Emergy Evaluation of a Production and Utilization Process of Irrigation Water in China

Table 3

Emergy evaluation of irrigated agriculture system^a.

Number	Item	Raw data		Solar transformity^b		Solar emergy
Renewable resources (R)						4.60𝐸+17	sej/year
1	Sunlight	6.96𝐸+14	J/year	1.00𝐸+00	sej/J	6.96𝐸+14	sej/year
2	Wind, kinetic energy	4.14𝐸+11	J/year	1.50𝐸+03	sej/J	6.22𝐸+14	sej/year
3	Rain, geopotential	9.83𝐸+09	J/year	1.05𝐸+04	sej/J	1.03𝐸+14	sej/year
4	Rain, chemical	8.26𝐸+11	J/year	1.82𝐸+04	sej/J	1.50𝐸+16	sej/year
5	Irrigation water	2.59𝐸+12	J/year	1.72𝐸+05	sej/J^c	4.45𝐸+17	sej/year
Nonrenewable resources (N)						1.09𝐸+15	sej/year
6	Net top soil loss	1.47𝐸+10	J/year	7.40𝐸+04	sej/J	1.09𝐸+15	sej/year
Materials (M)						3.52𝐸+17	sej/year
7	Nitrogenous fertilizer	1.28𝐸+07	g/year	2.41𝐸+10	sej/g	3.09𝐸+17	sej/year
8	Phosphate fertilizer	6.48𝐸+05	g/year	2.20𝐸+10	sej/g	1.43𝐸+16	sej/year
9	Compound fertilizer	8.46𝐸+06	g/year	2.80𝐸+09	sej/g^d	2.37𝐸+16	sej/year
10	Pesticide	2.70𝐸+06	g/year	1.62𝐸+09	sej/g	4.37𝐸+15	sej/year
11	Hybrid seeds	9.00𝐸+05	g/year	1.00𝐸+09	sej/g	9.00𝐸+14	sej/year
Services (S)						1.15𝐸+17	sej/year
12	Leasing operating costs	2.70𝐸+04	$/year	3.38𝐸+12	sej/$^e	9.12𝐸+16	sej/year
13	Basic charges for regional water engineering	1.62𝐸+03	$/year	3.38𝐸+12	sej/$^e	5.47𝐸+15	sej/year
14	Pumping water services	5.40𝐸+03	$/year	3.38𝐸+12	sej/$^e	1.82𝐸+16	sej/year
Total emergy yield (Y)						9.28𝐸+17	sej/year
Output (O)
15	Rice	6.52𝐸+12	J/year	1.42𝐸+05	sej/J^f	9.28𝐸+17	sej/year

aData sources and calculations are given in Appendix B. For the methods of energy transformation, refer to [25].
bTransformities from [25, 27].
cCalculated in Table 2 in this study.
dTransformity from [28].
eThe emergy/dollar ratio of Chinese economy 2002 is from [24].
fCalculated in this study.