Showing 3 results for J. Givi
S. Ayoubi, J. Givi, A. Jalalian, A. M. Amini,
Volume 6, Issue 3 (fall 2002)
Abstract
In quantitative land suitability evaluation, economic aspects land evaluation such as impact of environmental physical factors on crop production and the amount of yield per surface unit are considered. The purpose of this research was to study quantitative land suitability of northern Baraan area located in eastern Isfahan. The study was a continuation of the previously accomplished qualitative land suitability evaluation of the area. The economic studies include economic data collection, matching inputs and outputs and gross margins analysis.
Radiation-thermal production potential of the crops was calculated based on plant physiology and temperature (FAO model), which was 10.45, 10.11, 13.64 and 11.93 ton/ha for wheat, barley, maize and rice, respectively. Radiation-thermal production potential, observed and marginal yields and the results of the qualitative land evaluation were used to perform quantitative land evalution and to determine the corresponding suitability classes. The predicted yield in different land units varies between 1.64 and 9.17 ton/ha for wheat, 1.81 and 9 ton/ha for barley, 2.06 and 9.42 ton/ha for maize and 2.35 and 7.14 ton/ha for rice. Presence of significant statistical correlation between the observed and the predicted yield values reveals the validity of the evaluation methods used. The results from quantitative land evaluation show that most of the land units are slightly to moderately suitable for wheat, barley, maize and rice, while a few are not. The best land utilization type in each land unit can be selected through a combined consideration of quantitative land evaluation results, benefitability of each land unit and impact of the land use on the soil. Rice cultivation is not recommended in the study area, because of its adverse effect on soil physical properties and soil drainage.
A. Jalalian, J. Givi, M. Bazgir, Sh. Ayoubi,
Volume 10, Issue 4 (winter 2007)
Abstract
In Iran, the development of cultivated areas becomes gradually impossible due to ever-increasing population growth and urban area development. Therefore, it is very important to use the existing cultivated lands more efficiently. Land suitability evaluation makes the sustainable use of the lands feasible. The objective of this study was qualitative, quantitative and economic assessment of land suitability in Talandahst area for rainfed wheat, barley and chickpea. Talandasht plain with a surface area of 4500 ha is located southwest of Kermanshah city. The climate is semi-arid with cold winter and moderate summer. The successive stages of this research included soil survey in the field, soil analysis, qualitative and quantitative and economic evaluations of land suitability. In qualitative evaluation of land, climatic, topographic and soil suitability classes were determined according to the degree of the matching. Limitation and parametric methods were used in qualitative evaluation. Quantitative and economic evaluations made based on the observed yield and gross benefit, respectively. Based on qualitative evaluation, the studied area is marginally suitable for rainfed farming of wheat, barley and chickpea. This is due to water deficiency occurring during some stages of the growing cycle. The solution for this problem is supplementary irrigation. In addition to climate limitation, there are also topographic and soil restriction for the growth of the studied crops. On the basis of observed yield, the land units are moderately to highly suitable for rainfed wheat and barley production. Among the three named crops, the most and least profitable ones are chickpea and barley, respectively, and wheat ranks between them.
N. Yaghmaeian Mahabadi, M. Naderi Khorasgani, J. Givi,
Volume 15, Issue 58 (winter 2012)
Abstract
Remote sensing has been considered as an appropriate tool for temporal monitoring of some natural phenomena. Ardestan Region is prone to land degradation and masked by sand sheets, sand dunes, clay flats, desert pavement and different kinds of salt crust due to dry climate. To study the trends of land degradation in last three decades, four satellite data sets of Landsat MSS, Landsat TM, Landsat ETM+ and IRS acquired in 1976, 1990, 2001 and 2008, respectively were analyzed. The time series analysis revealed that the bare clayflats have decreased and clayflats with vegetation cover have expanded over 32 years. During this period, the areas which are covered by gravel have decreased 13 percent and both the area covered by salt crusts and aeolians have extended 2 percent. Puffy grounds have developed by 2001 but their magnitudes have decreased between 2001 and 2008 as they have been masked by the moving sand ripples. Reduction of 13 percent of sand sheets between 1990 and 2008 indicates that soil conservation practices have efficiently controlled land degradation and desertification in the area.
