武汉市禽畜养殖时空分布及其耕地污染负荷分析

Spatial and temporal distribution of livestock breeding and farmland pollution load in Wuhan

利用武汉市2009—2016年的统计数据,分析武汉市这8年禽畜养殖数量的时间变化特征和各区域禽畜养殖空间分布特征,估算禽畜养殖污染物产生量和禽畜粪便耕地负荷,并对武汉各地区禽畜养殖耕地污染进行风险评价.结果表明:①武汉市禽畜养殖数量整体呈先增后减的趋势,2009—2013年为增长期,年平均增幅为4.4%,2014—2016年为下降期,年平均降幅为9.7%;②武汉市中心城区与5个远城区的禽畜养殖数量差异明显,北部黄陂、新洲区和南部江夏区为禽畜养殖主要分布区域,猪、牛、羊、家禽养殖量占全市84.93%、87.11%、61.81%、85.86%;③污染物年产生量为COD>TN>TP,猪、家禽粪便是3种污染物的主要来源,其贡献率高达80%;④2009—2016年,禽畜粪便耕地负荷均超过耕地最大适宜施用量30 t·hm^(-2)·a^(-1),禽畜养殖环境承载压力最小的年份是2016年.耕地污染风险评价全市平均警报值1.02(Ⅳ级),耕地呈现较高污染状态;⑤武汉市中心城区与5个远城区禽畜粪便耕地污染负荷差异明显,表现出较强的空间聚集性,高值主要位于北部和南部地区,江夏区属于45 t/hm^(2)以上的高污染区.

Based on the statistical data of Wuhan from 2009 to 2016,the temporal change characteristics of livestock breeding number and spatial distribution features of regional livestock breeding were analyzed in the past 8 years.The amount of pollutants produced in livestock breeding and livestock manure load on farmland were estimated,and the risk assessment about pollution of farmland for livestock breeding in Wuhan was conducted.Results showed that:①The number of livestock breeding in Wuhan had a tendency to increase and then decrease.The increasing period was from 2009 to 2013,with an average annual growth rate of 4.4%,while the declining period was from 2014 to 2016,with an average annual sinking rate of 9.7%;②The number of livestock breeding in the central urban area was significantly different from that of the five far suburbs.Huangpi,Xinzhou,the north of Xinzhou and the south of Jiangxin were the main areas for livestock breeding.Pig,cattle,sheep,and poultry breeding in these districts accounted for 84.93%,87.11%,61.81%,and 85.86%respectively of the whole city;③The annual pollutant production is ranked as COD>TN>TP,pig and poultry manure were the main sources of the three pollutants,and their contribution rate were as high as 80%;④From 2009 to 2016,the load of manure farmland exceeded the maximum suitable application amount of arable land by 30 t·hm^(-2)·a^(-1),and the year with the lowest environmental bearing pressure of livestock breeding was 2016.The average alarm value of farmland pollution risk assessment in the whole city was 1.02(levelⅣ),which indicated that farmland was highly polluted;⑤The pollution load of farmland and livestock manure in Wuhan’s central areas significantly differed from that in the five remote districts,which showed a strong spatial aggregation,and the high values were mainly located in the north and south.Jiangxia District was highly polluted,and the contaminated area was above 45 t/hm^(2).