Salinity distribution reported by the research teams is a key success factor of this project because it aims to have a clear understanding of the distribution of salinity and the extent of land degradation in central and southern Iraq. To achieve this, a range of techniques including remote sensing and geographic information system has been deployed by the research team. Mr. Waleed al Shafie, an expert in geographic information systems (GIS), tells us more about the process and the initial results of his team.
How does the remote sensing technique help you identify the spatial distribution of salts? What are its limitations and advantages?
Spatial Salinity distribution follows an approach that integrates multi-temporal classification of remotely sensed data, physical and chemical soil properties and landform attributes. The maps we developed represent the changes in the distribution of salinity levels and its severity.
Advantages of remote sensing for land evaluation can be summarized as follows
- It is a rapid method of acquiring up-to-date information over a large geographical area and it is relatively cheap.
- It is the only practical way to obtain data from inaccessible regions.
- At small scales, regional phenomena which are invisible from the ground are clearly visible.
- It is a quick method of constructing base maps in the absence of detailed land surveys.
- Easy to manipulate with the computer, and combine with other geographic coverage in the GIS.
There are also some disadvantages of remote sensing for land evaluation
- There is no proper sampling or documentation of this phenomenon, so our team should dedicate effort to achieve that.
- All data must be geometrically recorded and geo-referenced.
- Resolution of satellite imagery is too coarse for detailed mapping and for distinguishing small contrasting areas.
Tell us about your activities over the next season?
We have several activities to complete over the next season. We have to continue with the documentation and collection of existing data and maps (soil salinity, soil types and properties, cannel and irrigation, water table and water quality, field sampling and investigation, remote sensing models development, multi-temporal high resolution remote sensing salinity mapping in each project area.
What data sources did you use for your analysis?
We collect information from several sources such as Iraqi ministries, ground truth, field sampling (Field visit and measurement), salinity studies and thesis, Reports etc.
In your five pilot study sites, what were the differences/ similarities between them?
There are differences in the Agricultural land use, Irrigation, river water and groundwater use, other human activities, construction and urbanization, oil exploitation and even impacts of war on land degradation, remote sensing model + existing data, parcel level biophysical and socioeconomic indicators.
The similarities are in Biome and landscape types, topography (1/25,000-100,000) as well as DEM, soil types & properties, rainfall and runoff, water quality, groundwater table and hydrological model.