ECOPERSIA
Volume:11 Issue: 4, Autumn 2023

Over the past twenty years, Iran has experienced a rise in extreme temperatures, particularly in hot events like extreme temperatures, as indicated by recent studies. This research seeks to analyze the annual maximum temperatures (AMT) in the dry Province of Kerman, Iran, focusing on both stationary (S) and nonstationary (NS) behavior.

Trend, homogeneity, and stationarity tests were utilized to identify the critical characteristics of the AMTs from 1979 to 2019. Frequency analysis of the AMTs was conducted using both stationary Generalized Extreme Value (S-GEV) and nonstationary GEV (NS-GEV) models, estimating distribution parameters through a maximum likelihood estimator(MLE). In addition to the time-varying NS-GEV (TNS-GEV) investigations, soil moisture (SM) was incorporated as a covariate. 

Results demonstrate that, compared to the S-GEV case, the NS-GEV frequency analyses significantly impact the return values of the AMTs, leading to an increase. The NS-GEV estimations for 50-year return levels were significantly higher than those in the S-GEV. The study’s findings revealed that the average Akaike Information Criterion (AIC) for both the S-GEV and TNS-GEV estimations decreased from 110 to 71 across all 12 selected stations in Kerman Province. The AIC value for the NS-GEV with the soil moisture (SM) covariate was approximately 94. Thus, the TNS-GEV frequency analysis of AMTs resulted in improved AIC values compared to the NS-GEV with soil moisture as the covariate.

Given the nonstationary (NS) conditions caused by natural and/or human activities, it is recommended to utilize NS frequency analysis for estimating hydrologic variables across different design periods. It has been noted that NS-GEV frequency analyses lead to higher return levels of AMTs than S-GEV analyses.

In this study, the response of individual trees and the stand structure to windstorm damage were investigated in a mixed broad-leaf forest stands located in Darabkola Forest, northern Iran. A full inventory was performed for all trees with diameter at breast height≥ 10cm and all damaged trees were identified within the study area. The number of the damaged trees varied with species, ranging from 0.04% (2 individuals) in Tilia begonifolia Stev to 53.7% (2709 individuals) in Fagus orientalis L. Among the damaged trees 5054 recorded, 2231 (44.20%) had been snapped and 787 (15.6 %) uprooted, and 2028 (40.20 %) were snags. Among the species, Fagus orientalis L. (47.7%), Alnus subcordata C. A. Mey. (19.7%) and Carpinus betulus L. (18.8%) were most susceptible to uprooting, whereas Populus caspica Bornm, Quercus castaneifolia C. A. Mey. and Ulmus glabra Huds. were the least susceptible to uprooting. Trees ≥60cm dbh were more likely to be snapped (78%) or snags (69%), whereas trees <60 cm dbh were more presumably to be uprooted (50%). Also, about one third (33%) of total trees larger than 60 cm (dbh) have showed distinct effects and individual trees >20 m were more commonly uprooted. Finding showed that Oriental beech and Common hornbeam to be species that were most susceptible to both being snapped and snagged, whereas Caucasian alder had the most uprooting damage among the other species. Overall, features like species, D.B.H, height and height to diameter ratio (H/D.B.H), were intensively related with the type and severity of windstorm damage.

Haft Barm is a series of five small lakes in the southern Zagros region which has encountered recent rapid development of human settlement. This article reports a survey on its essential ecological attributes.

Water samples were taken from three locations in March and June 2020 and analyzed regarding physical and chemical factors and plankton communities. Trophic state and primary production were estimated.

Results showed water temperature 8.2–23.1 °C, dissolved oxygen 6.3–8.3 mg.L-1, salinity as electrical conductivity 739 – 971 µS.cm-1, total nitrogen 0.1–1.1 mg.L-1, and total phosphorus 0.4 and 3.8 mg.L-1. Algae of the lake consisted of 24 taxa, the highest density of which counted 23360 cells per liter in June, and the Chlorophyceae were the dominant group. The Zooplankton composition was of four taxa from Cladocera (Bosmina sp. and Daphnia sp.), Copepoda (Cyclops sp.), and Rotifera (Rotaria sp.), with the highest densities in Rotaria (35 individuals per liter). Phragmites sp., and Juncus sp. were the dominant species in the macrophyte community besides Polygonum amphbium, and Potamogeton pectiatus. The very high concentration of total phosphorus is a strong sign for predicting a eutrophic condition. The average trophic index is estimated at 88, which suggests a eutrophic to hyper-eutrophic state for the lake. The estimated primary production of the lake was 1114 gC.m-2.A-1.

The current research was conducted with the purpose of analyzing the land use change in a 20-year period. In this regard, an integration of remote sensing and the DPSIR framework was done to investigation of the land use change in the Eskandari Watershed located in the Zayandeh roud Watershed.

Through conducting a workshop and stakeholder interactions, a set of drivers (D), pressures (P), state (S), impacts (I), and responses (R) were identified and investigated in the DPSIR framework. Satellite images of Landsat 5 and 8 (2011 and 2021) and the Markov model for predicting the land use changes (2031) were used to investigate the dynamics of land use change. Maps of land use the three times, the focus group discussions (FGDs), expert’s experiences and stakeholders were applied using an interview and questionnaire methods to identify the changes components based on the DPSIR framework.

The findings of the research showed that in 2011, 2021, and 2031, irrigation and dry farming were the best kind of land use in the Eskandari Watershed, covering 42.16%, 40.66%, and 52.19% of the total area, respectively. Also, moderate rangeland (28.57%), in the Eskandari Watershed showed a declining trend.

Due to the increasing process of land use destruction in the future and the ineffectiveness of solutions in the past years, to prevent the cross-sectional strategy of the isusues, is recommended to use the DPSIR comprehensive approach for problem solving and optimal management responses

The purpose of this research is to formulate a program and design a suitable model for environmental monitoring of water quality in order to reduce the costs of water quality monitoring and evaluation in No.1 Zabol Chahnimeh.

In this study eight sampling stations were selected in the bed of the reservoir No.1 in order to monitoring and measuring physical, chemical and microbial parameters. Sampling was conducted systematically on a month basis for one year. Then the data were analyzed with the help of multivariate statistical methods such as cluster analysis, Principal Component Analysis (PCA) and factor analysis.

Using multivariate statistical methods, No. 4, 5, 6 stations were selected as the main stations for sampling and factors of temperature, turbidity, DO, COD, magnesium, sodium, calcium, phosphate, chlorine, nitrite, sodium Absorption Ratio and pH was determined as the main water quality indicators. It was revealed that temperature, DO, nitrate and turbidity parameters should be sampled monthly, but the other parameters could be sampled periodically or even quarterly to model an optimal monitoring of water quality in reservoir No.1 during a year.

In general, the evaluation of the quality status of this valuable water resource by reducing the number of sampling stations, eliminating some unnecessary parameters and reducing the frequency of sampling completely and without defects and at a much lower cost is done for this reason, having the lowest costs and proper timing, management of the main reservoir will be possible considering all effective parameters.

Preventing rangeland degradation and conserving them is a challenging task that necessitates targeted changes in rangeland policy and management systems. Planning should aim for the optimal utilization of rangelands while meeting the needs of stakeholders. One of the most crucial measures involves adopting a systemic approach to rangeland management, encompassing all resources, livelihood potentials, and income generated from rangelands through multi-purpose use. To effectively manage rangelands, it is crucial to take a comprehensive approach that considers all resources, livelihood opportunities, and income generated from these areas through multi-purpose use. This involves adopting a systemic approach to rangeland management, encompassing the identification and utilization of non-sustainable potentials within the content of multi-purpose exploitation of rangelands. Such an approach can have a significant impact on reducing the livelihood dependence of pastoralists. Since numerous factors influence its successful implementation in rangeland management, particularly in the summer season, this research was conducted to investigate the influential drivers affecting the development of multi-purpose management in the summer rangelands of Mazandaran Province, utilizing a future studies approach.

This descriptive-applied study employed a survey method. The study population comprised experts, deputy heads of departments, and members specializing in rangeland management. Through purposive judgment sampling, 50 individuals were selected from these populations within the natural resources domain in Sari, Mazandaran Province. Data was collected using a researcher-developed questionnaire, and the Cross-Impact Analysis technique was applied to analyze 21 extracted indices from individual and group interviews. The MicMac software facilitated this analysis.

The study revealed that the primary influential drivers for the advancement of multi-purpose rangeland management included “decentralization and stakeholder participation in the implementation process of multi-purpose plans,” “The results indicated that the indicators “ decentralization and stakeholder participation in the implementation process of multi-purpose plans,” “ generation of new employment prospects and strengthening of rural income potentials,” “ establishment and fortification of rural cooperatives and organizations,” “ governmental support and assistance,” and “ trust-building communication between stakeholders and the government” were the most significant drivers with the highest coefficients of 607, 596, 585, 585, and 564, respectively. These indicators influenced the multi-purpose utilization of the studied region’s rangelands.

Based on the obtained results, the paramount recommendation of this study, employing a forward-thinking approach, is the development of a long-term vision document encompassing economic, socio-cultural, and environmental dimensions. This strategic move is poised to catalyze the transformation of the multi-purpose rangeland management system in Mazandaran Province.

The results of wind erosion threshold estimation in the studied area showed that the velocity of wind erosion threshold varied from 17-6 (m.s-1) and the erosion rate ranged from 30 to 2200 (gr.m-2.min-1) at a wind velocity of 20(m/s). The lowest threshold velocity is located in the sedimentary plains of Jarahi-Mahshahr, located in the northwest of the center, and the highest amount of erosion was in the alluviums and Alluvial Fans of Hendijan anticline, located in the southeast of the center. Conclusion This study considers the primary factor of dust emission potential based on land units and reveals the substantial of alluvium, alluvial fans, and alluvial plains as major contributors to the erodible sediment contributing to dust emissions in the study area. Alluviums and alluvial fans deposited by ephemeral rivers in the eastern foothills of Hendijan contain fine-grained sediments and marl that are highly erodible and must be stabilized early on. Furthermore, according to the results of granulation tests conducted in accordance with the Chepil theory, the erodibility of all samples collected from the dust sources of Khuzestan province was high, and all samples were sensitive to wind erosion. Overall, by locating dust sources based on land units, we can implement more accurate and effective land stabilization methods against wind erosion in alluvium, alluvial fans, and alluvial plains. Furthermore, using the Chipel theory and grain size, we can classify the soil erosion susceptibility of these areas