Saeid Gharachelo; Mohamad reza Ekhtesasi; Mojtabah Zareian Jahromi; Mohamad bagher Samadi
Volume 17, Issue 3 , October 2010, , Pages 402-420
Abstract
Nowadays, desertification is one of the ecological crises of the world. To control desertification, having a clear understanding of its factors and processes is necessary. Khezr Abad-Hemat Abad region of Yazd with area of 242 Km2 was considered to evaluate current condition of desertification using ICD. ...
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Nowadays, desertification is one of the ecological crises of the world. To control desertification, having a clear understanding of its factors and processes is necessary. Khezr Abad-Hemat Abad region of Yazd with area of 242 Km2 was considered to evaluate current condition of desertification using ICD. Iranian Classification of Desertification (ICD) was presented by M. Ekhtesasi and S. Mohajeri in 1995. First of all, available data were collected and basic studies were done. The data were entered in GIS and basic maps were produced through interpretation of aerial photos and satellite images using Arcview and Ilwis software. Eight desert homogenous units were separated according to the studies and by overlaying geomorphology, land use and vegetation cover maps. In next stage, effective factors in desertification including three environmental factors, three anthropogenic factors, soil erosion index, resilience potential and reconstruction of ecosystem were scored in a range of 0-10. Afterward, according to the sum of scores and comparing with table of desertification severity index, final desertification map was produced. The result showed that 81.53% of the region was in middle class of desertification while 18.47 % was in severe class. The environmental factors were determined as the main factor in desertification of 81.53 % area of the studied region while 18.47 % of that was affected by anthropogenic factors. Most main criterion in desertification of this region was water degradation process
Vahid Habibi arbatani; Mojtabah zareian jahromi; Ali sadeghi sangdehi
Volume 16, Issue 3 , December 2009, , Pages 419-430
Abstract
The goal of this research was climatic zoning of Esfahan province using Domarten and geostatistic methods. We used 30 years data of 35 climatologically stations. At first we calculated Domartan aridity index of climatological stations using mean annual precipitation and temperature. In order to climatic ...
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The goal of this research was climatic zoning of Esfahan province using Domarten and geostatistic methods. We used 30 years data of 35 climatologically stations. At first we calculated Domartan aridity index of climatological stations using mean annual precipitation and temperature. In order to climatic zoning, Kriging, Cokriging and IDW with powers of 1 to 5 were used. After normalization, the variogram were drawn. To fit the best model on empirical variogram, the lowest values of RSS were applied. Highly correlated values of precipitation with Domarten index were used in Cokriging method. For selection of the best interpolation method, cross validation and RMSE were considered and errors were calculated. Cokriging has the lowest error .Using cokriging and GIS, climatic zoning map of Esfahan province were prepared. Climatic zoning map showed that 80 % of studied area has arid and semi-arid climate