إضافة عامل جديد (دليل السنوات الممطرة)‎ إلى معادلة (Sys 1980)‎ في تقييم أراضي إقليمي الزراعة الممكنة و الهامشية

الملخص EN

Many equations, regimes and indices were used for land classification and evaluation.

When the pedologists find any factor of climate or soil that is necessary to evaluate the lands in correct way, they will add it.

The Sys equation 1980 needs anew factor when this equation is applied to evaluate the lands in the dry-farming regions.

This factor can be called (Rainy Years Index) .

When the new factor is used, the values of land indices become less than the values with out using it, so the land class moves at non suitability direction because of the shortage in rainfall at dry years, in addition to the rating of climate in the rainy years them selves is less than 100%.

This evaluation may be more realism because of lost production in the dry years and the production of rainy years is less than the optimum production.

The evaluation will differ from region to another according to the number of dry years and to rainy years precipitation quantities.