丹江上游土地利用/景观指数与水质关系初探

借助地理信息和景观分析技术，结合长系列水质数据，采用相关分析法、冗余分析法（RDA），研究了丹江上游土地利用/景观指数与水质的关系，重点探讨了景观指数与水质参数的关系。结果表明:（1）2000—2013年，耕地面积减少，林地、建筑用地面积不断增加，耕地是最不稳定的土地利用类型，大部分转为林地和草地。流域内景观多样性和聚集度逐渐增加，流域景观格局趋于规则化、高连通和高度聚集的方向发展。（2）耕地面积比与NO₃^--N呈极显著正相关，与DO呈现显著负相关，表明耕地强烈的影响着水质变化；林地面积比与BOD₅，COD_Mn呈显著负相关，林地对水质有显著的正效应。（3）从景观指数与水质参数的相关性可以得出，香农多样性指数（SHDI）、最大斑块指数（LPI）、景观形状指数（LSI）、斑块结合度（COHESION）可以作为景观尺度上来预测水质变化的关键因子，具体表现为SHDI与COD_Mn呈显著负相关，与BOD₅呈负相关；LPI与BOD₅，COD_Mn呈显著正相关；LSI与DO呈极显著负相关，与NO₃^--N呈显著正相关；COHESION与BOD₅，COD_Mn呈显著正相关。斑块密度（PD）和蔓延度指数（CONTAG）与水质的关系无法得到合理的解释。

Preliminary Study on the Relationship Between Land Use/Landscape Index and Water Quality in the Upper Reaches of Danjiang River

Based on the analysis on the technology of GIS and landscape, and a long series of water quality data, we used correlation analysis and redundancy analysis to study the relationship between land use and water quality in the upper reaches of the Danjiang River, discuss the relationship between the landscape index and water quality index. The results showed that: (1) in 2000—2013, cropland area decreased, woodland and building land area increased; cropland was the most unstable land use type, most of which was converted into woodland and grassland; the landscape diversity and aggregation degree increased gradually, and the watershed landscape pattern tended to be regular, highly connected and highly aggregated; (2) the effects of cropland and woodland on water quality was significant, and the proportion of cropland area was positively correlated with NO₃^--N, and negatively correlated with DO; proportion of woodland area was a significant negatively correlated with BOD₅ and COD_Mn; (3) with respect to the correlation between the landscape index and the water quality index, SHDI, LPI, LSI and COHESION could be used as landscape and environmental indicators on landscape scale to predict water quality change, SHDI was negatively correlated with COD_Mn and BOD₅; LPI was positively correlated with BOD₅ and COD_Mn; LSI was negatively correlated with DO, and positively correlated with NO₃^--N; COHESION was positively correlated with BOD₅ and COD_Mn. The relationship between plaque density and spread index and water quality can not be well described.