CN106033494A - Surface water information extraction method based on normalized water excavation index - Google Patents

Abstract

The invention belongs to the technical field of remote sensing information extraction, and specifically relates to a surface water information extraction method based on a normalized water excavation index. The method comprises the following steps: selecting a remote sensing characteristic index; establishing a typical ground object remote sensing characteristic curve; calculating a normalized surface water body excavation index; and extracting surface water body information. The method solves technical problems that an existing surface water body extraction method is low in automation degree and poor in working efficiency, and effectively overcomes phenomenon that water body is confused with other ground objects. The method is obviously improved in precision, and makes a new breakthrough in water body automatic extraction. The method is suitable to be used for automatic extraction of massive data surface water body.

Description

A kind of surface water information extracting method excavating index based on normalization water body

Technical field

The invention belongs to remote sensing information extractive technique field, be specifically related to a kind of based on the excavation of normalization water body The surface water information extracting method of index.

Background technology

Water resource is that the mankind depend on for existence and irreplaceable resource, and surface water is important water resource One of, it has consequence in the production, life of people.Extract surface water body information, and divide Analyse its distribution characteristics, calculate its area, the water yield, to water resources development, protect, utilization etc. has important Meaning.Along with the appearance of remote sensing, the extraction of Water-Body Information gradually to quick, efficient, in high precision, high from The direction of dynamicization degree is developed.

Method currently with Remotely sensed acquisition surface water body information mainly includes wave band threshold method, supervised classification Method, water body index method and spectrum-photometric method.

Wave band threshold method principle is simple, is the method extracting water body used the earliest, but the method is difficult to Distinguish small water-body and obscure the shade in water body, wave band threshold method it is crucial that the determination of threshold value, But choosing of threshold value just can determine that through repetition test, be a process the most loaded down with trivial details, efficiency and Automaticity is the lowest.Supervised classification be current Classification in Remote Sensing Image is applied more, algorithm is the most ripe One of sorting technique, its advantage is that classification results coincide preferable with actual atural object, but this model is more Complexity, workload is relatively big, and the purity requirement to classification model is higher, it is desirable to training region has typical case Property and representativeness, its precision also ratio is relatively low, is usually no more than 85%, and the scope of application compares limitation, only Can there iing the local use of priori.It is preferable that water body index method extracts water body effect in plains region, but It is that soil is similar to water body in the spectral signature of the two wave band with building, and shade also has with ripple The long feature increasing the reduction of reflectance entirety, thus easily cause and carry by mistake.Spectrum-photometric method can be preferably Identifying water body, Application comparison is extensive, and the model of foundation easily operates, good stability, but, the method Versatility is poor, and the different models used by survey region is variant, and for Mountainous Regions, water body Easily obscure with shade.

Summary of the invention

The technical issues that need to address of the present invention are: existing surface water body extracting method automaticity is low, Work efficiency is poor, it is difficult to overcome the problem that water body is obscured mutually with other atural objects.

Technical scheme is as described below:

A kind of surface water information extracting method excavating index based on normalization water body, comprises the following steps:

Step 1. chooses remote sensing features index；

Step 2. builds typical feature remote sensing features curve；

Step 3. calculates normalization surface water body and excavates index；

Step 4. extracts surface water body information.

Preferably: in step 1, described remote sensing features index includes: normalized differential vegetation index NDVI, the normalization difference water body index MNDWI of improvement, normalization building differential index (di) NDBI, Soil index SI, bare soil index BI and ratio vegetation index RVI, it is calculated by following formula:

$\mathrm{NDVI}=\frac{\mathrm{NIR}-\mathrm{RED}}{\mathrm{NIR}+\mathrm{RED}}---\left(1\right)$

$\mathrm{MNDWI}=\frac{\mathrm{GREEN}-\mathrm{MIR}}{\mathrm{GREEN}+\mathrm{MIR}}---\left(2\right)$

$\mathrm{NDBI}=\frac{\mathrm{MIR}-\mathrm{NIR}}{\mathrm{MIR}+\mathrm{NIR}}---\left(3\right)$

$\mathrm{SI}=\frac{\mathrm{RED}-(255-\mathrm{NIR})}{\mathrm{RED}+(255-\mathrm{NIR})}---\left(4\right)$

$\mathrm{BI}=\frac{\mathrm{SIR}+\mathrm{RED}-\mathrm{NIR}-\mathrm{GREEN}}{\mathrm{SIR}+\mathrm{RED}+\mathrm{NIR}+\mathrm{GREEN}}---\left(5\right)$

$\mathrm{RVI}=\frac{\mathrm{NIR}}{\mathrm{RED}}---\left(6\right)$

In formula:

NIR is near infrared band；

RED is red wave band；

GREEN is green wave band；

MIR is middle-infrared band；

SIR is short infrared wave band.

Preferably: in step 2, successively with RVI, SI, NDVI, NDBI, BI, MNDWI Six remote sensing features indexes are abscissa, build typical feature feature with remote sensing images gray value for vertical coordinate Exponential curve.

Preferably: in step 3, calculate normalization surface water body by following formula and excavate index NDSWDI:

$\mathrm{NDSWDI}=\frac{\mathrm{MNDWI}-\mathrm{BI}}{\mathrm{MNDWI}+\mathrm{BI}}---\left(7\right).$

Preferably: in step 4, if NDSWDI > 0, then surface water body information retrieval is carried out.

The invention have the benefit that

A kind of surface water information extracting method excavating index based on normalization water body of the present invention, by choosing Take six remote sensing features indexes, four kinds of typical features, analyse in depth each typical feature at remote sensing features curve On feature, it is proposed that normalization surface water body excavate index (NDSWDI), the method efficiently against The phenomenon that water body is obscured with other atural objects, in terms of precision, relatively additive method is significantly improved, and, The method need not manually set threshold value, has had new breakthrough in terms of automatization extracts water body.Therefore, should Method can be used for automatically extracting of mass data surface water body.

Accompanying drawing explanation

Fig. 1 is a kind of surface water information extracting method stream excavating index based on normalization water body of the present invention Cheng Tu；

Fig. 2 is typical feature characteristic index curve.

Detailed description of the invention

Below in conjunction with the accompanying drawings with embodiment to the present invention a kind of based on normalization water body excavate index earth's surface Water information extracting method is described in detail.

As it is shown in figure 1, a kind of surface water information retrieval excavating index based on normalization water body of the present invention Method, comprises the following steps:

Step 1. chooses remote sensing features index

Choose six remote sensing features indexes, i.e. can extract the normalized differential vegetation index NDVI of vegetation information Refer to the normalization difference water body of ratio vegetation index RVI, the improvement that can be good at extraction Water-Body Information Number MNDWI, can efficiently extract building information normalization building differential index (di) NDBI, with And the soil index SI and bare soil index BI of soil information can be extracted.

Employing following formula described six the remote sensing features indexes of calculating:

$\mathrm{NDVI}=\frac{\mathrm{NIR}-\mathrm{RED}}{\mathrm{NIR}+\mathrm{RED}}---\left(1\right)$

$\mathrm{MNDWI}=\frac{\mathrm{GREEN}-\mathrm{MIR}}{\mathrm{GREEN}+\mathrm{MIR}}---\left(2\right)$

$\mathrm{NDBI}=\frac{\mathrm{MIR}-\mathrm{NIR}}{\mathrm{MIR}+\mathrm{NIR}}---\left(3\right)$

$\mathrm{SI}=\frac{\mathrm{RED}-(255-\mathrm{NIR})}{\mathrm{RED}+(255-\mathrm{NIR})}---\left(4\right)$

$\mathrm{BI}=\frac{\mathrm{SIR}+\mathrm{RED}-\mathrm{NIR}-\mathrm{GREEN}}{\mathrm{SIR}+\mathrm{RED}+\mathrm{NIR}+\mathrm{GREEN}}---\left(5\right)$

$\mathrm{RVI}=\frac{\mathrm{NIR}}{\mathrm{RED}}---\left(6\right)$

In formula:

NIR represents near infrared band；

RED represents red wave band；

GREEN represents green wave band；

MIR represents middle-infrared band；

SIR represents short infrared wave band.

Step 2. builds typical feature remote sensing features curve

Successively with six remote sensing features indexes of RVI, SI, NDVI, NDBI, BI, MNDWI for horizontal seat Mark, builds the curve of typical feature characteristic index shown in Fig. 2 with remote sensing images gray value for vertical coordinate, in figure Remote sensing images carry out process makes its each characteristic index be stretched to 0-255 scope by linear transformation.This reality Execute in example, choose surface water body, man-made features, exposed soil and vegetation four quasi-representative atural object and study.

Step 3. calculates normalization surface water body and excavates index

According to the curve of typical feature characteristic index shown in Fig. 2, propose normalization surface water body and excavate index NDSWDI (Normalized Difference Surface Water Dig Index), it may be assumed that

$\mathrm{NDSWDI}=\frac{\mathrm{MNDWI}-\mathrm{BI}}{\mathrm{MNDWI}+\mathrm{BI}}---\left(7\right)$

Step 4. extracts surface water body information

In normalization surface water body excavates index, there is NDSWDI in only Water-Body Information > 0, and other Atural object does not has this rule.Therefore, NDSWDI is utilized > 0 can extract surface water body information.

Claims (5)

1. the surface water information extracting method excavating index based on normalization water body, it is characterised in that: Comprise the following steps:

Step 1. chooses remote sensing features index；

Step 2. builds typical feature remote sensing features curve；

Step 3. calculates normalization surface water body and excavates index；

Step 4. extracts surface water body information.

A kind of surface water information based on normalization water body excavation index the most according to claim 1 carries Access method, it is characterised in that: in step 1, described remote sensing features index includes: normalized differential vegetation index NDVI, the normalization difference water body index MNDWI of improvement, normalization building differential index (di) NDBI, Soil index SI, bare soil index BI and ratio vegetation index RVI, it is calculated by following formula:

$\mathrm{NDVI}=\frac{\mathrm{NIR}-\mathrm{RED}}{\mathrm{NIR}+\mathrm{RED}}---\left(1\right)$

$\mathrm{MNDWI}=\frac{\mathrm{CREEN}-\mathrm{MIR}}{\mathrm{CREEN}+\mathrm{MIR}}---\left(2\right)$

$\mathrm{NDBI}=\frac{\mathrm{MIR}-\mathrm{NIR}}{\mathrm{MIR}+\mathrm{NIR}}---\left(3\right)$

$\mathrm{SI}=\frac{\mathrm{RED}-(255-\mathrm{NIR})}{\mathrm{RED}+(255-\mathrm{NIR})}---\left(4\right)$

$\mathrm{BI}=\frac{\mathrm{SIR}+\mathrm{RED}-\mathrm{NIR}-\mathrm{GREEN}}{\mathrm{SIR}+\mathrm{RED}+\mathrm{NIR}+\mathrm{GREEN}}---\left(5\right)$

$\mathrm{RVI}=\frac{\mathrm{NIR}}{\mathrm{RED}}---\left(6\right)$

In formula:

NIR is near infrared band；

RED is red wave band；

GREEN is green wave band；

MIR is middle-infrared band；

SIR is short infrared wave band.

A kind of surface water information based on normalization water body excavation index the most according to claim 2 carries Access method, it is characterised in that: in step 2, successively with RVI, SI, NDVI, NDBI, BI, MNDWI Six remote sensing features indexes are abscissa, build typical feature feature with remote sensing images gray value for vertical coordinate Exponential curve.

A kind of surface water information based on normalization water body excavation index the most according to claim 3 carries Access method, it is characterised in that: in step 3, calculate normalization surface water body by following formula and excavate index NDSWDI:

$\mathrm{NDSWDI}=\frac{\mathrm{MNDWI}-\mathrm{BI}}{\mathrm{MNDWI}+\mathrm{BI}}---\left(7\right).$

A kind of surface water information based on normalization water body excavation index the most according to claim 4 carries Access method, it is characterised in that: in step 4, if NDSWDI > 0, then carry out surface water body information retrieval.