7193.200 7025. 400
.999483 7160.000 6992.600
ss7l72 71e4.e00 7Ol
.98835S 7252.200 70e2.
999621 7371.900 71599.S00
g0o098S 7532.506 7356. 400
g00e20 7690.S00 7510.600
.995101 7632.400 7649.200
001337 7956.900 7770.S00
goo0z25 sne5.400 78676, 800
998852 6176.700 7385.500
. 999384 8272.200 et7e.500
. 993030 8346.200 8151. 106
.939798 S411.100 e214.
1316.000 1280. 000
1323.900 1293. 000
1300.200 127e.300
1335.700 .1298.600
1535.900 1485. 700
1865.400 1621. 300
1876.400, 1825. 700
1813.600 1761.400
1771.700 1721.000
1761.800 1711.500
1777.200 1726.400
1806.400 1754.700
1645.800. 1792. 900
1984.500 1930.500
1919.200 1864. 300
1943.900 1893. 300
1976.400 1919.900
2003.600 1946. 300
2027.000 1969. 000
2045,200 19986. 700
2061.1090 2002. 100
. 352103
J. 933473
. 940239
. 038704
. ISSS52
. 868419
» 934178
x 397445
. 094118
. oo0o46
DOOORPHKORFOODOOHFOORFOOO
figure @
EPCLP --~amount expectancy of pig
EJGCLP---amount expectancy of domestic fowls
PCLO ---original amount of pig
PCLP
JQCLO ---original amount of domestic fowls
JOCLP'--~present amount of domestic fowls
PS -~-sensitivity .of pig amount
Jas --“sensitivity of domestic fowl amount
“present amount of pig
THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS’ SOCITY. CHINA 707
As a result all sensitivities are below 2, 42% of which are below 1.
Historical data examine
Here, we examine the behavior of 17 basic variables historically.
TIME
1981 1982 1983 1984 1985 1986
| VARTARBLES ‘
r T
i CULTIVATED ACTUAL 5893.9 | 5896.0 |5861.6 | 5844.9 | 5827.5 | 5800.3
| LAND AREA FITTED 5893.9 | 5881.6 | 5861.2 | 5842.1) 5828.4 | 5807.4
(E3#mu) RE. ERROR O% 0.087% | 0.007% | 0.082% | -0.02% 4 -0.12%
LAND FOR FOOD} ACTUAL 8581.1 | 8690.9 | 8715.7 | 8695.81 84675,5 | 8521.3
CROPS AREA FITTED 8550.1 | 8691.5, |8739.3 | 8263.2 | 8699.1 | 8537.8
(E3#mu) RE,ERROR | 0.361% |'0,007% |-0.27% | 0.835% | -0.27% 70.19%
LAND FOR ACTUAL 704.1 818.5 |816.9 1797.1 915.2 )1032.7
INDUSTRIAL
CROPS AREA FITTED 700.3 |818.4 [850.8 |796.2 |915.7 11034.2
(E3#mu) RE-ERROR | 0.539% | 0.012% 1-4,15% | 0.129% | -0.05% |-0.15%
LAND FOR ACTUAL 106.43 | 145.37 |175.54 [175.41 | 168.48 1175.58
BaRneN CROPS
FITTED 106.43 [144.60 1170.20 [172.58 [167.75 1177.89
(E3#mu) RE,ERROR | 0 % 4.070% 3.041% | 1.732% | 0.512% }-1.20%
AQUATIC ACTUAL 278.65 [304,03 1315.73 1330.81 1344.28 1379.61
BREED AREA FITTED 278.55 | 300.08 [313.43 [326.97 | 349.83 1390.37
(E3#mu) RE.ERROR | 0 % 1.320% ]0.729% |1,610% |-1.61% [-2.84%
FIXED ACTUAL 55.29 [61,03 [64,74 [71.71 84.68 198,13
CAPITAL FITTED 55.29 [60.71 464.72 73.27) (85.62 |95.94
(E4¢vuan) RE.ERROR | 0 % 1,670% [0.395% |-2.17% [1.110% 1-0.82%
AMOUNT OF ACTUAL 373.67 |390.95 [391.76 |411.07 1431.25. ]471.20
ox FITTED 373.67 [383.03 1393.50 |412.44 [438.44 (478,15
(E3*head) RE.ERROR | 0 % 2.031% |-0.44% |-0.33% |~4.67% ]- 1.48%
AMOUNT OF ACTUAL 1316.0 ]1330,1 [1298.3 |1314.6 |1403.4 1505.5
PIs FITTED 1316.0 [2323.2 [1310.2 [1516.5 [1417.3 ]1547.5
(E3#head) RE,ERROR | 0 % 0.467% |-0,82% [-O.15% |-0,99% |-2.99%
708 THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA
AMOUNT OF ACTUAL 1436.0 [1314.0 ]1215.0 |712.0 | 903.0 1482.4
SHEEP FITTED 1436.0 [4372.2 [1125.1 | 751.0 [879.9 | 1509.7
(E3thead) RE.ERROR | 0 % WAASK |-7.40% [-5.48% | - 2.57% [1.87%
BUTE PRUE ACTUAL 479.45 |529.87 |539.92 | 600.13 | 624,90 | 618.66
FITTED 978.8% [922.24 }559.96 (588.38 | 630.38 | 616.25
(E4yuan) > | RELERROR | 0.134% | 1.440%. |-3.71% | 1.960% | -0.92% [0.391%
OUTPUT VALUE | ‘ACTUAL 21.653] 30.347- 130.342. | 29.216 | 35.916 [56.180
OF INDUSTRIAL -
CROPS FITTED 21.720 | 27.825 134.481 [30.255 | 35.712 {56.364
{E4eyuan) RE.ERROR | 0.263% | 8.3102 |-3.75% | =3.56% | 0,568% | -0.33%
OUTPUT VALUE | ACTUAL 71.38. (99.98 [84.40 |83.98 | 92.62° | 109.20
OF FORESTRY FITTED 71,56 101,35 182,98 | 85.88 | 92.09 109,12
(E4¢yuan) RE. ERROR 70.25% [1.037% [2.390% | 2.26% | -0.47% | -0.07%
SUTEUT eLUE: ACTUAL 128,27 [128,44 .1-233,44 | 129,92 | 148.02 | 160,97
HUSBANDRY FITTED 127.27 [128.66 [127.95 | 131.49 | $43.12 | 160.81
(E4#yuan) RE.ERROR | 0.780% | -0.02% [4.041% | -1,21%]. 3.31124 9.584%
he HA het ACTUAL 222.75 [128.62 | 134,52 [166.66 | 200,23 | 130.75
ENTERPRISES FITTED 122.74 | 135.52. }140.33]170.57 | 202.41 | 237.44
tES#yuan) RE.ERROR | -0.08% | -5.37% | -4.32% | -2.35% | -1,09% | -2.89%
; CUTET VALUE | ACTUAL 902.30 | 1042.6 | 1090.9 1133.4 | 1155.8 | 1217.8
AGRICULTURE FITTED 899.60 | 969.70 {1012.1 [1121.1 | 1200.0 | 1255.9
{E4#yuan) RE,ERROR |. 0.301% | 7,001% | 7.210% | 1.042%) -3.82% | -3.13%
FOREST-LAND ACTUAL 15.82 16,30 18.78 17.46 17.90 18.54
AREA FITTED 15,82 16,30 17,46 17,84 17.97 18,52
(E4#mu) RE.ERROR | 0.% 70.63% | -8.36% [0.229% | -G,41% | 0.113%
POPULATION ACTUAL 3796.7 | 3861.9] 3921.0 | 3941.1] 4002.9] 4056.6
FITTED 3796.7 | 3854.8 | 3915.7 | 3979.0) 4044.8 | 4112.8
(E3#person) RE.ERROR, | 0 % 0.184%) 0.135% 70, 45% | wLORR | 71,595
NOTE: RE.ERROR
MEANS RELATIVE ERROR
figure 9
THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA 709
As figure 9 shows, 4.9%of the relative error are between 578%,
16.7/6 of that are between 2/—5/. 78.4/ of that are below 2,
POLICY ANALYSES
Tow scenarios
Scenario 1
Policy assumptions:
1. Don't exploit rural resources any more.
2. The output value-per mu of crops, the comprehensive transfer rate
of rural domestic energy, the policy of family planning and annual
investments in rural enterprises maintain the state of 1985.
458: 8.6
we u~ 8 Se
358 / a3
Coal Ne a
nae On
208 “0.2
1981
FIG. 10 = FG. it
Evonomic targets:
The agriculture output value per capita AOP1 will be increasing from
249.24 yuan in 1980 to 307.14 yuan in -1990, but decreasing to 243.91
yuan in 2000 again. The rural gross social product! per vapita« RBSFI
will be increasing from 284.19 yuan in 19780 to 400.29 yuan in 2000
(figure 10).
Ecological targets:
The percentage of forest cover PFC1 has been increasing from 4
1980 to a7 fin 1985, but will be 43 Zunly up tu 2000. The shur Lage
rate of rural domestic energy SRDN1 will be increasing from 71% in
1980 to 50% in 2000 (figure 11). Because of the fact that the
Su ies of ‘rura jamestic ener amoun vu the reasonable
1 £ 1d t ay tito tl 2
expluilions uf biulogical energy, the shortage. of rural domestir
710 THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA
energy will result in the deterioration of the rural ecosystem
quality. The soil erosion area SEA! will be increasing from 3162 kmu
in 1980 to 18089 kmu in 2000 (figure 12). The annual cost for
control soil erosion CCSE1 will be 226110 kyuan in 2000, almost
amount to the total annual production cost in agriculture PCIatin 2000
(figure 13).
Be
38
PIAL
258;
288
158
BL
188
58
RFCIL
i 2001 oi 1981 2001
meat FIG, 12 FIG, 13
The shortage rate of workforce SRWD1 will be increasing from 14.85%
to 14.42% in 2000 (figure 11). Qwing to the fact that the workforce
demand per mu here is derived from the average workforce demand of
. the period 1980—1985, agriculture production would be held up if the
Reoduettvi ty wouldn’t increase any more.
CuCOL
788
308
208
‘Fes 1981 ea
FIG, 14
_ CLCO-~-output value of cultivated land crops
DAEO---output value of diversified agriculture economy
In a word, under scenario 1 the quality of rural ecosystem will be
deteriorating and the rural economy will be held up. Moreover, the
unreasonable economic structure won't be changed any more (figure
14), Thereforce, it is necessary to exploit and protect the rural
resources.
THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA 721/
Scenario 2
Policy assumptions:
1. The exploition plan, derived from the long-term programme for
this district, will be taken as a policy.
2. The comprehensive transfer rate of rural domestic energy will be
increasing from 13.2% in 1980 to 34.4% in 2000,
3. The policy of family planning, that the rate of single baby is
of, will be accepted Step by step in 2000. ;
owe
30
308
0 ore
00
388
ae ort
aa
208
E - 2
198 Tat
HG, 15 413i vic. 16 =
Economic targets:
The output value of agriculture per capita ADP2 in 1990 will be
439.95 yuan, which increase by 80//as compared with that in 1980.
The rural gross social product per capita RGSP2 in 1990 will be
557.57 yuan, which increase by 96/4 as compared with that in 1980.
By 2000, the output value of agriculture per-capita AOP2 will be
578.31 yuan,.a more than 132% increase over 1980 and the output
value of rural gross social product RGSP2 will be 833.20 yuan, a
more than 193% increase over 1980..(figure 15,14), The unreasonable
structure of rural economy will be improved some more. The output
value of diversified agriculture economy DEAD2 will began greater
than the output valu@ of the cultivated land crops CLCO2 since 1991
(igure 17). Although the production cost in agriculture under
scenario 2 PCTA2, which is 161fover that under scenario 1 PCIAL in
2000, will be greater than the PCIAI, the output value AZ will
increase more than‘the production cost in agriculture PCIA2 (igure
18,19). Moreover the capital flow under scenario 1 CF1 will be
decreasing until 2000 while that under scenario 2 CF2 will began
increasing since 1993 and be yreater than zero in 1999 (figure 20),
In other words, the strenth of rural economy will be enhancing step
by step since 1993 and the external debts for agriculture praduction
will be cleared of € in 1999,
712 THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA
60a
PCTAZ
asa vm = a
200 peat
138 a ae ee
20 =
ff
500) eg
bw 128) ~ To
ast ‘ a SER
19 7081
Bes IG. 17 Bee FG, 18 ui
Pa 5%
3080 1608
230 ®
2008 @
“L008: CF2
1500 es
{ 2000
1089 crt
500. ee ~3000
Ta Be 198i ° : Es)
8 K
me ist Hie. 19 Fig. 20
| Ecological targets:
The percentage of forest cover PCF2 will be increasing from 40% in
1980 to 54.74% in 2000 (figure 21). Owing to the fact that the
comprehensive transfer rate of rural domestic energy SRDN2 will be
increasing some more and the additional area of fuel forest will be
exploited, so the shortage problem of rural domestic energy will be
disappeared in 2000 (figure 22,23). Moreover, the soil erosion area
will be decreasing from 8308 kmu in 1985 to 1632 kmu in 2000 (figure
23). The annuak cost for control swil erosion COSE2 will be
decreasing since 1987, which will be 22910 kyuan only in 2000(#igure
18).
8.68 a6
as
0.55
a4
0.58) Lica ia
0465 a2 SHIN
immer | at an ~~
aa
ae
0.35 om a
1901 708 198 baa
WG, at NG, 2
THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA 713
54
4 1981 tet 20a
HG. 33 FG, 24
Social targets:
Under scenario 2 the shortage problem of workforce will be serious
more and more. The shortage rate of workforce SRWD2 will be
increasing from ~14.85% in 1980 to 22.34% in 2000 (figure 24).
Hence, under scenario 2 the quality of rural ecosystem will be
improved and the rural economy will be developed some more. But the
shortage problem of workforce would become the main barrier for
exploiting and protecting the rural resources further if the
productivity wouldn t be increased any more.
Look forward to the 21st century
To cope with the problem with “long term, such as the problem of
population in whict the term is about 70 years, it is necessary to
luok forwardato the 21st century.
Situation 1: the policy of family planning will maintain the state
of 1985 ive. the rate of single baby is always 30.03/.
Situation 2: The rate of single baby will be controled to a level
B9/o prouressively in 2000, i
sme AA as
oy 1.08
7e08, 4.75 Co
some mt 8.598
5080 a
ine
2090
f
He. 3 HG. 2%
714 THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA
As figure 25 shows, there is almost no deference between the rural
population under situation 1 RF1 and that under situation 2 RP2 in
2000, but up tp 2050 the rural population under situation t will be
116f over that under situation 2. Because of the fact that the rural
population increases greatly, so the output value of agriculture per
capita under situation 1 ADP! will be decreasing since 2005 (figure
26). The shortage rate of rural damestic energy under situation 1
SRDNi will be increasing since 2015 again (figure 29). The soil
erosion area, which would disappear in 2010 originally, will be
ihcreasing since 2021 because uf the fact that the shortage problem
of rural domestic wneryy will have been ser inns ayain sine 2018
(Figure 30).
300 1750
a0re
a «crt ONENESS 150 ne a
cr) 4258
300 On 108, vest
108 150
308 see
aol - sa 28 k—
FG, 27 im AG. 28 ad
Pa
ib08
1 8
\ we 00!
. ; ie /
08 ss al 6008 f
“Bt & 3000 SEAL /
“0.2 \ 960 sm /
8.2 X cond spe \
2008
“eat eT \
casl 8 SS ane
19a BEL pen y90r 2758
HG, 29 AIG, 38
As hey heen ticenssed, Gf ois very important te cossider
comprehensively Lhe Lrade-uff between the shor lage problem of rural
domestic energy and that of workforce.
THE 1987 INTERNATIONAL CONFERENCE OF THE SYSTEM DYNAMICS SOCITY. CHINA 715
THE END
Dur purpose is not only to set force a final policy recommendations
by ourselves. The policy analyses here just cast a brick to attract
jade. The further analyses will be proceeded together with the
clients.
REFERENCE
1. Forrester, Jay W., 1941. Industrial Dynamics.
Cambridge, Ma: The MIT press.
2. Forrester, Jay W., 1948b. Principles of Systems.
Cambridge, Ma: The MIT press.
3. George P. Richardson & Alexanderl. Pugh, 1981. Introduction to
System Dynamics Modeling with DYNAMO. Cambridge, Ma: The MIT Press.
