Environmental Data
Embedded Files
Environmental data is hard gainable data type as deriving information usually requires earth observation systems. Though, big companies like NASA, European Space Agency, derive global environmental data. Nowadays, we have vast access to such datasets. Even though open data resolution is not mostly highest, access to such data creates an opportunity for general analysis related to local environmental issues.
The assignment project analysis is based on Georgia's example and aims to identify areas with croplands susceptible to soil erosion. The project's main tasks include following environmental elements: elevation, elevation derivates - slope, aspect, soil, hydrological modelling, land cover and erosion. Project is done in ArcMap.
The initial data downloaded from the open-source required processing in GIS. Usage of several spatial analysis tools ensured having "cleaned" and "ready" data inside the study area. After data processing, the first element which was analysed is elevation. The map represents the elevation variety across Georgia.
Slope
I have created Slope analysis by using the elevation dataset and "Slope" tool. For representing slope across the country, I have used the data classification method.
Analysing slope is vital in many fields. For example, it is essential for agricultural purposes, as well as spatial planning.
Aspect
I have created Aspect analysis by using the elevation dataset and "Aspect" tool. For representing aspect across the country, I have used the data classification method.
Aspect is one of the essential elements we have to take into account in many fields. The map represents aspect analysis across Georgia and shows two examples of spatial areas, where analysing aspect takes essential place: 1. main agricultural area, in particular with vineyards; 2. main ski resort, with major ski tracks.
Soil
For soil analysis, I have used a different data source and data format. Downloaded World Soil Database file required implementing additional tools including format transformation, joining, extracting and other tools. To map the result, I have used a unique symbology method based on Topsoil USDA Texture Classification.
Hydrological modelling
For hydrological modelling, I have used the same elevation dataset to identify the movement paths for flow. Modelling involved more spatial analysis tools, including "Fill" - to fill sink areas by removing small imperfect data; "Flow Direction" - to define the direction of flow; "Flow Accumulation" - for creating a stream network; "Extract by Attributes", "Stream Order", "Stream to Feature". The result represents Georgia's real picture, though with some faulty parts. Thus, when working on data, especially on global data, it is important to stay critical.
The land cover analysis data belongs to the European Space Agency and represents the open data type. Before creating the land cover map of Georgia, I have used spatial tools for data extraction and projection. After preparing data inside the study area, making a visualisation was needed. I have used additional files for defining land cover types and downloaded from the European Space Agency, which provided code names for each classification type.
The Land cover map of Georgia (above on the left side) shows the spatial distribution of land cover types. The map has all the necessary map elements, including legend, which is essential for identifying each colour on the map by its respective class. As the project aimed to identify croplands susceptible to soil erosion, I have extracted all agricultural croplands from the land cover dataset. The below map on the left side represents all agricultural croplands across Georgia. I have pulled the most susceptible soils from the soil map and steeper slope from the slope map for the next step. Finally, by using croplands file and extracting soil and slope files, I have identified croplands on erodible soils and steep slopes.
Thus, the final map (on the right) shows three main layers: croplands on no erodible soils and steep slope, croplands on erodible soils, croplands on erodible soils and steep slopes across Georgia.
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