基于干湿度规律的中国温带城市与区域NDVI空间变化研究

Research on NDVI Spatial Variation of Cities and Region in Temperate Zone of China Based on Dryness and Humidity Regularity

[目的]探索中国温带地区城市与区域生态差异的地带性规律,为不同区域城市生态建设提供重要依据。[方法]利用250m空间分辨率MODIS NDVI遥感影像数据,采用最大合成法和高斯函数拟合方法,选择中国从东部到西部的临沂、许昌、白银、吐鲁番和克拉玛依5个典型地级城市的植被归一化指数(NDVI),去探索中国温带地区城市与区域生态差异的地带性规律。[结果]从城市中心到边缘10km范围内,由湿润区到极干旱区域,城市与区域NDVI指数的变化呈现由"U"型—波浪型—"倒U型"的变化规律,但干旱区与极干旱地区由于依托绿洲建设城市,其NDVI指数可表现为"花M型";不同地带城市内部的NDVI指数有趋同现象,但人为强化城市生态建设,可有效提高城市NDVI指数。[结论]按照不同地域城市与周边区域的NDVI关系,在城市与周边区域NDVI呈"U型"的城市,应以楔入式引入型生态建设为主体,在"倒U型"的城市,应以圈层式防护型生态建设为主体。

[Objective] To explore zonal regularity of ecological differences among different cities and regions in temperate zone of China and to discover the significance exerted on the development of urban green construction.[Methods] By employing the 250 m resolution data offered by NDVI MODIS remote sensing image and with the aid of the maximum synthesis method and Gauss＇s function fitting method, the study intended to explore zonal regularity of urban areas and regional ecological differences in temperate regions of China in terms of vegetation normalization index（NDVI）, which covered Linyi, Xuchang, Baiyin, Turpan and Karamay 5 typical cities in China from east to west.[Results] Viewed from the humid region transition to the hyper-arid region, the change of urban and regional NDVI index presented a ＂U＂ type to wave type to ＂inverted U＂ changes regulations from center city to the 〈10 km edge and. However, because these cities rely on oasis in the arid area and hyper-arid region, NDVI index can be expressed as ＂M＂ type. In conclusion, the study demonstrated that NDVI index presented a convergence trend in different regions of the city, whereas, it can be effectively improved the city NDVI index by strengthening urban ecological construction artificially.[Conclusion] When NDVI index of a city is the ＂U＂ type,the urban green arrangement should be arranged with dot and line as the main part. When NDVI index of a city is the ＂inverted U＂ type,the city green arrangement should be arranged with several rings as the main part.