基于SWAT模型的梅江流域农业非点源污染时空分布特征分析

发布时间：2018-01-06 12:05

本文关键词：基于SWAT模型的梅江流域农业非点源污染时空分布特征分析　出处：《江西师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着社会经济发展速度加快和人类活动强度的日益增大,水体污染问题己成为全球性关注的环境问题。由于点源污染相对分布范围固定、形成过程单一的特点,决定了其控制与治理相对容易,非点源污染己经成为水环境污染的主要威胁。在导致地表水体污染的主要因素中,农业非点源污染所占点源污染的比重又是最大的。由于农业非点源污染具有影响因子复杂多样,范围分布广,输移过程随机性大等特点,增加了研究和控制农业非点源污染的难度。为了定量的估算流域内污染负荷、分析农业非点源污染的迁移转化机制,水文模型模拟法成为评估人类活动对泥沙和营养物质流域系统影响的主要方法。本文以江西省梅江流域为研究区,在综合考虑流域地形特征、土壤性质、气象条件、土地利用等自然特征的基础上,利用模型SWAT(Soil and Water Assessment Tools)模型——分布式连续性环境水文机理性模型,模拟了中亚热带季风湿润区红壤背景和农业生产管理活动方式下农业非点源污染输移机制。运用实测的水质水文数据对模型的参数进行了率定和验证,在保证模型适用性的基础上,进行氮、磷营养盐负荷计算,分析梅江流域非点源污染负荷时空分布特征。本文主要得出以下结论:(1)在时间序列上分析农业非点源污染物输移规律,年负荷变化:在2005-2011年7 a中,硝态氮的排放方式以下渗为主,贡献率达63%,与流域高植被覆盖率有关,氮、磷营养盐负荷与降雨量有明显的相关性;月负荷变化:根据2010-2011年24个月的模拟结果可知,有机氮、有机磷变化趋势基本一致,且受降雨、径流量的影响,变化波动较大。(2)在农业非点源污染空间分布特征分析中,以子流域为单位分析2011年有机氮、有机磷空间分布特征,氮、磷的淋失量与流域内产水、产沙量有关。在梅江流域中下游水系发达的黄陂河流域和会同河流域产水、产沙量较高,导致该区域污染物排放量较高。(3)不同土地利用方式下氮、磷营养盐的排放差距很大,耕地污染物排放量最大,有机氮、磷贡献率分别是整个流域的64.8%和65.8%。模拟结果分析显示,在实际耕作管理制度与施肥措施下,梅江流域非点源污染表现出明显的时空分布规律。水文响应单元(HRU)下非点源污染物负荷中,由农业生产导致的氮、磷贡献率很高。
[Abstract]:With the social and economic development speed and intensity of human activities is increasing, the water pollution problem has become a global environmental problem of concern. Because of the point source pollution is relatively fixed distribution range, forming characteristics of single process, determines its control and management is relatively easy, non-point source pollution has become a major threat to the water environment pollution. The main factors leading to pollution of surface water, the agricultural non-point source pollution point source pollution is the largest proportion. Due to agricultural non-point source pollution is the impact factor is diverse, range wide distribution and transport characteristics of random process, increase the research and the difficulty of controlling agricultural non-point source pollution. In order to estimate the pollution load in watershed quantitative analysis, migration and transformation mechanism of agricultural non-point source pollution, hydrological model simulation method to evaluate human activities on sediment and nutrients basin. The main method of rang. Taking Jiangxi River Basin in Meijiang Province as the study area, considering the basin topography, soil properties, meteorological conditions, land use and other natural features based on the model of SWAT (Soil and Water Assessment Tools) model -- distributed continuous environmental hydrology machine rational model and Simulation of non-point source pollution the transport mechanism of agriculture in subtropical monsoon region of red soil background and agricultural production management activities. Using the measured data of the hydrological parameters of water quality model was calibrated and verified, nitrogen based on ensuring the applicability of the model, and phosphorus load calculation, analysis of non-point source pollution load distribution characteristics of Meijiang basin. This paper draws the following conclusions: (1) analysis of agricultural non-point source pollutant transport rules in time series, annual load change: in 2005-2011 7 A, the nitrate nitrogen emissions. The following type of infiltration, the contribution rate of 63%, and in the high vegetation coverage rate, nitrogen, phosphorus load and rainfall have significant correlation; monthly load change: according to the simulation results of 2010-2011 years and 24 months showed that organic nitrogen, organic phosphorus and consistent trend, affected by rainfall, runoff effect the change of volatile. (2) in the analysis of agricultural non-point source pollution spatial distribution characteristics, sub basin as a unit 2011 analysis of organic nitrogen, organic phosphorus spatial distribution, nitrogen, and phosphorus leaching basin produced in water, sediment. The Huangpi River Basin in Mei River Basin in the middle and lower reaches of river developed in conjunction with the river basin and water yield, sediment yield is higher, resulting in the regional pollutant emissions is high. (3) under different land use patterns of nitrogen, phosphorus discharge gap, farmland maximum pollutant emissions, organic nitrogen, phosphorus contribution rates were 64.8 in the whole basin The analysis of% and 65.8%. simulation results showed that under the actual farming management system and fertilization measures, the non-point source pollution in the Meijiang River Basin showed obvious spatio-temporal distribution rule. Under the hydrological response unit (HRU), the contribution rate of nitrogen and phosphorus caused by agricultural production was very high under the non-point source pollution load.

【学位授予单位】：江西师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52;X71

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