جستجوی مقالات مرتبط با کلیدواژه « سیستم اطلاعات جغرافیایی » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

In recent decades, the ever-increasing population, human needs, and changes in the consumption patterns of societies require the planning and management of water resources more than ever. Among the management strategies of underground water resources, we can point out the compensation of these resources through artificial nutrition and exploitation according to the capacity of aquifers. The studied area is located in the Qorve watershed with an area of ​​232.17 km2. In this research, which was carried out in Qorve plain in Kurdistan province, nine parameters of the slope, land use, the thickness of unsaturated alluvium, hydraulic conductivity, distance from the river, geology, electrical conductivity, aquifer transfer capability, and vegetation were investigated. The research method was based on the weighted-linear combination (WLC) method. The weights entered in this method were extracted by the AHP model in Super Decisions software. The results of this method showed that about 23.4% of the total area of ​​the plain and 54.4 km2 have a great value for feeding, and about 19% of the total area of ​​the plain is considered unsuitable.

Saffron (Crocus sativus L) is an expensive and highly valuable plant recognized globally for its many medicinal properties and low water demand. Hence, the development of saffron farms in semiarid regions has received much attention as it increases water use efficiency (WUE) in such water-deficient areas. Considering the different factors involved in saffron growth and yield, the geographical information system (GIS) is the best and most cost-effective method to identify areas potentially favorable to saffron cultivation. The current study aimed at zoning the land area favorable to saffron cultivation in Kerman Province was conducted over the period 2017-2019. The required daily data were collected from 13 synoptic stations recorded during the years 1998 to 2016, which were subjected to the homogeneity test before the relevant GIS information layers including altitude, slope, frost, rainfall, absolute maximum and minimum temperatures, and probability of temperatures below 5º Celsius in November were prepared. Subsequently, the relevant variograms were drawn. Also, the slope map was extracted using the digital elevation model. Finally, weights were assigned to the above layers using the Analytical Hierarchy Process (AHP) technique, and the final zoning map was prepared in ArcMap. The map thus prepared revealed that the southern and eastern stretches of the province were not suitable for saffron cultivation while the more favorable areas were located at the foothills in Baft, Bardsir, Zarand, and Shahrbabak towns. Moreover, Kahnuj, Manojan, southern parts of Jiroft, eastern stretches of Bam, and southern stretches of Baft, accounting for around 59% of the total provincial land area, were recognized as unfavorable to saffron cultivation. The remaining lands of the total provincial area were classified as follows: 15% relatively suitable, 16% suitable, and about 10% highly suitable for saffron cultivation.

Ecotourism, as a side activity of rangeland, can be effective in improving the livelihood of rangers and will reduce the pressure on rangelands by economizing rangeland. In this study, with the aim of evaluating the potential rangelands of Dermian , for ecotourism use, based on environmental and ecological factors (climate, topography, soil, distance from water sources and vegetation attractions) and infrastructure (distance from the city and from roads), was done. From the combination of maps in the GIS environment and based on the FAO limiting factor approach,, the rangeland suitability was determined. Based on the results, 36.7% of rangelands are in the middle suitability category (S2), 46.5% in the low suitability category (S3) and 16.8% in the non-suitable category (N) in terms of ecotourism. In this regard, 61.5% of the rangelands for livestock grazing, have low suitability (S3) and 38.5%, unsuitable (N). The percentage of vegetation and,, the poor condition of soil erosion, are factors limiting the suitability for ecotourism and livestock grazing. , it is necessary to reduce the number of livestock and graze livestock in accordance with ecological principles; that used the rangeland of the region for ecotourism along with livestock. This, in addition to compensating for the economic problems, will also help restore vegetation. Due to the need to preserve rangeland,, forest parks can be created to accommodate tourists, up to a suitable radius of the desired rangelands, and by placing remote viewing platforms and sidewalks, from the amount of damage to vegetation and reduced soil degradation.

Evaluating ecological capability is of at most importance in preventing significant damages to natural and environmental resources in addition to its pivotal roles in ecosystem sustainability and sustainable development as well. Therefore, this study aimed to evaluate the ecological capabilities of Khorasan Razavi Province for the conservation of key mammal species. Accordingly, eleven indices derived from nine general criteria including distance from roads, slope, elevation, vegetation density, geographical direction, distance from protected areas, distance from water sources, distance from residential and agricultural areas, were selected and evaluated. The relative importance of the indices was then determined using a hierarchical GIS environment. Based on the results, the slope was the most important driving force for the conservation of species such as the wild goat and wild sheep with the coefficients of 0.372 and 0.342, respectively while the elevation was detected as the most contributing factor for the species of the pallas’s cat, leopard, sand cat, and caracal with the coefficients of 0.227, 0.338, 0.228 and 0.332, respectively; The factors most determinant for the habitat suitability of the Asiatic cheetah, were the distance from agricultural and residential lands with a coefficient of 0.29 while for the goitered gazelle, the vegetation weighted the most with a coefficient of 0.311. In conclusion, the identified locations are recommendable to be included in the current conservation network

Assessment of the potential ecological and natural capacity of each area with proper planning can lead to sustainable and continuous utilization of natural areas. By increasing the population and psychological pressures resulting from the bustle of cities, ecotourism has become doubly important as one of the ways to reduce the pressures on people. The development of ecotourism to conserve natural resources should be commensurate with the natural and social potential of the region. Due to the importance of conserving natural resources, the purpose of this study is to evaluate the ecotourism potential of Chaharbagh summer rangelands in Golestan province based on the FAO limiting method and using GIS. The factors assessed include two ecological categories (climate, altitude, slope, soil, water resources, distance to attraction places, value attractive vegetation) and infrastructure (distance to city, amenities, roads, and access routes). The results showed that the total area of the region is 25.36% (2249.29 ha) with medium potential and competence (S2), 28.65% (2542 ha) with low potential and competence (S3), and 45.98% (4079) hectare lacks ecotourism competence and potential (N). The results also showed that water resources, soil, slope percentage, vegetation attraction value, access routes, and distance to attractions are factors that reduce the potential and merit of tourism and altitude factors, distance to city and facilities, welfare as well as climate (temperature) are factors that increase the potential and merit of tourism. Chaharbagh rangelands have suitable facilities and potentials in terms of tourism, and observing the principles of tourism and preserving natural resources, in addition to creating employment and income for the residents of the region, can help the protection and sustainable development of the region.

The complicated relationship between land use (LU) and environmental factors influences human livelihood; hence, it is essential to monitor LU changes and to prepare pertinent maps due to their relevance to such vital fields as urban planning, climate change, and environmental monitoring. In this study, a supervised classification was applied to three Landsat images collected over time (1990, 2000, and 2018) in order to derive the data on land use changes in Bushehr region. The supervised classification results were further improved by employing image enhancement and classification accuracy of the Landsat images was enhanced by visual interpretation to enhance. Finally, eight LU categories were identified and mapped. It was found that land reclamation projects over the last three decades had had drastic effects on LU changes throughout the study area. Land use changes during the study period show increasing trends as evidenced by the 29.19 hectares of agricultural land with a rise of 30.19% and the 15.78 hectares of urban and rural residential land with a rise of 16.39%. In contrast, declines are observed in barren land covering 4.15 hectares with a change of -4.31%, salty land covering 11.66 hectares with a negative change of -12.11, and sandy land covering 5.21 hectares with a change of -5.41. Hence, agricultural land area as well as urban and rural residential areas show significant increases whereas barren, salty, and sandy land areas show decreases. These changes in LU reflect regional policies and the dynamics of human impacts (agricultural and construction activities) on land use changes in the study region. Identifying the causes underlying these changes, the present article tries to formulate policy recommendations toward improved land use management.

Although groundwater resources have long been selected as a safe choice for resolving human water requirements, overexploitation of them, especially at Ardabil plain, has promoted a decrease in the quality and quantity of these resources. One of the significant solutions is to identification of the groundwater potential zones and exploitation of them according to their potentials. The aim of this study was to compared the efficiency of two objective models: Index of Entropy (IE) and Naïve Bayes (NB) in groundwater potential mapping of Ardabil plain, located in northwest of Iran. For this purpose, ten groundwater occurrence factors including elevation, slope, soil, rainfall, distance from river, land cover, normalized difference vegetation index (NDVI), lithology, groundwater depth, and transmissivity were used based on the availability of data. In order to reduce subjectivity in groundwater potential modeling, all spectral groundwater data layers were classified into objective classes by using Jenks optimization technique. After computing groundwater potential index for the models, receiver operating characteristic (ROC) curve and the area under the curves (AUC) were implemented for validation of the models. The AUC values for the IE and NB models are 0.728, and 0.821, respectively. The overall results approved that both of the models have good capability for demarcating groundwater potential zones but the NB model performed better than the IE model for groundwater potential mapping in Ardabil Plain. The results of accurate groundwater potential mapping at Ardabil plain can be useful for groundwater resources management and avoiding overexploitation in the plain.

Identification of habitats potential of endemic species can facilitate conservation planning and rehabilitation programs in watershed. The purpose of this study is modelling the distribution of Artemisia aucheri habitats in watershed of Baladeh Nour city, Mazandaran province. For achieve of this objective, environmental map variables (physiographic, soil and climate parameters) was prepared with geographic information systems techniques in cell size of 10 x 10. Also; 60 site as well as the presence or absence of species were recorded by sampling classified – random. For each sampling site were recorded information about the presence or absence of species and environmental variables, and the relationship between species distribution and environmental factors was determined by using logistic regression (LR), and forecast maps the distribution of the Artemisia aucheri Boiss was produced in the study area. According to LR results, between 14 environmental variables: Slope, pH, Sodium Absorption Ratio, Silt and Annual Mean Temperature were the most important environmental factors influencing the distribution of the species. Evaluate the correctness statistical models were performed by using the kappa coefficient and ROC area under the curve plots. Value indices respectively are 0.5 and 0.75 for the logistic regression model; their values indicated the logistic regression method can to create potential habitat map on local scales. This model, therefore, can be applied to recognize potential sites for rangeland reclamation projects.

Rainwater harvesting is a management technique with many positive results that can be used to supply the water needed by livestock in rangelands. In this study, suitable sites for the construction of rainwater harvesting systems using multi-criteria analysis (MCE) and hydrological model (HM) in the GIS environment were identified in the nomadic ecology of Ab Bahareh at the interval of Bahmaei and Lendeh counties in Kohgiluyeh and Boyer-Ahmad province. For this purpose, appropriate criteria maps to identify sites of rainwater harvesting system including slope, rock type, land use and land cover, runoff depth, and drainage density were provided in the GIS environment. After classifying the suitability map of each criterion, the classified map of the criteria was overlaid into the geographic information system environment and the appropriate sites for the rainwater harvesting system were identified. The results showed that in terms of each of the selected parameters, except for the slope, about 30 to 50 percent of the Ab Bahareh area was very suitable for the construction of rainwater harvesting systems. Due to the mountainous nature of the region, the slope parameter is the main limitation for the construction of rainwater harvesting systems. Based on the combined analysis of all the criteria selected, about 25% of the nomadic ecosystem of Ab Bahareh is highly suitable for the construction of rainwater harvesting systems, especially pits and ponds, rock outcropping catchment, road catchment, and check dams that can be provided during the dry season between rains. In regard to the number of 4000 goats and sheep in 5 villages in the nomadic ecosystem of Ab Bahareh, assuming the daily requirement of each livestock to 4 liters of water and the dry period of 30 days between the main rains, the total catchment area for the 25 mm rainwater harvesting system to meet the needs of livestock in the region is about 2.4 hectares.

Assessing the potential habitat and studying the geographical distribution of species is a key issue in many ecological studies, environmental protection, wildlife, and assessing the trend of changes at various scales. Therefore, in the present study, modeling of potential habitat of Ferula ovina in the present and future years was performed using a generalized incremental model in Fereydunshahr region. The results showed that in 2030 and 2080, in exchange for all climatic factors remaining constant, except the average annual temperature, the probability of surviving the Ferula species has increased; in other words, the probability of its occurrence increases. The habitat area in the class where the species is most likely to be present is currently about 12,970 hectares in Fereydunshahr, Isfahan, which in 2030 and 2080 will be reached about 27157.3 and 31036.9 hectares, respectively. This indicates that the increase in the average annual temperature in 2030 and 2080 compared to now will have a positive effect on the presence of the species in the habitats studied. Because according to the results obtained in response curves, by increasing annual temperature, the probability of the presence of Ferula species increases. The results of this research can be used to improve and rehabilitate the vegetation of areas with similar conditions, which is one of the important achievements of this research.

Planning for management of the forests in the future is not possible without having sufficient information about the forest degradation conditions in the past. The present study was conducted to model the forest degradation levels using logistic regression in the Masal watershed NO: 12. In this study, the factors of slope, altitude, geographic direction, distance from rivers, distance from the road networks, distance from residential areas, population centers and distance from barns as independent variables and different degrees of forest degradation entered into the regression model as dependent variables. Extraction of independent variables is done by using the digital maps of the area and recording the forest degradation degrees is done through terrestrial field work. To determinate the impact of each factor a hierarchical analysis method and to model the factors the logistic regression with five connects functions including: Cauchit, Negative log-log, Complementary log-log, Logit and Probit were used. The statistical tests of similarity and Wald were used to examine the significance of the model and its coefficients. The results showed that the model constructed with the Probit connection function has the appropriate capability in modeling the forest degradation. The results also showed that 20760.32 hectares of studied forests (equivalent to 83 percent of the total forest area) were degraded from very low to moderate levels. As a result, the conservation plans for 83% of the watershed forest areas and the implementation of recovery operations for 17% of the forest area (according to the forest degradation map presented in this study) have a favorable effect on improvement of the forest condition in the studied watershed.

The Identification of the affecting factors for establishment of native vegetation in area can help to manage rangelands correctly. Desirable habitat will have a significant impact on the survival and reproduction of species. The development of science of statistics and geographic information systems has been made to determine of the habitat prediction of plant species using modeling approaches. So, this study has been done by the purpose of prediction of habitat Artemisia aucheri map using Ecological Niche Factor Analysis in summer rangelands of Balade, Nour city in the Mazandaran province. For achieving to this purpose, the map of environmental variables (physiographic, soil and climate parameters), was prepared after sampling soil profiles and collecting climate variables information from the meteorological organization of Mazandaran province and physiographic maps, via GIS techniques in cell size of 10 x 10. Also; 30 sites were recorded as the presence of species with sampling classified – random. Ecological niche factor analysis counted as a profile model and it is one of the most frequently used techniques to generate species distribution map which uses species “presence-only” data. According to this results A.m.p, Aspect, Ec, TNV were used as influential environmental variables. Also, the evaluation of the model indicates a high accuracy model of the Ecological Niche Factor Analysis of the Artemisia aucheri by using Boyce index in the study area. Furthermore, the results of this study showed that Artemisia aucheri has sort of limited study area and tends to live in its own special habitat conditions.

Fire is considered as one of the main causes of disruption and change in natural ecosystems. Identifying the effective factors in the occurrence of a fire and providing a spatial pattern of its risk is one of the basic tools for achieving fire control. The statistics showed that 1124 incidents of fire caused to burning of 7364 hectares of forests and rangelands in Kurdistan province, between 2006 and 2015. Therefore, in this research, a fire risk map was developed in natural areas in Kurdistan province using statistical index method (SI) and Geographic Information System (GIS). In this study, in order to prepare a fire hazard map, six parameters including three natural variables: slope percentage, aspect, elevation and three human variables, distance from the village, distance from the road and distance from the agricultural land were used. From all of 1124 fire cases, 70% of the data (787 cases) were used for modeling and 30% (337 cases) were used for model verification. The results showed that about 50% of the area of Kurdistan province (14400 km2) is in high and very high fire hazard classes. Also, findings showed the high accuracy of the statistical index method in identifying areas with a fire hazard with a precision of 93.5% (315 out of 337 cases of fire).