Land suitability evaluation of Aq-Qalla region for rainfed Chickpea cropping by Boolean logic and analytical hierarchy process (AHP)

To evaluate land suitability of Aq-Qalla region for rainfed chickpea cropping, Boolean logic and analytical hierarchy process (AHP) methods were used in geographic information system (GIS). To achieve this, firstly, climatic and agronomical requirements of chickpea,were identified according to scientific resources. Then, thematic requirement maps were provided. The studied environmental-components were average, minimum and maximum temperatures, precipitation, slope percent, elevation, organic matter, pH, EC, K, P, Ca and soil texture. Then, each layer is classified into suitable (score = 1) and non-suitable (score = 0) based on Boolean logic. Also, they were classified into 4 suitability classes (high suitable, suitable, less suitable and non-suitable) based on weighted overlay. The digital environmental layers overlaid in ArcGIS media for each method, separately. The results of Boolean logic method showed that about 17730 hectares (16%) of Aq-qall agricultural lands were suitable for rainfed chickpea. Moreover, average, minimum and maximum temperatures, precipitation and slope percent parameters were suitable for chickpea production in the studied areas. The limiting factors for chickpea production were high soil K, P, Ca concentrations, salinity and low organic matter. Results of weighted overlay by AHP indicated that 27.5% and 13.9% of Aq-Qalla areas were highly suitable and suitable for chickpea production, respectively; but 16.8% of lands had at least one limiting factor, and therefore were not suitable for chickpea cultivation.