水口库区流域农业面源污染评价及其防治对策

通过对水口库区流域内18个镇（乡）的农业面源污染源（包括生活污染、人粪尿、农村固体废物及生活垃圾、化肥、畜禽养殖、农田养分流失、村镇地表径流、水产养殖等）调查，并采用等标排放量进行评价，结果显示：2005年该流域全年CODer、TN和TP的排污量分别为6288．87t．4450．07t和1448．82t，总等标排放量为19357．55×10^6m^3，其中CODer、TN和TP的污染率指数分别为2．17％、22．99％和74．85％，故磷和氮是水口库区流域水体污染的主要污染物。污染率指数大小排在前3位的污染源为农田水土流失、水产养殖和畜禽粪尿，分别为41．95％、36．81％和10．60％，三者总和占全流域污染率的89．36％，是该流域农业面源污染的主要污染源。各乡镇间相比较，2005年全年等标排放量以黄田镇居第1位，达2942．14×10^6m^3，污染率指数为15．20％；水口镇和东桥镇次之。不同乡镇的主要污染源有所不同，例如黄墩办、水东办以生活污水为主，炉下镇、大横镇等以畜禽粪尿为主，梅溪镇、东桥镇等以农田养分流失为主，水口镇、尤溪口镇等以水产养殖为主，不同乡镇在治理农业面源污染问题上应各有所侧重。最后提出水口库区流域农业面源污染的防治对策，主要包括：完善农业立法、强化经营管理措施，加强农化物质投入最小化技术研究，开展畜禽粪便多用途综合利用，发展生态农业和有机农业、提倡清洁生产，合理投放鱼饲料和药物、减少流失率。

Evaluation of agricultural non-point source pollution and countermeasures in Shuikou Reservoir Drainage Area

Agricultural non-point sources pollution (including living contaminants, human feces and urine, rural solid trash and living rubbish, chemical fertilizer, livestock and bird aquatics, farm nutrient loss, surface runoff from villages and small towns, aquiculture, etc.) in 18 townships in Shuikou Reservoir Drainage Area were surveyed and evaluated by equivalent standard discharge amount method. The results show that the total discharge of CODcr, TN and TP are 6 288.87 ton, 4 450.07 ton and 1 448.82 ton respectively, with a total equivalent standard discharge of 1.936×10¹⁰m³. The pollution rate index of CODcr, TN and TP is 2.17%, 22.99% and 74.85%, respectively. Therefore, N and P are the primary contaminants in the drainage area. Furthermore, the largest three pollution rate indexes for the pollution sources are farm nutrient loss, aquiculture, livestock and bird feces & urine, with percentages of 41.95%, 36.81% and 10.60% respectively. The cumulative pollution rate index of the three pollution sources is 89.36%, hence they constitute the primary pollution sources in the area. Among the 18 villages and townships surveyed, the total equivalent standard discharge of Huangtian in 2005 is 2.942×10⁹m³, with a pollution rate index of 15.20%, the largest in the basin. Those of Shuikou and Dongqiao are the second and third, in that order. The results also indicate that different villages and townships have different primary pollution sources. For example, living sewage is the leading pollution source in Huangdun and Shuidong, livestock and bird feces & urine is the leading one in Luxia and Dahuang, farm nutrient loss in Meixi and Dongqiao, and aquiculture leads the rating for Shuikou and Youxikou. Therefore, different villages and townships should take varying measures to address agricultural non-point source pollution. Finally, advanced prevention, remediation and other countermeasures to agricultural non-point source pollution in Shuikou Reservoir Drainage Area include improving agricultural legislation and intensifying management measures, strengthening research and technology devoted primarily to agricultural chemical substances, developing all-purpose and comprehensive use of dejecta of livestock and birds, developing ecological and organic agriculture, advocating cleansing production and enhancing rational application of fish feed and medication to reduce losses.