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灌区是构成绿洲的最基本单元,在人工灌渠系统的强烈控制与引导下,渠系的供水量决定了灌溉面积(水浇地)的大小,而水浇地的规模又决定人口的承载能力,因此,水-土-人系统存在着高度的相互依存性和共生性。论文应用空间自相关分析模型的Getis-Ord Gi*指数,选取张掖39个灌区中的3个灌区(新坝、平川、盈科)分别代表沿山独立灌区、绿洲边缘区灌区和绿洲中腹灌区进行分析。结果表明,新坝灌区受独立水系和水资源保证程度的深刻影响,渠系、水浇地和居民点自干渠向外,由热点地区逐渐转变为冷点地区,居民点、干渠、水浇地具有明显的空间聚集特征,渠系对水浇地分布具有显著的控制和引导作用。平川灌区受黑河干流走向的影响,居民点、水浇地表现出明显的核心-外围特征,黑河沿岸干渠对居民点和水资源具有较强的基础性作用。盈科灌区由于水资源丰富,保证程度高,渠系对于水浇地和居民点的控制作用反而低于其他两类灌区。
Irrigation areas constitute the most basic unit of oasis. Under the strong control and guidance of artificial irrigation canal system, the water supply of canal system determines the size of irrigated area (irrigated land), and the size of irrigated land also determines the carrying capacity of population. Therefore, there is a high degree of interdependence and symbiosis with the water-earth-human system. Based on the Getis-Ord Gi * index of spatial autocorrelation analysis model, three irrigation districts (Xinba, Pingchuan, and Yingke) in 39 irrigated areas of Zhangye were selected to represent the independent irrigated area along the mountain, the irrigated area at the edge of the oasis and the middle irrigated area in the oasis . The results show that the Xinba Irrigation District has a profound impact on the degree of independent water system and water resources guarantee. The canal system, irrigable land and settlements are changed from the mainstream to the cold spots, settlements, canals and irrigated areas With obvious spatial aggregation characteristics. Canal system has significant control and guidance on the distribution of irrigated land. Due to the influence of the Heihe main stream direction, the Pingchuan Irrigation District shows obvious core-periphery features in settlements and irrigated areas. The main channels of the Heihe River Basin have a strong foundation for settlements and water resources. Due to the rich water resources and high degree of assurance, Yingke Irrigation District has less control over irrigated land and residential areas than the other two types of irrigated land.