安徽省县域耕地畜禽养殖废弃物养分负荷时空演变特征

摘要

耕地畜禽养殖废弃物养分负荷量具有明显的时空分布特征,研究其区域特征和格局演变对于畜禽养殖业可持续发展具有重要意义.基于2004—2012年安徽省县市级畜禽养殖统计数据和耕地面积数据,利用空间自相关分析方法开展安徽省县域耕地畜禽养殖废弃物氮负荷量的空间格局和空间演变研究.结果表明,2004—2012年安徽省各县市畜禽养殖废弃物氮负荷在空间和时间上都存在不同程度的差异.Global Moran′sⅠ 指数值(0.24~0.37)显示2004—2012年安徽省各县市耕地畜禽养殖废弃物氮负荷具有显著的空间正相关性和潜在的空间依赖性,表明安徽省耕地畜禽养殖废弃物氮负荷一直处在相对集聚的发展阶段.Getis-Ord Gi*指数表明2004—2012年安徽省耕地畜禽养殖废弃物氮负荷热点区域主要分布在安徽省北部和东南部,尤其是宣州市的绩溪县始终属于热点区域.此外,黄山市的歙县、宿州市的萧县、宣州市的旌德县、宿州市的砀山县和毫州市的利辛县也多次属于热点区域.该研究结果可为畜禽养殖废弃物处理、环境污染防治和区域畜禽养殖总量控制研究提供决策依据.%Nutrient load from livestock manure in farmlands feature apparent spatio-temporal variation. The study on effects of regional characteristics and distribution of the load means significantly to the study on environmental pollution caused by livestock breeding and sustainable development of livestock breeding. Based on the county-leveled 2004-2012 statistics of livestock breeding and area of farmlands in Anhui Province, spatial autocorrelation analysis was performed to explore spatial pattern and spatial evolution of N load from livestock manure in the farmland on the county scale in Anhui. Results show that nitrogen load from livestock manure in the farmland varied spatially and temporally with the county in the period of 2004-2012. The Global Moran′s Ⅰ index (0.24-0.37) shows that the nitrogen load had a significant positive re-lationship with space and potential dependence on space, which indicates that the nitrogen load had been in the develop-ment stage of relative agglomeration. The Getis-Ord Gi*index also shows that the hotspots of nitrogen load were mainly dis-tributed in northern and southeast parts of Anhui Province, especially Jixi County in Xuanzhou City, which was always a hotspot region during the period. In addition, the counties including Shexian, Xiaoxian, Jingde, Dangshan and Lixin were several times sorted as hotspot regions. The findings of this study may serve as scientific basis for researches on decision-mak-ing on livestock manure disposal and environmental pollution control, and regional total amount control of livestock feeding.