發(fā)布時(shí)間：2017-12-31 05:28

  本文關(guān)鍵詞：模擬土地利用變化對(duì)地下水硝酸鹽面源污染影響的研究　出處：《西南交通大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 土地利用 農(nóng)業(yè)面源污染 硝酸鹽 輸出系數(shù) ArcGIS 地下水模擬

【摘要】：近年來(lái)農(nóng)業(yè)生產(chǎn)過(guò)程中,過(guò)量的肥料向下滲透污染地下水,地下水中硝酸鹽濃度日益增加。特別是我國(guó)一些平原地區(qū),農(nóng)業(yè)生產(chǎn)發(fā)達(dá)、地勢(shì)平坦、地表徑流量小、降雨入滲量高并且地下水埋深淺等特點(diǎn),導(dǎo)致地下水中硝酸鹽含量超標(biāo)現(xiàn)象尤為突出。本文以地下水開(kāi)發(fā)利用時(shí)間早,程度高,具有較完整的水文地質(zhì)參數(shù)資料的德陽(yáng)市旌陽(yáng)區(qū)作為研究區(qū),基于ArcMap軟件平臺(tái)分析歷年土地利用數(shù)據(jù)并以此開(kāi)展硝酸鹽污染負(fù)荷時(shí)空估計(jì),建立和校正地下水污染遷移模型,預(yù)測(cè)不同土地利用變化情景及其對(duì)地下水硝酸鹽的影響程度,從而揭示土地利用變化在農(nóng)業(yè)面源污染控制方面的功效。研究結(jié)果表明:(1)2000年至2016年整個(gè)研究區(qū)硝酸鹽負(fù)荷逐年上升并出現(xiàn)明顯的區(qū)域特征,污染由城區(qū)向北演化。德新鎮(zhèn)地下水硝酸鹽因地下水流向向黃許鎮(zhèn)區(qū)域遷移,導(dǎo)致黃許鎮(zhèn)2010年至2016年污染羽面積增長(zhǎng)10倍以上。在城區(qū)附近,農(nóng)業(yè)污染負(fù)荷低于230 kg/km2,且由于綿遠(yuǎn)河和石婷江附近地下水補(bǔ)給排泄途徑較短,因此有利于地下水中硝酸鹽污染遷移稀釋,使得城區(qū)及城區(qū)以南的硝酸鹽污染逐漸降低。(2)研究區(qū)硝酸鹽負(fù)荷受季節(jié)影響較大,7、8月的大量降雨一方面加快了硝酸鹽下滲,另一方面會(huì)稀釋地下水中硝酸鹽含量;9、10月月平均降雨量和月平均硝酸鹽負(fù)荷都較高,從而進(jìn)入地下水含水層的硝酸鹽含量增加;12、1月,月平均降雨量和月平均硝酸鹽負(fù)荷較低,進(jìn)入地下水含水層的硝酸鹽含量顯著減少;2月施肥負(fù)荷量大,但降雨量低,因此淋溶進(jìn)入含水層的硝酸鹽量有限。(3)通過(guò)對(duì)研究區(qū)土地利用變化的綜合分析預(yù)測(cè),單純地增長(zhǎng)耕地面積會(huì)使污染面積進(jìn)一步擴(kuò)大,局部地下水硝酸鹽濃度將超過(guò)20 mg/L。若全區(qū)推廣測(cè)土配方施肥,肥料利用率的提高可以減少農(nóng)業(yè)面源污染負(fù)荷,使污染面積顯著減少。但總體上來(lái)說(shuō),部分區(qū)域地下水硝酸鹽的污染較2016年嚴(yán)重,污染羽面積擴(kuò)大9.33%。本研究揭示出土地利用變化對(duì)地下水硝酸鹽面源污染影響伴有很強(qiáng)的時(shí)空特征,地下水?dāng)?shù)值模擬結(jié)合ArcGIS空間分析較好地解決了面源污染復(fù)雜性和隨機(jī)性的難題,為控制地下水農(nóng)業(yè)面源污染提供了理論依據(jù)。
[Abstract]:In recent years, in the process of agricultural production, excessive fertilizer downward infiltration of contaminated groundwater, increasing nitrate concentration in groundwater. Especially some plain areas in China, agricultural production developed, flat terrain, surface runoff, rainfall infiltration volume and high depth of groundwater, resulting in nitrate content in groundwater is exceed the standard phenomenon prominent. In this paper the groundwater exploitation time early, with a high degree of hydrogeological parameters more complete information Jingyang District of Deyang city as the study area, analysis of ArcMap software platform in land-use data and to carry out the nitrate pollution load estimation based on time and space, the establishment and correction of groundwater pollution migration model, different land use change and forecast effect of nitrate in groundwater level, so as to reveal the effect of land use change in agricultural non-point source pollution control results. Show that: (1) from 2000 to 2016 in the study area of nitrate load increased year by year and the emergence of obvious regional characteristics, pollution from urban evolution. North De Xin Zhen groundwater nitrate because of underground water to Huang Xu Zhen Huang Xu Zhen lead to regional migration, from 2010 to 2016 plume area increased more than 10 times. In the vicinity of the city. Agricultural pollution load is lower than 230 kg/km2, and the Mianyuan River and stone Tingjiang near the groundwater replenishment and drainage way is short, it is beneficial to the migration of dilution of groundwater nitrate pollution, makes the city and the city to the south of nitrate pollution gradually reduced. (2) the study area of nitrate load affected by season, heavy rainfall 7,8 month on the one hand to speed up the nitrate infiltration, on the other hand will dilute the nitrate content in groundwater; 9,10 month average rainfall and monthly average nitrate load is higher, thus entering groundwater nitrate Increased acid salt content; 12,1 months, average monthly rainfall and monthly average nitrate load is low, the content of nitrate into groundwater aquifer was significantly reduced; fertilization in February load, but the low rainfall, so the leaching of nitrate into the amount of aquifer is limited. (3) based on the research of comprehensive analysis to predict the changes of the land the study area, simply increase cultivated area will further expand the area of pollution, local groundwater nitrate concentration will be more than 20 mg/L. if the promotion of soil testing and fertilizer, increase the utilization ratio of fertilizer can reduce agricultural non-point source pollution, the pollution area was significantly reduced. But on the whole, part of the regional groundwater nitrate pollution compared with 2016, serious pollution plume, expand the area of 9.33%. in this study reveal spatial and temporal characteristics of land use change on groundwater nitrate pollution effects associated with strong groundwater, numerical simulation with Arc The GIS spatial analysis solves the problem of the complexity and randomness of non-point source pollution, and provides a theoretical basis for controlling the pollution of groundwater agricultural non-point source.

【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：X523

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相關(guān)期刊論文 前1條

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本文編號(hào)：1358372