نشریه پژوهش های آبخیزداری
پیاپی 116 (پاییز 1396)

Rangeland habitats of the Avrin Mountains, Khoy are representing a wide range of mountainous vegetations in terms of climate, soil, topography and plant cover in Western Iran. In this regard, plant species were sampled periodically during the 2013–2014 period, and identified using the existing floral references. Their life-forms were determined based on the Raunkiaer’s classification and rare and endangered species of the area were recognized based on the criteria of Association for Protection of Genetic Resources. Moreover, their geographical distribution was determined on the basis of classification of vegation regions. Floristic study of the collected vegetation resulted in the identification of 287 species belonging to 52 families and 172 genera of vascular plants. The largest plant family is Asteraceae with 46 species and the largest genus is Astragalus of Fabaceae with 19 species. The diagram of plant life formed by the Raunkiaer method showed that the dominant life forms of the area were hemicryptophytes with 47% and geophytes (Cryptophytes) with 18%, whose high percentage demonstrate the cold climate and mountainous region. Cryptophytes(18%), chamaephytes (16%), therophytes (15%) and phanerophytes (4%) have the less degrees of abundance. The geographical distribution of plants showed that 48% of species belong to the Irano–Turanian zone. The distribution of 7% of the flora in the region is multi-regional, 22.5% are Irano-Turanian and Euro-Siberian, 2.5% are Irano-Turanian and Mediterranean, 0.7 % are Euro-Siberian and Mediterranean, 4.5% are Euro-Siberian, and 1.3% are Mediterranean-related. Among the identified species, 2.5% have cosmopolitan distribution and 11% are endemic to Iran. According to the Protection Association of Genetic Resources, 14 species are classified as rare and endangered plant species.

Land-use planning is a science that specifies the optimized land-use based on ecological and socioeconomic characteristics. This study investigated ecological capability evaluation for agriculture and rangeland uses using the GIS in the Sepidan County, Fars Province. There are different methods for weighting of parameters. A proposed quantitative method was used in this research for weighting criteria and land-use evaluation compared to the current method of multi-criteria evaluation. In relation to the common method of multi-criteria evaluation, it uses weighting approach based on the Modified Analytic Hierarchy Process (M-AHP). The performance of each of the mentioned models was evaluated throughout error matrix. Results showed that the proposed method of Regional Weighting (RW) has higher accuracy than MCE (M-AHP) in estimation of the ecological potential of the study area. In overall, the results showed that the proposed method of Regional Weighting can be replaced with common methods of weighting due to simplicity, as it has no need for questionnaires, which saves time and costs.

Landslide can be defined as mass movement of steep slopes affected by the force of gravity, which causes numerous life and property damages in the mountainous, high-rainfall and earthquake-prone regions each year. Diagnosis of the time and amount of sliding mass deformation is essential to understand the physical causes of landslide occurrence and to warning announcements for potential hazards. In this research, the relationship between displacements of the Tavan landslide in the north east of Qazvin Province and land use factor was evaluated. A network of 20 fixed points was created on various land uses inside and outside of the sliding mass to monitor the amount of displacement. The displacements of each point were measured using dual frequency GPS for 5 periods. The results of monitoring during 511 days showed that total horizontal displacement of moving points in five monitored periods was 1876 mm, with a mean monthly movement rate of 110 mm. The total vertical displacement of the moving points in the same periods was 898 mm, with a mean monthly movement rate of 53 mm. The results showed that there was a good relationship between the land use and the amount of mass displacement. Northwestern parts of the sliding mass, with the orchard land use, exprienced much greater displacements than those placed on the pasture. From the total measurements of the points with orchard land use, 70% had horizontal displacement and 40% had vertical displacement, while these percentages were reduced to 20 for pasture land use. Therefore, considering the location of the Tavan village in the vicinity and downstream of orchards region, limiting the development of orchard land use in the upstream, and conversion of irrigation system from flooding to pressurized can largely prevent the risk of subsequent landslides.

Quantitative and qualitative characteristics of the suspended load may affect soil and vegetation. After drawing an area map, soil and vegetation were examined at both floodwater spreaders and control areas. The soil was sampled and examined by chemical analysis as three-factor randomized complete block design including condition of basin, distance and proximity to the banks, depth of soil 0–20 cm and 20–60 cm in triplicate. Condition, trends and plant production in two stages (before and after floodwater spreading) were studied by the four-factors method, trend balance and clipping and weighing, respectively. Results showed that spate irrigation affected soil sodium absorption ratio (SAR), sodium, calcium and CaCo3 with a significant increase compared to control in all three phases of soil texture became heaveier in some localities. SAR significantly increased with depth. An Increase in EC and SAR caused little salinity and sodicity, respectively. The rangeland condition, which was poor prior to spate irrigation (40 kg dry matter per hectare per year), and Showing a negative trend, improved to the intermediate category, it was with a positive trend and production of 110 kg dry matter per hectare per year after spate irrigation.

Indigenous knowledge plays an important role in the sustainable management of natural resources. This study was performed on the Khurtab Rudbar watershed, the Noor County, to investigate the role of indigenous knowledge in the conservation, restoration, and sustainable utilization of the rangeland. The stratified random sampling method was performed in the descriptive-survey type framework. The Questionnaires used in data collection was based on the Likert Spectrum. Validation of the research tools was confirmed by seeking expert opinion and their reliability by determining the Cronbach٫s alpha coefficient for the main variables. The sampling population consisted of 280 area stakeholders, out of which 40 were selected by using the of the Cochran٫s relationship. The data were analyzed using the SPSS software, determining the Spearman٫s correlation coefficient, and calculating the significance of correlation coefficient of the linear regression. The results indicated that there existed a significant relationship between the levels of indigenous knowledge of the graziers and their participation in the study with the correlation coefficient of 0. 686 and the confidence level at the 99%. This further indicated that the stakeholder٫s participation in the rangeland restoration was more effective than their influence in its protection and sustainable utilization. The take home message is: Application of the indigenous knowledge is essential for the sustainable management of the rangeland.

Finding suitable locations for floodwater spreading and its infiltration into the aquifer is the first and most important requirement in any floodwater spreading project. In this study, a combination of geospatial information system (GIS) and multi criteria decision making (MCDM) is used in the form of analytic network process (ANP) method in order to determine the most appropriate areas of floodwater spreading. In the first step, necessary, effective, and available criteria, which influence the spreading of floodwater in the region, were identified. The information layers were prepared in the GIS and weights of the criteria and layer classes were calculated using the ANP and paired comparisons method, and the whole region was partitioned in terms of the weighted criteria. Finally, by combining layers of information based on the ANP process, ranges were divided into five categories from very poor to very good. Results showed that 9% of the area has very good potential for floodwater spreading, and these places are located on alluvial fans, quaternary formation and slopes less than 3%. Moreover, according to the field survey, it was determined that the already performed floodwater spreading have mainly been practiced in suitable areas.

Despite the long history of implementing watershed management restorative projects, evaluation of the effects of these projects on vegetation and in particular the species diversity of plants has been neglected. The purpose of this study was to investigate the effect of watershed management projects (Check Dam) on the variation of sub-basin species diversity in Anbaran area of Ardabil. In 2017 sub-basins where check dams were established about a decade ago, were considered as
experimental watersheds, and subbasins with no implementation and similar in terms of environmental characteristics, were considered as control. Using a systematic randomized method, 20 plots of one square meter were established in each of the subbasins, along with six transects of 150–100 meters along the sides of the waterways.Percentage of crown cover and the number of bases of any species were recorded, and numerical indices of species richness, evennsess and
species diversity were calculated. Results showed that despite means of Margalef Species Richness Index, Simpson Uniformity Index, and Shannon-Weiner Diversity Index (1.74, 0.65 and 1.41) were higher in experimental watersheds than controls (1.68, 0.63 and 1.36), differences were not statistically significant. However, based on the Renyi Index based diversity curve, the experimental basins had a high diversity in comparison with the control basins. Meanwhile, the mean Margalef Species Richness, Simpson Uniformity Index and Shannon-Weiner Diversity Index in the northern watersheds (1.85, 0.67 and 1.47, respectively) were significantly higher than the southern watersheds (1.58, 0.61 and 1.30). Accordingly, it can be concluded that the check dam projects have had a significant impact on the improvement of diversity index and supporting the biological objectives in the subbasins. According to the results, implementation of check dam projects is recommended in other similar environmental conditions. Sub basins with check dams can be considered as priority locations to protect vegetation diversity.