Geological disaster-prone areas refer to geological disaster-prone areas.
According to the urban geological environment conditions and the development characteristics of geological disasters, it can be divided into two categories: mountainous and hilly areas and plain land subsidence areas which are prone to sudden geological disasters.
Mountainous and hilly areas prone to sudden geological disasters;
According to the isoline method of comprehensive risk index, the prone areas are divided into 4 areas and 26 sub-areas, including high, medium, low and non-prone areas, as shown in Table 3 (list of geological disaster-prone areas in Taizhou).
High-risk area (H): the area is 752. 1 km2, accounting for 8.0% of the city's total area.
H 1 Xianju Qiushan Yixigang Anling Geological Disaster-prone Area
H2 Xianjubu Road Zhang Shang Zhangyizhuxi Geological Disaster High Risk Area
H3 Tiantai Xintianbei Highway Geological Disaster-prone Area
H4 The next big maple geological disaster prone area is in Tiantai Baigeng.
H5 Sanmen Zhu 'ao South-Gaojian Geological Disaster-prone Area
H6 Linhai Jiangnan Street —— Geological disaster prone area along the Yangtze River
H7 Toyama-Ningxi Geological Disaster-prone Area in Huangyan
Moderately prone area (M): area 196 1. 1 km2, accounting for 20.8% of the city's total area.
M 1 Xianju North Geological Disaster-prone Area
M2 Xianju Danzhu-Baitanan Geological Disaster-prone Area
M3 Xianju Zhuxi East-Linhai Youxi-Huangyan Shangyang Geological Disaster-prone Area
M4 Tiantai International Airport-Tatoukeng Geological Disaster-prone Area
Geological disaster prone area on the north pavilion side of M5 Sanmen Zhuhai-Macao.
M6 Geological Disaster-prone Area of Changyu Dong Tian Scenic Area in Wenling
M7 Luqiao Chengnan-Xiazhi Geological Disaster-prone Area
M8 Yuhuan Lupu-Truman Geological Disaster-prone Area
Haimen-Baiyun geological disaster prone area in Jiaojiang River.
Low-risk area (L): covers an area of 3,647.5 square kilometers, accounting for 38.8% of the total area of the city.
L 1 Geological disaster-prone areas in the west and north of Tiantai
L2 Yong 'an Xibei-Linhai West Geological Disaster-prone Area
L3 Southwest Yong 'an-Huangyan East Low-prone Area of Geological Disasters
L4 Sanmen-Low-prone area of geological disasters in the nearby sea area
L5 Huangyan South-Luqiao West-Wenling West-Yuhuan East Geological Disaster-prone Area
L6 South Yuhuan Geological Disaster-prone Area
Difficult Development Zone (N): covers an area of 3,050.3 square kilometers, accounting for 32.4% of the city's total area.
N 1 Xianju Yonganxi-Linhai Lingjiang Valley is not prone to geological disasters.
N2 Tiantai basin is not prone to geological disasters.
N3 Sanmen No.1 coastal port area is not prone to geological disasters.
N4 warm yellow plain is not prone to geological disasters.
Plain land subsidence area:
The plain land subsidence area is defined on the basis that the accumulated land subsidence in the plain area exceeds 100 mm, with an area of 435.05 square kilometers, accounting for 48% of the original total area of Ping Huang. The settlement centers are located in Tongyu, Mapu, Jinqing, Hengfeng, Shishan, Shu Lian and Dongpu of Luqiao.
(2) Geological hazard zoning and key prevention and control areas.
On the basis of the division of physical geography and administrative units in our city, "people-oriented", according to the regional geological environment conditions, combined with the population density of counties (cities, districts), socio-economic development, the distribution and development of geological disasters and the relative integrity of administrative divisions, our city is divided into:
A: Landslide, collapse and debris flow prevention and control areas in western mountainous areas.
B: Coastal hills and island landslide prevention and control areas.
C: Huangwen Plain Land Subsidence Geological Disaster Prevention Area.
According to the development characteristics of geological disasters in the counties (cities, districts) in the prevention and control area, it is further divided into 14 key prevention and control sub-areas.
A: Landslide, collapse and debris flow prevention and control areas in western mountainous areas.
This area is located in the west and southwest of our city, including Xianju County, Tiantai County, the west of Linhai City and the west of huangyan district, with an area of about 5086.2 square kilometers and a population density of about 297 people per square kilometer. The area is dominated by low mountains and hills, with fragile geological environment, and the climate is in the rainstorm area in the west of Taizhou, with high precipitation intensity. The economy in this area is underdeveloped and the traffic is relatively backward. People in mountainous areas are eager to get rid of poverty and become rich, and get through the traffic channels with surrounding areas as soon as possible to develop and utilize mountain resources. Most of the "Tenth Five-Year Plan" 100 major projects in our city will be implemented in this area, such as: Taiga Expressway, Taizhou section of coastal railway trunk line, 104 national highway double track, An Xia Reservoir, Yuxi Reservoir, Zhuxi Reservoir, Huanglong Reservoir, Wu Tong, Tongbai, Jiulong Pumped Storage Power Station, West-East Gas Transmission Project, etc. And human engineering activities are intensive.
Sudden landslides, collapses and mudslides are the main disasters in this area, among which soil landslides are the most serious, followed by collapses. With the gradual implementation of ecological engineering, the forest coverage rate is increasing, and the probability and hidden dangers of debris flow are decreasing year by year.
At present, there are 233 geological disasters (hidden dangers) of landslides, collapses and mudslides in this area, accounting for 66.6% of the disasters (hidden dangers) in the city, and the area density coefficient is 4.6/100 square kilometers. There are 27 geological disasters (hidden dangers) that are potentially dangerous and seriously threaten the safety of people's lives and property, which are the hardest hit areas of geological disasters in our city. According to the distribution characteristics, development degree and harm (potential threat) degree of geological disasters (hidden dangers), combined with urban and social and economic development planning, six key prevention and control sub-regions are divided.
A 1: Xianju anling, Xigang and Qiushan key prevention and control sub-districts, with an area of 165.2 square kilometers and 3 1 existing geological hazards (hidden dangers).
A2: Xianju Zhuxi, Bulu and Zhang Shang key prevention and control sub-districts, covering an area of 237.8 square kilometers, with 29 existing geological disasters (hidden dangers).
A3: Tiantai Xintianbei Highway-National Treasury Saiji Key Prevention and Control Division, with an area of 35.6 square kilometers and geological hazards (hidden dangers) 17.
A4: Tiantai Baigengxia-Longxi-Liangkeng key prevention and control sub-zone, covering an area of 27.3 square kilometers, with 6 existing geological disasters (hidden dangers).
A5: Coastal-riverside key prevention and control sub-zone of Jiangnan Street, with an area of107.2km2, and existing geological hazards (hidden dangers) 1 1.
A6: Huangyan Fushan-Ningxi Key Prevention and Control Zone, covering an area of 144.2 square kilometers, with 3 existing geological disasters (hidden dangers).
With the development of economic construction in this area, various large-scale human engineering activities have intensified, which has changed the eco-geological environment, and the possibility of man-made geological disasters and the risk of engineering construction suffering from geological disasters will increase. Therefore, it is particularly important to eliminate the hidden dangers of geological disasters in this area and prevent them.
The focus of prevention and control of geological disasters in this area is:
Recently, the county (city, district) geological disaster investigation division and geological disaster prevention planning have been fully completed; By the end of 2005, the map of the distribution and prone areas of geological disasters in townships (towns) will be completed, and the network for prevention and control of geological disasters and group monitoring and prevention will be established; Strengthen the prevention and management of geological disasters and the propaganda of disaster prevention and reduction; Investigate and manage important geological disasters (hidden dangers) and dangerous areas (road sections) that endanger people's lives and property safety, and implement the relocation and avoidance project for residents in dangerous geological disaster areas as soon as possible; Geological hazard risk assessment must be carried out for engineering construction projects in this area; Establish demonstration townships (towns) for geological disaster relocation and avoidance projects in Zhuxi Town and Bulu Township of Xianju County.
In the long run, in addition to continuing to strengthen the prevention and control of geological disasters, we will also improve the management system for prevention and control of geological disasters, the network for prevention and control by groups and the monitoring and forecasting system combining groups and specialties, conduct special investigations and assessments on important transportation, water conservancy and tourism projects and geological parks with geological disasters (hidden dangers), and strengthen the construction of geological disaster supervision system. Strengthen the enforcement of laws and regulations on geological disasters, rationally develop and protect the ecological geological environment, and control various man-made geological disasters.
B: Coastal hills and island landslide prevention and control areas.
This area is mainly located in the east of our city, including Sanmen County, Linhai City (low hilly plain area in the east), huangyan district City (low hilly plain area in the east), Wenling City (part of it) and Yuhuan County. , with an area of about 3242.4 square kilometers and a population density of about 747 people/square kilometer. The area is characterized by hills and islands, and the topography is relatively small. It is an area severely affected by typhoon and rainstorm in the climate of our city, and has suffered from storm surge disasters many times in history. In recent years, the economy in this area has developed rapidly and the urbanization process is relatively fast. The basic projects that have been built, under construction and planned mainly include: Shangsan Line, Jintai Line, Yongtaiwen Double Line and other expressways, urban coastal expressway (Linhai-Sanmen), Yongtaiwen Bridge-road and bridge connecting line, Jintai Railway, Yongtaiwen section of coastal railway, sanmen nuclear power plant, Huaneng Yuhuan Power Plant, Sanmen Thermal Power Plant and other important infrastructure.
The geological disasters of hills and islands in this area are mainly rock collapse and soil landslide, followed by landslides in soft soil around the island, harbors, seawalls and beaches. At present, there are a total of geological disasters (hidden dangers) 108 in this area, accounting for 30.8% of the disasters (hidden dangers) in the city. The area density coefficient is 3.3/100 square kilometers. According to the present situation and harm degree of geological disasters in this prevention and control area, combined with the urban and social and economic development planning, it is divided into:
B 1: Sanmen Pavilion-Gaojian-Haiyang Key Prevention and Control Zone, covering an area of 56.6 square kilometers, with existing geological hazards (hidden dangers) 1 1.
B2: Haimen-Baiyun key prevention and control division of Jiaojiang River, covering an area of 22.0 square kilometers, with 3 existing geological disasters (hidden dangers).
B3: The key prevention and control division of Dongting Scenic Spot in Wenling Dongyu, covering an area of 3 1. 1 km2, with 3 existing geological disasters (hidden dangers).
B4: Yumen-Lupu key prevention and control division of Yuhuan, covering an area of 75.9 square kilometers, with existing geological hazards (hidden dangers) 1 1.
The focus of prevention and control of geological disasters in this area is:
Recently, the county (city, district) geological disaster investigation division and geological disaster prevention planning have all been completed, and the geological disaster group monitoring and prevention network has been established; Special investigation, treatment or relocation of important geological disasters (hidden dangers) that endanger people's lives and property safety; Standardize mining, especially quarry mining, to eliminate hidden dangers of mine collapse; Implement the risk assessment system of geological disasters; Strengthen engineering geological investigation for seawalls, docks, coastal highways and other projects to prevent soft soil landslides; Establish a demonstration section of Kan Ze highway geological environment treatment project.
In the long term, in addition to continuing to strengthen the prevention and control of geological disasters, we will also improve the management system for prevention and control of geological disasters, establish a standardized and orderly mining system, build a 1-2 mine standardized mining demonstration site, completely eliminate hidden dangers in mines, implement the project of returning farmland to green, build a "green Taizhou" and build beautiful coastal mountains and rivers.
C: the land subsidence area of Huangwen Plain.
This area is located in the south-central part of our city, including Wenling City, huangyan district, luqiao district and Jiaojiang Plain, with an area of about 1082.4 square kilometers. This area is densely populated, economically developed and highly urbanized, with a population density of 65,438+0,603 people /km2. This area is flat and densely covered with rivers, with an altitude of 2-4 meters.
Due to long-term over-exploitation of deep confined water, regional land subsidence has been formed in the surrounding area of Tongyu-Mapu in luqiao district and in Zeguo, Wenling, such as Melia azedarach, Shiqian, Muyu and Hengfeng. The maximum accumulated land subsidence has reached more than 600- 1000mm, and the average subsidence rate of the subsidence center is expected to be 30mm/ year. According to the cumulative settlement, the prevention and control zones are divided into:
C 1: the key prevention and control zone of land subsidence in Tongyu-Mapu of Luqiao, with an area of 3 1.5 square kilometers.
C2: Luqiao Jinqing Land Subsidence Prevention Sub-area, with an area of13.8km2. ..
C3: Shu Lian, Shiqian, Muyu and Hengfeng key prevention and control zones of land subsidence in Wenling City, with an area of 34.5438+0 km2.
C4: key prevention and control sub-district of land subsidence in Dongpu, Wenling, with an area of 13.4 square kilometers.
The focus of prevention and control of geological disasters in this area is:
Recently, the government has strengthened the management of the development and utilization of groundwater resources, strictly controlled the exploitation of groundwater, further strengthened the monitoring of groundwater dynamics and land subsidence, set several groups of layered subsidence monitoring targets, and established a dynamic monitoring network of land subsidence by using the global positioning GPS monitoring network system. At the same time, carry out environmental geological disaster investigation focusing on land subsidence; Strictly implement the examination and approval system for groundwater exploitation and control groundwater exploitation; Using surface water diversion project to solve the problem of groundwater replacing water source; Establish a demonstration area for monitoring geological disasters of land subsidence in Hengfeng-Shishan, Wenling City.
In the long run, strictly control the development and utilization of groundwater, so that the amount of groundwater exploitation is determined within a reasonable range. All groundwater exploitation wells will be closed in the first and second water supply pipe network areas of Taizhou; Using the water supply source of Taizhou Phase II, we will strengthen the improvement of surface environment and the protection of surface water sources, continue to develop and improve the construction of land subsidence monitoring network, and carry out research on the mechanism and prevention of land subsidence, so as to provide a basis for regional land subsidence disaster management and land improvement in the affected areas.