小浪底大坝对黄河中下游农业景观格局的影响

THE INFLUENCE OF XIAOLANGDI DAM ON THE AGRICULTURAL LANDSCAPE IN THE MIDDLE AND LOWER REACHES OF THE YELLOW RIVER

小浪底大坝所处地理位置和运用方式特殊,改变了黄河的地表径流,而黄河的脉动又牵动着该区农业景观的格局和过程,影响着黄河中下游农业生态系统服务的形成和维持。本文运用景观生态学的理论和方法,分析小浪底大坝对黄河中下游农业景观格局的影响。结果表明:小浪底大坝建成后,水田面积不断减少,破碎化明显;河渠和湿地变得零星,部分转变为旱地和建设用地。林地面积和斑块个数都有所增加,建设用地不断扩张。旱地景观、林地景观、建设用地景观、河渠景观复杂程度增加,斑块变得离散和不规则。各景观组成的分维数的波动变化说明其在空间上不断交错、渗透的动态变化过程。小浪底大坝建成初期,景观趋于均匀分布,整体上景观优势组成没有明显变化。

Xiaolangdi dam is located in a special geographical location and application mode, which strongly changes the surface runoff of the Yellow River, and the pulsation of the Yellow River affects the pattern and process of agricultural landscape in this area, and affects the formation and maintenance of agricultural ecosystem services in the middle and lower reaches of the Yellow River. By using the theory and method of landscape ecology, the influence of Xiaolangdi dam on the agricultural landscape pattern in the middle and lower reaches of the Yellow River is analyzed. The results show that after the Xiaolangdi dam is completed, the area of paddy field is decreasing and the fragmentation is obvious. Canals and wetlands have become sporadic, partly to dry land and construction land. The land area and the number of patches have increased, and the construction land has been expanding. The landscape of dry land, landscape of woodland, landscape of construction land, the complexity of canal landscape increased, the plaque became discrete and irregular. The fluctuation of fractal dimension of each landscape shows the dynamic process of interleaving and infiltration in space. In the early stage of Xiaolangdi dam, the landscape tended to be evenly distributed, and the composition of the overall landscape advantages did not change significantly.