CN102024200A - Technology for dynamically predicting diffusion condition of oil spilling in rivers - Google Patents

Abstract

Aiming at the oil spillage accidents which possibly occur to ships conveying oil substances in inland river water bodies such as rivers and long and narrow reservoirs and the like, the invention provides a technology for predicting the oil film diffusion process after oil spillage occurs by utilizing combination of a dynamic model and an oil spilling diffusion model on the basis of a geographic information system (GIS). The technology has the characteristics that the response speed is fast and the cost is low, and has very important realistic significance for shipping management and environmental protection of the inland river water bodies.

Description

River oil spilling diffusion performance prediction technology

Technical field

The invention belongs to the water environment management domain, relate in particular to a kind of hydrodynamic model and oil spilling model of utilizing and combine, the later diffusion process of oil spilling takes place in the river based on the GIS platform simulation.

Background technology

Oil is the blood of industry, and along with going deep into of process of industrialization, the exploitation and the use amount of oil increase gradually, and its transportation scale is also progressively enlarging.In the transportation of oil and Related product thereof, the leakage accident happens occasionally.The major oil spill accident that the annual whole world takes place more than 1000 tonnes in the ocean has 41 times, and hundred tonnes of accidents have nearly 100 times approximately, and oil spillage to be tens tons accident can't definitely add up.Betide surrounding waters, Alaska oil spill disaster in 1989, revealed the crude oil that is equivalent to one day consumption of the U.S.; The oil tanker in the English Channel in 1979 has bumped against accident leakage and has been equivalent to the oil of 6 times of Alaska leakage accidents; The oil in the tendency Persian Gulf is beyond count especially in during the Gulf War.In the oils transportation of inland river, also there is the danger of leaking.The oil spill accident that the Iguacu river of Brazil in 2000 takes place has leaked 4000 tons of product oils, the oil tanker in U.S. Delaware river in 2004 has bumped against accident leakage 1200 tons of crude oil.

Oil spilling causes the destruction of ecologic environment, and its influence is many decades.The oil that leaks out floats on the water surface usually and expands rapidly and forms oil film, and more and more thinner, the final thin layer that forms as rainbow.Oil spilling is maximum to aquatic bird and mammal harm, also can endanger fish and shellfish.Oil can destroy the outlet capacity of scolding of the insulating capacity of otter one class mammal fur and plumage, even enters in its body by food, causes the death of large quantities of animals.Inland river oil spill accident leakage rate is less, but because the inland river ecosystem more than the marine ecosystems fragility, the influence that its ecosystem is subjected to is greater than the marine oil spill accident.

Analysis to the oil spilling diffusion is basis and the foundation that oil spill accident is handled and made a strategic decision with prediction. countries such as America and Europe just predict that to marine oil overflow .Blokker has set up the model of oily diffusion and volatilization since the sixties in 20th century, Fay has studied the oil spilling diffusion model of tranquil ocean, and has founded three stages oil film expansion theory.The emergent information that provides of repairing is provided in the migration that the SpillSim of Texas, USA water development council exploitation utilizes current, wind and out of Memory prediction to have.The GNOME of NOAA exploitation has obtained widespread use in the U.S., has set up the ocean current database of U.S. surrounding sea areas, can predict oil spilling rapidly.Since the eighties, Chinese scholar has been opened fruitful work.Grandson Fu becomes and Wang Wenzhi etc. (1994) develops South Sea marine oil overflow drift DIFFUSION PREDICTION microcomputer and looks the calculation system and can utilize South Sea wind field and flow field data, calculates the offshore spilled oil CONCENTRATION DISTRIBUTION by selected marine oil overflow drift diffusion calculating pattern simulation.Zhang Cunzhi and Dou Zhenxing etc. (1997) have set up the three-dimensional numerical value model of simulation marine oil overflow behavior based on " elaioleucite " notion, and utilization Deterministic Methods simulation advection process adopts randomization method simulation turbulent diffusion process.And also lack relevant technology for the simulation of inland river oil spill accident.

This shows, the exploitation analogue technique, the Diffusion Law of oil film behind the oil spill accident takes place in the simulation boats and ships in the process of inland water transport oils, and for the protection of river water environmental and aquatic ecosystem, raising oil spill accident treatment effeciency has very important realistic meaning.

Summary of the invention

The present invention is directed to the shortage of current inland river oil spilling diffusion simulations technology, provide a kind of based on the GIS technology, tie water dynamic model and oil spilling diffusion model, the performance prediction of realization inland river water body oil spill accident improves work quality and efficient that oil spill accident has emergency processing.Compared with prior art the art of this patent has the following advantages:

(1) can predict that the dynamic diffusion of back oil film takes place inland river water body oil spill accident;

(2) institute's invention technology is easy to transplant, can be fast at the performance prediction of water bodys such as landlocked river and long and narrow reservoir realization to oil spill accident;

(3) can reduce the cost of oil spill accident emergency processing, the back takes place in the input of band non-dangerously in accident after can reducing, and reduces the oil spill accident cost more than 50%.

Description of drawings

Accompanying drawing has provided process flow diagram of the present invention.

Embodiment

Below describe principle of work of the present invention in detail:

The constructed forecasting techniques of the present invention is mainly divided two steps: (1) selects suitable hydrodynamic model to carry out the hydrodynamic simulation of survey region; (2) select suitable oil spilling model, the result of utilization hydrodynamic simulation exports to the oil spilling model after treatment with the result, carries out the oil spill accident simulation.

Here hydrodynamic model and oil spilling model are combined, utilize the hydrodynamic simulation water body to flow, its result is exported to the oil spilling model, set simulated scenario and simulate.In order to improve simulation precision and effect, GIS is introduced simulation, utilize intermediate conversion program transmission data.

(1) hydrodynamic model

The controlling party formula of hydrodynamic model comprises the continuity equation and the equation of momentum:

Continuity equation

$\frac{\∂h}{\∂t}+h(\frac{\∂u}{\∂x}+\frac{\∂v}{\∂y})+u\frac{\∂h}{\∂x}+v\frac{\∂h}{\∂y}=0---\left(1\right)$

The x-direction equation of momentum

$h\frac{\∂u}{\∂t}+\mathrm{hu}\frac{\∂u}{\∂x}+\mathrm{hv}\frac{\∂u}{\∂y}-\frac{h}{\mathrm{\ρ}}(E_{\mathrm{xx}}\frac{{\∂}^{2}u}{{\∂x}^2}+E_{\mathrm{xy}}\frac{{\∂}^{2}u}{{\∂y}^2})+\mathrm{gh}(\frac{\∂a}{\∂x}+\frac{\∂h}{\∂x})$

$+\frac{{\mathrm{gun}}^2}{{\left(C_0{h}^{1/6}\right)}^2}{(u^2+v^2)}^{1/2}-\mathrm{\ξ}{V}_a^2\cos \mathrm{\ψ}-2\mathrm{hv\ω}\sin \mathrm{\Φ}=0---\left(2\right)$

The y-direction equation of momentum

$h\frac{\∂v}{\∂t}+\mathrm{hu}\frac{\∂v}{\∂x}+\mathrm{hv}\frac{\∂v}{\∂y}-\frac{h}{\mathrm{\ρ}}(E_{\mathrm{yx}}\frac{{\∂}^{2}v}{{\∂x}^2}+E_{\mathrm{yy}}\frac{{\∂}^{2}v}{{\∂y}^2})+\mathrm{gh}(\frac{\∂a}{\∂y}+\frac{\∂h}{\∂y})$

$+\frac{{\mathrm{gvn}}^2}{{\left(C_0{h}^{1/6}\right)}^2}{(u^2+v^2)}^{1/2}-\mathrm{\ξ}{V}_a^2\sin \mathrm{\ψ}+2\mathrm{hu\ω}\sin \mathrm{\Φ}=0---\left(3\right)$

In the formula, h: the depth of water

U, v: Ka Shi coordinate x, the velocity component on the y direction

X, y: Ka Shi coordinate

T: time

ρ: fluid (water) density

E: the coefficient of eddy viscosity (turbulent current exchange coefficient)

E _Xx: at the coefficient of eddy viscosity of the vertical direction of x axial plane

E _Yy: at the coefficient of eddy viscosity of the vertical direction of y axial plane

E _Xy, E _Yx: at the coefficient of eddy viscosity of the shearing direction of Different Plane

G: acceleration of gravity

N: graceful peaceful (Manning) n value

ξ: pneumatic shear force coefficient (empirical value)

V _a: wind speed

A: bottom elevation

ψ: wind direction

ω: the angle slewing rate of the earth

Φ: local latitude

C ₀: coefficient, metric system are 1.0; English system is 1.486

Gal ruthenium gold method (Galerkin method) according to (Weighted Residuals Approach) in the residual value method of weighting is found the solution, set up finite element equation, adopt quadrilateral eight node elements, with secondary shape function (Shape function) expression speed component; Represent the depth of water with linear shape function, the above-mentioned governing equation of abbreviation is handled with newton-La Fusen (Newton-Raphson) method the nonlinear terms in space, and time integral is used complete recessive method.

(2) oil spilling simulation

Oil film is to be made of a series of unit that moves along the water surface on the water surface, and its drift mainly is subjected to the influence of current and wind, defers to formula (4):

U _slick＝α _velU+α _driftU _wind (4)

Wherein, U _SlickThe migration velocity of oil mould barycenter, U is a water velocity, U _WindBe wind speed, α _VelBe speed correction factor, α _DriftIt is the wind speed coefficient of deviation.Influence in bending river course apoplexy is less, and in the smooth river course of broadness, the influence of wind is bigger.

Mass-conservation equation is as follows:

$\frac{\mathrm{dm}}{\mathrm{dt}}={\∫}_{\mathrm{lengthofslick}}[-k_{\mathrm{dis}}W(X_o{C}_W^{\mathrm{sat}}-C_W)-k_{\mathrm{evap}}W\left(\frac{X_o{P}^o{M}_i}{\mathrm{RT}}\right)]\mathrm{dx}+r---\left(5\right)$

Wherein, m is oily mould quality, k _DisBe coefficient of dissociation, W is oily Mould Breadth degree, X _oBe molal fraction,

Be saturation concentration, C _wBe concentration of ordinary dissolution in the water, k _EvapBe evaporation coefficient, P ^oBe air pressure, M _iBe molecular mass, x is a channel length, and r is a rate of release.

Embodiment

With important shipping river course, certain great river is survey region, and this zone is oil spill accident risk district occurred frequently, and concrete parameter is as follows:

Oil spill type: light oil (gasoline);

Oil spillage: 50 tons, leak 10 minutes duration;

Wind: wind speed 1.5 meter per seconds, wind direction are north wind;

Upland water amount: 3500m ³/ s;

Downstream water depth: 2.5 meters.

Utilize GIS software to convert the data layout that can read in near the electronic chart in waters, the operation hydrodynamic model is found the solution the flow field.

Pass through computing and adjust parameter repeatedly, finally try to achieve flow field as shown in Figure 2, the flow velocity that the different colours representative is different.The gasoline leakage accident takes place in the waters near supposing, simulation light oil leaks the diffusion-condition in back 6 hours, and basic data is provided for taking emergency measures.With the diffusion of oil spilling modeling light oil with water movement, accompanying drawing 3 shows is oil spilling scatter diagram after 1 hour, 2 hours, 4 hours and 6 hours.After 1 hour, the center of oil film floats to position (106.648,29.593), is positioned at (106.658,29.592) foremost, has some greasy dirts on the riverbank of oil film process and adheres to.After 2 hours, the center of oil film floats to position (106.688,29.567), is positioned at (106.700,29.570) foremost, and the riverbank between (106.628,29.617) and (106.700,29.570) has greasy dirt and adheres to.After 4 hours, the front end of oil film floats to position (106.777,29.611), because river course bending herein is more, the greasy dirt great majority are attached to the Riparian Zone between (106.628,29.617) and (106.777,29.611).After 6 hours, the printing ink front end do not have a clustering phenomena, the front end of oil film floats to position (106.528,29.527), the greasy dirt great majority are attached to (106.535,29.400) and (106.528,29.527) between Riparian Zone or float in this regional water the trend of assembling in the opposite side of knee, the river course oriented tortuous channel of greasy dirt.

Claims (1)

1. river oil spilling DIFFUSION PREDICTION technology is characterized in that: based on the GIS platform, hydrodynamic model is combined with oil spilling diffusion simulations model, can the moving process of back fast prediction oil film take place and in the distribution range of the water surface at oil spilling.

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