Ghasem Ali Abrsaji; Mohammad Mahdavi; Mohmmad Hasan Jouri
Volume 22, Issue 2 , August 2015, , Pages 308-318
Abstract
This research was aimed to investigate some ecological characteristics of Frankenia hirsuta in saline rangelands of Golestan Province. This region has saline soil with high underground water table, and halophytes usually grow naturally in this area. For this purpose, some factors such as soil characteristics, ...
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This research was aimed to investigate some ecological characteristics of Frankenia hirsuta in saline rangelands of Golestan Province. This region has saline soil with high underground water table, and halophytes usually grow naturally in this area. For this purpose, some factors such as soil characteristics, vegetative cover, phenology, forage quality, preference value and so forth were determined. According to the results, this species is usually distributed on silt-loam soils with an acidity of 7.7 to 7.8 and EC (Electrical Conductivity) ranged between 28.2 to 30.2 dS/m. The autumn regrowth of this species starts in October but, active vegetative growth begins at the middle of February, flowering occurs in June and seed ripening occurs in August. At vegetative growth stage, this species consists of 10.3% crude protein, which is decreased to 8.7% at flowering stage and 7.1% at seed ripening stage. In addition to the main root, this species has also lateral roots. The main root length is usually short around 5 cm but the lateral root length is about 50 cm, moving horizontally at first and then penetrates deeply. Overall, in saline rangelands of Golestan Province, this species has been distributed as patches in low lands and the places with suitable moisture and relatively less salinity. In order to protection and sustainable utilization of this species, it is suggested that the seeds of this plant be sown every few years in the prone areas. In addition, the time of enter and exit of livestock have to be chosen carefully.
Sadigheh Mohammadi; Ali Salajegheh; Mohammad Mahdavi; Reza Bagheri
Volume 19, Issue 1 , June 2012, , Pages 60-71
Abstract
Due to the variation of ground water properties in temporal and spatial scale, these properties can not be assumed constant over time and space. This research was conducted to assess spatial and temporal variations of ground water table in Kerman plain during a 10-year period (1375-1385) by using the ...
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Due to the variation of ground water properties in temporal and spatial scale, these properties can not be assumed constant over time and space. This research was conducted to assess spatial and temporal variations of ground water table in Kerman plain during a 10-year period (1375-1385) by using the best geostatistical estimator. Firstly, available statistical resources related to the ground water table of this plain (including 67 wells) were collected. After controlling for quality, accuracy and normality of the data, different interpolation techniques were used including kriging (with and without logarithm), cokriging, inverse distance (with exponents of 1 to 5). The best technique was selected based upon MAE and MBE criteria and provided spatial zonation maps in the beginning and end of the period. Spatial zonning maps were prepared at the beginning and end of the study and ultimately, iso-falling map was provided in Arc GIS 9.1 package. Our findings showed that Gaussian variogram model was the best for spatial structure of these data and inverse distance method with exponents of 5 and 4 were the best interpolation methods in the beginning and end of the period, respectively. Zonation maps showed a falling trend of the ground water level in majority of the plain. Maximum falling data (32 meters), was recorded respectively for the northern outlet of the plain with an effective range of 17 and 62 pizometers and western outlet with an effective range of 8 pizometers. Also, the results showed an upward trend of water, as 7 meters, in effective range of some wells with 50 and 52 pizometers in Kerman city due to being located in sewage and waste water zone of the city.