CN105821797A - Running water landscape water requirement amount calculating method suitable for mountain rivers - Google Patents

Abstract

The invention discloses a running water landscape water requirement amount calculating method suitable for mountain rivers and aims to reasonably evaluate landscape flow needing to be discharged by a power station so as to maintain river landscapes. The method includes the steps that main factors reflecting river landscape quality are obtained and corresponding indexes are selected; according to the selected indexes, the relation between the indexes and the river landscape quality is analyzed through an analytic hierarchy process, and a river landscape quality evaluation index system is established; values of the indexes of the evaluation system are determined hierarchically, the relation between the obtained values of the indexes and the flow change is established, relevant weight values are determined, and a river landscape quality evaluation model is established; by means of the established landscape quality evaluation model, landscape quality of control sections or control river segments under different water reducing conditions is calculated, and the reduction degree compared with that of the corresponding period under natural conditions is calculated; and control standards of landscape water requirement are designed according to the landscape sensitivity degree of the control sections or river segments, and the minimum riverway inner flow meeting the standards is calculated according to the control standards, that is to say, the landscape water requirement amount recommended in the position.

Description

A kind of running water landscape water requirement estimation method being applicable to mountain stream

Technical field

The present invention relates to the running water landscape water requirement estimation method of mountain stream, specifically, be the assessment computational methods taked of the view flow let out under water channeling type power station, mountain area Tao River needs.

Background technology

Water channeling type power station, mountain area is generated electricity by massif tunnel diversion outside river course to downstream, and therefore instream flow reduces, and causes Tao River, and in river course, water level falls, and water area reduces, and reduced velocity flow, point bar is exposed；Developing earlier in engineering, retaining and let out certain flow even without being thought of as former river course and cause river course to be dehydrated, some section is close to dry.Therefore, natural river is changed into streams state or dry riverbed state to stream mode, and river discharges is by bigger adverse effect, and this is accomplished by under the stem of power station letting out certain flow, slows down the impact of river discharges, referred to as view flow.

In recent years, the ecological functions in river are progressively realized and pay attention to, and let out certain flow and meet ecological functions under water channeling type power station is primary, commonly referred to as ecological flow.Researcher proposes definition and the computational methods of a lot of ecological flow both at home and abroad, but the computational methods of ecological flow mainly propose from the angle maintaining river ecosystem basicly stable, and the ecological flow determined therefrom that the most just meets river discharges demand.Owing to view has subjectivity and many uncertainties, lack the view water requirement estimation method of scientific system the most all the time, the most also get the brush-off.But in the water channeling type development process of current substantial amounts of mountain area; river discharges wrecks, and is badly in need of wanting one to operate effectively method, reasonable assessment calculate power station be safeguard river discharges required under the view flow let out; coordinate landscape reservation and hydroelectric development economic benefit, instruct engineering practice.

Summary of the invention

The technical problem to be solved is: propose a kind of running water landscape water requirement estimation method being applicable to mountain stream, reasonable assessment calculate power station be safeguard river discharges required under the view flow let out.

The technical solution adopted for the present invention to solve the technical problems is: a kind of running water landscape water requirement estimation method being applicable to mountain stream, comprises the following steps:

A, the research scale in river, landscape situation and function thereof are analyzed, according to section landscape function feature and Landscape Sensitivity, judge control section or the region of river discharges, extract the principal element of reflection river discharges quality, and choose corresponding index and reflect that these factors are on the impact of river discharges quality or contribution situation；

The index that B, basis are chosen, utilizes analytic hierarchy process (AHP) to analyze the relation between these indexs and river discharges quality, builds river discharges quality evaluation system；

C, index to appraisement system carry out classification value, set up the relation of itself and changes in flow rate, and determine associated weight value, thus set up river discharges Environmental Evaluation Model；

Landscape quality in the case of D, the evaluation for landscape model calculating control section utilizing foundation or control section difference diminishing, and calculate the range of decrease degree under the relatively its natural environment same period；

E, formulating view according to the view sensitivity of control section or section and need the control standard of water, depending on view sensitivity is according to the concerned degree in section, view needs water management standard to be that this section meets view requirement and should be not less than the limit value of how many ranges of decrease；Minimum meets the instream flow of this standard and is the view water requirement recommended at this.

Further, in step B, described river discharges quality evaluation system is divided into destination layer, system layer, state layer and four level of variable layer:

Wherein using hydraulic development section landscape quality as destination layer, carry out decomposing to it and obtain system layer:

System layer includes river course Study of Platycladus orientalis-Robinia pseudoacacia quality and Riparian Zone landscape quality；

System layer is decomposed again acquisition state layer:

River course Study of Platycladus orientalis-Robinia pseudoacacia quality includes: mobility, seriality and water body form；Riparian Zone landscape quality includes: bank band forms and bank band color；

State layer is decomposed again and obtains variable layer:

Mobility specific targets are mean flow rate；Seriality specific targets include water surface width and mean depth；Water body form specific targets include wetted perimeter rate, water transparency and water colour；Bank band forms specific targets include river shoal, riverbank form and river valley flexibility；Bank band color specific targets are Riparian Zone Landscape Color.

Further, in step C, when the index in assessment indicator system is carried out value, to mean flow rate, water surface width, mean depth, wetted perimeter rate and these indexs of water transparency, with reference to the grade scale preset and value table employing quantitative manner value:

$\begin{array}{cc}{b}_i=\frac{2}{x_i-x_{i-1}}(x-x_{i-1})+t_{i-1}& x_{i-1}\&le;x<x_i\end{array}---(1-1)$

In formula: b_iFor the value of quantitative indices, x_iRepresenting the real data of quantitative indices, this real data is according to measuring and elevation computation acquisition；t_i-1For x_iThe lower limit of index correspondence classification；

With reference to grade scale and index is gone to use qualitative fashion value water colour, Riparian Zone Landscape Color, river shoal, riverbank form and these indexs of river valley flexibility.

Further, in step D, the landscape quality in the case of utilizing the evaluation for landscape model set up to calculate control section or control section difference diminishing, concrete calculation is as follows:

$M_i=\underset{k=1}{\overset{K}{\&Sigma;}}{r}_k*\underset{s=1}{\overset{S}{\&Sigma;}}{r}_{ks}*\underset{t=1}{\overset{T}{\&Sigma;}}{r}_{kst}*M_{kst}---(1-2)$

$\stackrel{\&OverBar;}{M}=\underset{i=1}{\overset{n}{\&Sigma;}}\frac{M_{i-1}+M_i}{2}*\frac{l_i}{L}---(1-3)$

In formula:

M_iFor landscape quality value under i section a certain diminishing state；

For Tao River overall landscape quality value；

r_k, r_ks, r_kstBeing respectively system layer, state layer index weights corresponding with variable layer, K, S, T are the number of each layer correspondence index；

M_kstFor variable layer index value；

l_iBeing the spacing between i-th-1 and i section, Tao River is altogether chosen and N number of is represented section；

L is the length of Tao River.

Further, in step D, described landscape quality uses following formula to calculate compared with the range of decrease degree under same period its natural environment:

$P=(1-\frac{M_i-M_i^0}{M_i^1-M_i^0})*100\%---(1-4)$

Mi is landscape quality value under i section a certain diminishing state,It is respectively the landscape quality value under i section or the section its natural environment same period and when stopping.

The invention has the beneficial effects as follows: reasonable assessment calculate power station be safeguard river discharges required under the view flow let out, coordinate landscape reservation and hydroelectric development economic benefit, instruct engineering practice.

Accompanying drawing explanation

Fig. 1 is running water landscape water requirement estimation method flow diagram in the present invention.

Detailed description of the invention

As it is shown in figure 1, the running water landscape water requirement estimation method in the present invention comprises the following steps:

One, the research scale in river, landscape situation and function thereof etc. are analyzed, according to section landscape function feature and Landscape Sensitivity, judge control section or the region of river discharges, extract the principal element of reflection river discharges quality, choose suitable index and reflect that these factors are on the impact of river discharges quality or contribution situation, the index chosen is tried one's best quantification, and can set up attainable quantitative relationship with flow.

Two, according to the index chosen, utilize analytic hierarchy process (AHP) to analyze the relation between these indexs and river discharges quality, build river discharges quality evaluation system.

Three, according to research section river regime and the General Principle of view, the index of appraisement system is carried out reasonable classification value, set up the relation of itself and changes in flow rate, and determine the weight value about calculating, thus set up a more complete river discharges evaluation model.

Four, utilizing the evaluation for landscape model set up, the landscape quality in the case of calculating control section or controlling section difference diminishing is compared with the range of decrease degree under same period its natural environment.Range of decrease degree can obtain compared with the landscape quality value in the case of diminishing state two kinds according to the native state same period.

Five, evaluation for landscape method and standard are combined, view sensitivity according to control section or section is formulated view and is needed the control standard of water, depending on view sensitivity is according to the concerned degree in section, view needs water management standard to be that this section meets view requirement and should be not less than the limit value of how many ranges of decrease.Minimum meets the instream flow of this standard and is the view water requirement recommended at this.

On being embodied as, it is divided into following link:

(1) evaluation index:

Appraisement system is divided into four levels, and the first level is the final goal section view situation of hydraulic development section evaluation for landscape, is then decomposed into the sub-index that can embody this index, again decomposes by this principle, until the single item evaluation index of the bottom.It is specific of Tao River that hydraulic development section view is audience, and the river discharges that the natural cause in the range of visual experience is directly presented by various forms of combinations, it includes the various key elements of the perception such as people's vision, audition, olfactory sensation.It is attributed to river course Study of Platycladus orientalis-Robinia pseudoacacia feature and bank band Landscape Characteristics, including form, color and the harmony thereof of various components.Owing to Tao River view situation is based on river natural flow, on the basis of river seriality and mobility, each key elements such as water body and bank band are able to layout, contact and form river discharges, so in terms of river key property and form component etc. selective goal, with two system constructing hydraulic development section evaluation for landscape index systems of bank band in point river course, refer to table 1.

Table 1: hydraulic development section evaluation for landscape index system table

(2) specific targets value explanation:

All indexs of upper table are all the landscape quality quality classification values reflected according to index, classification obtaining value method includes qualitatively and quantitatively two kinds, quantitative includes flow velocity, water surface width, the depth of water, wetted perimeter rate, water transparency, includes water colour, Riparian Zone Landscape Color, river shoal, riverbank form, river valley flexibility qualitatively.Index grading standard and rank value refer to table 2.

Table 2: River Landscape quality each Index grading standard and value table

1) quantitative indices:

Flow velocity in table 2, water surface width, the depth of water, wetted perimeter rate, the real data of water transparency obtain according to mensuration and elevation computation.The data that calculating obtains, according to grade scale, carry out quantitative Analysis by formula 1-1, thus preferably quantify this index.

$\begin{array}{cc}{b}_i=\frac{2}{x_i-x_{i-1}}(x-x_{i-1})+t_{i-1}& x_{i-1}\&le;x<x_i\end{array}---(1-1)$

In formula: b_iFor quantitative indices according to the value of table 2 stage division, x_iRepresent quantitative indices data, t_i-1For x_iThe lower limit of index correspondence table 2 classification.

2) qualitative description index:

For qualitative description landscape feature index, mainly dividing it from the angle of form aesthetic, form aesthetic includes the form of landscape feature itself, color and harmony thereof.Mainly investigate in terms of river valley, Riparian Zone, river shoal three.Value is shown in Table 2.For convenience of operation, corresponding values at different levels are a fixed number, respectively 9,7,5,3,1, and intermediate value the most at different levels.

(3) landscape quality calculates:

Feature according to institute's analysis indexes and data can availability, use analytic hierarchy process (AHP) (AHP) that the weight of each index in table 1 is determined.Use integrated evaluating method, calculate with formula 1-2 according to weight and variable layer value, obtain single section, calculate with formula 1-3, obtain the landscape quality value of whole Tao River.

In formula:

M_iLandscape quality value under i section a certain diminishing state；

Tao River overall landscape quality value；

r_k, r_ks, r_kstBeing respectively system layer, state layer index weights corresponding with variable layer, K, S, T are the number of each layer correspondence index；

M_kstVariable layer index value；

l_iSpacing between i-th-1 and i section, Tao River is altogether chosen and N number of is represented section；

The length of L Tao River, i.e. section distance between lock site and factory site.

Calculate the landscape quality value letting out single control section under different flow operating mode under dam site according to formula 1-2, the landscape quality value of multiple control sections can calculate the landscape quality value of whole Tao River according to 1-3.

(4) the landscape quality range of decrease calculates:

According to the investigation of river Landscape metrics under same period native state, calculate the landscape quality value under its natural environment same period with (3) step, calculate by formula 1-4 and represent the landscape quality range of decrease (%) under section or the section relatively natural conditions same period same period.

Because Cut off is not allowed to, therefore, regarding river discharge as landscape quality when 0 is minimum, and the luffing of landscape quality value is based on this.

Mi is landscape quality value under i section a certain diminishing state,It is respectively the landscape quality value under i section or the section its natural environment same period and when stopping.The landscape quality value of whole section is obtained by multiple landscape quality value weightings representing section.

(5) sensitivity judges to control with landscape quality range of decrease standard:

Sensitivity is used to weigh public's concept to a certain scenic spot degree of attentiveness.The scenic spot that people's attention is more concentrated, its sensitivity level is the highest.The section that sensitivity is high, people are the highest to the expectation of its landscape quality, the lowest to its affected acceptable degree, otherwise, the section that sensitivity is the lowest, people are the lowest to the expectation of its landscape quality, and the acceptable landscape quality range of decrease is the biggest.For hydraulic development section, mountain area, general without open the navigation or air flight, rowing the boat, functional planning and the demand such as amusement on water, people is little with directly contacting of water body, is mainly and is experienced by vision.According to landscape function Regional survey, landscape sensitivity criterion is shown in Table 3.

Table 3: the sensitivity table of hydraulic development section, mountain area river discharges

Sensitivity is divided into three kinds of situations higher, general, relatively low by table 3, i.e. A, B, C tri-class.Minimum view for all kinds of view sections requires it is different, weighs representing the landscape quality range of decrease under section or the section relatively natural conditions same period, obtains mountain area Tao River landscape quality and controls standard, is shown in Table 4.I.e. A class view requires that representing the landscape quality range of decrease under section or the section relatively natural conditions same period is not higher than 20%；B class view requires that representing the landscape quality range of decrease under section or the section relatively natural conditions same period is not higher than 35%；C class view requires that representing the landscape quality range of decrease under section or the section relatively natural conditions same period is not higher than 45%.

Table 4: mountain area Tao River landscape quality controls standard

(6) control section or section view water requirement estimation

Selected Tao River landscape control section, can be single or multiple.Set and let out different flow rate working conditions under dam site, according to control section under (3) and (4) step calculating different flow operating mode or the landscape quality value of whole Tao River and the landscape quality range of decrease.Flow-landscape quality range of decrease relation curve can be drawn according to the corresponding data of different flow Yu the landscape quality range of decrease.

According to this curve, judge that landscape quality controls standard control with the table 4 in step (5), it is judged that meet the flow value corresponding to view minimum essential and be under the view water requirement of recommendation, i.e. dam site need the minimum view flow let out.

Claims (5)

1. the running water landscape water requirement estimation method being applicable to mountain stream, it is characterised in that comprise the following steps:

A, the research scale in river, landscape situation and function thereof are analyzed, according to section landscape function feature and Landscape Sensitivity, judge control section or the region of river discharges, extract the principal element of reflection river discharges quality, and choose corresponding index and reflect that these factors are on the impact of river discharges quality or contribution situation；

The index that B, basis are chosen, utilizes analytic hierarchy process (AHP) to analyze the relation between these indexs and river discharges quality, builds river discharges quality evaluation system；

C, index to appraisement system carry out classification value, set up the relation of itself and changes in flow rate, and determine associated weight value, thus set up river discharges Environmental Evaluation Model；

Landscape quality in the case of D, the evaluation for landscape model calculating control section utilizing foundation or control section difference diminishing, and calculate the range of decrease degree under the relatively its natural environment same period；

E, formulating view according to the view sensitivity of control section or section and need the control standard of water, depending on view sensitivity is according to the concerned degree in section, view needs water management standard to be that this section meets view requirement and should be not less than the limit value of how many ranges of decrease；Minimum meets the instream flow of this standard and is the view water requirement recommended at this.

A kind of running water landscape water requirement estimation method being applicable to mountain stream, it is characterised in that in step B, described river discharges quality evaluation system is divided into destination layer, system layer, state layer and four level of variable layer:

Wherein using hydraulic development section landscape quality as destination layer, carry out decomposing to it and obtain system layer:

System layer includes river course Study of Platycladus orientalis-Robinia pseudoacacia quality and Riparian Zone landscape quality；

System layer is decomposed again acquisition state layer:

River course Study of Platycladus orientalis-Robinia pseudoacacia quality includes: mobility, seriality and water body form；Riparian Zone landscape quality includes: bank band forms and bank band color；

State layer is decomposed again and obtains variable layer:

Mobility specific targets are mean flow rate；Seriality specific targets include water surface width and mean depth；Water body form specific targets include wetted perimeter rate, water transparency and water colour；Bank band forms specific targets include river shoal, riverbank form and river valley flexibility；Bank band color specific targets are Riparian Zone Landscape Color.

A kind of running water landscape water requirement estimation method being applicable to mountain stream, it is characterized in that, in step C, when the index in assessment indicator system is carried out value, to mean flow rate, water surface width, mean depth, wetted perimeter rate and these indexs of water transparency, with reference to the grade scale preset and value table employing quantitative manner value:

$b_i=\frac{2}{x_i-x_{i-1}}(x-x_{i-1})+t_{i-1},x_{i-1}\&le;x<x_i---(1-1)$

In formula: b_iFor the value of quantitative indices, x_iRepresenting the real data of quantitative indices, this real data is according to measuring and elevation computation acquisition；t_i-1For x_iThe lower limit of index correspondence classification；

With reference to grade scale and index is gone to use qualitative fashion value water colour, Riparian Zone Landscape Color, river shoal, riverbank form and these indexs of river valley flexibility.

A kind of running water landscape water requirement estimation method being applicable to mountain stream, it is characterized in that, in step D, the landscape quality in the case of utilizing the evaluation for landscape model set up to calculate control section or control section difference diminishing, concrete calculation is as follows:

$M_i=\underset{k=1}{\overset{K}{\&Sigma;}}{r}_k*\underset{s=1}{\overset{S}{\&Sigma;}}{r}_{ks}*\underset{t=1}{\overset{T}{\&Sigma;}}{r}_{kst}*M_{kst}---(1-2)$

$\stackrel{\&OverBar;}{M}=\underset{i=1}{\overset{n}{\&Sigma;}}\frac{M_{i-1}+M_i}{2}*\frac{l_i}{L}---(1-3)$

In formula:

M_iFor landscape quality value under i section a certain diminishing state；

For Tao River overall landscape quality value；

r_k, r_ks, r_kstBeing respectively system layer, state layer index weights corresponding with variable layer, K, S, T are the number of each layer correspondence index；

M_kstFor variable layer index value；

l_iBeing the spacing between i-th-1 and i section, Tao River is altogether chosen and N number of is represented section；

L is the length of Tao River.

A kind of running water landscape water requirement estimation method being applicable to mountain stream, it is characterised in that in step D, described landscape quality uses following formula to calculate compared with the range of decrease degree under same period its natural environment:

$P=(1-\frac{M_i-M_i^0}{M_i^1-M_i^0})*100\%---(1-4)$

Mi is landscape quality value under i section a certain diminishing state,It is respectively the landscape quality value under i section or the section its natural environment same period and when stopping.