Journal of Range and Watershed Managment
Year:2019 | Volume:71 | Issue:4|Papers Count:19

In order to model the potential habitat of Bromus tomentellus Boiss and study the effect of climate change on the habitat of this species in Isfahan province method of modeling maximum entropy (MAXENT) were used. The species event data were determined by random categorization method using field visits and geographic information system including 60 rangeland locations as educational points. Also, 20 points of occurrence were surveyed using GPS in the western region of Isfahan as points of assessment. 22 environmental layers including 3 physiographic variables and 19 climate variables derived from temperature and rainfall were used in the modeling process. Using by Maxent, the relationship between species incidence and environmental factors was determined. Then, the effect of climate change using cluster variables of CCSM4 general circulation model was evaluated under two scenarios RCP2. 6 (optimistic) and RCP8. 5 (pessimistic) on geographic distribution of Br. tomentellus Boiss. Regarding the photo curves, the specie’ s behavior relative to the environmental variables of Br. tomentellus Boiss in the range of 2500 to 3500 altitudes, slope 10 to 30 degrees, annual precipitation is 240 to 260 mm and the average temperature is 8 to 10 ° C are more likely to occur. The habitat of the species studied during the two periods of 2050 and 2070, it was observed that under the optimistic scenario, 46. 1 square kilometers to the appropriate level of the habitat of the Br. tomentellus Boiss is increased and under a pessimistic scenario, about 35. 74 km2 is reduced from the appropriate level of habitat of this species.

Landslide susceptibility mapping is considered as the first important step in landslide risk assessment. The main purpose of this study is to compare the performance of a machine learning algorithm (a logistic model tree), and a statistical model (a logistic regression), for landslide susceptibility modeling in the Sarkhoon watershed, Chaharmahal and Bakhtiari province. For this purpose, at first, a landslide inventory map including a total of 98 landslide locations was constructed using historical landslides, and extensive field surveys. In addition, a total of 100 non-landslide locations were also identified to construct a database. The landslide and non-landslide locations were randomly selected and divided into two groups with a 70/30 ratio for modelling and validation processes. Twenty conditioning factors were selected based on literature review and geo-environmental properties in the study area. Subsequently, the logistic model tree (LMT) and the logistic regression (LR) models were applied to identify the influence of conditioning factors on landslide occurrence. Finally, the performance of the models in landslide susceptibility mapping was investigated using the area under the receiver operating characteristics curve (AUC). The results concluded that the LR model (AUC = 0. 797) outperformed and outclassed the LMT (AUC = 0. 740) model in the study area. Although both models were reliable tools for spatial prediction of landslide susceptibility; however, the LR model was more accurate that it can be proposed as an alternative tool for better management of areas prone to landslide in the study area.

Soil is known as a dynamic media so it easily degrade with inapplicable usage so with increasing in degradation of this limited source, the world’ s food safety would be in danger. Thus, applicable and sustainable usage of agricultural lands are become an essential and inevitable agenda. Therefore, the aim of this study is to Digital soil mapping using decision tree for agricultural land suitability, In order to constitute management programs for sustainable use of agricultural lands. For this aim, samples were collected based on cLHS and after some laboratory experiments, modeling and digital soil mapping were created by Random Forest Model. Also, agricultural land suitability for dominant crops were investigated by parametric method. The results showed that the land evaluation for irrigated wheat with surface irrigation 75. 27% of the total area S2 class and 24. 73% of the land in the class S3, respectively. In assessing the suitability of land for Maize irrigation, 14. 78% of the land in classes S1, S2 84. 82 of class and 0. 39% of the land in the class S3, respectively. Results for alfalfa irrigation land evaluation showed that 11. 10 percent of the land in classes S1, 88. 49% in the S2 class and 0. 4% of the class S3, respectively

Any Changes in a dry land surface ecosystem will be affected by the climate near the ground or microclimate in the vertical plane. In recent decades' wetland drying cause to reduced vegetation significantly. Assessing Zabol synoptic station statistics shown an increased temperature of this place. It seems that there has a direct relationship between the changes in land surface vegetation and increases the ambient temperature. The situation ground roll on microclimate has been investigated to illustrate this relationship. In this study we compare and assessment temperatures at depth of 5cm and surface and height about 150 cm and heat fluxes and energy in three microsites with different vegetation cover. The distance between the experiment microsites is about 20 km, and the elevation difference is less than 10 meters. Microsite A with the total vegetation average about 65%, B microsites 20% and microsites C with 100% bare soil. It evaluated the equation ρ c_p z_a (dT_air)/dt to investigate the role and effects of vegetation on the ground surface. Data analyzes showed temperatures in the period of study at the C microsites were higher than other microsites. It seems the lack of vegetation in microsites C has a major role in the higher air temperature. In micro site C At 00: 30 Am (local time) the air temperature was 3. 2º C higher than microsite A and B. The results showed there is a direct relationship between the vegetation cover percentage and air temperature because of different soil heat fluxes and surface temperature.

One of the types of water erosion and land degradation which causes imbalance, is the gully erosion phenomenon. Land degradation, a broken ecological balance of the land and landscape and risk of falling at biological resources in these areas, the study of the gully, is inevitable and necessary especially in the Darrehshahr Township. In this regard, Gully 36 number were selected in Darrehshahr area in the ilam province. To this end, were identified environmental factors, Physical-Chemical Soil properties, cover and hydrological properties of gullies tested using aerial photography, the digital maps and field operations. To determine the extent effect these factors on each of the gully geometry characteristics using fuzzy logic and information theory, the membership function and the weights of the membership function of each of the factors was calculated. Then relationship between the independent and dependent variables was obtained by using multivariate regression. Results of statistical analysis using multiple regression (stepwise method) revealed that length of gully with upstream area of the gully, top and bottom width and cross section of the Gully with basin elongation, deep gully with basin elongation and slope curvature, high of head Gully with local slope of the gully and steep walls of gully with percentage cover have a significant relationship. So could be concluded that characteristics of geometry gully in the study area would be a function of the upstream, basin elongation, curvature slope, Local slope of the gully head and the percentage of canopy cover catchment area of gully.

Current study is investigate the effects of range improvement treatments on vegetation performance in Zaloo-Ab rangeland that is 10 Kilometers far from west south of Abdanan County in Ilam Province. Vegetation sampling was done randomly in every control and corrective operation sites in length of three transects of 100 meters in 30 plots of one square meter. Vegetation specifications including production, density, percentage of cover crown, bare soil, stone and pebbles, litters and different classes of palatability. Obtained data were analyzed by version 16 of SPSS software using t-independent test and variance analysis to compare each corrective and control sites and three corrective sites together. The obtained results showed that provided corrective operations have caused increase in cover crown, production, density of class I and II plants and decrease in class III plants, bare soil and pebbles respected to control site (in one percent level). Results of one-way variance analysis and comparison of averages of measured vegetation specifications in three treatment sites also showed a significant difference in one percent level.

In this regard, the present study aimed to evaluate the performance of some of the non-oil mulch to stabilize sand dunes in the Kashan's Rig-boland desert. monthly surveys are conducted in the desert areas. To evaluate the effect of mulch on stabilizing the sand dunes, the effect stabilization index was used. The results indicate there is a significant difference between different mulch. The comparison test showed that the highest coefficient effect of stabilization with significant effect done on the biological mulch. After that, however, three other mulches including resins, inorganic and polymer are, respectively had the most significant effectiveness. Although there was not significant difference between these three types of mulches. Biopolymer Mulch with the lowest coefficient of stabilization effect showed significantly different from other mulches. Mulching in the hills with biological mulch, due to tightly crust formation against erosion, removal of sand and dunes almost stopped and hill completely has been stabilized. In this study, used mulches were initially very resistant and feasting the sands dune surface such as resistance crusts which were loss against any tensile and compressive force before mulching practices. . Therefore, different mulches treatments according to their durability and nature of structural have different effectiveness in reducing wind erosion effect. Among the studied mulches, just biological mulch and has usability and is capable for executive pilots.

The evaluation of Elymus hispidus var. hispidus ecotypes in different ecological zones of Kurdistan province was carried out at Baharestan Agricultural Research Station in order to nomination of the best ecotypes in terms of adaptability and establishment. The experiment started in 2010 and continued to 2015. For each Ecotype adequate seed of different stocks in whole of the province was reaped. In reproduction phase (2010 autumn) and after soil preparation, all ecotypes were planted on plots with 5*6 m2. In 2011 and 2012autumn, the Ecotype of each Species based on complete randomized block design with 3 replications and 2 meter intervals on 2*4 m2 plots and 4 lines with 4-meter length and 50 cm intervals (In order to elimination of marginal effects) planted. The measured traits for plant selection were 1) growing 2) flowering 3) seeding 4) Yield 5) canopy cover 6) height and 7) regrowing, all data were statistically compound analyzed by SPSS and averages were compared using Duncan method. Results showed that there were significant differences among the measured traits and ecotypes (P≤ 0. 05) in all studied years (2012-2015). In terms of measured parameters for all ecotypes of Elymus hispidus var. hispidus, Dolab Ecotype, showed superiority in the Baharestan research station conditions. it seems that altitude, soil properties and aspect factors have had most efficacy on different ecotypes operation of this specie in this study.

Given the increasing trend of application of Geographic Information System (GIS) for natural resources study in one hand and complication of biological, geomorphological, hydrological and ecosystem mechanisms on the other hand, scale is an overlooked but very impressive and flourishing concept. As for any natural resources study consistent with its phase, various maps are used and produced so in order to make the achieved results usable for planning as well as management of resources, determination of scale of the study and application domain for the results is very significant. Since using GIUH model in the basins without hydrological data have been widely recommended by hydrologist and this model developed in accordance to the relationship between geomorphological properties of basins and their effects on hydrological responses, so before using that it is essential to determine the optimal scale (in view points of accuracy, time and cost) which in this paper will be selected from 1: 50000 and 1: 25000 scales, inclusively used in topographic maps in Iran, using multi-scale analysis. Of course, it should be mentioned that giving a comparison between the results of GIUH and the recorded data as well as the model’ s effectiveness in our research basin has not been the purpose.

Dust event is one of the secondary complications of ecosystem in arid and semi-arid areas. This phenomenon results from system feedback against multiple factors of pressure and destruction. One of the most important foundations of ecosystems is vegetation. Because the vegetation factor reflects many factors in the ecosystem, therefore, the interaction of factors can be understood by studying the relationship between its changes and other factors such as dust phenomena. The aim of this study was to investigate the effect of vegetation and relationship with dust events in Esfahan province during 2000-2016 using Geographic information system and Normalized difference vegetation index. The data of dusty days in the region synoptic stations were provided from Meteorological Organization and the frequency of dusty days in different years were determined. Using the method of Normal Kriging in GIS; dusty days were zoned. Vegetation map was prepared based on NDVI in July for each year using MODIS image. The regression analysis of annual dust and vegetation index were also performed to quantitatively analyze the effect of vegetation cover on the occurrence of dust. The results showed. Vegetation cover has been the lowest during the study period in the east and center of the province. The NDVI was also the lowest in 2011-2012 and 2015, with a change from 0. 69 to-0. 19. The results showed significant correlation between the number of dust event and vegetation distribution

The studies of functional features of patches of rangelands will help effectively in the detection the healthiness of arid and semi-arid rangelands, the improvement of soil conditions as well as the recognition of the effects of managerial and natural changes of rangelands. In order to investigate the function of landscape, sampling from Niatak region of Sistan was conducted in the same condition that had some native plant species such as Alhagi camelorum and Salsola rigida and two planted species namely Tamarix ramosissima and Haloxylon persicum. Effect of these plant pots was investigated on characteristics of ecosystem function. 4 transect with 150 meters long was established and 11 soil surface indices was determined by using of three characteristics of stability, infiltration and cycling of nutrient from LFA method. The results indicated that two planted plant species had higher function rather than native plant species and differences were significant. Tamarix ramosissima had the highest function among the native and established plant species. In general, high function in planted patches ecological could be suggested to select suitable species in restorations of similar rangeland.

Many environmental challenges such as stormwater runoff and flood risk, chemical and particulate pollution of urban air, soil and water, the urban heat island, and summer heat waves are exacerbated in urban environments. Runoff from heavy rainfall in many parts of the world lead to erosion, sedimentation and transportation of elements that forest covers is the most important factor in controlling it. In this research, the qualitative and quantitative characteristics of runoff in Chitgar forest park have been investigated. For this purpose, runoff discharge, physicochemical parameters including total suspended solids, total dissolved solids, pH, and chemical parameters including calcium, magnesium, sodium, potassium, nitrate and phosphate were measured and analyzed during three storm events. The results of the present study indicated that the average values of the measured parameters were 1988. 3 l / h, 40. 64 mg/l, 2064. 8 mg/l, 7. 75, 2. 95 mg/l, 2. 23 mg/l, 584. 4 mg/l, 5. 71 mg/l, 1. 36 mg/l, and 0. 71 mg / l. Also, the correlation between parameters showed that there was a strong relationship between measured parameters, with the highest correlations between calcium with discharge (0. 66) and total dissolved solids (0. 69) and sodium with pH (0. 7) and total dissolved solids (0. 65). Comparison of the results obtained from this study and with those of other studies on water quality status of different rivers indicates that the qualitative pattern of urban runoff and also the relationships among the qualitative parameters of urban runoff are very different from surface runoff of rivers.

The phenomenon of climate change, especially the drought in Iran during the past decades are increasingly on the rise. In this respect the role of institutions and institutional entrepreneurship in areas that suffer from drought are can be used as the perfect solution for the management of drought. The aim of this study was to analyze the institutional management of drought with approach of social network analysis. The statistical research community is smallholder farmers of Saveh town. The dominant statistical method in this study is to measure and extract the total network indexes through the network analysis technique. Based on information obtained from the institutional rankings were determined that the most current information on educational information network two-sided with ministry of agriculture and veterinary. In the context of the flow of information, banks and credit institutions support the centrality of the ranking. In terms of information flow as well as the largest specialized veterinary related role information to current technical and specialized in order to catch up with climate change. The research results show that the different dimensions of social networks effect on the mobilization of resources and on the other hand, the lack of institutional entrepreneurship can damage caused by climate change will intensify. At the end, suggestions are made to improve the management of droughts.

Quantifying source contribution of aeolian sediments is essential to prioritize sources and mitigate wind erosion. The objective of this research is quantifying uncertainty associated with results of sediment fingerprinting method using Monte-Carlo simulation technique in the Sirjan plain. Six sediment samples were collected from the sand sheets and forty source samples consisting Qt (n=13); Qc (n=17); Qsg (n=5); and Dc (n=5) were collected from geological spatial sources in the surrounding area. Concentration of eight geochemical elements were measured in both sample group. A two-stage statistical method including Kruskal Wallis H test and a stepwise discriminant function analysis applied for discriminating of aeolian sediment sources. Based on two-stage statistical method, four geochemical properties consisting Fe, K, Mg and Cu were selected as optimum fingerprints. The Qc and Dc were recognized as dominant sources for aeolian sediments in the study area and also, full uncertainty or full range (0-100%) calculated for some source contributions. Therefore, management activities for mitigation of wind erosion should establish at the Qc and Dc source regions. This technique has great potential for quantifying source contribution of aeolian sediments at other area with active wind erosion.

The purpose of this study is to investigate the relationships between aboveground net primary production (ANPP) and environmental factors (such as elevation above sea level, slope, aspect, compound topographic index, seasonal and annual precipitation, seasonal and annual temperature) which was carried out in the rangelands of Hir and Neur in Ardebil province. Initially, considering the vegetation types and different classes of environmental factors, at the maximum vegetative growth stage, using one square meter plot with clipping and weighing (harvesting) method ANPP was estimated. Using digital elevation model (DEM) map, the maps of slope, aspect, elevation classes and topographic index were extracted. In addition, using gradient equations (calculated from the study areas stations) the seasonal and annual precipitation and temperature maps were extracted. One-way analysis of variance (ANOVA) was used to evaluate the factors between different sites. Then, to determine the most important environmental factors affecting on the ANPP changes, the principal component analysis (PCA) was used. Also, the ANPP map prepared using regression equation in GIS. The results showed that the variables are significantly different in sampling sites (P<0. 01). The results of PCA indicated that the components of one (include annual precipitation, annual temperature, elevation) and two (include slope) with 76. 10% had the most effect on ANPP. Also, ANPP map prepared using the extracted regression equation and the accuracy of the map was 0. 71, which indicates the validity of the model.

Landslide causes many social and economic losses in many parts of the world every year. These losses can be greatly reduced by using appropriate management measures such as mapping landslide susceptibility mapping in the basin. The aim of this study is landslide susceptibility mapping using Mahalanobis distance in the Latyan catchment. First, a total of 208 cases of landslides identificated and geo-referenced using geographic information systems based on an interpretation of aerial photographs and extensive field surveys and provided a landslide inventory map. The map of 12 factors, including rainfall, land use, distance to fault, distance from river, distance from road, lithology, altitude, slope, aspect, plan curvature, Peak Ground Acceleration and topographic wetness index as the most important factors in landslides was prepared. Then the correlating each factor and the landslide was examined. Finally landslide susceptibility zoning map was provided based on the Mahalanobis distance in Latyan catchment. To evaluate the results, the ROC and chi-square tests were used. The results show more than 80 % of the catchment located in range of high and very high susceptibility classes and need to suitable management operations. AUC index (area under the curve ROC) for this model is achieved to 0. 896 or 89. 6% which represent capability and high accuracy. Chi-square test results also reflect the proper separation of landslide susceptibility classes by model.

The role of shepherds in maintaining, managing and distributing livestock in rangelands is very important. Flock guidance plays a major role in the distribution of grazing and livestock performance in rangelands. Therefore, it is necessary to evaluate the existing spatial system and it is clear to what extent livestock are given in appropriate places according to ecological criteria and indices. The present study was conducted to evaluate the role of shepherds in herding and distribution of livestock (sheep) and its adaptation to rangeland suitability map. Record of movement of livestock in different months of the grazing season by GPS and its adaptation to rangeland suitability map which is led by shepherds in areas where the limitations of forage production and sometimes, the sensitivity of soil to erosion, have little value for why. Therefore, the hypothesis of the study that shepherd does not play an effective role in the distribution of livestock on the basis of rangeland merit is confirmed and given that shepherds have given the animals in places where they have little merit for why, it is concluded that the spatial system in the rangelands of the region is not efficient. Therefore, the use of new technologies such as GPS and electrical fences along with native knowledge in order to properly control the herd and reduce the burden of livestock grazing in the areas that are not based on ecological criteria and indicators, do not have the necessary merit, is suggested.

In order to provide animal’ s nutritional requirements and production of animal protein, it is necessary to adjust the balanced diet and the correct nutrition plan., which is based on proper understanding of food and this is possible through the analysis of nutrients. This research aimed to study and compare of forage quality in seven species that are grazing by camel including: Nitraria schoberi, Smirnovia iranica, Seidlitzia rosmarinous, Stipagrostis plumosa, Astragalus squarrosus, Alhaji persarum and Zygophyllum eichwaldii conducted in two stages of vegetative growth at Maranjab desert rangelands. For this purpose, the indices of dry matter (DM), Crude Protein (CP), Dry Matter Digestibility (DMD), Acid Detergent Fiber (ADF), Metabolic Energy (ME), Nitrogen (N), Phosphorus (P), Potassium (K) and Sodium (Na) were subjected to chemical analysis. The results showed that the forage quality indices between the species and phonological stages were significantly different (P<0. 01). In all species, as the growth stages and plant maturity progressed, the amount of crude protein, metabolic energy and phosphorus were decreased and the amount of dry matter and ADF were increased. While N. shoberi had the highest amount of crude protein (26. 51) in vegetative growth stage, S. rosmarinous showed the lowest protein (3. 91) at seeding stage. In addition to, with regard to both phonological stages, while the highest dry matter digestibility, metabolic energy, potassium and sodium were found in S. rosmarinous species, the highest amount of crude protein, nitrogen and phosphorus was observed in S. iranica species.

Given the importance of having data on vegetation and soil in different geographical aspect, the aim of this study is the assessment the geographical aspect's impact on Functional Potential and soil surface indicators in Chhar-Bagh Summer Rangeland, Golestan province. For the study used the method Landscape Function Analysis (LFA) and main Geographical aspect. For this purpose, in the four main geographical aspect, three transects 100, m were established and along the transects type, length and width patches and interpatches were measured. To calculate the Functional Potential (Soil Stability, Infiltration and Nutrient Cycling and and Vegetation Organization Index). To investigate the functional significance potential of SAS Software and ANOVA, for mean potential functional classification of Duncan Test used. To investigate the soil surface along each transect, 5 plots and 11 indicators way quality and using the scoring tables and to check the normality of the data, the Kolmogorov-Smirnov test was used. To investigate the significance Kruskal-Wallis nonparametric test and classification of soil surface indicators grouped Duncan test was used. The results showed a significant difference between the functional potential in different geographical aspects (P> 0. 05), So that the highest percentage of functional potential to the north and lowest in the East was estimated. Vegetation organization index for geographical aspects North, South, East and west were respectively 0. 53, 0. 43, 0. 38 and 0. 51. The results showed that except cryptogam cover and Micro-topography indexes, all indicators were significant in different geographical aspects (P> 0. 05).