Using GIS and Multi-Criteria Evaluation for Land Suitability Assessment

Land evaluation is a very important link in the chain that leads to sustainable management of land and soil resources. Exploitation of lands according to their capabilities, in addition to meeting the needs of the present and future generations, also maintains the ecological balance of the earth. Analyzing the suitability of land by using a variety of factors affecting the quantitative and qualitative production of products and examining the intricacies of their relationships with each other, as well as simultaneously with land use analysis, is one of the most useful applications of spatial information systems in agricultural land management. Many methods have been developed since the presentation of the FAO framework for land suitability assessment, and some of them are still widely used. In the present study, the qualitative assessment of land suitability using geographic information system (GIS) and multi-criteria evaluation (MCE) for three strategic crops of wheat, barley and rice was investigated in four study areas in northern Iran.

In order to implement the proposed model, data related to soil characteristics, climate data, topography data, geological map and land cover map were collected. Among the collected data, temperature plays an important role in determining the suitability of land for agricultural products, spatial patterns of rainfall are important for assessing water availability, and the slope of the land has a great impact on drainage, the amount of light received from the sun and, consequently, the required energy. It has plants to grow. Then, according to the climatic diversity in the north of Iran and the diverse set of crops that are grown in this region, appropriate criteria were selected. The selected criteria are: soil type, temperature, precipitation, slope and geological parameters. In order to assign weight to each of the criteria and intensify their effect in the land suitability assessment stage, a weight assignment process was carried out. This weight allocation was done by experts. Each criterion was evaluated based on its effect on the cultivation of different crops in this area and the weight of each layer was determined. Finally, a detailed examination of the results and analysis of suitability of land for agriculture in the studied areas was carried out.

The analysis of the results of the geospatial information system showed that the west of Gilan Province is an ideal place for rice cultivation, but this area has challenges for barley and wheat cultivation. Relatively good scores for all three crops, wheat, barley and rice in the east of Gilan Province showed that this area is prone to growing diverse crops. The center of Mazandaran Province did not get good points for the cultivation of wheat, barley and rice crops. Also, the center of Golestan Province was determined as a very suitable place for wheat and barley cultivation.

In conclusion, the areas with a relatively suitable score provide facilities for diversifying the cultivation methods, which increases flexibility and reduces the risks associated with market fluctuations and climate changes. Also, in areas with a low suitability score, the role of environmental protection and sustainable land management practices is important. From another dimension, the classification of land suitability allows the policy makers and managers of the agricultural sector to allocate resources correctly and optimally. For future research, it is suggested to analyze the time series of satellite data using deep learning models.