| The emergence, development and research trends of agroforestry systems were first reviewed in this thesis, then the assessment methods applied before were summarized, in order to study the impacts of agroforestry systems on environment, the indicator system was set up based on the local conditions. By this indicator system, the environment of model TI (where the dominant intercropping model is apple and crops intercropping) and model T2 (in which the dominant model is Chinese prickly ash and crop intercropping) were monitored, analyzed and evaluated. The results as follows:1. The contaminative environmental quality of T1 and T2 all belonged to grade one by the result of fuzzy synthetic evaluation, it showed the agricultural fertilizer and pesticides used in this region did not result in serious environmental pollution. However, the quality of Ta was better than T1 by grey correlativity analysis, which was coincident with the fact that the larger amount of pesticides and fertilizer were used in T1 than T2. More attention should be paid to the appropriate use of pesticides and fertilizer in later agricultural management.2. The biological environmental quality of fruits and vegetables in T1 and T1 all belonged to grade one, and it showed the biological environmental quality was excellent in the whole. However, the result of grey correlativity analyzing showed the environmental quality of biology in T2 was better than in TI where more pesticides and fertilizer were used. On the precondition that the agriculture environmental management level were almost equal, the quality of fruits and vegetables was negatively correlative with the amount of fertilizer and pesticides used, but it was converse as for the residue of nitrate and nitrite in the fruits and vegetables.3. The ecological environmental quality of T2 and TI were the second grade and the third grade respectively. T2 was better than T1. In the aspect of ecology, the model of T2 where the Chinese prickly ash and crops intercropping dominated is worthpopularizing.4. The socioeconomic quality of model T1 and T2 were grade two and grade three respectively. It showed that T2 was better than TI in contaminative environmental quality, product quality and ecological environmental quality, but the socioeconomic quality was worse and thus the model T2 was not popular.5. The result of environmental quality synthetic assessment in T1 and T2 all belonged to the first grade, and the grey correlativity of TI and T2 were r1= 0.6663 and r2=0.6670. We can see from above that the whole environmental quality of TI was a little worse than T2, but the difference was less, and the whole environment of T1 was very good. So both economic benefit and environmental benefit can be obtained in T1 as long as the agroforestry systems were managed scientifically the pesticides and fertilizer were properly used.6. The multi-grade fuzzy synthetic evaluation-grey correlativity analysis complex model of environmental quality assessment has the merits of multi-grade fuzzy synthetic assessment. By applying this complex model, not only the grade and difference of every subsystem can be shown, but also the difficulty of deciding indicator weight when there are too many indicators in the first-grade evaluation was overcome. In addition, this complex model also can distinguish the difference of every evaluated region which belonging to the same grade environmental quality. It provides a scientific method for synthetic assessment of many indicators.7. In this thesis, the improved standard weight deciding method which based on the difference of indicators' importance was applied in environmental quality assessment of single factor, The practice showed that the improved standard weight deciding method can not be disturbed by factual monitoring data, and can avoid the subjectivity of factitiously deciding weight, thus it can exactly decide the weight of indicator.8. The decision of indicator weight is very pivotal in environmental quality asses... |
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