A kind of algae and water contamination detection method based on multi-spectral remote sensing image
Technical field
The present invention relates to the algae and water contamination detection methods based on multi-spectral remote sensing image.
Background technique
Water resource, especially freshwater resources are for the survival of mankind basic.However, by mankind's activity or earth environment
Change, shortage degree of water resources gradually aggravates.Algae and water pollution is the main contributor for currently endangering freshwater resources.Promote water
The real time monitoring and detectability of body algae pollution can effectively improve water pollution prevention and treatment efficiency, it is existing to alleviate water resources shortage
Shape has a very important significance.
Current large area water pollution monitoring depends on remote sensing images, especially multispectral remote sensing monitoring means.Mostly light
Composing remote sensing has the advantages such as imaging area is big, revisiting period is short, data resource is numerous, with the obvious advantage in water pollution monitoring.So
And suffering from the drawback that 1. serious polluted water regions usually using multi-spectral remote sensing image progress algae and water pollution detection can judge by accident
For land, the missing inspection to water pollution region is caused;2. the pollution minimum in water body value, small of traditional chlorophyll index (NDVI)
It will result in the erroneous judgement to water pollution region.
Summary of the invention
The present invention is to solve make when water pollution large area quickly detects using multi-spectral remote sensing image in tradition
At the missing inspection of serious water pollution region, the erroneous judgement of water pollution region the problem of, and propose a kind of water based on multi-spectral remote sensing image
Body algae contamination detection method.
A kind of algae and water contamination detection method detailed process based on multi-spectral remote sensing image are as follows:
Step 1: corresponding wave band parameter in the multi-spectral remote sensing image data in input monitoring region and the data;
Step 2: corresponding wave band is respectively with fixed three in the multi-spectral remote sensing image data in screening input monitoring region
A wave band for algae and water pollution detection closest to wave band;
Step 3: calculating new water body index WI according to step 2, water area extraction is carried out based on new water body index WI;
Step 4: calculating the NDPI in waters region according to step 3;
Step 5: according to step 4 carry out algae and water pollution drawing, and according to the algae pollution early warning index of setting into
Row algae and water Polluted area extracts.
The invention has the benefit that
Present invention improves over the algae and water pollution detection abilities based on multi-spectral remote sensing image, improve algae and water dirt
The detection efficiency and detection accuracy of dye realize the new quick accurate policing algorithm to algae pollution outburst.Algorithm is mainly sharp
The serious missing inspection of water pollution region, water pollution region caused by being carried out when water pollution large area quickly detects with multi-spectral remote sensing image
The problem of erroneous judgement, promotes country to the quickly and effectively monitoring capacity of water pollution.
In order to verify the performance of method proposed by the invention, carried out for a width Landsat8 multi-spectral remote sensing image
Test, image observation region are Chaohu region of summer in 2014, which has occurred more serious algae pollution.Fig. 2
For the grayscale image of the 5th wave band of the multispectral image.It can substantially judge waters range.Fig. 3 is to obtain by this method
Waters range (white area).It can see many river complete displays, illustrate that the improved waters detection method proposed is that have
Effect.Fig. 4 is the water pollution region obtained by this method, and Polluted area and seriously polluted journey can be clearly apparent from image
Degree.
Detailed description of the invention
Fig. 1 is implementing procedure of the invention;
Fig. 2 is the Landsat8 multi-spectral remote sensing image that width Chaohu region has serious water pollution situation.
Fig. 3 is the improved water body range obtained by the present invention
Fig. 4 is water pollution index's drawing in all waters obtained by the present invention.
Specific embodiment
Specific embodiment 1: embodiment is described with reference to Fig. 1, one kind of present embodiment is based on multispectral remote sensing figure
A kind of algae and water contamination detection method of picture, it is characterised in that: algae and water pollution detection based on multi-spectral remote sensing image
Method detailed process are as follows:
Step 1: corresponding wave band parameter in the multi-spectral remote sensing image data in input monitoring region and the data;
Step 2: corresponding wave band is respectively with fixed three in the multi-spectral remote sensing image data in screening input monitoring region
A wave band for algae and water pollution detection closest to wave band;
Step 3: calculating new water body index WI according to step 2, water area extraction is carried out based on new water body index WI;
Step 4: calculating the NDPI in waters region according to step 3;
Step 5: according to step 4 carry out algae and water pollution drawing, and according to the algae pollution early warning index of setting into
Row algae and water Polluted area extracts.
Specific embodiment 2: the present embodiment is different from the first embodiment in that: it is fixed in the step 2
The central wavelength of three wave bands for algae and water pollution detection is respectively 0.56 μm (Green), and 0.66 μm (Red), 0.83 μ
Wave band corresponding in the multi-spectral remote sensing image data in input monitoring region is used for water body with fixed three respectively by m (NIR)
Algae pollution detection wave band closest to wave band be respectively set as Band1, Band2 and Band3;
NIR is near infrared spectrum.
Other steps and parameter are same as the specific embodiment one.
Specific embodiment 3: the present embodiment is different from the first and the second embodiment in that: base in the step 3
In the water area extraction for improving water body index;Detailed process is as follows:
Step 3 one has used new water body index for reducing the mistake of region caused by water pollution serious in Watershed segmentation
Sentence, new water body index WI calculation method is as follows:
Step 3 two sets threshold value m, and when WI > m, this regional determination is waters, and when WI≤m, then this region is not determined as water
Domain.
Other steps and parameter are the same as one or two specific embodiments.
Specific embodiment 4: unlike one of present embodiment and specific embodiment one to three: the threshold value m is set
It is set to 0.
Other steps and parameter are identical as one of specific embodiment one to three.
Specific embodiment 5: unlike one of present embodiment and specific embodiment one to four: the step 4
The middle NDPI that waters region is calculated according to step 3;Specific step is as follows:
The NDPI in waters region is calculated, calculation method is as follows:
NDPI is algae and water pollution index.
Other steps and parameter are identical as one of specific embodiment one to four.
Specific embodiment 6: unlike one of present embodiment and specific embodiment one to five: the step 5
It is middle that algae and water pollution drawing is carried out according to step 4, and algae and water pollution is carried out according to the algae pollution early warning index of setting
Extracted region;Detailed process are as follows:
Step 5 one carries out the drawing of algae and water pollution index according to the NDPI value in waters region;
When step 5 two, setting algae pollution early warning index n, NDPI > n, which is algae and water Polluted area;NDPI
When≤n, then the region is not algae and water Polluted area.
Other steps and parameter are identical as one of specific embodiment one to five.
Specific embodiment 7: unlike one of present embodiment and specific embodiment one to six: the algae is dirty
Dye early warning index n can be set according to different pollution levels, and n is set as 0.15 under normal conditions.
Other steps and parameter are identical as one of specific embodiment one to six.
Beneficial effects of the present invention are verified using following embodiment:
Embodiment one:
A kind of algae and water contamination detection method based on multi-spectral remote sensing image of the present embodiment is specifically according to following step
Suddenly it prepares:
In order to verify the performance of method proposed by the invention, carried out for a width Landsat8 multi-spectral remote sensing image
Test, image observation region are Chaohu region of summer in 2014, which has occurred more serious algae pollution.Fig. 2
For the grayscale image of the 5th wave band of the multispectral image.It can substantially judge waters range.Fig. 3 is to obtain by this method
Waters range (white area).It can see many river complete displays, illustrate that the improved waters detection method proposed is that have
Effect.Fig. 4 is the water pollution region obtained by this method, and Polluted area and seriously polluted journey can be clearly apparent from image
Degree.
The present invention can also have other various embodiments, without deviating from the spirit and substance of the present invention, this field
Technical staff makes various corresponding changes and modifications in accordance with the present invention, but these corresponding changes and modifications all should belong to
The protection scope of the appended claims of the present invention.