三峡库区兰陵溪小流域土地利用及景观格局对氮磷输出的影响  

Effects of Land Use and Landscape Pattern on Nitrogen and Phosphorus Exports in Lanlingxi Watershed of the Three Gorges Reservoir Area,China

作　　者：韩黎阳[1] 黄志霖[1] 肖文发[1] 田耀武[1,2] 曾立雄[1] 吴东[1] 

机构地区：[1]中国林业科学研究院森林生态环境与保护研究所,国家林业局森林生态环境重点实验室,北京100091 [2]河南科技大学林学院,洛阳471003

出　　处：《环境科学》2014年第3期1091-1097,共7页Environmental Science

基　　金：国家自然科学基金项目(31370481);“十二五”国家科技支撑计划项目(2011BAD38B04)

摘　　要：以三峡库区兰陵溪小流域为研究对象，分析了流域水体氮、磷等输出时空特征及土地利用景观格局对其产生的影响．结果表明，流域总氮（TN）、总磷（TP）、硝态氮（NO3-N）主要来源于园地，6-9月汛期的氮磷输出显著大于1-5月的非汛期；非汛期铵态氮（NH4-N）主要来源于住宅用地，汛期NH4-N则来源于园地，以林地为主的集水区氮磷输出在两个时期均较低．林地面积比与非汛期NO3-N、TP及汛期的TN、TP显著负相关；住宅用地面积比与非汛期的NO3-N、TN及汛期的NO3-N、TN、TP显著正相关；园地面积比与汛期的Nh4-N、TN显著正相关．PD与非汛期的氮素及汛期的NO3-N、NH4-N显著正相关；CONT与汛期的氮素及非汛期的TP呈负相关；耕地、未利用地比例以及景观格局指数ED与氮磷输出的相关性较弱，而SHMN和水域比例尚未表现出显著相关性．此外，两个研究时期NH4-N与土地利用及景观格局变量的回归关系要优于NO3-N、TN和TP，R2分别为0．885和0．969，而汛期的回归关系也比非汛期显著．典型相关分析进一步显示，不同土地利用斑块类型导致的景观破碎化能较好解释氮磷输出的影响，两典范轴累积解释氮磷输出变量的90％，景观变量PD贡献最大，对流域水质评价与预测具有重要意义．The temporal and spatial characteristics of N, P exports and effects of land use and landscape pattern on N, P exports were analyzed in the Lanlingxi Watershed of the Three Gorges Reservoir Area. The results showed that the TN, TP and NO3-N were mainly generated by non-wood forest, the N, P exports in flood period （June to September） were significantly higher than the non-flood period （January to May）. The NH4-N export was derived from the residential area in the non-flood period, while from non-wood forest in the flood period. In addition, the performance of samples N, P exports with forest distributed were lower in both two periods. Also, the proportion of forest significantly negatively correlated with NO3- -N, TP in the non-flood period and TN, TP in the flood period. The residential area proportion notably positively correlated with NO3-N, TN in non-flood period and NO3-N, TN, TP in the flood period. The non-wood forest proportion also significantly positively correlated with NHf-N, TN in the flood period. Moreover, PD closely positively correlated with N exports in non-flood period, with NO3- -N, NH4＋ -N in flood period. The CONT index strongly negatively correlated with N exports in flood period and TP in non-flood period. However, the proportions of farmland, unused land and the indices of ED were relatively weakened with N, P exports in both periods, while SHMN and water proportion did not show any positive or negative correlation. Moreover, the regression fitting degree of NH4-N was superior to NO3-N, TN and TP with the adjust R： of 0. 885 and 0. 969 in two periods, while the regression relation was better than that of non-flood period. The result of redundancy analysis further demonstrated that the landscape fragmentation caused by patches types of different land uses could better explain impacts on the exports of nitrogen and phosphorus. The two canonical axes accumulated explained the 90% proportion of the variables and the highest contribution was P1）, which was an important indicator

关 键 词：土地利用 景观格局 氮磷输出 时空特征 非点源污染 

分 类 号：X52[环境科学与工程—环境工程]