乐山"绿心"因面积大、地势高、临江河、覆盖度高,成为调节城市生态环境的重要景观。采用多时相Landsat-5 TM遥感数据和GIS技术获取绿心的地温信息,研究表明:区内地温的最大值、最小值、平均值、标准差等指标在四季均表现出低值→高值→低值的变化过程,各项指标基本满足绿心〈建成区〈乐山地区的规律,绿心的相对低温特征最为稳定;绿心平均地温11.16~29.71℃,冬季最低,夏季最高,绿心的降温效应随地温升高而递增;绿心平均地温在四季比建成区低1.29℃、比乐山地区低0.13℃,绿岛效应明显;绿心地温的四季标准差1.54℃,比建成区低3.30℃,比乐山地区低1.46℃,绿心的地温分布最集中;绿心比建成区小规模绿地的地温低2.0℃以上,绿心低温的规模效应最显著。鉴于绿心地温与植被、湿度、气温的联系,绿心地温的多重生态意义值得研究。
Because of large area, high terrain, near river, and good vegetation coverage, Leshan "Green Heart" becomes important landscape in adjusting urban ecological environment. Multi-temporal Landsat-5 TM remote sensed data and GIS technology are used to extract ground temperature.The results show that ground temperature of maximum, minimum, average, and standard deviation rises from low to high, then falls in the four seasons.The four indicators show the basic law of the Green Heart<the built-up area<the Leshan area. The relative low temperature characteristic of Green Heart is most stable . The average ground temperature of Green Heart is 11.16-29.71 ℃, from lowest winter to highest summer.The cooling effect of Green Heart be-comes significant when the ground temperature rises.Green Heart average ground temperature is 1.29 ℃ lower than the built-up area, 0.13 ℃ lower than the Leshan area.Green island effect is very obvious.The standard deviation of Green Heart ground temperature is 1.54 ℃, 3.30 ℃ lower than the built-up area, and 1.46 ℃lower than the Leshan area.Ground temperature distribution of the Green heart is concentrated.The ground temperature of Green Heart is 2.00 ℃ lower than the small green-land in built-up area, its magnitude effects of cooling is significant.In the relationship of ground temperature, vegetation, humidity, temperature, Green Heart multi-ecological study is significant.