Machine Learning models are based on mathematical algorithms that are used to process and analyse the data. Some of the mathematical concepts that are commonly used in the analysis of greenness change include:
Linear and non-linear regression: This is used to model the relationship between vegetation cover and various predictor variables such as temperature, precipitation, and land use.
Time series analysis: This is used to analyse time-series data of vegetation cover over time to identify patterns and trends, which can be used to make predictions about future greenness changes.
Artificial Neural Networks (ANN): This technique is based on the mathematical concept of a neural network, which is a type of function approximator that can be used to model complex non-linear relationships between inputs and outputs.
Image processing: This is the field of mathematics and computer science that deals with image processing and computer vision. Techniques such as Image classification, Object-based image analysis, etc. are used to extract information from satellite imagery.
Indices calculation: Indices such as NDVI (Normalized Difference Vegetation Index) are used to assess the greenness of the vegetation, these indices are calculated using mathematical formulas.
In addition, when using machine learning techniques, it's important to have a good understanding of the mathematical concepts that underlie the algorithms that are used, such as gradient descent, backpropagation, and overfitting, etc. This is particularly important when it comes to fine-tuning models and optimizing their performance.
In conclusion, there is a significant amount of mathematics involved in analysing greenness change in Dehradun using machine learning, from the mathematical concepts underlying the machine learning algorithms, to the mathematical concepts used in image processing and indices calculation. A good understanding of these mathematical concepts is important for effectively analysing greenness change and making accurate predictions about future greenness changes.
True and False colour composites are generated from multispectral remote sensing images, and the mathematics involved in generating these composites is primarily related to image processing and colour space transformations.
True colour composite is a composite image that is created by displaying the red, green, and blue bands of an image as red, green, and blue in the output image, respectively. This composite is used to simulate the natural colour of the scene being imaged, as it would appear to the human eye.
False colour composite is a composite image that is created by displaying the red, green, and blue bands of an image as different spectral bands in the output image, such as near-infrared, red, and green. This composite is used to enhance certain features of the scene, such as vegetation, water bodies, and urban areas.
To create a true colour composite, the image data from the red, green, and blue bands of the image are typically scaled and then combined into a single image using a process known as "image mosaicking." The process of mosaicking involves aligning the images and then combining them into a single image.
To create a false colour composite, the data from the different spectral bands of the image are typically transformed into a different colour space, such as the RGB colour space, using a process called "colour space transformation." This transformation is usually done using mathematical functions, such as linear or non-linear equations, that map the data from the original colour space to the desired colour space.
In conclusion, the mathematics involved in creating true and false colour composites primarily involves image processing techniques such as image mosaicking and colour space transformations, which are mathematical operations used to combine and transform the data from different spectral bands of an image into a single image that can be easily interpreted by humans.
True colour composite:
The true colour composite is generated by combining the red, green, and blue bands of an image into a single image. The equation for creating a true colour composite is as follows:
TrueColor = [ RedBand, GreenBand, BlueBand]
Where RedBand, GreenBand, and BlueBand are the data from the red, green, and blue bands of the image, respectively. The data from these bands are typically scaled and then combined into a single image using a process known as "image mosaicking."
False colour composite:
The false colour composite is generated by combining the data from different spectral bands of an image into a single image. The equation for creating a false colour composite is as follows:
FalseColor = [ BandX, BandY, BandZ]
Where BandX, BandY, and BandZ are the data from different spectral bands of the image, such as near-infrared, red, and green. To create a false colour composite, the data from these bands are typically transformed into a different colour space, such as the RGB colour space, using a process called "colour space transformation."
A common example is the NDVI, Normalized Difference Vegetation Index, which is an index that is calculated using the following equation:
NDVI = (NIR - Red) / (NIR + Red)
Where NIR is the Near-infrared band, and Red is the red band of the image. NDVI is commonly used to assess vegetation cover, and the results are used to create a false colour composite image where vegetation appears in different shades of green.
It's important to note that these equations are simple examples and there are many other variations and methods that can be used to create true and false colour composites, and the choice of methods and equations will depend on the specific data and application.
In the discussion section of a research paper on the topic of analysing the greenness change in Dehradun city over the last 5 years using machine learning, the researcher would summarize the main findings of the study and interpret their significance. The researcher would also discuss the limitations of the study and suggest directions for future research.
The main findings of the study would be the changes in greenness in Dehradun over the past 5 years, as mapped and quantified by the machine learning model. The researcher would interpret these findings by discussing the possible causes and consequences of the changes in greenness. For example, the researcher might discuss how urbanization and land-use change can lead to decreases in greenness (Zhang et al., 2020), and how increases in greenness can provide benefits such as improved air and water quality and reduced heat island effect (Nowak et al., 2002).
The researcher would also acknowledge the limitations of the study, such as the use of a single dataset of satellite imagery, and the use of NDVI as the sole measure of greenness. The researcher would suggest directions for future research, such as using additional datasets and measures of greenness, or incorporating other types of data, such as social and economic data, to better understand the drivers of changes in urban greenness.
Overall, the discussion would provide an in-depth analysis of the changes in greenness in Dehradun over the past 5 years, and would demonstrate the utility of machine learning for monitoring and understanding changes in urban greenness.
Yes, there is a significant amount of research available on the decline of greenery in various regions around the world. The causes of the decline can vary depending on the region, but some common factors include urbanization, deforestation, mining, agriculture, and climate change.
For example, a study published in the journal "Landscape and Urban Planning" in 2019 found that urbanization is a major cause of the decline of green spaces in urban areas, leading to the loss of biodiversity and ecosystem services. Another study published in the journal "Global Change Biology" in 2016, found that deforestation in tropical regions can lead to changes in local climate patterns and decreased water availability.
A study published in the journal "Nature Sustainability" in 2019 found that mining activities can have a negative impact on vegetation, leading to decreased green cover and loss of biodiversity in mining-affected areas.
A study published in the journal "Agriculture, Ecosystems & Environment" in 2018 found that agriculture practices such as monoculture, intensive tillage, and overgrazing can lead to the decline of green cover in rural areas.
A study published in the journal "Global Change Biology" in 2018, found that the effects of climate change such as increased temperature, altered precipitation patterns, and more frequent extreme weather events can lead to declines in green cover in many regions around the world.
Overall, the decline of greenery in regions around the world is a complex issue with multiple causes. Many studies have been done and the research continues to identify the causes, impacts and ways of sustainable management and restoration of greenery.
The Normalized Difference Vegetation Index (NDVI) is a commonly used index in remote sensing to assess vegetation cover. It is calculated using the following equation:
NDVI = (NIR - Red) / (NIR + Red)
Where NIR is the Near-infrared band and Red is the red band of the image.
NDVI is based on the fact that vegetation reflects more near-infrared light than red light, so the NDVI value will be high for areas with healthy vegetation, and low for areas with little or no vegetation.
The NDVI value ranges from − 1 to 1. NDVI values close to -1 indicate areas without vegetation, NDVI values close to 0 indicate barren or urban areas and NDVI values close to 1 indicate dense vegetation.
NDVI is calculated using the reflectance data from the image, this data can be obtained by using the following equation:
Reflectance = (DN/DNmax) * 100%
Where DN is the digital number of the image and DNmax is the maximum digital number that the sensor can measure.
It's important to note that NDVI values are affected by atmospheric conditions, shadows, and sensor noise, so it's important to correct for these effects before calculating NDVI, also NDVI can be affected by the presence of snow, water bodies, and other non-vegetation surfaces, so it's important to take these factors into account when interpreting NDVI values.
he Random Forest algorithm is a machine learning algorithm that is based on decision trees and uses the concept of ensemble learning.
A decision tree is a flowchart-like tree structure that is used to make predictions about an outcome based on certain input features. Each internal node in the tree represents a test on an input feature, and each leaf node represents a class label. The path from the root node to a leaf node represents a decision path.
In a Random Forest, multiple decision trees are created, and each tree is trained on a different random subset of the data. The final prediction is made by averaging the predictions of all the individual decision trees, which is called ensemble learning.
The math behind the Random Forest algorithm mainly involves the following concepts:
Decision Trees: The decision tree algorithm is based on information theory and the concept of entropy, which measures the disorder or impurity of a set of data. The goal of the decision tree algorithm is to partition the data into subsets that are as pure as possible, which is done by recursively splitting the data on different input features.
Bagging: Bagging stands for Bootstrap Aggregating, which is a technique used to create multiple subsets of the data by randomly sampling the data with replacement. Each subset is then used to train an individual decision tree.
Random Subspaces: Random subspaces is a variation of bagging, which is used to create multiple subsets of the features instead of the data. This is done by randomly selecting a subset of the features to use at each split in the decision tree.
Gini impurity: Gini impurity is a measure of the impurity of a set of data and it's calculated as the probability of an incorrect classification of a random sample from the set. The goal of the decision tree is to minimize the Gini impurity, so the decision tree is able to split the data into subsets that are as pure as possible.
In conclusion, the Random Forest algorithm is based on decision trees and ensemble learning, which is a combination of multiple decision trees. The math behind the Random Forest algorithm mainly involves decision trees, bagging, random subspaces and Gini impurity, which are mathematical concepts used to create a robust model that can make accurate predictions.