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Among different models for runoff estimation in watershed management, the Soil Conservation Services-Curve Number (SCS-CN) method along with its modifications have been widely applied to ungauged watersheds because of quickly and more accurate estimation of surface runoff. This approach has been widely accepted by hydrologists, water resources planners, foresters, and engineers, as well. Therefore, this work was aimed to estimate the curve number using CN-values through several methods viz. SCS, Sobhani (1975), Hawkins et al. (1985), Chow et al. (1988), Neitsch et al. (2002) and Mishra et al. (2008) in Bar Watershed, Iran. According to the results, the Neitsch formula showed the best performance for estimating the Curve Number in situation with low (CNI) and high (CNIII) antecedent moisture conditions. However, the weakest performance was related to Mishra (2008) in CNI and CNIII-conversions. The weakest performance was resulted from the exponential form of the Neitsch et al. formula and the variable meteorological conditions of the Bar Watershed over the year.

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Drought is a complex natural phenomenon that can occur in any climate. Hydrologic drought in the river flow of arid and semi-arid areas causes serious shortages, threatens the quality of life, and impacts on the economy. Understanding this feature is then essential for the management of water resources. Hydrologic drought in the sense of deficient river flow is defined as the periods that river flow does not meet the needs of planned programs for system management. In the present study, changes in the monthly discharge of 14 hydrometric stations throughout the Gorganroud watershed over 30-year period (1980-2010) were studied. Then the deficit flow was determined based on threshold level method, and the results were analyzed. It was revealed that periods of severe shortages have happened in the very humid and semi-arid climates and the downstream of the study area, while longer periods (28 months) of low flows have occurred in the arid climate. The trend of severity and persistence in the central stations of the watershed was increasing. Also shortages occurred with greater frequency at the end of the study period, and river flow shortage during the years 1998-99, 2007-2008, 2008-2009 and 2009-2010 has occurred in most of the stations. So in these years, flow deficit has happened in 50, 85.9, 64.3 and 92.8 %of the stations, respectively.

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Nowadays, studies have been developing in order to use antimicrobial properties of plants instead of using synthetic preservatives. Jujube is one of the famous herbs.  Jujube (Ziziphus jujube. Mill) belongs to family of Ramnaseh and native to the central areas of the Iran plateau. The fruit, leaves and root of this plant have medicinal and wellness properties. In this study, evaluated some physico-chemical of jujube extract (Extraction yield, Moisture, water activity, Fat content, Ash, Brix) and its effect on the mold of Aspergillus flavus. Extraction of dried and Ground jujube fruit was done by soaking with Hydroethanol solvent. Chemical composition of the extract was determined by GC-MS method. So the evaluated minimum inhibitory concentration (MIC) and the minimum fungal concentration (MFC) of extract against Aspergillus fulvous (PTCC 5004) by the dilution method in a liquid medium. In the next step, different concentrations of the extract were sprayed on corn grains and after placing a disk containing suspension of Mold spores in each petri dish. Growth of mold on corn grains was measured during 7 days. The results showed that the hydroethanolic extract of jujube fruit has an anti-mold effect against Aspergillus fulvous and the minimum inhibitory concentration of extract in the culture medium was determined 350 μg / ml and there was not observed any lethality at concentrations less than 1000 μg / ml. The minimum inhibitory concentration of the extract in the blanched corn grain medium was 5000 μg / ml. Therefore, the hydroethanolic extract of jujube fruit has an inhibitory effect on Aspergillus flavus but does not have the inactivation effect on this mold and its spores.