中国各省市区种养业灰水足迹分析与评价

ANALYSIS AND EVALUATION OF GRAY WATER FOOTPRINT FOR PLANTING-ANIMAL HUSBANDRY INDUSTRY IN PROVINCIAL REGIONS, CHINA

关键词:  灰水足迹  水环境压力  种植业  畜禽养殖业  综合评价

Key words:  gray water footprint  water environment pressure  planting industry  animal husbandry industry  comprehensive evaluation

摘要:

目的 深入挖掘第二次全国污染源普查成果，科学评价与分析各地区农业源水污染排放现状与环境压力，将有助于区域污染物减排与政策制定。方法 文章拟核算2017年中国31个省（市、区，不含港澳台）种养业的灰水足迹，构建评价指标体系，选取熵值法和理想点法作为综合评价方法，系统性评价与分析种养业水污染物排放量与产量、产值的协同关系，表征水污染物排放对区域地表水的环境压力。结果 （1）2017年全国种植业和畜禽养殖业灰水足迹分别为4 898亿m³和6 841亿m³，分别呈现“南高北低”和“东高西低”的地理分布特征。（2）畜禽养殖业水污染物排放带来的水环境压力大于种植业，尤其是黄淮海地区。（3）在种植业中，江苏和海南的灰水足迹综合评价结果相对较低；在畜禽养殖业中，河北、西藏、天津和宁夏相对较低。结论 建议种养业未来以减排增效为核心发展目标，海南优化肥料施用结构与方式、黄淮海地区调控种养业生产规模与方式、长江中下游地区拦截稻田退水污染。该文从水环境保护角度为中国种养业绿色发展提供政策建议。

Abstract:

As a crucial national survey in China, Second National Pollution Census comprehensively verifies the discharge of various pollutants and provides data in support of the formulation of national economic and social development outlines and ecological and environmental policies. According to Second National Pollution Census Bulletins, the emissions of COD, ammonia nitrogen, total nitrogen and total phosphorus from agricultural sources accountes for 49.77%, 22.44%, 46.52% and 67.22% of the total national emissions, which are the main sources of water pollutants. However, there are large differences between different regions in agricultural water pollutant emissions. Therefore, it becomes an urgent problem how to dig deeper into the results of the Second National Pollution Census and scientifically assesses the water pollutant discharges from the planting-animal husbandry industry. This paper is intended to account for the gray water footprint of the planting-animal husbandry industry in 31 provinces (cities, autonomous regions, excluding Hong Kong, Macao, and Taiwan in China) based on the results of the Second National Pollution Census. And an evaluation index system and a comprehensive evaluation method was constructed, which could be used to analyze and evaluate the current situation of water pollution discharge from the planting-animal husbandry industry, and explore its characteristics and regular patterns. It was expected to provide a theoretical basis for the green development for planting-animal husbandry industry. The results showed that the total gray water footprint of the national planting industry and animal husbandry industry was 489.8 billion m³ and 684.1 billion m³ in 2017, respectively. An obvious aggregation effect in the spatial distribution was observed, showing the characteristics of ‘high in the South and low in the North’ for planting industry, and ‘high in the East and low in the West' for animal husbandry industry. In the water environment pressure evaluation index, the discharge of water pollutants from the animal husbandry industry caused higher water environment pressure than the planting industry. In the comprehensive evaluation results of the gray water footprint of the planting industry, the results of Qinghai, Xinjiang, Tibet and Inner Mongolia were relatively high, while the results of Jiangsu, and Hainan were relatively low. In the animal husbandry industry, the results of Shanghai and Zhejiang were relatively high, while the results of Hebei, Tibet, Tianjin and Ningxia were relatively low. Therefore, in the future, it is urgent to reduce emissions and increase efficiency as the development goal for the planting-animal husbandry industry, and each region should adopt the corresponding methods according to the local conditions, such as, fertilizer application structure and methods should be optimized in Hainan, the production scale for planting-animal husbandry industry should be regulated scientifically to alleviate water environment pressure in the Huang-Huai-Hai region, and in the middle and lower reaches of the Yangtze River, more attention should be paid to agricultural wastewater from paddy fields. So, this research provides policy recommendations for the green development for planting-animal husbandry industry from the perspective of water environment protection in China.