Measuring the extent and impact of urban expansion in an agricultural-urbanized landscape in Central Iran.

The unplanned urban expansion is a major environmental challenge in Iran resulting in vast degradation of agricultural lands. Focusing on an agricultural-urbanized landscape in Central Iran, the spatial pattern of built-up expansion was assessed from Landsat data processed in 1992 (TM), 2002 (ETM+), 2012 (TM), and 2022 (OLI). Multi-year crop NDVI was also used as a proxy for cropland suitability to assess the intensity of the urban growth impact. Results showed that (1) the area of built-up surfaces increased almost up to double than that of 1992 and passed 36% (413.42 km2) by 2022, (2) the region experienced a coalescence-diffusion transition phase with decreasing spatial connectivity of newly developed patches with old ones, (3) the most suitable croplands were lost in the middle period (2002-2012) when urban patches started to diffuse, and (4) a significantly positive spatial (Spearman's) relationship (r (22100) = 0.181, p = 0.000) was found between the area and quality of croplands which further highlights the high importance of cropland protection in the region.

Spatial modeling of land-use change in a rapidly urbanizing landscape in central Iran: integration of remote sensing, CA-Markov, and landscape metrics.

In the present paper, land use/land cover (LULC) change was predicted in the Greater Isfahan area (GIA), central Iran. The GIA has been growing rapidly in recent years, and attempts to simulate its spatial expansion would be essential to make appropriate decisions in LULC management plans and achieve sustainable development. Several modeling tools were employed to outline sustainable scenarios for future dynamics of LULCs in the region. Specifically, we explored past LULC changes in the study area from 1996 to 2018 and predicted its future changes for 2030 and 2050. For this purpose, we performed object-oriented and decision tree techniques on Landsat and Sentinel-2 satellite images. The CA-Markov hybrid model was utilized to analyze past trends and predict future LULC changes. LULC changes were quantitatively measured using landscape metrics. According to the results, the majority of changes were related to increasing residential areas and decreasing irrigated lands. The results indicated that residential lands would grow from 27,886.87 ha to 67,093.62 ha over1996-2050 while irrigated lands decrease from 99,799.4 ha to 50,082.16 ha during the same period of time. The confusion matrix of the 2018 LULC map was built using a total of 525 ground truth points and yielded a Kappa coefficient and overall accuracy of 78% and 82%, respectively. Moreover, the confusion matrix constructed base on the Sentinel-2 map, as a reference, to judge the predicted 2018 LULC map with a Kappa coefficient of 88%. The results of this study provide useful insights for sustainable land management. The results of this research also proved the promising capability of remote sensing algorithms, CA-Markov model and landscape metrics future LULC planning in the study area.

Occurrence and depositional history of organochlorine pesticides in the sediments of the Zayandehrud River in the arid region of Central Iran.

In this study, surface sediments along the Zayandehrud River (14 samples), and two dated core sediments (46 samples) from small artificial urban lakes at the middle section of the Zayandehrud River in the Gavkhooni basin in the central arid regions of Iran were analyzed for residual levels of 20 organochlorine pesticide (OCP) compounds. Total OCP concentrations ranged from 0.1 to 50.1 ng g-1 dry weight and from 1.9 to 51.5 ng g-1 dry weight in surface and core sediments, respectively. Dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD) were found to be the predominant OCPs in these sediments. The calculated metabolic and isomeric ratios confirmed the aged nature of residual dichlorodiphenyltrichloroethane (DDT) in sediments. Moreover, the isomeric ratios indicated the aged nature of technical HCH (hexachlorocyclohexane), while the contribution of γ- HCH (lindane) as a main source has increased, especially in the last two decades. Past usage, as well as current usage of endosulfan technical mixture in the Gavkhooni basin, has been found in the last four decades. Analyses of sedimentary cores, as natural archives, have shown the successful ban on the use of organochlorine pesticides (especially DDT) in the Gavkhooni basin, and to some extent, in the central plateau of Iran. In general, it can be concluded that natural factors (i.e., floods and wet years) lead to soil leachate and play an essential role in remobilization and transfer of residual OCPs from soil to inland aquatic ecosystems in the Gavkhooni basin, which is an arid region.

Road-induced fragmentation and the environmental value of roadless areas in a partly protected landscape in Central Iran.

This study assessed the effect of road development on vegetation fragmentation in and around a protected area network in western Isfahan Province, Central Iran. As the first study in Iran, an attempt was also made using the weighted linear combination-informed ecological value index of roadless area (EVIRA), to evaluate the environmental value of roadless areas based on a set of ecological and anthropogenic factors. Toward these aims, a Landsat 8-OLI image was processed to delineate land use/cover of the region. Road-induced fragmentation was then estimated by comparing the results of a small set of landscape metrics (DIVISION, SPLIT, MESH, LPI, and NP) measured from the original and road-included LULC map. The results showed road-induced increasing DIVISION (by 4.8-85.9%) and SPLIT (by 0.01-23.1%) and decreasing MESH (by 2.7-14%), LPI (by 1.3-32.4%), and NP (by 6-97.8%) values within all protected areas and across the entire study area, indicating a significant rise in landscape fragmentation and habitat loss. Roadless patch area and Thiessen connectivity stood out as the most salient criteria in determining environmentally valuable roadless areas. The results of EVIRA showed that the study region comprises some valuable but unprotected roadless areas which should be protected against road development or any kind of destructive human activities by laying out conservation plans or their inclusion to the current protected area network.

Monitoring land cover changes in Isfahan Province, Iran using Landsat satellite data.

Changes in land cover and land use reveal the effects of natural and human processes on the Earth's surface. These changes are predicted to exert the greatest environmental impacts in the upcoming decades. The purpose of the present study was to monitor land cover changes using Multispectral Scanner Sensor (MSS) and multitemporal Landsat Thematic Mapper (TM) data from the counties of Isfahan Province, Iran, during 1975, 1990, and 2010. The maximum likelihood supervised classification method was applied to map land cover. Postclassification change detection technique was also used to produce change images through cross-tabulation. Classification results were improved using ancillary data, visual interpretation, and local knowledge about the area. The overall accuracy of land cover change maps ranged from 88 to 90.6%. Kappa coefficients associated with the classification were 0.81 for 1975, 0.84 for 1990, and 0.85 for 2010 images. This study monitored changes related to conversion of agricultural land to impervious surfaces, undeveloped land to agricultural land, agricultural land to impervious surfaces, and undeveloped land to impervious surfaces. The analyses of land cover changes during the study period revealed the significant development of impervious surfaces in counties of Isfahan Province as a result of population growth, traffic conditions, and industrialization. The image classification indicated that agricultural lands increased from 2520.96 km(2) in 1975 to 4103.85 km(2) in 2010. These land cover changes were evaluated in different counties of Isfahan Province.

Monitoring landscape changes in Caucasian black grouse (Tetrao mlokosiewiczi) habitat in Iran during the last two decades.

Caucasian black grouse (Tetrao mlokosiewiczi) is on the 'red' list of species of high conservation concern as nearest threatened (NT) and also in level (I) of Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). The black grouse distribution range in Iran is restricted to the Arasbaran region, Northwest of Iran, and the populations and range of this specialist bird species have been declining over the last decades. Management of forest and grassland structures is important for black grouse population survival. The main goals of this study were to monitor and quantify the landscape pattern changes in Caucasian black grouse habitat in the Arasbaran biosphere reserve in two periods of 14 years (1987-2001) and 10 years (2001-2011). For quantifying landscape pattern changes, various landscape metrics were derived by spatial analysis software FRAGSTATS 3.3, including NP (number of habitat patches), LPI (largest patch index) and TE (total edge). The results indicated that the proportion of forest decreased from 39.95 to 31.95% and the proportion of grassland decreased from 44.45 to 38.44% in the 24-year span. NP of forests increased in the first period and decreased in the second period of study. TE of dense forest at altitude above 1800 m decreased. Reduction of forest edge is an indicator of reduction in habitat availability for Caucasian black grouse which use the forest edge for living, lekking and hatching in upland. Our results provided quantitative data on habitat loss and fragmentation in the Arasbaran biosphere reserve and indicated negative impacts of the landscape structure changes on Black grouse habitat.

Assessment of land cover changes & water quality changes in the Zayandehroud River Basin between 1997-2008.

Water quality of rivers is strongly influenced by landscape characteristics of their watershed, including land use /cover types, and their spatial configuration. This research evaluates the effects of land cover changes on the water quality of the Zayandehroud River, which is the most important river in the center of Iran. The main goal of this study was to quantify the change in rangelands, forests, and bare lands in the Zayandehroud river basin, which suffered intense human interference, in a period of 11 years (1997-2008), and to evaluate how landscape patterns (including the number of patches, edge density, percentage of rangelands, forests, and bare lands) influence on the 14 water quality indices (including BOD5, EC, NO3, P, and TDS) measured in 10 stations along the river. Results showed that from 1997 to 2008, bare lands increased from 5.8 to 20%, while rangelands decreased from 70 to 55% in the whole basin. The results indicated that water quality was significantly correlated with both the proportions and configuration of rangeland and bare land areas. The total edge (TE) of rangeland area had positive effects on water quality, especially on BOD5 and EC. Percentage of landscape (PLAND) and largest patch index (LPI) metrics of rangeland had positive effect on decreasing nutrient (NO3, PO4). The results showed that water quality was more likely degraded when there was high edge density (ED) of bare lands. Results of this study also revealed that degradation of rangeland lead to the degradation of water quality. Finding of this study highlights the importance of rangeland conservation in water quality management at landscape scale.