Assessment Of Regional Agro-ecosystem Environment And Ecological Economy Based On The GIS And Models

Regional agro-ecosystem is one of the important parts of regional ecological system, which achieve a sustainable development that can improve the whole country's development. The harmonious development of ecological environment and economic is the key to the regional agro-ecosystem sustainable development, and the ecosystem, which carries economic activities, can provide different kinds of natural resources of ecosystem for economic development, while positive economic development can protect the ecological environment.According to the primary eco-environment issues, the index systems for assessing regional agro-ecosystem environmental quality and ecological economy and their relative models were established through taking into account the benefit of environment, society and economy comprehensive. And then, taking Jiangsu province as an example, based on the methods of RS (Remote sensing) and GIS (Geographical information system), the regional agro-ecosystem environmental quality and ecological economic development level and the single factors of the eco-environment were analyzed. At last, according to the evaluation and analysis results, the paper put forward a series of counter measure to achieve the agro-ecosystem sustainable development of Jiangsu province.1. Based on the sustainable development theory, environment carrying capacity theory, ecological economic theory and the index for assessing regional agro-ecosystem environment and economy, the study evaluated the agriculture eco-environmental subsystem and eco-economic subsystem respectively, and established a ecological environment-economic coordinate model based on the conception of harmonious development to account the coordinate degree which was the measurement of sustainable development.2. This paper constructed a perfect and multilayer index systems for assessing regional agriculture eco-environment and eco-economic respectively. The former was made of composite environmental quality index (target arrangement), natural environment status, ecological status and environmental pollution (rule arrangement), and 16 indictors (indicator arrangement). They were: active accumulated temperature≥10℃, mean annual temperature, annual precipitation, annual sunshine hours, vegetation cover, land multiple cropping index, volume of water and soil loss, cation exchange capacity in soil, PH of soil, organic matter content in soil, nitrogen content in soil, phosphorus content in soil, potassium content in soil, use of pesticides per hm² of farm land, use of fertilizer per hm² of farm land, discharge intensity of industrial waste water, discharge intensity of industrial waste gas and discharge intensity of SO₂. The latter was made of the level of ecological economic sub-system sustainable development (target arrangement), agricultural environment status, agricultural society status and agricultural economic status (rule arrangement), and 13 indictors (indictor arrangement). They were: agricultural ecological environmental index, regional population size (inhabitants per km²), proportion of agricultural laborer, engel coefficient of rural households, electricity consumption per Gross agricultural output value, science and education expenditure as a share of fiscal expenditure, average number of student per 10000 ppulation, net income per villager, agricultural labor productivity, agricultural land productivity, per capita average GDP of agriculture, grain per capita, total powers of agriculture machine per hm².3.①Based on the Analytic hierarchy -grey correlation complex model, taking the country as the assessment unit, the regional agro-ecosystem composite environmental quality index and ecological economic development level index were calculated respectively.②Based on the agricultural ecological environment-economic correlate model: combined the composite environmental quality index and ecological economic development level index, calculated the harmunious degree between environment and economy which measured the level of agro-ecosystem sustainable development.4. Assessment the regional agro-ecosystem situation from 1996 to 2005 about 6 economic regions in Jiangsu province as a case. The evaluation results indicated: the vegetation cover was reduced from 54.74% to 50.42%, the proportion of light water and soil loss area was decreased from 8.12% to 6.76% in representative years 1996 and 2000. The index of regional agricultural ecological environmental quality in Yanjiang, Yanhai and Lianghuai regions was higher than the three others during 1996-2005, but environmental quality in most regions was improved. Ecologic economy development level, during 1996-1999, had a wavelike rising tendency and subsequently decreased year by year, but the harmony was keeping good or perfect.