CN-120298913-B - Assessment method and system for forest water composite ecological area

CN120298913BCN 120298913 BCN120298913 BCN 120298913BCN-120298913-B

Abstract

The invention relates to a method and a system for evaluating a forest water composite ecological area. The evaluation system of the forest water composite ecological area comprises the steps of obtaining image data of the forest water composite ecological area, wherein the image data comprises rainy season data and non-rainy season image data, performing ground type identification on the forest water composite ecological area based on the image data, obtaining vegetation frequency of a water body based on the non-rainy season image data, obtaining water body frequency of a forest land based on the rainy season image data, obtaining forest water composite degree of the forest water composite ecological area, and performing evaluation classification on the forest water composite ecological area based on the vegetation frequency, the water body frequency, the forest water composite degree and a threshold evaluation system of a zero model. The evaluation method of the forest water composite ecological area can accurately evaluate and classify different forest water composite ecological areas, provides scientific basis for fine management of urban ecological systems, and can optimize ecological construction and management.

Inventors

CHENG FANGYAN
XI XIAOSONG
WANG JIE
CHENG XIAOYAN
DING YISHENG
ZOU DONGHUI

Assignees

上海园林绿化建设有限公司
浙江农林大学

Dates

Publication Date: 20260512
Application Date: 20250326

Claims (10)

1. The method for evaluating the forest water composite ecological area is characterized by comprising the following steps of: Acquiring image data of a forest water composite ecological area, wherein the image data comprises rainy season data and non-rainy season image data; performing ground type identification on the forest water composite ecological area based on the image data, wherein the ground type comprises a water body and a forest land; acquiring vegetation frequency of the water body based on the non-rainy-season image data; acquiring the water body frequency of the forest land based on the rainy season image data; Acquiring the forest water compounding degree of the forest water compounding ecological area; The vegetation frequency, the water body frequency, the forest water compound degree and a zero model threshold evaluation system are used for evaluating and classifying the forest water compound ecological area, wherein the evaluation content of the zero model threshold evaluation system design comprises the following components: Threshold sensitivity evaluation: Wherein S (t) is a sensitivity coefficient of a threshold t and represents the influence degree of threshold change on a classification result, A i(t) is the area of an i-th type region under the threshold t, A i(t-Δt) is the area of the i-th type region under the threshold (t-delta t), delta t is the step length of the threshold change, and 5% or 10% of the step length is taken; threshold stability assessment: wherein ST (t) is the stability index of the threshold t, the value range is [0,1]; classification balance evaluation: Wherein B (t) is the classification balance degree of the threshold t, the value range is [0,1], A i(t) /A total is the proportion of the area of the i-th type area to the total area, A total is the total area of the evaluation area, 1/n is the area ratio of each type of area under ideal conditions, n is the total class number of classification, and n-1 is the normalization factor; Based on the above indicators, a composite score is calculated: CS(t)=w 1 ×ST(t)+w 2 ×B(t)+w 3 ×AC(t) wherein CS (t) is the comprehensive score of the threshold t, w 1 ,w 2 ,w 3 is the weight coefficient and represents the importance degree of stability, balance degree and accuracy respectively, AC (t) is the classification accuracy under the threshold t, the classification accuracy is obtained by comparing with the field investigation sampling point, and the threshold with the highest comprehensive score is selected as the optimal threshold.
2. The method for evaluating a forest water composite ecological area according to claim 1, wherein the acquiring vegetation frequency of the water body based on the non-rainy-season image data comprises: carrying out multiple effective observations on the water body to obtain non-rainy-season image data of the multiple effective observations; obtaining an enhanced vegetation index, a normalized vegetation index and a land surface moisture index based on the non-rainy season image data; Determining whether the body of water is a vegetation coverage based on the enhanced vegetation index, the normalized vegetation index, and the land surface moisture index; and judging the water body as the ratio of the number of times of the vegetation coverage area to the effective observation number of times as the vegetation frequency of the water body.
3. The method for evaluating a forest water composite ecological area according to claim 2, wherein the image data comprises Sentinel-2 l1c image data, and the obtaining the enhanced vegetation index, the normalized vegetation index, and the land surface moisture index based on the non-rainy-season image data comprises: the enhanced vegetation index is obtained based on the following formula: wherein EVI is the enhanced vegetation index, NIR is the reflectivity of near infrared band, RED is the reflectivity of RED band, BLUE is the reflectivity of BLUE band; the normalized vegetation index is obtained based on the following formula: Wherein, NDVI is the normalized vegetation index, NIR is the reflectivity of near infrared band, RED is the reflectivity of RED band; the land surface moisture index is obtained based on the following formula: Wherein LSWI is the land surface water index, NIR is the reflectivity of near infrared band, SWIR is the reflectivity of short wave infrared band.
4. The method of assessing a forest water composite ecological area of claim 3, wherein said determining whether the body of water is a vegetation coverage based on the enhanced vegetation index, the normalized vegetation index, and the land surface water index comprises: and if EVI is more than or equal to 0.1, NDVI is more than or equal to 0.2 and LSWI is more than 0, judging that the water body is the vegetation coverage area.
5. The method for evaluating a forest water composite ecological area according to claim 1, wherein the acquiring the water body frequency of the forest land based on the rainy season image data comprises: effectively observing the forest land for a plurality of times to obtain rainy season image data of the plurality of times of effective observation; Obtaining an enhanced vegetation index, a normalized vegetation index and an improved normalized difference water body index based on the rainy season image data; determining whether the woodland is a body of water based on the enhanced vegetation index, the normalized vegetation index, and the improved normalized difference body of water index; And judging the woodland as the ratio of the number of times of the water body to the effective observation number of times as the water body frequency of the woodland.
6. The method of claim 5, wherein the obtaining the enhanced vegetation index, the normalized vegetation index, and the improved normalized difference water body index based on the rainy-season image data comprises: the enhanced vegetation index is obtained based on the following formula: wherein EVI is the enhanced vegetation index, NIR is the reflectivity of near infrared band, RED is the reflectivity of RED band, BLUE is the reflectivity of BLUE band; the normalized vegetation index is obtained based on the following formula: Wherein, NDVI is the normalized vegetation index, NIR is the reflectivity of near infrared band, RED is the reflectivity of RED band; The improved normalized difference water index is obtained based on the following formula: wherein MNDWI is the improved normalized difference water index, GREEN is the reflectivity of the GREEN band, and SWIR is the reflectivity of the short wave infrared band.
7. The method of assessing a forest water composite ecological area of claim 5, wherein said determining whether the forest land is a body of water based on the enhanced vegetation index, the normalized vegetation index, and the improved normalized difference body of water index comprises: If EVI <0.1, MNDWI > EVI or MNDWI > NDVI, the woodland is judged to be a water body.
8. The method for evaluating a forest water composite ecological area according to claim 1, wherein the acquiring the forest water composite degree of the forest water composite ecological area comprises: Identifying a shared boundary of the body of water and the woodland; Acquiring the length of the shared boundary; Acquiring the total circumference of the water body; taking the ratio of the perimeter of the shared boundary to the total perimeter as the forest water compounding degree of the forest water compounding ecological area.
9. The method of assessing a forest water composite ecological area according to claim 8, wherein the threshold assessment system based on the vegetation frequency, the water body frequency, the forest water composite degree and the zero model assesses and classifies the forest water composite ecological area, comprising: A threshold evaluation system based on the zero model determines a preset threshold through threshold sensitivity evaluation, stability evaluation and classification balance evaluation; Dividing a water body which has a shared boundary with a forest land and has vegetation frequency not lower than the preset threshold value into an ecological fusion area, wherein the ecological fusion area represents an ideal forest water composite state with a complete land-water transition zone and stable vegetation coverage; Dividing a water body which has a shared boundary with a forest land and has vegetation frequency lower than the preset threshold value into a basic forest water junction area, wherein the basic forest water junction area represents a transitional state with adjacent forest water but insufficient vegetation coverage; Dividing a forest land which has no shared boundary with the forest land and has vegetation frequency not lower than the preset threshold value and a forest land with the vegetation frequency not lower than the preset threshold value into a water forest area to be restored, wherein the water forest area to be restored represents an ecological restoration potential area with a siltation foundation or poor drainage.
10. An evaluation system of a forest water composite ecological area, characterized in that the evaluation system of a forest water composite ecological area is used for executing the evaluation method of a forest water composite ecological area according to any one of claims 1 to 9, the evaluation system of a forest water composite ecological area comprising: The data acquisition equipment is used for acquiring image data of a forest water composite ecological area, wherein the image data comprises rainy season data and non-rainy season image data; The land type recognition module is used for recognizing the land type of the forest water composite ecological area based on the image data, wherein the land type comprises a water body and a forest land; The vegetation frequency acquisition module is used for acquiring vegetation frequency of the water body based on the non-rainy-season image data; the water body frequency acquisition module is used for acquiring the water body frequency of the forest land based on the rainy season image data; the forest water compound degree acquisition module is used for acquiring the forest water compound degree of the forest water compound ecological area; And the evaluation and classification module is used for evaluating and classifying the forest water composite ecological area based on the vegetation frequency, the water body frequency, the forest water composite degree and a threshold evaluation system of a zero model.

Description

Assessment method and system for forest water composite ecological area Technical Field The invention relates to the technical field of ecological assessment, in particular to a method and a system for assessing a forest water composite ecological area. Background The global wetland area has been reduced by nearly 20% over the last three centuries, and the degradation and loss of the wetland ecosystem has become a global environmental problem. The forest water composite ecological system (such as water forests and riverbank forests) is considered as an important carrier for improving the development of urban ecological space and protecting dilemma, and plays a key role in maintaining biodiversity, improving water quality, regulating microclimate, improving urban livability and the like. Different from the coastal wetland, the urban forest water composite ecological system has the unique characteristics that firstly, the flooding situation is irregular, the change rule of the urban forest water composite ecological system can be mastered by long-term monitoring, the coastal wetland is affected by tide and presents regular flooding situation, secondly, the urban forest water composite area can exist as vegetation with ground cover in a non-rainy season and is submerged for a long time in a rainy season, the seasonal change brings special requirements to an evaluation method, thirdly, the requirements of landscape systems such as urban parks and the like on the policy of improving the water landscape level are growing increasingly in recent years, and a scientific method is needed to determine the optimizing sequence and mode of the water landscape. The prior art is mostly based on static characteristic division of a single time phase, and is difficult to meet special requirements of forest water composite ecological system evaluation. How to effectively identify, evaluate and optimize the forest water composite habitat is a great challenge for urban ecological planning and management. Disclosure of Invention Based on the above, it is necessary to provide a method and a system for evaluating a forest water composite ecological area. Aiming at the specificity of the urban forest water composite ecological system, the invention establishes a set of system assessment method by comprehensively considering the vegetation frequency of the water body, the water body frequency of the forest land and the forest water composite degree, and can provide scientific basis for the fine management and the landscape optimization of the urban ecological system. In order to achieve the above object, in a first aspect, the present invention provides a method for evaluating a forest water composite ecological area, the method comprising: Acquiring image data of a forest water composite ecological area, wherein the image data comprises rainy season data and non-rainy season image data; performing ground type identification on the forest water composite ecological area based on the image data, wherein the ground type comprises a water body and a forest land; acquiring vegetation frequency of the water body based on the non-rainy-season image data; acquiring the water body frequency of the forest land based on the rainy season image data; Acquiring the forest water compounding degree of the forest water compounding ecological area; And evaluating and classifying the forest water composite ecological area based on the vegetation frequency, the water body frequency, the forest water composite degree and a threshold evaluation system of a zero model. The evaluation method of the forest water composite ecological area comprises the steps of obtaining image data of the forest water composite ecological area, carrying out ground type identification on the forest water composite ecological area based on the image data, wherein the ground type comprises a water body and a forest land, obtaining vegetation frequency of the water body, obtaining water body frequency of the forest land, obtaining forest water composite degree of the forest water composite ecological area, and carrying out evaluation classification on the forest water composite ecological area based on the vegetation frequency, the water body frequency and the forest water composite degree. The evaluation method of the forest water composite ecological area can accurately evaluate and classify different forest water composite ecological areas, provides scientific basis for fine management of urban ecological systems, and can optimize ecological construction and management. In some of these embodiments, the acquiring vegetation frequency of the body of water based on the non-rainy season image data comprises: carrying out multiple effective observations on the water body to obtain non-rainy-season image data of the multiple effective observations; obtaining an enhanced vegetation index, a normalized vegetation index and a land surface moisture index based on the non-rainy season