【作者】 李现勇；

【导师】 易秀；

【作者基本信息】 长安大学 ， 环境科学， 2008， 硕士

【摘要】 灌区在我国经济发展尤其是粮食生产中发挥了举足轻重的作用。但近年来灌区在生产和建设过程中,也出现了一系列的生态环境问题。本研究在对泾惠渠灌区农业生产和环境现状调查基础上,通过采集水样和土壤样,分析了泾惠渠灌区农药及化肥施用等农事活动对农业环境造成的影响,并根据灌区的特点,选择了合适的评价模型,对泾惠渠灌区的生态环境质量进行了综合评价,提出了相应的措施和建议,为灌区农业生产合理健康的发展提供了科学依据。得出以下研究结论:(1)灌区生产资料使用情况调查表明,泾惠渠灌区的农药公顷施用量是陕西省农药公顷使用量的4倍,化肥公顷施用量按复种指数2折算,超过了发达国家设置的安全线的0.56倍,氮肥施用量过高,氮肥、磷肥和钾肥的比例为1∶0.204∶0.148,比例失调。(2)灌区的地下水调查结果显示,地下水含盐量高,超过地下水的IV类标准,长期用地下水灌溉会使灌区土壤面临盐渍化的威胁。(3)运用层次分析法和主成分分析法对灌区生态环境质量评价得出:影响灌区土壤肥力质量的关键因子是有机质,其次是速效磷和速效钾;影响灌区地下水水质的第一因子是总盐量,其次是COD;影响灌区土壤环境质量的主要因子是重金属Hg和Cr,而土壤中的Zn的含量增加幅度最大,排在第3位。(4)运用建立的灌区生态环境质量综合评价指标体系,对泾惠渠灌区生态环境质量进行评价,结果表明,泾惠渠灌区的生态环境质量属于中等水平,主要原因是农药和化肥的施用量过高,以及灌区的植被覆盖率低造成的。(5)针对灌区农业生产现状,提出实行规模化种植,发展科学施肥和灌溉相结合的综合型农业;提高植被的覆盖率,因地制宜地在地下水丰富但水质较差且不能满足灌溉的地区,发展林业,加强当地生态的稳定性。更多还原

【Abstract】 Irrigation area has been playing a crucial role in the economic development of China, especially in grain production. However, there are a series problems happened during the production and construction of irrigation area in the recent years. This study is on the basis of the investigation of agricultural activities and environmental current situation in Jinghui-Irrigation area by collecting water and soil samples, to analyzes the environmental impact cause by pesticide, the chemical fertilizer and other agricultural activities, meanwhile, selects the appropriate evaluation model according to the characteristics of the Jinghui-Irrigation, and evaluates synthetically the quality of the ecological, and proposes the corresponding measures and suggestions, provides a scientific basis for the reasonable and healthy development of the agricultural production . The conclusions are following:(1) The survey of the use of capital goods showed that pesticide application per hectare in the Jinghui-Irrigation area is four times than Shaanxi Province, fertilizer application outgrows the security line of the developed countries at 0.56 times, in the 0.2 times of multiple cropping index. The ratio imbalance is caused by the excessive use nitrogen fertilizer, and the ratio of nitrogen: phosphorus: potassium is 1:0.204:0.148.(2) In the Jinghui-Irrigation area, the groundwater survey showed that the groundwater is rich in salt content, exceeded the class IV of the groundwater standards, the long-term use of groundwater irrigation make soil salinization.(3) Evaluate eco-environmental quality of the Jinghui-Irrigated area by level analysis and principal component analysis. Carry out the conclusion that the key factor influence the quality of soil fertility of the irrigation area is organic matter, followed by the phosphorus and potassium; the first factor that impact the quality of the groundwater irrigation area is salt, followed by COD; the main factor that impact the soil environmental quality are Hg and Cr, because the large increase rate of Zn in the soil, ranked No. 3.(4) Application comprehensive evaluation index system of the eco-environment quality to evaluate Jinghui-Irrigation area, it show that the Irrigation area is in average level, mainly because the pesticides and fertilizers be used heavily, and vegetation cover scare.(5) In view of the agricultural production of the Jinghui-Irrigation area, propose the large-scale cultivation, develop comprehensive agriculture of cooperating scientific fertilization with irrigation. Enlarge the vegetation coverage, according to local conditions, develop forestry in which groundwater is rich but poor quality that can not be irrigated, strengthen the local ecological stability.更多还原