Hi Armando,

Questions like yours get asked quite often on RG, and responses quickly go to specific technical suggestion of data types and algorithms. It is worthwhile first to think a bit more about what you are after, and clearly define your objectives. For that you first need to be clear on what land use is, including how it differs from land cover. Remote sensing is natively suited to determine land cover (water, soil, grass, etc.). Going from there to land use is already a big step (e.g., is a forest a natural forest or a production forest, or is a patch of water a natural pond or similar, or some artificial water body with a specific purpose). Hence you need some form of contextual analysis to go from cover to use, such as object-based image analysis (OBIA), though there are also many other techniques.

Now, your questions even goes beyond the above. What is “level of intensity”, specifically? Well, first of all, this will differ for different land use types. It could mean that if you have an agricultural land some form of crop rotation can be used – e.g., plant a different crop every year for 3 years, then leave it fallow for one year. This could be seen as intense use, and if you had 4 yearly satellite images taken at the right time in the phonological cycle (not in winter, for example), you could detect this. If, for example, you found that the field is not left fallow in the 4th year, maybe you could say that the use is too intense. However, if you had a system where 2 crops are planted on a field per year, you would already have to get more images to detect that dual use per year. Point is that you need a clear concept and definition of the types of land use in question, and what defines “intense” use. Only then can you determine the type of imagery you need (do you need RGB, or also NIR, what spatial resolution, etc.).

In sum, establish a clear concept and definition first!

Good luck, Norman

download satellite images of that area you want to study by Ikonus, Quickbird images etc minding the spectral differentiation. then depending on the year you are considering the intensity for example for the last 10 years ( i.e 2005). keep that and get that of the present 2015. you can interpret the spread and intensity using the the two images you have downloaded. with that Remote sensing can help you actualize that task. by image comparison and interpretation  

Dear Armando,

Yes, we can use remote sensing to get a rough idea. But for detailed analysis and decision making this won't help you as there are many parameters which can't be assessed through remote sensing. In general, for tentative data and figures, you can always use remote sensing data and for real life decision making processes, please use the actual topographic information through reliable sources.

Guess, this will help.

Regards.

Sekar Gopal.

Buen día Armando,

Con sensores remotos puedes identificar de forma sazonal/temporal la actividad agrícola, utilizando, como dicho anteriormente, imágenes de la misma área de épocas distintas;

Caso quieras una evaluación vinculada a los niveles de fertilización, estes están asociados a la composición química de tus suelos, por lo tanto, deberás realizar estudios químicos y espectrales de tus suelos, una vez tengas la respuesta espectral de tus suelos tienes que generar tu biblioteca espectral y posteriormente utilizarla en la busca de áreas similares.

Saludos

Best regards

Carlos Tapia Calle

Hi Armando,

Questions like yours get asked quite often on RG, and responses quickly go to specific technical suggestion of data types and algorithms. It is worthwhile first to think a bit more about what you are after, and clearly define your objectives. For that you first need to be clear on what land use is, including how it differs from land cover. Remote sensing is natively suited to determine land cover (water, soil, grass, etc.). Going from there to land use is already a big step (e.g., is a forest a natural forest or a production forest, or is a patch of water a natural pond or similar, or some artificial water body with a specific purpose). Hence you need some form of contextual analysis to go from cover to use, such as object-based image analysis (OBIA), though there are also many other techniques.

Now, your questions even goes beyond the above. What is “level of intensity”, specifically? Well, first of all, this will differ for different land use types. It could mean that if you have an agricultural land some form of crop rotation can be used – e.g., plant a different crop every year for 3 years, then leave it fallow for one year. This could be seen as intense use, and if you had 4 yearly satellite images taken at the right time in the phonological cycle (not in winter, for example), you could detect this. If, for example, you found that the field is not left fallow in the 4th year, maybe you could say that the use is too intense. However, if you had a system where 2 crops are planted on a field per year, you would already have to get more images to detect that dual use per year. Point is that you need a clear concept and definition of the types of land use in question, and what defines “intense” use. Only then can you determine the type of imagery you need (do you need RGB, or also NIR, what spatial resolution, etc.).

In sum, establish a clear concept and definition first!

Good luck, Norman

Hi Armando,

I quite agree with Norman on how the task can be conceptualized. When you develop a clear concept of the task, RS, together with relevant ancillary data, may help you achieve the goal. Land use can be deduced from land cover (which can be derived from relevant RS images). Given the fact that you are looking at the intensity ( based on your definition), you may need a time series data analysis-perhaps 3 or 6 monthly, reflecting agricultural seasons in the area of interest. Your preferred image should also be able to  help you identify possible different crops/agricultural activities in the area. Hopefully, your data analysis will reveal the trend of land use over the time period as well as intensity of such land use/agricultural land use (depending on your definition).

Best Regards, Elijah.

Remote sensing data of >5m spatial resolution would be ideal for mapping the land use intensity levels.

As mentioned in the above answers, it depends mostly on what you exactly wish to study and what data you have available for the study area, before going too deep into discussions about specific analyses or algorithms and their benefits. It's always best to develop a clear plan how to proceed before starting out with any actual GIS analyses.

Cheers, Oula

Norman: I think your answer is very clear, when I ask the question I referred to the intensity of agricultural production units in relation to the use of agrochemicals, mechanization, intensity of labor, irrigation at a municipal level to get it's cartography 1:25 000 or smaller scale. His remarks are illustrative of that is required to be clear the purpose and scope of the investigation. Thanks for your reply. Best regards, Dr. de la Colina.