国产热热热精品,亚洲视频久久】日韩,三级婷婷在线久久,99人妻精品视频,精品九热人人肉肉在线,AV东京热一区二区,91po在线视频观看,久久激情宗合,青青草黄色手机视频

Global EditionASIA 中文雙語Fran?ais
China
Home / China / Society

Xi'an City Wall gets health checkup after heavy rains

By Qin Feng in Xi'an and Wang Songsong | China Daily | Updated: 2025-11-07 09:14
Share
Share - WeChat

Cultural relics protection authorities in Xi'an, Shaanxi province, are implementing comprehensive measures to protect the iconic Xi'an City Wall from heavy rains linked to climate change, particularly over the past few months.

Since September, the province has experienced three prolonged rainy periods, with 87 monitoring stations recording more than 20 days of rainfall. The stations collectively recorded an average precipitation of 314 millimeters, 1.6 times higher than the normal level for this period. This marks the second-highest precipitation since 1961, trailing only 2021.

The risks posed by heavy rainfall became clear five years ago. In August 2020, a 20-meter section of the protective masonry on the southern part of the Qin Prince Palace wall in Xi'an collapsed due to heavy rainfall. It was confirmed that only the recently restored outer layer was damaged, while the original Ming Dynasty (1368-1644) rammed-earth structure remained intact.

"The primary cause of damage to the wall over the years has been water," said Gao Heng, head of the cultural heritage protection department of the Xi'an City Wall Management Committee.

According to Gao, increased moisture leads to two main types of damage: surface deterioration and structural issues. Surface deterioration primarily involves the growth of moss and lichen in the brick joints due to a more humid microclimate. While this does not threaten the wall's overall structural integrity, the growth requires manual removal.

A more significant concern is water seeping into cracks and reaching the wall's core, which is made of rammed earth. Once water infiltrates the rammed-earth structure, the soil's bearing capacity decreases, potentially leading to localized settlement or collapse.

"This, in turn, triggers localized subsidence and collapse. These cracks and depressions then channel rainwater, accelerating infiltration and creating a self-reinforcing vicious cycle that continuously threatens the structural safety of the wall," Gao said.

To address these problems, the committee has adopted a differentiated maintenance approach. Routine maintenance includes promptly sealing cracks to block water seepage pathways and addressing settlement by re-leveling surface bricks and replacing damaged ones in affected areas. Engineering measures are required when severe cracks or significant settlement appear. These involve more thorough solutions such as re-compacting loose, unconsolidated soil on the wall's summit to enhance its bearing capacity and prevent water seepage.

A key drainage project, approved by the National Cultural Heritage Administration, is being implemented around the wall's foundation to divert rainwater.

"Keeping water away from the wall's base is crucial to its long-term stability," Gao said.

The committee has also introduced a "wall chief" system, assigning individuals to oversee specific sections for routine monitoring and the early reporting of issues.

Technology plays a vital role in these efforts. Since 2018, a "digital cabin" system that integrates more than 3,000 sensors has been deployed to monitor settlement, crack displacement and other vital signs. Drones are deployed once every three months for aerial inspections. A four-color warning system — red, orange, yellow and green — assesses risks based on the severity and rate of change of any damage, allowing for targeted responses.

In 2023, a full "CT health scan" of the 13.74-kilometer-long wall was conducted using ground-penetrating radar and high-resolution surface wave technology. It revealed more than 1,300 historical cavities and 800 areas of less compact soil within the wall.

"These are not immediate dangers, but they are hidden risks we must monitor," Gao said.

Collaboration is another cornerstone of the preservation work. Gao said the local meteorological bureau provides specialized weather forecasts and early warnings, while universities such as Northwest University and a multidisciplinary committee of experts offer academic and technical support.

Top
BACK TO THE TOP
English
Copyright 1995 - . All rights reserved. The content (including but not limited to text, photo, multimedia information, etc) published in this site belongs to China Daily Information Co (CDIC). Without written authorization from CDIC, such content shall not be republished or used in any form. Note: Browsers with 1024*768 or higher resolution are suggested for this site.
License for publishing multimedia online 0108263

Registration Number: 130349
FOLLOW US
 
营山县| 湘乡市| 军事| 汾阳市| 鄂尔多斯市| 罗江县| 凤庆县| 赤壁市| 博兴县| 呼伦贝尔市| 沁源县| 宜君县| 广东省| 安阳市| 洞头县| 元朗区| 德钦县| 中牟县| 阿图什市| 镇远县| 辉县市| 读书| 建水县| 胶南市| 科技| 桓台县| 张掖市| 龙海市| 彰化县| 长葛市| 长阳| 文登市| 平安县| 微山县| 景谷| 肇庆市| 高清| 枣阳市| 佛坪县| 虹口区| 宜丰县|