Study On Space-time Characteristics And Prediction Of Pollution Load Of Livestock And Poultry Feces In Hubei Province

Through establishment of comprehensive pollution evaluation system and pressure-state-response（PSR）model,analysis was carried out on the"pressure"index-pollutant generation,loss and its space-time dynamic characteristics and the status"index-pollutant equal standard pollution index and cultivated land early warning value of 103counties of 17 cities and regions of Hubei Province from 2009 to 2016 in this paper,proposing"response"method for livestock and poultry feces pollution--Division Control and Resource Utilization,etc.and predicting the fecal pollution caused by livestock and poultry industry in the coming 8 years with the grey prediction model,so as for certain theoretical basis and reference to effective control of livestock and poultry feces in Hubei Province.Principal conclusions are as following:（1）From the time scale,about 16.7618 million tons of livestock and poultry feces pollutants were generated in Hubei Province in 2016,and the pollutant generation was COD>TN>TP,pig feces,cow dung is the main pollution source of livestock and poultry excrement in Hubei province,pig and cow feces is the main pollution source of livestock and poultry in Hubei Province;the Provincial cultivated land load of livestock and poultry feces 32.66 t/hm²that is beyond the maximum load of the cultivated land;the pollutant loss is 842500 tons,the equal standard emission is 45.42×10¹⁰m³,and TP is the principal cause to water pollution by livestock and poultry in Hubei Province;Xiangyang City,livestock and poultry fecal pollutant generation,loss and equal standard discharge ranked the Provincial first in the 17 cities and cities;from 2009 to 2016,all pressure indexes show a trend of decreasing from increasing and a peak in 2014;the warning value of livestock and poultry feces load in cultivated land during the last 8 years was overall atⅢ-Ⅳ,and the threat of pollution by livestock and poultry feces in cultivated land in the whole Province is very serious;the pollution degree of water body by livestock and poultry feces is in gradeⅠ-Ⅱand in low risk.（2）From the spatial layout,the pollution of livestock and poultry feces in Hubei Province appears strong spatial aggregation mainly with high value located in the northern and eastern regions,where Xiaogan,Xianning,Xiangyang,etc.are the highest risk of water pollution;Nanzhang County,Gucheng County,Echeng District,Zengdu District,Maojian District and Yidu City,etc.are the largest threat to farmland pollution.Because of the small gravity-center-analysis-model,the migration amplitude of gravity center of each index and the spatial change of livestock and poultry breeding quantity deviates little.For the division of comprehensive environmental effect control and the spatial distribution of organic fertilizer resources of livestock and poultry feces,integrate Hubei Province into four levels of different modes of agricultural ecological economic development areas:level 1 of severe pollution control area（including 13 sub-areas）---deep processing of agricultural products and strict control area of livestock and poultry feces pollution;level 2 of medium pollution control area（including 16 sub-areas）---planting and breeding combined with ecological agriculture and livestock and poultry feces pollution control area;level 3 of mild pollution control area（including 8 sub-areas）---"livestock-marsh gas-fruit"and ecological agriculture and livestock and poultry feces pollution supervision area and level 4 of micro-pollution control area（including 4 sub-areas）---ecological circulating agriculture and livestock and poultry feces pollution prevention and control area.（3）The prediction results show an increasing trend in the number of cattle,pigs,sheep and poultry in Hubei Province from 2017 to 2024 in the premise of no external interference,and In 2024,pressure indexes will increase by an average of 30%compared with 2016;the cultivated land load of livestock and poultry feces will reach 45.15t/hm²,and the pollution risk of cultivated land will be increased from level IV to V,the TP load of cultivated land will reach 72.06 kg/hm²more than twice of the limit standard of cultivated land,and the TN load will reach 440.72 kg/hm²more than 2.6 times of the limit standard of cultivated land with the pollution risk more intensive.Therefore,it is necessary to establish a scientific and normalized resource system for livestock and poultry feces application,and strictly supervise its entire process from source to discharge so as to achieve the healthy and circular development of livestock and poultry breeding industry.