关键词: 生态环境质量, 南瓮河自然保护区, 主成分分析, 遥感生态指数

Abstract: A microplot field experiment with automatic rain shelter was carried out to study the effect of irrigation quota on water consumption characteristics, grain yield and water use efficiency (WUE) of maize by shallowburied drip irrigation (SDI) in a semiarid region of western Liaoning. The results showed that the water consumption of maize under SDI displayed a fluctuating trend during the whole growth period. The water consumption was larger during the jointing to heading and filling to harvesting stages, and a larger water consumption intensity was observed at the jointing to heading and heading to filling stages. With the increase of irrigation quota, the grain yield of different treatments increased; the increase of 100grain weight and grains per spike were the main reasons for the increase of grain yield. Compared with the conventional furrow irrigation (CFI), SDI with an irrigation quota of 2908.0 m³·hm^-2 reduced the irrigation amount by 30%, the grain yield decreased by only 3.4% (no significant difference), but the water use efficiency (WUE) and irrigation water use efficiency (IWUE) increased by 22.1% and 27.5%, respectively. There was a quadratic parabola relationship between grain yield and irrigation quota. When the irrigation quota was less than 3816.4 m³·hm^-2, the grain yield increased with irrigation quota until the maximum yield 12161.9 kg·hm^-2. However, the grain yield decreased as irrigation quota over 3816.4 m³·hm^-2. With a comprehensive consideration of grain yield, WUE and IWUE, a SDI irrigation quota of 2908.0-3816.4 m³·hm^-2 would be appropriate in the semiarid region of western Liaoning.

Key words: eco-environmental quality, remote sensing ecological index, principal component ana-lysis, Nanweng River Nature Reserve