屋顶农业微系统功能分析

发布时间：2019-04-02 06:23

【摘要】：城市化进程的加快,不但导致耕地资源的大量减少,也使脆弱的城市生态愈加恶化,土地格局重新分配,探索低碳城市生活方式和新型食物生产方式已迫在眉睫。屋顶农业是城市空间农业的重要组成部分,在补偿土地资源、改善局域生态等方面发挥着巨大作用。但作为一种新型农业生产方式,其在全球范围内尚处于理论探索阶段,缺乏系统研究。本文将屋顶农业系统功能细化为生产、生活、生态三大属性,按照种植方式、灌溉方式等划分为不同类型,并选取中国农业科学院屋顶农场作为主要研究对象,分别对屋顶农业生产、生活、生态功能进行分析评价,对“三生”功能的属性、比例以及未来发展方向进行初步探索,主要结论如下:(1)生产方面:北方屋顶农业产量不及大田。通过对2014年全年屋顶农业的换茬和采收,统计年总产量为1.58kg/m2,约为当地常规农业平均亩产量的48.7%,通过CO2排放强度折合减排CO2为14.71kg/m2,经济产值51.50元/m2。(2)生活方面:采用人体热舒适度法评价结果表明,种植屋顶全天达到舒适以上水平的出现频率为33.3%,时间分布与人群活动时间契合度较高;相对而言,裸屋顶全天舒适以上水平的出现频率远低于种植屋顶,仅为5.6%,基本不具备生活功能。另外,屋顶农业的存在可以使夏季室内平均降温2.7℃左右,减少空调冷负荷169.32k Wh/m2以上,折合CO2减排量达105.0kg/m2。(3)生态方面:主要以植物碳汇量、滞尘等碳汇数据以及减少的食物里程和休闲里程作为量化指标并分别计算。其中,年植物碳汇量分别为108.27 g/m2、30.58 g/m2,折合固定CO2量0.51kg/m2;由屋顶产出可减少的食物里程约0.19kg/m2,折合CO2减排量为8.45×10-2kg/m2,仅占生态功能总价值的2.1%;屋顶农业每年可为206户家庭提供休闲采摘服务,由此减少休闲里程排放的CO2平均每年3669.50kg,约为生态功能属性构成比的74.67%。系统生态功能CO2减排量约为40.95kg/m2。在理想情况下,北方屋顶农场的年产量在2.92kg/m2左右,生产、生态、生活三种属性在系统中的收益比例分别为19.95%、47.02%、33.03%,间接固碳价值远大于农产品直接产出价值,系统生态功能收益最高,生活功能次之。受当年局域灾害和养护经验不足等原因,实验地屋顶农业全年产量仅为1.58kg/m2,上述三种属性比为14.30%、39.79%、45.91%,生态功能与农场产量成正相关,生态功能略低于生活功能,间接证明了屋顶农业在城市环境系统中的合理性与必要性。
[Abstract]:The acceleration of urbanization not only leads to a large reduction of cultivated land resources, but also aggravates the fragile urban ecology. The redistribution of land pattern and the exploration of low-carbon urban life style and new food production mode are imminent. Roof agriculture is an important part of urban spatial agriculture, which plays an important role in compensating land resources and improving local ecology. However, as a new mode of agricultural production, it is still in the stage of theoretical exploration and lack of systematic research. In this paper, the function of roof agriculture system is divided into three attributes: production, life and ecology, and it is divided into different types according to planting mode and irrigation method, and the roof farm of Chinese Academy of Agricultural Sciences is chosen as the main research object. The function of roof agriculture, life and ecology are analyzed and evaluated respectively, and the attribute, proportion and future development direction of the function of "Sansheng" are preliminarily explored. The main conclusions are as follows: (1) production: the northern roof agricultural output is not as good as the field. Through the replacement and harvesting of roof agriculture for the whole of 2014, the total annual output is calculated to be 1.58kg / m2, about 48.7% of the average yield per mu of local conventional agriculture, and the emission reduction of CO2 through CO2 emission intensity is 14.71kg / m2. The economic output value was 51.50 yuan / m2. (2) Life aspect: the result of human body thermal comfort evaluation showed that the frequency of planting roof reached above comfort level was 33.3%, and the time distribution was in good agreement with the time of crowd activity; Relatively speaking, bare roof above the level of comfort throughout the day appears far less than the planting roof, only 5.6%, basically do not have the function of life. In addition, the existence of roof agriculture can reduce the average indoor temperature by about 2.7 鈩，

本文编号：2452329