Hadi Eskandari Damaneh; Hamid Gholami; Rasool Mahdavi; Asad Khoorani; Junran Li
Abstract
In this study, water use efficiency index (WUE) was used to assessing the effect of drought on the carbon and water cycle. To calculate this index, we used the gross primary product (GPP) and evapotranspiration (ET) products obtained from the MODIS sensor, and the trend of their changes and reaction ...
Read More
In this study, water use efficiency index (WUE) was used to assessing the effect of drought on the carbon and water cycle. To calculate this index, we used the gross primary product (GPP) and evapotranspiration (ET) products obtained from the MODIS sensor, and the trend of their changes and reaction of this index to drought were calculated for the period 2017-2001 in Fars province. Finally, we assessed the land degradation and desertification in different land uses for study area. The results showed that the indices of evapotranspiration, GPP, water use efficiency, and drought increased by 75.25%, 29.9%, 78.51%, and 67.23%, respectively. The effects of drought on evapotranspiration in agricultural lands and grasslands showed more than 67% positive relationship and also, in these land uses, we observed a significant positive relationship (33.4% and 12.5% for the agricultural lands and grassland, respectively). However, in shrubs lands, and savannas, it is more than 66.6% and 87.5%. The effect of drought on water use efficiency in grassland showed that more than 87% of these areas have a positive relationship. The effectiveness of water use efficiency in plants shows a positive relationship in 40.9% in this area, of which only 0.9% has a significant positive relationship. The negative relationship of this land use is about 59.1% of it. Of this negative amount, only 1.6% of the area had a significant negative relationship. The study of this relationship in the use of savannas shows 75% of this area, which includes 1.5 square kilometers.
Gholamreza Zehtabian; Hassan Khosravi; Ali Azareh
Abstract
Need to Increasing agricultural land in order to improve food resources in the past two centuries recentlead to widespread changes in land use and improper management of these lands. Continue thisprocess can lead to land degradation and desertification, and improve such soils is very costly;Therefore, ...
Read More
Need to Increasing agricultural land in order to improve food resources in the past two centuries recentlead to widespread changes in land use and improper management of these lands. Continue thisprocess can lead to land degradation and desertification, and improve such soils is very costly;Therefore, prevention of land degradation is more desirable. This function requires to research on theutilization of land agricultural and how to use. With this aim, the Khatam city was selected as thestudy region and various maps of the region, including soil, land use and height maps was prepared tohelp ArcGIS9.3 and ENVI software. Four dominant land region mention mono cultivated and multicultivated systems under irrigation, garden lands and range lands as control treatments wereconsidered as the treatments. The soil was sampled and soil factors in two corrective factors, includingcorrection factors N, P, K, CO, Caco3, Mg and damaging factors Hco3, Cl, Na, pH, EC and SAR atdepth 0 to 30 cm of the soil surface horizons were studied. Factors the design of split plots showed thatthere are significant differences between treatments in the region and soil of region is relatively poorfrom CO, N, K and P in soils Rdhy. The comparison of treatment means with Duncan MeanComparison indicated that the garden lands as the most suitable treatments and range lands as the mostunsuitable one.
