| 摘要: |
| 灌丛沙堆作为一种典型的风积地貌，其形成与演化过程受到学界的普遍关注。在我国北方河套地区，灌丛沙堆广泛分布于库布齐沙漠和毛乌素沙地边缘，其发展与区域农业活动联系紧密。本文选取河套地区灌丛沙堆集中分布的红旗一社和红眼沙样点，基于近年遥感影像分析和野外调查等方法，关注灌丛沙堆发展过程与农业活动之间的关系。研究发现：研究区内灌丛沙堆的发育规模和数量变化在很大程度上受到区域农业活动的影响。2009—2020年，红旗一社和红眼沙研究点灌丛沙堆面积均呈现出明显递减趋势，分别减少了约7.38×104 m2和35.02×104 m2。研究得出当地农民的垦荒行为是区域灌丛沙堆消亡现象发生的主要原因；此外，发现农民利用灌丛沙堆进行土壤改良，此活动可在一定程度上缓解河套平原黄河灌溉区存在的土地盐渍化问题。但考虑到灌丛沙堆对于风沙危害的防治作用，建议未来需对其进行有规划的保护。 |
| 关键词: 灌丛沙堆 人地关系 遥感影像 河套地区 土地利用 |
| DOI：10.7515/JEE222020 |
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| 基金项目:国家自然科学基金项目（41901094，41930641）；中央高校基本科研业务费专项资金（GK202103148） |
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| A preliminary study on relationship between the extinction of nabkhas and agricultural activity in farming-pastoral ecotone in Hetao Region of China |
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LI Yijing, LIU Xiaokang, LU Ruijie, XIAO Fengjun
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1. School of Geography and Tourism, Shaanxi Normal University, Xi’an 710119, China
2. Engineering Center of Desertification and Blown-Sand Control of Ministry of Education, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
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| Abstract: |
| Background, aim, and scope As a typical eolian landform, nabkhas are widely distributed in the Hetao Region in the arid and semi-arid areas of China. The formation and evolution of nabkhas have received widespread attention, however, during our field investigation, we found that nabkhas in this region are utilized by humans, but only a few people have taken note of this phenomenon. Hence, this study aimed to use sites in Hongqiyishe and Hongyansha in a farming-pastoral ecotone in the Hetao Region as the main study area to explore nabkhas and the reason for their extinction, further analyze the impact of their reduction on the natural environment and the relationship between them and human utilization, and put forward some suggestions for the development of nabkhas in the Hetao Region. Materials and methods The Hongqiyishe site in Jargalangt Town, Hanggin Banner, Ordos City, Inner Mongolia Autonomous Region and the Hongyansha site in Yangqiaopan Town, Jingbian County, Yulin City, Shaanxi Province were selected as the study areas. Historical remote sensing images of the two sites from 2009 to 2020 were acquired using Google Earth. Combined with field investigation methods, the reason for the extinction of the nabkhas in the farming-pastoral ecotone in the Hetao Region was investigated. To study the effect of precipitation on the growth of the nabkhas, the precipitation variability of the study site from 2009 to 2020 was calculated. Results We found that the area of nabkhas showed a decreasing trend from 2009 to 2020, with a decreasing rate of 14400 m2·a−1 at the Hongqiyishe site and 40500 m2·a−1 at the Hongyansha site. The area of nabkhas at the Hongqiyishe site was 73800 m2 less in 2010 when compared to 2019 while the Hongyansha site was 350200 m2 less in 2009 when compared to 2020. The reason for the reduction in the nabkhas is the reclamation behavior of the local farmers and herdsmen and because, before the annual sowing season, local farmers use nabkhas to improve the soil quality to alleviate soil salinization in the Yellow River irrigation area. Discussion The ecosystem in the farming-pastoral ecotone in northern China is very sensitive to climate change and human activity, and therefore, the vulnerability of the ecosystem in the ecotone should be considered to fully guarantee national food security. The growth cycle of nabkhas is a slow and gradual process in nature, and the speed of utilization by humans is far faster than their natural decay. Hence, from a long-term perspective, and in terms of the special ecological environment in the Hetao Region, the decrease in the number of nabkhas leads to the weakening of the protective effect of the ecological environment in the oasis edge area, which will likely result in a series of problems such as accelerated desertification and even affect ecological security in the middle and lower reaches of the Yellow River. Therefore, the utilization and protection of nabkhas should be prioritized by relevant departments, local farmers, and herdsmen, and mutual transformation of the two should be fully considered in the future sustainable development, to better balance the correlation between the two in a strategic way. Conclusions The extinction of nabkhas in the farming-pastoral ecotone in the Hetao Region is closely related to agricultural activities but is not related to precipitation. Local farmers use nabkhas to improve the soil, leaving flat land for cultivation. Given the important strategic position of the farming-pastoral ecotone in economic development and the ecological environment protective role of nabkhas in sand-fixing, in the future, it will be necessary to protect nabkhas more strategically and to prioritize sustainable agricultural and animal husbandry development. Recommendations and perspectives Based on the relationship between the extinction of nabkhas and human utilization in the Hetao Region, it is suggested that the utilization of nabkhas should be more strategic in the future. Mountains, rivers, forests, croplands, lakes, grasslands, deserts and glaciers are interrelated, interactive, and complementary to the community. These eight elements should be regarded as a whole in the governance of the regional ecological environment, and each one should neither be ignored nor emphasized. Although it is necessary to expand the farmland area and improve grain output, it is also necessary to prevent and control desertification and protect the ecological environment. Only by keeping the balance between the two can the high-quality development of the Yellow River Basin be promoted. |
| Key words: nabkhas man-land relationship remote-sensing image Hetao Region land utilization |
