GB/T 50027-2024 Standard for hydrogeological investigation of water-supply
1 General provisions
1.0.1 This standard is formulated to standardize the hydrogeological investigation of water-supply, correctly reflect hydrogeological condition, reasonably evaluate, develop and protect groundwater resources, ensure the water supply security and maintain the ecological environment.
1.0.2 This standard is applicable to hydrogeological investigations using groundwater as the water supply source.
1.0.3 In addition to this standard, the hydrogeological investigation of water-supply shall also meet the requirements of the current relevant standards of China.
2 Terms and symbols
2.1 Terms
2.1.1 hydrogeological investigation of water-supply
hydrogeological investigation work conducted for the purpose of water supply.
2.1.2 hydrogeological condition
general term for the burial, distribution, recharge, runoff and discharge of groundwater, water quantity and quality, and the geological conditions for its formation
2.1.3 hydrogeological unit
groundwater system with uniform boundaries and recharge, runoff, drainage conditions
2.1.4 hydrogeological parameters
general term for indicators characterizing hydrogeological characteristics of strata, including the permeability coefficient, water release coefficient, water supply degree, precipitation infiltration coefficient, phreatic evaporation coefficient, and overflow parameters
2.1.5 groundwater regime
state of elements of groundwater, such as the water level, water quantity, water temperature, and chemical composition, over time under the comprehensive influence of various factors
2.1.6 hydrogeological exploration borehole
borehole constructed according to the requirements of hydrogeological drilling to identify the hydrogeological conditions or parameters
2.1.7 steady-flow pumping test
pumping test in which the groundwater flow field and various elements can reach a new stable state in the process of pumping
2.1.8 unsteady-flow pumping test
pumping test in which the groundwater flow field and various elements cannot reach a new stable state in the process of pumping
2.1.9 single well pumping test
pumping test in which water is pumped from only one pumping well and no observation well is configured
2.1.10 single well pumping test with observation wells
pumping test in which water is pumped from one pumping well and observation wells are configured
2.1.11 pumping test of well group
pumping test in which water is pumped from two or more pumping wells at the same time, observation wells are configured, and the water level and water quantity of each well have obvious mutual influence
2.1.12 trail-exploitation pumping test
pumping test as required under trail-exploitation conditions or a condition close to such conditions
2.1.13 separate-interval pumping test
pumping test in which pumping and observation are carried out respectively while the target aquifer of the pumping test is isolated from other aquifers
2.1.14 groundwater recharge
volume of water entering an aquifer per unit of time under natural or exploitation conditions
2.1.15 groundwater storage
volume of gravitational water residing in an aquifer
2.1.16 groundwater discharge
volume of water discharged from an aquifer per unit time under natural or exploitation conditions
2.1.17 groundwater resource evaluation
evaluation to demonstrate, under certain economic and technical exploitation conditions, exploitable reserves, under which the water level does not drop beyond the allowable range, the volume of exploitable water does not decrease, the water quality does not deteriorate, the water temperature complies with the standards, and no environmental geological problems exist, or environmental risks caused are acceptable
2.1.18 evaluation of groundwater quantity
comprehensive evaluation of the recharge, discharge, storage and exploitable reserves of groundwater sources or a certain area or aquifer, as well as the suitability of calculation methods used, reliability of hydrogeological parameters, accuracy of resource calculation results, and resource exploitation guarantee degree
2.1.19 exploitable reserves of groundwater
maximum volume of water that can be exploited from the hydrogeological unit or water intake section per unit time, through investigation or exploitation verification, during the whole exploitation period provided that the change of groundwater quality meets the utilization requirements, the groundwater level does not continue to decline, and no harmful ecological and environmental geological phenomena occur
2.1.20 allowable withdrawal of groundwater
volume of water allowed to be exploited from the hydrogeological unit or water intake section per unit time, through investigation or exploitation verification, under the current economic, technical, ecological and environmental conditions and when the requirements for groundwater resource management and control are met
2.1.21 conceptual hydrogeological model
simplified model that is convenient for mathematical and physical simulation and formed by generalizing the actual boundary type, internal structure, permeability properties, hydraulic characteristics and conditions of recharge and excretion of aquifers with language or graphics
2.1.22 numerical model of groundwater
a set of mathematical relations that are established based on the conceptual hydrogeological model, and close to the actual groundwater system structure, water flow movement characteristics and various infiltration elements
2.1.23 calibration of numerical model
calculation process used to analyze the calculation results of the numerical model of groundwater according to the known initial and boundary conditions to select reasonable parameters (i.e. parameter calibration) and correct the established numerical model
2.1.24 verification of numerical model
process during which the data different from the calculation period used for model calibration are selected for numerical simulation using the model parameters after model calibration and initial and boundary conditions and the calculated data are compared with the actual observation data to test the simulability of the numerical model to select a reasonable mathematical model
2.1.25 groundwater forecast
forecast of the changes in groundwater level and water quantity over time and space under given exploitation conditions based on the selected numerical model
2.1.26 radioactive tracer logging
method to determine some hydrogeological parameters of aquifers by tracing or dilution principle using artificial radioisotopes, such as 131I and 82Br, to mark groundwater flow in natural flow fields or borehole in artificial flow fields
2.2 Symbols
B —— the width of the calculated section, and the overflow parameter;
C —— the phreatic evaporation coefficient;
E —— the evaporation discharge of groundwater;
F —— the aquifer area and precipitation infiltration area;
h —— the pressure head height of the confined groundwater aquifer from the roof, the thickness of the phreatic aquifer in the pumping test, the water level height of the phreatic aquifer in the observation well before precipitation, and the thickness of the phreatic aquifer at the time of water level recovery;
—— the average thickness of the phreatic aquifer under natural conditions and at the pumping test;
△h2 —— the square difference between the thickness, H, of the phreatic aquifer under natural conditions, and the thickness, h, during the pumping test;
H —— the thickness of the phreatic aquifer under natural conditions;
i —— the slope at the inflection point of the curve;
I —— the hydraulic gradient of groundwater;
K —— the permeability coefficient;
L —— the length of the filter;
L0 —— the inlet length of filter at phreatic aquifer under natural conditions;
M —— the thickness of confined groundwater aquifer;
N0 —— the initial count rate of isotopes;
N b—— the radioactive background count rate;
N t—— the count rate of isotopes at time t;
P —— the precipitation;
Q —— the water output, groundwater runoff, and precipitation infiltration recharge;
r —— the radius of the pumping well filter, the distance from the observation well to the pumping well, and the inner radius of the filter;
r0 —— the probe radius;
rw —— the pumping well radius;
R —— the radius of influence;
S —— the water release coefficient of confined aquifer;
s —— the water level drop value, the residual drop value when water level recovers, the water level drop depth;
t—— the time;
V —— the volume and flow velocity of phreatic aquifer;
V f—— the infiltration velocity at the measuring point;
W(u) —— the well function;
W —— the storage and elastic storage of groundwater;
△W —— the change in groundwater storage;
α —— the precipitation infiltration coefficient, and flow field distortion correction coefficient;
β —— the irrigation leakage recharge coefficient;
ε —— the evaporation discharge of phreatic water;
ε 0—— the evaporation discharge from water surface;
μ —— the specific yield of phreatic aquifer.
Contents
1 General provisions (1)
2 Terms and symbols (1)
2.1 Terms (1)
2.2 Symbols (4)
3 Basic requirements (7)
4 Hydrogeological mapping (11)
4.1 General requirements (11)
4.2 Basic requirements (14)
4.3 Special requirements (16)
5 Geophysical exploration for hydrogeological investigation (20)
5.1 General requirements (20)
5.2 Geophysical exploration arrangement and method selection (20)
6 Drilling and pore-forming (22)
6.1 General requirements (22)
6.2 Arrangement of exploration holes (22)
6.3 Structure of exploration holes (24)
6.4 Pumping well filter (24)
6.5 Construction of exploration holes (26)
6.6 Sampling of exploration holes (27)
7 Pumping test (29)
7.1 General requirements (29)
7.2 Steady-flow pumping test (31)
7.3 Unsteady-flow pumping test (32)
8 Groundwater regime observation (34)
8.1 General requirements (34)
8.2 Water level observation (34)
8.3 Water quantity observation (36)
8.4 Water quality observation (36)
8.5 Water temperature and air temperature observation (37)
9 Calculation of hydrogeological parameters (38)
9.1 General requirements (38)
9.2 Hydraulic conductivity (39)
9.3 Specific yield and storage coefficient (44)
9.4 Infiltration coefficient of precipitation (45)
9.5 Phreatic water evaporation coefficient (46)
9.6 Radius of influence (46)
10 Groundwater resource evaluation (48)
10.1 General requirements (48)
10.2 Evaluation of groundwater quantity (51)
10.3 Evaluation of groundwater quality (60)
11 Environment evaluation and protection of ground water resources (62)
11.1 General requirements (62)
11.2 Evaluation of ambient environment (62)
11.3 Evaluation of environment forecast (63)
11.4 Protection of groundwater resources (63)
12 Data archiving and file management (65)
12.1 General requirements (65)
12.2 Data archiving (65)
12.3 File management (66)
Annex A Preparation of outline of hydrogeological investigation of water-supply (68)
Annex B Common geophysical exploration methods of hydrogeological investigation (71)
Annex C Common methods of groundwater evaluation and forecast (75)
Explanation of wording in this standard (86)
List of quoted standards (87)
Addition: Explanation of provisions (89)
供水水文地質勘察標準
1 總則
1.0.1 為規范供水水文地質勘察，正確地反映水文地質條件，合理地評價、開發和保護地下水資源，保障供水安全，維持生態環境，制定本標準。
1.0.2 本標準適用于以地下水作為供水水源的水文地質勘察。
1.0.3 供水水文地質勘察，除應符合本標準外，尚應符合國家現行有關標準的規定。
2 術語和符號
2.1 術語
2.1.1 供水水文地質勘察 hydrogeological investigation of water-supply
以供水為目的而進行的水文地質勘察工作。
2.1.2 水文地質條件 hydrogeological condition
地下水的埋藏、分布、補給、徑流和排泄，水量和水質及其形成 的地質條件等的總稱。
2.1.3 水文地質單元 hydrogeological unit
具有統一邊界和補給、徑流、排泄條件的地下水系統。
2.1.4 水文地質參數 hydrogeological parameters
表征地層水文地質特征指標的統稱，包括滲透系數、釋水系 數、給水度、降水入滲系數、潛水蒸發系數、越流參數等。
2.1.5 地下水動態 groundwater regime
在各種因素綜合影響下，地下水的水位、水量、水溫及化學成分等要素隨時間的變化狀態。
2.1.6 水文地質勘探孔 hydrogeological exploration borehole
為查明水文地質條件或參數，按水文地質鉆探要求施工的鉆孔。
2.1.7 穩定流抽水試驗 steady-flow pumping test
在抽水過程中地下水流場及各要素能夠達到一種新的穩定狀態的抽水試驗。
2.1.8 非穩定流抽水試驗 unsteady-flow pumping test
在抽水過程中地下水流場及各要素不能夠達到新的穩定狀態的抽水試驗。
2.1.9 單孔抽水試驗 single well pumping test
只在一個抽水孔中進行的不帶觀測孔的抽水試驗。
2.1.10 多孔抽水試驗 single well pumping test with observation wells
在一個抽水孔中抽水并帶觀測孔的抽水試驗。
2.1.11 群孔抽水試驗 pumping test of well group
在兩個或兩個以上的抽水孔中同時抽水并配置觀測孔，各孔的水位和水量有明顯相互影響的抽水試驗。
2.1.12 開采性抽水試驗 trail-exploitation pumping test
按開采條件或接近開采條件要求進行的抽水試驗。
2.1.13 分層抽水試驗 separate-interval pumping test
將抽水試驗的目標含水層與其他含水層隔離，分別進行抽水及觀測的抽水試驗。
2.1.14 地下水補給量 groundwater recharge
在天然或開采條件下，單位時間內進入含水層的水量。
2.1.15 地下水儲存量 groundwater storage
賦存于含水層中的重力水體積。
2.1.16 地下水排泄量 groundwater discharge
在天然或開采條件下，單位時間內從含水層中排出的水量。
2.1.17 地下水資源評價 groundwater resource evaluation
在一定的經濟技術開采條件下，論證水位下降不超過允許范圍、可開采水量不發生減少、水質不發生惡化、水溫符合標準、不產生環境地質問題或產生的環境風險是可接受條件下的可開采量。
2.1.18 地下水資源量評價 evaluation of groundwater quantity
對地下水水源地或某一地區、某個含水層的補給量、排泄量、儲存量、可開采量以及對所用計算方法的適宜性、水文地質參數的可靠性、資源計算結果精度、資源開采保證程度所做出的全面評價。
2.1.19 地下水可開采量 exploitable reserves of groundwater
經勘察或開采驗證，在整個開采期內，地下水水質變化符合利用要求，地下水水位不發生持續下降，不發生危害性的生態、環境地質現象的前提下，單位時間內從水文地質單元或取水地段中能夠開采出來的最大水量。
2.1.20 地下水允許開采量 allowable withdrawal of groundwater
經勘察或開采驗證，在當前經濟、技術、生態、環境允許條件下并滿足地下水資源管控要求時，允許單位時間內從水文地質單元或取水地段中開采出來的水量。
2.1.21 水文地質概念模型 conceptual hydrogeological model
用語言或圖示將含水層實際的邊界類型、內部結構、滲透性質、水力特征和補給、排泄等條件概化后所形成的便于進行數學與物理模擬的簡化模型。
2.1.22 地下水數值模型 numerical model of groundwater
以水文地質概念模型為基礎所建立的，能接近實際地下水系統結構、水流運動特征和各種滲透要素的一組數學關系式。
2.1.23 數值模型識別 calibration of numerical model
根據已知的初始、邊界條件，對地下水數值模型的計算結果進行分析，以達到選擇合理參數(即參數識別)，校正已建數值模型的計算過程。
2.1.24 數值模型檢驗 verification of numerical model
采用經模型識別后的模型參數和初始、邊界條件，選用不同于模型識別所用計算時段的資料進行數值模擬，將計算所得數據和實際觀測數據進行對比，檢驗數值模型的仿真性，從而選定合理數學模型的過程。
2.1.25 地下水預報 groundwater forecast
在采用選定的數值模型基礎上，在給定開采條件下，預報地下水的水位、水量在時間和空間上的變化。
2.1.26 同位素示蹤測井 radioactive tracer logging
采用人工放射性同位素131I，82Br等標記天然流場或人工流場中鉆孔內的地下水流，利用示蹤或稀釋原理測定含水層某些水文地質參數的方法。
2.2 符號
B —— 計算斷面的寬度、越流參數；
C —— 潛水蒸發系數；
E —— 地下水的蒸發量；
F —— 含水層的面積、降水入滲面積；
h —— 承壓水含水層自頂板算起的壓力水頭高度、潛水含水層在抽水試驗時的厚度、潛水含水層在降水前觀測孔中的水位高度、水位恢復時的潛水含水層的厚度；
—— 潛水含水層在自然情況下和抽水試驗時的厚度平均值；
△h2 —— 潛水含水層在自然情況下的厚度H和抽水試驗時的厚度h的平方差；
H —— 天然情況下潛水含水層的厚度；
i —— 曲線拐點處的斜率；
I —— 地下水水力坡度；
K —— 滲透系數：
L —— 過濾器的長度；
L0 —— 天然情況下潛水含水層過濾器進水長度；
M —— 承壓水含水層的厚度；
N0 —— 同位素初始計數率；
N b—— 放射性本底計數率；
N t—— 同位素t時計數率；
P —— 降水量；
Q —— 出水量、地下水徑流量、降水入滲補給量；
r —— 抽水孔過濾器的半徑、觀測孔至抽水孔的距離、過濾器內半徑；
r0 —— 探頭半徑；
rw —— 抽水孔半徑；
R —— 影響半徑；
S —— 承壓含水層釋水系數；
s —— 水位下降值、水位恢復時的剩余下降值、水位降深；
t—— 時間；
V —— 潛水含水層的體積、水流速度；
V f—— 測點的滲透速度；
W(u) —— 井函數；
W —— 地下水的儲存量、彈性儲存量；
△W —— 地下水儲存量的變化量；
α —— 降水入滲系數、流場畸變校正系數；
β —— 灌溉滲漏補給系數；
ε —— 潛水蒸發量；
ε 0—— 水面蒸發量；
μ —— 潛水含水層給水度。
