Determining the Apropriate Lands for Chickpea Cultivation in Kermanshah Province Using Climatological and Environmental Data

Considering the fact that more and better food production is one of the necessities of today''s world and since the production of the agricultural products of one region depends on the air and climatic factors، it is important to examine the role of climate in agriculture (Mohammadi & et al، 1383:123). In relation agroclimatology، numerous studies by scientists and agricultural climatologists have been carried out in Iran and the world. Tobaybsir (2004) in their research says that in most regions of the country، especially in Lorestan province like the other arid regions in Asia and North Africa chickpea are usually planted in the spring and inadequate soil and water، is the main limitation for this crop production. Chalakyan (1390) using data on annual precipitation، growing season precipitation، temperature، growing season، relative humidity، elevation، slope، aspect and soil depth and wind speed did zoning agroclimatic cultivated chickpea using AHP method in Ardabil province. The results show that the temperature and height of Ardabil Province are the main factors in order to cultivation of chickpea. 120،000 to 150،000 hectares of land in Kermanshah Province is dedicated to planting chickpea and the average yield is 450 kg per hectare (Haghparast، 1391:13). Summarize the literature shows that all the studies conducted on this specific product and exclusively in agricultural areas. This article of using spatial analysis functions of GIS، AHP and TOPSIS model to identify areas to be cultivated chickpea in Kermanshah province to put at the center of their attention. The data consist of annual precipitation، growing season precipitation، minimum temperature، growing season، the mean temperature for germination، flowering and ripening temperature، maximum and minimum mean monthly relative humidity of the growing season، mean monthly sunshine during the growing season، the 20-year period (2010-1991) for 17 synoptic stations were used. Environmental data، elevation، slope and soil type were also included in the study. Delphi technique was used to obtain the parameters of the weighting methods of comparing two or AHP (Qodsypour، 1389:7) was used. Pairwise comparison matrix of random variables by 40 rain fed cultivation experts completed، and the final criteria were extracted by Expert choice software. To convert the point data to the surface data، with interpolation methods it was found that the best method for the precipitation، the method of Co-Kriging and IDW methods for other elements. In addition، the DEM for elevation and slope parameters were used. Digital Soil Map of the Department of Natural Resources Kermanshah Province in 1:250000 scales were used. Then according to Login different layers، with the aim of homogenizing values، standardization layers were performed. In this case، each layer in direct or inverse effect determining potentials، while standardization (poor to excellent value from 0 to 1) is considered. The weights obtained from AHP were multiplied by the corresponding layers. Then the positive and negative ideal values for each layer were extracted and entered into the TOPSIS model. The results indicate that annual rainfall with 0. 793% the most effective and wind up with 0. 028% the lowest effects have in chickpea cultivation. Rainfall has a positive effect and the precipitation less than 250 mm in the range of not more inhospitable region is not observed in this variable. Western areas of highest power and southwest regions، East and Northeast have the lowest potential for germination. Western parts of the province such as Qasr-e Shirin and Srplzhab due to the higher temperature of 27 ° C for chickpea cultivation stage are inappropriate and southwestern regions; north-east and East provinces will receive the highest score. City of Qasr-e Shirin inappropriate consideration in determining the temperature of the chickpea is grown. Minimum temperature varies between 15-5 degrees; the minimum temperature will increase the growing season to provide suitable environments for the germination and growth of peas، so the western parts of the province are having the greatest potential. Lowest average relative humidity of about 28 percent in the city of Qasr-e Shirin and maximum 52% in the southwest and northeast of the province، whatever the value of this variable increases، the more points will receive. Due to the low relative humidity، southwest and northeast regions points close to 1 and the western parts of the province will receive a score close to zero. In most parts of the study area، maximum relative humidity is 60 percent and the resulting exposure of Kermanshah Province، Songhor، Eslamabad-e-gharb rating is good. The highest amount of sunshine hours per day growing season 9. 9 hours in southern and central provinces and the lowest value of 4/8 time is observed in the North-West Province. The mean wind speed during the growing season، which varies between 3 to 7 meters per second، the highest in the region peers، Kermanshah and falcon are between 7-5 meters per second Kangavar and western regions including Qasr-e Shirin، Srplzhab، Gilangharb and Eslamabad-e-gharb conditions are suitable. The central plains of the province with an elevation of 800 to 1،500 meters and has better conditions in terms of slope، mostly between the levels of 30-0 per cent. By exploring the soil، Kermanshah province is in moderate to good conditions. Integration of environmental and climatic GIS layers with TOPSIS model and incorporate layers of dry land farming it was found that 4 factors including above 1500 meters northwest and northeast areas، slopes over 30 percent except in the central area of the high temperature at flowering and maturity in areas West Province (Qasr-e Shirin and Srplzhab)، resulting in unfavorable conditions for chickpea cultivation. In other regions of Kermanshah provinces، regions prone at a high level with 0. 073%، good 26. 43% and average 73. 48 % are included. Lands with very good features are located in Nosoud and Ravansar cities. Areas with average ability are located in Harsin، Kangavar and parts of the southern province and areas with good potential are located in some parts of the Eslamabad-e-gharb، Kermanshah and East of Sarpolzahab.