塔里木河干流区天然植被的空间分布及生态需水

塔里木河流域荒漠河岸林具有重要的生态、经济和社会效益。本文以塔里木河干流的荒漠河岸林系统为对象，借助于卫星遥感、GIS等技术，研究塔里木河干流区各河段天然植被分布特征，应用缓冲区梯度分析方法对林地分布结构和生态需水进行分析。结果表明： （1）塔里木河干流区天然植被面积为146.1×10⁴ hm²，占研究区总面积的35.18%；北岸天然植被面积较南岸多46.34×10⁴ hm²。（2）塔里木河干流区荒漠河岸林分布随距离河道的增加呈波动下降趋势。在影响保护带、基本保护带和重点保护带下，天然植被保护范围分别为4.7～30.1 km、2.2～24.2 km和0.8～12.3 km。（3） 塔里木河干流区天然植被总的生态需水量为21.932×10⁸ m³，在重点保护带、基本保护带和影响保护带下，生态需水量分别为9.56×10⁸ m³、14.97×10⁸ m³和19.08×10⁸ m³。根据荒漠河岸林的分布特征和保护目标，对塔里木河干流用水作统一规划和协调是符合实际的生态治理措施。

Spatial Distribution Characteristics and Ecological Water Requirement of Natural Vegetation along the Mainstream of the Tarim River

The Tarim River riparian forest is highly prized in the Tarim Basin for its great ecological, economic and social benefits. In a lot of analysis, on the basis of remote sensing, GIS for technical and field surveying support, study on the distribution characteristics of natural vegetation and the water requirement were done by using the methods of buffer analysis. The results show that: (1) The area of natural vegetation is 146.1×10⁴ hm² (35.18% of the total). The width and abundance of natural vegetation of north bank is larger than that of south bank. (2) The desert riparian forests show a spatially exhibit zonal distribution of centering around river, the distribution of desert riparian forest showed downtrend along with far from the riverbed. The scope of protection of the natural vegetation separate were 4.7～30.1 km, 2.2～24.2 km and 0.8～12.3 km in the effect band, basic band, key band. (3) The total ecological water requirement of natural vegetation was 21.932×10⁸ m³ water, the ecological water requirement of the key band, basic band, effect band were 9.56×10⁸ m³, 14.97×10⁸ m³ and 19.08×10⁸ m³, respectively. According to the distribution characteristics of the desert riparian forest and conservation goals, unified plan and coordinate of water resources should be actual ecological management measures.