ECOPERSIA
Volume:8 Issue: 1, Winter 2020

Time prediction of the main failure is of great assistance in managing the risk involved in landslide occurrence. The complexity of subsurface structure, lack of sufficient information about the slip surface, and complexity of seasonal factors make the prediction more difficult. Most of the solutions proposed for modeling the prediction of the main failure are not efficient and are associated with considerable errors due to the oversimplification. It makes the simultaneous incorporation of all effective factors nearly impossible. In this study, a reliable method was proposed for selecting the appropriate time to analyze the landslide movement and providing the speed threshold leading to the main landslide occurrence in a large-scale rockslide in the Anguran Open-Pit Mine.

In this study, the data set of two years movement of a reliable creep type landslide in Anguran Mine (Zanjan, Iran) were implemented to modify the prediction method suggested by the previous study. The method of this study was a careful comparison of accelerator factors and landslide motion.

The independence of the movement speed from the effective factors such as precipitation could be a reliable situation that can be used to predict the critical condition of landslide motion toward final and rapid failure. In this rockslide, 1.5 million m3 block of stone slid into the open pit.

The employed method presented in this study allows predicting the occurrence of a final rockslide within a reasonable interval of time and preventing the damage occurred through the timely evacuation of workers and equipment.

Affecting factors on runoff generation in mountainous areas, where the hydrological processes are complex, play an important role in the recognition of hydrological phenomena. The aim of the present study was to simulate the water balance of Farsan Basin using the SWAT model.

In this semi-distributed research, SWAT model was used to simulate the monthly runoff the basin of interest. The study area was Farsan watershed, it is the part of Beheshtabad Basin. Basin's curve number was estimated using a remotely sensed NDVI. The calibration and validation of the model were carried out by using the SUFI2 Algorithm (sequential uncertainty fitting) for two periods, one from 2001 to 2011 and another from 2012 to 2015.

The threshold depth of water in the shallow aquifer to start evaporation (REVAPMN) had the least sensitivity, while the soil evapotranspiration (ESCO), the time delay of the transferring water from the last soil profile to the groundwater level (GW_DELAY), and curve numbers in normal condition (CN2) were the most sensitive factors, respectively. To evaluate the simulation, R2 (coefficient of determination), bR2 (weight correlation coefficient), and NS (Nash Sutcliffe model efficiency) at the calibration stage were 0.63, 0.33, and 0.57, respectively. Whereas at the validation phase, these coefficients were found to be 0.69, 0.68, and 0.52, respectively.

A proper specification of these sensitive parameters may be the key factor for runoff simulations. The impact of change in surface parameters may have a great influence in both generating runoff and mountain hydrology.

The present study aimed to 1) determine the extent of arbuscular mycorrhizal fungi symbiosis with Amygdalus scopariain in Melah-Roteh region in Dareshahr City, western Iran, and 2) model the presence or absence of different arbuscular mycorrhizal fungi on Almonds (A. scoparia) in relation to soil physicochemical properties.

In the study area (Melah-Roteh region in Zagros Woodlands), 57 soil samples were taken from the 0-30cm depth under A. scoparia in the Dareshahr City forest west of Iran. Soil samples were processed in the laboratory to extract and identify spores and fungi, determine spore frequency, and to measure physicochemical soil properties.

The results of two-way indicator species analysis (TWINSPAN) classification showed that arbuscular mycorrhizal fungi symbiotic with A. scoparia in the study could be classified into two groups. The evaluation of indicator species in each group using the importance value method and significance of indicator values based on Monte Carlo tests (p<0.01) showed that Rhizophagus fasciculatus and Funneliformis caledonium (Indicator value= 90 and 89, respectively) were prominent in the first group and Funneliformis mosseae, Claroideoglomus drummondii, and Glomus gigantea (Indicator value= 95, 93, and 81, respectively) were representative of the second group.

The presence-absence, symbiosis rate and spore density of arbuscular mycorrhizal fungi species associated with Almonds changes with varying physicochemical soil properties that can be modeled using certain soil attributes.

Eucalyptus camaldulensis is one of the most productive and best adapted species in the afforestation. The aim of the present study was to investigate the growth and survival rate of five Eucalyptus camaldulensis provenances (two from Mazandaran, one from Guilan, one from Ahwaz, and one from Ilam) at the Research Center of Tropical Plants in Mehran, Iran, during 2009-2013.

The experiment was carried out in Mehran Research Station in Ilam Province with a randomized complete block design and three replications, at 25 plants in each block at a distance of 4×4m. At the end of the growing season, survival, height, circumference at breast height (C.B.H), canopy diameter growth (C.D.G) 147 trees were evaluated.

The result of ANOVA indicated a significant difference between the provenance origins for all traits (p<0.01). The survival rate of the studied provenances ranged from 41.7% to 98.3%, whereas Shafarood and Mehran provenances had the highest rate of survival. The mean of annual height growth of five studied provenances varied from 64.57 to 205.29cm. In addition, the characteristics of C.B.H and C.D.G in the selected provenances ranged between 3.60 to 9.44 and 25.51 to 75.26cm, respectively. Among the above mentioned characteristics, Shafarood followed by Ahwaz had the greatest values.

The seedlings from the Shafarood origin indicated the highest average in all the studied characteristics. The results provide useful information for choice of E. camaldulensis provenances to apply future afforestation in the Mehran region.

Medusahead (Taeniatherum caput-medusae (L.) Nevski) and barbed goatgrass (Aegilops triuncialis L.) are two annual species that drastically affect rangelands worldwide. In the present study, the current distribution range of these species was investigated using ecological niche modelling (ENM), and then their distribution was predicted in 2040 and 2070.

In this study, using 19 bioclimatic variables and the recorded presence locations, the current distribution of T. caput-medusae and A. triuncialis was predicted using MaxEnt. Moreover, changes in the distribution ranges of these species in the future (2040 and 2070) were estimated.

According to the results, the mean temperature of the coldest quarter and Isothermality had the greatest effect on the distribution of A. triuncialis in the present and future. For T. caput-medusae distribution in the present, 2040, and 2070 the mean temperature of the coldest quarter had the highest effect on determining the potential distribution range of this plant. Accordingly, climate change will not affect the distribution range of barbed goatgrass, however, it may facilitate the expansion of medusahead to the upper elevations.

In the present, comparing the two, barbed goatgrass had a higher probability to invade rangelands of Iran. Climate change might facilitate the invasion of medusahead to upper elevations. Grazing exclusion is advised to control the range expansion of these two species where they are present.

The aim of the present study was to determine the most important environmental factors affecting aboveground net primary production (ANPP) of plants along the altitude gradient in QezelOzan-Kosar rangelands, Iran.

Eight sites along the altitude gradient were selected, in each of which three transects parallel and perpendicular to the slope were established. Along each transect (totally 240 plots), ANPP and soil samples were measured. Using digital elevation model (DEM) map, the maps of slope, aspect, elevation, topographic index (CTI), stream power index (SPI), plan curvature (PC), precipitation and temperature were extracted. The soil parameters measured in soil laboratory. To determine the important effective factors, principal component analysis (PCA) was used. Moreover, the ANPP prediction equation was simulated using the parameter which had the greatest impact and correlation with ANPP (precipitation), using 2nd-order polynomial model and mapped further.

The results of PCA revealed that six components had the highest effect on the ANPP variations (76.35% of ANPP variations). The result of simulated equation and map indicated acceptable accuracy (R2= 0.95, RMSE= 0.73).

The results of the present study highlight the importance of topographic, climatic, and soil factors in ANPP variations, and can be used to manage QezelOzan-Kosar rangelands for establishing balance between biomass and carbon of the ecosystem and ecosystem supply and demand.

In the present study, effect of different hydro seed binder combinations were evaluated on stability clay soil cut slope of road in the campus of Gorgan University of Agricultural Sciences and Natural Resources, Iran.

The hydro-seed treatments were classified as A (5L m-2 water, 50g m-2 Festuca arundinacea L., 40g m-2 polyacrylamide tackifier, 30g m-2 starter fertilizer and 20g m-2 super absorbent polymer), B (5L m-2 water, 70g m-2 Festuca arundinacea L., 50g m-2 polyacrylamide tackifier, 40g m-2 starter fertilizer and 30g m-2 super absorbent polymer) and C (5L m-2 water, 90g m-2 Festuca arundinacea L., 60g m-2 polyacrylamide tackifier, 50g m-2 starter fertilizer and 40g m-2 super absorbent polymer). Then mean weight diameter, aggregate stability, liquid limit, friction angle and, soil cohesion indices experiments in wet and dry conditions conducted in three replications for each treatment.

Results showed that the maximum value of MWDwet (0.91mm), MWDdry (5.4mm), aggregate stability (88%), liquid limit (48%), plastic limit (35%), friction angle (44.9 degree) and soil cohesion (13.5kPa) obtained by application of hydro-seed C. Minimum percentage of aggregate destruction (38%) and plastic index (13%) obtained in results of hydro-seed C application.

The application of hydraulic seeding treatments improved the structural stability, plastic index and shear strength of the soil. Future research in this subject requires to perform in the field. This study will eventually be used in the implementation section.