Data collection and arrangement of environmental geological phenomena related to groundwater

By sorting out and analyzing the results of environmental geological survey in the 60 years since the founding of New China, the content and scope of this supplementary survey are arranged to provide basic information for comprehensive evaluation of environmental geology in China.

2. 1. 1 1.2 Basic principles

Relevant survey data since (1) 1955.

(2) Mainly collect and sort out all kinds of environmental geological problems related to groundwater.

2. 1. 1.3 Contents

2. 1. 1.3. 1 karst collapse

(1) unified number of karst collapse.

(2) Karst collapse field number: field number.

(3) Latitude and longitude: degrees-minutes-seconds.

(4) Elevation: m

(5) Geographical location: province (autonomous region or municipality directly under the Central Government), city, county, township (town) and village.

(6) Name of collapse: named after the name of the collapse site.

(7) Collapse type: bedrock collapse or soil collapse, what kind of bedrock collapse, etc.

(8) Collapse time: the time when the collapse occurred.

(9) Collapse area: calculated by the surface area of the collapse pit, in square meters (m2).

(10) Total number of pits: calculated according to the number of pits that have appeared during the investigation period, in unit.

(1 1) Morphological characteristics of potholes: describe the geometric characteristics of single form and group combination of karst collapse.

① According to the plane shape, karst collapse monomer can be divided into four categories: a. Round or nearly round; B. Ellipse, the ratio of major axis to minor axis is1.5 ~ 4; C. a strip with a length of more than 4 times the width; D. irregular shape.

② According to the profile shape, karst collapse units can also be divided into four categories: a. The wall of the collapse pit extends downward with a small mouth (upper part) and a large mouth; B good shape, steep collapse wall, and the same or similar collapse pit size; C. Funnel-shaped, the collapse pits are large and small, which are funnel-shaped, and most of them occur in areas with slightly thick overburden, especially in peak-cluster depressions; D. Dish-shaped, mostly occurring in the coverage area, with small soil thickness, large area and small collapse pit depth.

(3) The group combination of karst collapse and the plane distribution of a plurality of single collapse pits have three situations: a. Island formation or sporadic distribution, and small pieces appear in groups or scattered; B, banded distribution, with certain directionality and banded distribution; C. Area distribution, even collapse distribution, no obvious directionality.

For the combination and plane distribution of multiple single collapse pits, it is necessary to describe the positional relationship between them.

(12) Maximum diameter: calculated according to the maximum diameter that can be observed, and the unit is m.

(13) Maximum depth: the maximum measurable depth in the collapse pit, in m.

(14) Maximum pit area: the maximum surface area of the collapse pit, in m2.

(15) Collapse strength of collapse pit: expressed by collapse density coefficient (average value of the total number of collapse pits per unit area within the collapse range), unit /km2, divided into:

The strongly developed collapse density coefficient is greater than100/km2;

The moderately developed collapse density coefficient is 10 ~ 100/km2;

The weakly developed collapse density is less than 10 /km2.

For the settlement point whose area is less than 1km2, the area of density coefficient shall be calculated as 1km2.

(16) Folding ratio:

(1) According to the area of karst subsidence area, it is divided into:

The total area is > > 10km2.

Medium-sized total area 1 ~ 1~ 10km2.

Small total area < < 1km2.

(2) According to the diameter of the collapse pit, it is divided into four levels:

The collapse diameter of giant collapse is more than 20m.

The collapse diameter of large-scale collapse is 10~20m ~ 20m.

The diameter of medium-sized collapse pit is 5 ~ 10m.

The diameter of small collapse pit is less than 5m.

(17) development stage: mainly refers to the active stage, development stage or stable stage.

(18) Groundwater level: refers to the buried depth of groundwater level in karst subsidence area, in m.

(19) characteristics of subsidence area: topography, landform, stratum, lithologic combination, hydrology and other characteristics.

(20) Investigation on the causes, development and changes of collapse:

Causes of collapse: it can be divided into man-made collapse and natural collapse. Collapse caused by human activities mainly includes: ① tunnel drainage or water inrush; ② pumping karst groundwater; (3) reservoir water storage or water diversion; ④ Caused by vibration or load; (5) Surface water and sewage infiltration.

Analysis of development trend: according to human activity intensity, geological and geomorphological conditions, hydrometeorology, lithologic combination characteristics, Quaternary coverage characteristics, etc. , analyze the development trend of karst collapse, whether it continues to develop or tends to be stable.

(2 1) Population casualties and economic losses.

(22) Plane location map of survey point: According to the size of karst collapse pit, the scale should be1:500 ~1:1000. The location map should be based on the unchangeable features in the subsidence area, such as railways, highways and houses.

(23) Number and description of field photos: The photos should be numbered and briefly described, mainly describing the contents, shooting time, location, photographer, photo volume number, photo number, etc.

Fill in the attached table 13.

2. 1. 1.3. 2 Ground fissure

(1) Ground fissures are numbered uniformly.

(2) Ground fissure field number: the field number of the research group.

(3) Latitude and longitude: degrees-minutes-seconds.

(4) Elevation: m

(5) Geographical location: province (autonomous region or municipality directly under the Central Government), city, county, township (town) and village.

(6) Ground fissure name: named after the place where the ground fissure occurred.

(7) Types of ground fissures: According to the causes of ground fissures, ground fissures can be divided into structural ground fissures, non-structural ground fissures and mixed ground fissures; According to the dynamic properties of ground fissures, they can be divided into compressive ground fissures, torsional ground fissures and tensile ground fissures.

(8) Fracture area: m2.

(9) Length of main crack: m

(10) main crack width: calculated at the widest part of the main crack, in m.

(1 1) Main fracture depth: calculated according to the observed depth, and the unit is m.

(12) strike, dip and dip of main fault: measured according to rock occurrence.

(13) dislocation direction and distance of the main crack: the dislocation direction is described by north, northeast and northeast, and the distance unit is m. ..

(14) Fracture deformation characteristics: mainly describe the geomorphological deformation characteristics of the area where ground fissures occur.

(15) Investigation on the causes and development of ground fissures: The causes of ground fissures can be divided into man-made causes and natural causes.

① Man-made reasons are mainly caused by over-exploitation of groundwater. Natural causes mainly refer to structural ground fissures, non-structural ground fissures and mixed ground fissures.

(2) Development trend: whether the development of ground fissures will increase or remain unchanged, whether there will be new activities, areas prone to ground fissures, etc.

(16) Schematic diagram of the plane location of ground fissures: according to the size of the fissure area, the scale is1:500 ~1:1000. The location map should be based on the unchangeable features in the crack area, such as railways, highways and houses.

(17) Description of field photo number: Pay attention to the photo number and make a brief description, mainly recording the photo content, shooting time, location, photographer, photo volume number, photo number, etc.

Fill in the attached table 14.

2. 1. 1.3. 3 Land desertification

(1) The measuring points are numbered uniformly.

(2) Field number of investigation points: the number of the research group during the investigation period can be made by itself.

(3) Latitude and longitude: degrees-minutes-seconds.

(4) Geographical location: province (autonomous region or municipality directly under the Central Government), city, county, township (town) and village.

(5) Desertification types: wind erosion desertification, sandstorm desertification, water erosion desertification, salinization, freeze-thaw and rocky desertification.

(6) Degree of desertification: severe, moderate and mild.

(7) Sand blowing wind speed: m/s

(8) Sample collection: The sample types include soil samples, rock samples, water samples and ice and snow samples, and the status, weight, structure, structure, sampling position and analysis items of various samples shall be briefly described.

(9) Changes in groundwater and animal husbandry.

(10) Wind erosion landform: Wind erosion landform mainly includes wind erosion columns, wind erosion mushrooms, wind erosion ridges and troughs (Ya Dan landform), wind erosion depressions, wind erosion castles (windy city) and wind erosion residual hills. Wind erosion landforms mainly include honeycomb dunes, fish-scale dunes, crescent dunes, dune chains and other dunes. Describe their morphological characteristics, development degree and scale.

(1 1) Desertification history:

Causes of desertification: climate, topography and human activities, in which climate is the main factor and human activities are the leading factor.

Development trend: reverse trend, control trend, obvious development trend and rapid development trend. During the investigation, we should describe the current situation at that time, determine which stage of desertification is in combination with other materials, and put forward corresponding control countermeasures.

(12) Schematic diagram of the plane position of the investigation point (1∶ 500 ~1∶1000): According to the location map of the investigated soil erosion area, it should be based on unchangeable features such as railways, highways and houses.

(13) Number and description of field photos: Pay attention to the number of photos and give a brief description, mainly recording the photo content, shooting time, location, photographer, number of photos, photo number and so on.

Fill in schedules 15 and 16.

2. 1. 1.3. 4 Land salinization

(1) The saline area is numbered uniformly.

(2) Field number of saline-alkali area: The number of the research group can be made by itself during the investigation.

(3) Latitude and longitude: degrees-minutes-seconds.

(4) Elevation: m

(5) Geographical location: province (autonomous region or municipality directly under the Central Government), city, county, township (town) and village.

(6) Saline area types: primary saline soil and secondary saline soil types.

(7) Salt source: ① Local leaching and aggregation; (2) It is brought by distant flowing water and deposited in low-lying areas; (3) In the process of groundwater rising and evaporation, salt will be brought to the surface and accumulated.

(8) Salt classification: slight salinization, moderate salinization, severe salinization and saline soil. See table 2. 1. 1 for specific indicators.

Table 2. 1. 1 salinity classification

(9) Formation conditions of saline area: mechanism of salt source, water source and salt migration to the surface; Low-lying and shallow groundwater, etc.

(10) Saline soil zoning: distribution range and area of saline soil.

(1 1) Landmark of saline-alkali land: crops are the growth of vegetation.

(12) sample collection: sample types include soil samples and water samples, and the status, weight, structure, structure, sampling position and analysis items of various samples shall be briefly described.

(13) Groundwater burial conditions: groundwater burial depth, variation of groundwater burial depth, hydraulic gradient, hydraulic properties of rock and soil, such as permeability, water content, water supply, capillary action, etc.

(14) Causes and trends of salinization;

Causes of salinization: ① natural factors, understanding meteorological, hydrological, geomorphological, geological and hydrogeological conditions. (2) Human factors, focusing on the investigation of soil secondary salinization caused by human factors, such as long-term irrigation with excessive drainage or irrigation without drainage, poor phreatic runoff, a large number of irrigation seeping into the ground, causing the groundwater level to rise, and the salt in the soil is enriched on the surface under the strong evaporation.

Salinization trend: intensification, development, slowdown, control and improvement.

(15) Schematic diagram of the plane position of the investigation point (1∶ 500 ~1∶1000): According to the location map of the investigated soil erosion area, it should be based on unchangeable features such as railways, highways and houses.

(16) Number and description of field photos: Pay attention to the number of photos and give a brief description, mainly recording the photo content, shooting time, location, photographer, number of photos, photo number and so on.

Fill in schedules 17 and 18.

2. 1. 1.3. 5 Groundwater pollution

(1) Pollution points are numbered uniformly.

(2) Site number of pollution point: The number during investigation can be made by yourself.

(3) Latitude and longitude: degrees-minutes-seconds.

(4) Elevation: m

(5) Geographical location: province (autonomous region or municipality directly under the Central Government), city, county, township (town) and village.

(6) Name of the polluted area: named after the place where the pollution occurred.

(7) Types of groundwater pollution: organic pollution, inorganic pollution and heavy metal pollution.

(8) Pollution area: square kilometers.

(9) Groundwater pollution marks: TDS, total hardness, nitrate, nitrite, ammonia nitrogen, iron, manganese, chloride, sulfate, fluoride, organic matter, heavy metal pollution, pH value, etc. , in addition to transparency, smell, color, etc.

(10) pollutant content: mg/L.

(1 1) Groundwater pollution degree: Grade I, II, III, IV and V.

(12) Groundwater pollutants:

① Organic matters, the main pollutants are ammonia nitrogen, permanganate index, COD, BOD, volatile phenol, cyanide, petroleum, organophosphorus, organic nitrogen, CCl4, CH4Cl3 and other organic matters. ② Inorganic substances: inorganic phosphorus, inorganic nitrogen and other inorganic substances. ③ Heavy metals: copper, zinc, arsenic, chromium, mercury, lead, cadmium, etc.

(13) Groundwater pollution sources: ① industrial structural pollution; ② Non-point source pollution of pesticides and fertilizers in rural areas; ③ Urban sewage pollution; ④ Sea (salty) water intrusion in coastal areas.

(14) Ways of groundwater pollution: ① Discharge of surface sewage and wastewater, which pollutes groundwater through river leakage; (2) urban septic tanks and sewage pipes leak, and rainwater from garbage dumps is leached; ③ Non-point source pollution leads to excessive nitrate content in groundwater in agricultural areas; ④ Petroleum and petrochemical products often pollute groundwater (NAPL) in the form of non-aqueous liquid. When the density of NAPL is greater than that of water, pollutants will pass through the surface soil and aquifer to reach the aquiclude, that is, they will be submerged in groundwater and spread horizontally along the aquiclude. When the density of NAPL is less than that of water, the vertical migration of pollutants is blocked on the groundwater surface and widely spreads along the vadose zone above the groundwater surface.

(15) Groundwater exposure type: well or spring.

(16) Buried depth of groundwater level: m

(17) sample collection: groundwater samples and spring water samples, briefly explaining the depth, water quantity and analysis items of groundwater samples.

(18) aquifer characteristics: aquifer thickness, lithology, depth, age, etc.

(19) pollution mechanism and trend;

Pollution mechanism: leaching, migration and infiltration characteristics of surface garbage, groundwater pollution law, and temporal and spatial distribution law of groundwater pollutants migration and diffusion.

Pollution trend: aggravation, development, slowdown, control and improvement.

(20) Schematic diagram of the plane location of the survey point (1:500 ~1:1000): The location map of the survey area should be based on unchangeable features, such as railways, highways and houses.

(2 1) Number and description of field photos: number the photos and give a brief description, mainly describing the content, shooting time, location, photographer, photo volume number, photo number, etc.

Fill in the attached table 19.

2.1.11.3.6 land subsidence

Mainly fill in the location, area, maximum settlement, causes and development trend of the land subsidence area.

Fill in Schedule 20 and Schedule 2 1.