| 河湟谷地不同时空尺度下土地利用及空间格局对水质的影响 |
| 摘要点击 4684 全文点击 628 投稿时间：2021-10-11 修订日期：2021-12-30 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 河湟谷地 土地利用结构 空间格局 随机森林模型 水质评价 |
| 英文关键词 Hehuang Valley land use structure land cover patterns random forest model water quality evaluation |
| 作者 | 单位 | E-mail | | 李好好 | 西北农林科技大学资源与环境学院, 农业农村部西北植物营养与农业环境重点实验室, 杨凌 712100 | lhh1996@nwafu.edu.cn | | 黄懿梅 | 西北农林科技大学资源与环境学院, 农业农村部西北植物营养与农业环境重点实验室, 杨凌 712100 | ymhuang1971@nwsuaf.edu.cn | | 郭威 | 西北农林科技大学资源与环境学院, 农业农村部西北植物营养与农业环境重点实验室, 杨凌 712100 | | | 侯宏洋 | 西北农林科技大学资源与环境学院, 农业农村部西北植物营养与农业环境重点实验室, 杨凌 712100 | | | 范梦苑 | 西北农林科技大学资源与环境学院, 农业农村部西北植物营养与农业环境重点实验室, 杨凌 712100 | | | 齐熙平 | 西北农林科技大学资源与环境学院, 农业农村部西北植物营养与农业环境重点实验室, 杨凌 712100 | | | 贾鹏辉 | 西北农林科技大学资源与环境学院, 农业农村部西北植物营养与农业环境重点实验室, 杨凌 712100 | | | 郭庆波 | 西北农林科技大学资源与环境学院, 农业农村部西北植物营养与农业环境重点实验室, 杨凌 712100 | |
|
| 中文摘要 |
| 基于青海省河湟谷地湟源县、互助土族自治县和民和回族土族自治县内湟水河各级支流平水期和丰水期实测水质数据，结合遥感技术和数理统计等方法，分析土地利用结构及其空间格局对区域季节性水质的影响.结果表明：①河湟谷地地表水中总氮、总磷浓度偏高，Ⅳ和Ⅴ类水质多集中于河流下游和各支流交汇处.②河湟谷地平水期土地利用对水质的解释率高于丰水期，平水期最优尺度为200 m缓冲区，耕地和城镇为主要的影响因子；丰水期最优尺度为5 km缓冲区尺度，主要的影响因子为林地.③平水期耕地面积占比与总氮、高锰酸盐指数浓度呈正相关，而与总磷浓度呈负相关；城镇面积占比与污染物浓度基本呈正相关；丰水期草地面积占比与河流高锰酸盐指数呈正相关；林地面积占比在两个时期均与污染物浓度呈负相关.耕地、草地和城镇是污染物"源"景观，但耕地在一定程度上也起到拦截污染物的作用；林地是污染物的"汇"景观.④平水期200 m缓冲区尺度下林地空间格局对水质的解释率较高，其中LPI （最大斑块占景观面积比例）和PD （斑块密度）等指标为主要的影响因子，与污染物浓度呈负相关.研究表明，合理规划居民用地和耕地面积占比，提高河岸带周边的林地覆盖率及聚集度，是净化河湟谷地地表水水质的重要措施. |
| 英文摘要 |
| Based on the measured water quality data of Huangyuan County, Huzhu Tu Autonomous County, and Minhe Hui Tu Autonomous County in Hehuang Valley of Qinghai province in the normal and wet seasons, the effects of land use and land cover patterns on regional seasonal water quality were analyzed using remote sensing technology and mathematical statistics. The results showed that:① the concentrations of total nitrogen and total phosphorus in the surface water of Hehuang Valley were high. Water pollution areas (Class Ⅳ and Ⅴ) were mainly concentrated in the lower reaches of the river and the junction of tributaries. ② The explanation rate of land use to water quality in the normal season was higher than that in the wet season. The optimal scale was the 200 m buffer scale in the normal season, and farmland and towns were the main influencing factors. The optimal scale in the wet season was the 5 km buffer scale, and the main influencing factor was the forest. ③ In the normal season, the proportion of farmland was positively correlated with the concentration of total nitrogen and permanganate index but negatively correlated with the concentration of total phosphorus. The proportion of town area was positively correlated with the water quality index. The proportion of grassland area in the wet season was positively correlated with the permanganate index. The proportion of forestland area was negatively correlated with water quality index in both periods. Farmland, grassland, and town areas were the "source" landscape of pollutants, but farmland also played a role in intercepting pollutants to a certain extent. Forest land was the "sink" landscape of pollutants. ④ The pattern of forestland in the 200 m buffer zone in the normal season had a high explanatory rate for water quality, and the largest patch index (LPI) and patch density (PD) were the main factors. The study showed that it is an important measure to purify the surface water quality of Hehuang Valley by rationally planning the proportion of residential land and cultivated land and improving the coverage rate and aggregation degree of forestland around the riparian zone. |
|
|
|
