【摘要】：人類(lèi)活動(dòng)對(duì)流域水質(zhì)的影響受到越來(lái)越多的關(guān)注.為探討人類(lèi)活動(dòng)對(duì)巖溶地表水體水-巖作用的影響,以受農(nóng)業(yè)、工業(yè)、旅游業(yè)活動(dòng)及城市發(fā)展綜合影響的漓江流域?yàn)檠芯繉?duì)象,于2016年7~11月采集河水樣,分析水化學(xué)和δ~(13)C_(DIC)數(shù)據(jù).結(jié)果表明:(1)漓江水化學(xué)類(lèi)型為HCO_3-Ca.在陰離子成分中,SO_4~2和NO_3~-僅次于HCO_3~-,并且在漓江桂林至陽(yáng)朔段,因城市及城鎮(zhèn)分布密集,旅游業(yè)發(fā)達(dá),濃度較高.(2)[Ca~(2+)+Mg~(2+)]/[HCO_3~-]當(dāng)量比值在1.01~1.51之間,[Ca~(2+)+Mg~(2+)]/[SO_4~(2-)+NO_3~-+HCO_3~-]比值在0.85~1.12之間,說(shuō)明硫酸、硝酸參與了水-巖作用.(3)碳酸溶蝕碳酸鹽巖的比例平均為75.89%.硫酸和硝酸溶蝕碳酸鹽巖的比例平均為24.11%.硝酸、硫酸溶蝕碳酸鹽巖的能力多雨期強(qiáng)于少雨期.此外,硫酸和硝酸溶蝕碳酸鹽巖的比例從上游到下游呈波動(dòng)增大趨勢(shì),最高值出現(xiàn)于靈川縣城,最低出現(xiàn)于漓江上游的華江.(4)碳酸風(fēng)化碳酸鹽巖對(duì)HCO_3~-的貢獻(xiàn)最大,平均為83.58%;其次為硫酸和硝酸風(fēng)化碳酸鹽巖,平均為14.24%;碳酸風(fēng)化硅酸鹽巖對(duì)HCO_3~-的貢獻(xiàn)最小,平均為2.18%,華江和峽背碳酸風(fēng)化硅酸鹽巖對(duì)HCO_3~-的貢獻(xiàn)較其他點(diǎn)突出,這與流域地質(zhì)背景相符合.(5)δ~(13)C_(DIC)值介于-11.95‰~-7.61‰之間;通過(guò)端元混合模型估算的δ~(13)C_(DIC-rock)介于-14.24‰~-7.23‰之間.多雨期δ~(13)C_(DIC)值與δ~(13)C_(DIC-rock)值比較接近,少雨期δ~(13)C_(DIC)值明顯重于δ~(13)C_(DIC-rock).δ~(13)C_(DIC)與δ~(13)C_(DIC-rock)之間存在一定差異,是由于受到水生植物光合作用的影響.
[Abstract]:More and more attention has been paid to the impact of human activities on water quality in river basins. In order to study the influence of human activities on the water-rock interaction of karst surface water bodies, the Lijiang River basin, which is affected by agriculture, industry, tourism activity and urban development, was studied. The water samples were collected from July to November of 2016, and the hydrochemistry and 未 ~ (13) C _ (DIC) data were analyzed. The results show that: (1) the chemical type of Lijiang River is HCO_3-Ca.. In the anionic composition, NO_3~- and NO_3~- are only inferior to HCO_3~-, and in the section of Guilin to Yangshuo of the Lijiang River, due to the dense distribution of cities and towns, the tourism industry is developed and the concentration is high. (2) the equivalent ratio of [Ca~ (2) Mg~ (2) / [HCO_3~-] is between 1.01 and 1.51, and the ratio of [Ca~ (2) Mg~ (2)] / [SO_4~ (2-) NO_3~- HCO_3~-] is between 0.85 and 1.12, indicating that the ratio of sulfuric acid, [Ca~ (2) Mg~ (2)] / [SO_4~ (2-) NO_3~- HCO_3~-] is between 0.85 and 1.12. Nitric acid is involved in water-rock interaction. (3) the ratio of carbonate rock dissolved by carbonic acid is 75.89 on average. The ratio of sulphuric acid to nitric acid dissolved carbonate rock is 24.11 on average. The ability of nitric acid and sulphuric acid to dissolve carbonate rock is stronger in rainy period than in less rain period. In addition, the ratio of sulphuric acid and nitric acid dissolved carbonate rock fluctuates and increases from upstream to downstream, with the highest value in Lingchuan county and the lowest in Huajiang River in the upper reaches of Lijiang River. (4) Carbonate weathered carbonate rocks contribute the most to HCO_3~-. The average value was 83.58; the second was weathered carbonate rock with sulphuric acid and nitric acid, with an average of 14.240.The contribution of weathered carbonate to HCO_3~- was the least, with an average of 2.18. The contribution of weathered carbonate silicate from Huajiang and isthmus to HCO_3~- was more prominent than that of other points. The values of 未 ~ (13) C _ (DIC) are between -11.95 鈥，

本文編號(hào)：2204972