Journal of Environmental Studies
Year:2002 | Volume:28 | Issue:29|Papers Count:21

Siah-Keshim Protected Area is situated in the southwest of Anzali wetland (4200 hectars). In this wetland a total of 103 species and subspecific taxa were identified. They belong to 48 families and 78 genera. Among these plants, 5 families are pteridophyta, 29 families. are dicotyledones, and 14 families belong to monocotyledones. Geophyte with 44 species (43.1%) is the most frequent life form of the Protected Area. 61.8 percent of species are distributed in different regions, they are considered as cosmopolitan species. The vegetation of Siah-Keshim wetland was studied, using the Braun-Blanquet school. 105 releves in different association individuals were recorded. Phytosociological data were analysed by FCA and HAC methods, using the software Anaphyto. 32 associations were distinguished. They belong to 4 classes, 4 orders and 13 alliances. The following associations constitute the major part of the natural vegetation of the area: Phragmitetum australis, Trapo-Potametum crispi, Sparganietum neglecti, Bidento tripartitae - Polygonetum hydropiperis and Typhetum latifoliae. The distribution of plant associations are mainly affected by physical and chemical properties of water, quantity and quality of sediments, depth and intensity of water, as well as, some biological factors.

New towns in Iran have been planned and constructed on the basis of the theoretical framework of {Garden Cities} and on the basis of their development process. During the last fifty years certain changes have taken place in their objectives and roles. The new towns of Iran can be classified in the pre-and post-revolution periods. The planning for new towns during the pre-revolution period was based on political and military objectives and especially on providing the industrial workers and particularly the workers of the oil industry with housing and shelter facilities. With the exception of two towns, namely, Fouladshahr and Shahinshahr, none of the newly constructed towns conform to the theoretical framework of new towns. In the post-revolution period, new towns are being constructed in view of the objectives of spatial organization of metropolitan cities, for absorbing the surplus populations of big cities and in view of providing housing and shelter facilties. In this period, a detailed and comprehensive planning for 18 new towns has been worked out within the framework of a systematic process of site allocation along with surveys for the preparation of land, but the manner of work progress and settlement in the above towns is lagging far behind the objectives and time schedule of the work plan.

This Survey was conducted in Selkeh and Espand International Wetlands (78 and 45 ha., respectively). In Selkeh wetland 57 and, in Espand 39 species were identified. The average monthly waterfowl and wader birds counts were 5021 and 2695, respectively. The average density of birds in Selkeh and Espand wetlands was 64 and 60 birds per ha., respectively. In both areas common teal (Anas crecca) was the major species. The major population in Selkeh consists of autumn, winter and spring migrants and for Espand it was winter migrant only. The species number, population size, biodiversity indices of Menhinick, Simpson's and Shanon- Wiener diversity and evenness in Selkeh habitat was more than in Espand habitat. Here, only Margalef richness and Simpson's dominance indices greater.

Gomishan Wetland which is located at the extreme south eastern part of the Caspian Sea has very important characteristics. The zooplanktons of the wetland are determined in 15 groups, belonging to 5 phyla. The density of these microscopic animals is studied within 5 chosen stations and during 12 continued months, via sampling, laboratory and statistical investigations. The seasonal variations were noticeable. The minimum density of the zooplanktons is found in February and then in January. The maximum density for most of the groups was observed from the beginning of the summer until the mid autumn. The annual mean density for any 15-zooplankton groups, as well as, the minimum and maximum density, with %95 confidence limits, are calculated for all of the stations and also the whole wetland. The spatial distribution of the individuals within the population of each of the groups is computed, according to regular, contagious or random distributions. Diversity indices are calculated for the zooplanktons of each station. Comparison of the wetland, with the south eastern Caspian Sea, from the point of view of zooplankton density and diversity is also given in the paper. As a result of the study, the zooplankton density of the wetland is quite higher than the neighboring sea.

Past experiences revealed a crucial fact that development of human activities must be carried out in a sound manner. Increasing the availability of terrestrial ecosystems of the southern coast of the Caspian Sea has brought an extensive development, so that the outcomes of the past developments endangered the health of the environment. In general, considering the rapid increasing growth of population, there is no possibility to stagnate or encounter the fast development induced by the incremental population increases. In present research, terrestrial ecosystems of the southern coast of the Caspian Sea have been classified on the basis of ecological sustainability and extent of ecological susceptibility. Using the object-oriented method in determination of ecological susceptibility and interaction analysis method, land classification of the study area has been carried out to define the sustainable and also susceptible areas to human activities in subwatershed scale in the northern part of Iran. Based on the findings of this research about 17.84 percent of the study area have been determined as resistant (class 2), 53.36% medium (class 3), 16.62% sensitive (class 4) and 12.18% highly sensitive (class 5). No highly resistant ecosystems (class 1) have been found throughout the study area. The results showed that the study area is not prone for development, considering ecological susceptibility of its terrestrial ecosystems, in spite of its abundant ecological resources.

The variations of meteorological conditions significantly influence human comfort. People often experience greater discomfort when the weather is both hot and humid. Such a discomfort feeling does depend, in part, on the ability of human body to lose heat via evaporative cooling. Since a considerable portion of Iranian population are living alongside the coastal regions in southern and northern parts of the country, combined increase of temperature and humidity could cause physical discomfort for these people. In recent decades, researchers have introduced heat index or apparent temperature index that gauge the impact of combined temperature and humidity on human comfort. In the present study the amounts of apparent temperature for two Iranian cities (Yazd and Gorgan) are computed and compared. Gorgan is situated near the western side of the Caspian Sea coasts. In contrast, Yazd is located in central parts of the country, far from sea and moisture-laden winds. Suitable calculation methods are selected to measure the amounts of apparent temperature for critical hot and muggy conditions. It was concluded that during hot summers, the potential of sunstroke, heat cramps or heat exhaustion, in Gorgan is greater than these hazards for Yazd.

Concerning the destructive effects and frequent damages of the flood in the country, studying the dimension and reasons of the flood of Neka city, as one of the greatest floods in the recent years and its preventive measures are objectives of this research. By using direct observation method and statistical data and working on maps, this paper examines the dimensions of the flood of Mordad 18 (August) of Neka city with regard to the role of the existing conditions and geographical and natural structure of the region including the climate and rainafall, the basin's height discrepancy, type of land, the rate of destruction of the forests and pastures, the river-beds deposits, coefficient of basin form, violation of the river limits, bridge status and river meander. The results indicate the main role of inhabitants of the region in neglecting to perserve the biological harmony. The geographical structure of the natural conditions is also the contributing and intensifying factors which brought about the Neka flood.

In this study zoning for the preparation of management plan for Golestan National Park (GNP is the first national park of Iran, with an area 91895 ha) has been implemented. First, ecological and socio-economic resources were surveyed and mapped (scale 1:50000). Then data analysis and integration with system analysis approach were performed. As a result, 775 micro-ecosystems (Makhdoum, 1992) were mapped. Ecological capability of mapping unit (Mu) was evaluated for restricted nature reserve, protected area, extensive use, intensive use, rehabilitation, domestic use, cultural-historical and buffer zones, with the aid of specified ecological park management models (Makhdoum, 1378). Finally with the coordination of socio-economic data and ecological capability of Mu, periority ranking and arrangements of zones were .mapped. The results show that %49.43 of allocated zones is suitable for restricted nature reserve zone, %35.05 for protected area zone, %4.58 for extensive use zone, %0.54 for intensive use zone, %9.91 for rehabilitation zone, %0.11 for domestic use zone, %0.38 for cultural-historical zone and %5.69 for buffer zone (with protected area & rehabilitation zones).

Catchment area of the Zagros forests, a sensitive ecosystem of the Zagros range. The Geographical Information System (GIS), and remote sensing techniques were used for the study. Firstly, land-sat data (TM imagery for 1990 and -f997) were used as inputs to prepare land-use maps for those years, using Idrisi software. Then, those land-use maps, together with "Optimal Spatial land-use maps" (based on sustainability, and prepared elsewhere using the system analysis method), were added to the GIS, using Arc/Info software, so as to build a data base. Subsequently, a process based model was created to compare existing land-uses with optimal one. Using this model and the Structured Query language (SQL) in the GIS the status of the land uses were mapped for 1990 and 1997, grouped in three categories: sustainable, non-sustainable, and conditionally sustainable. By comparing those maps, land-use changes from 1990 to 1997 were recorded. The results indicate that non-sustainable uses of land during this period have increased substantially due to, among other factors, the use of land for grazing purposes in places where land is suitable for commercial and protection forestry. Changing land uses to agriculture, where it is suitable for pastural uses was also observed. The research also indicates that the prevalence and increases of unsuitable land uses in the area have resulted in degradation of the environment and poverty for its inhabitants. Therefore, the research concludes with a strong recommendation for the preparation and implementation, by the relevant authorities, of an "Optimal spatial land-use. plan" for the area, so as to slow down further ecological and socio-economic degradation.

Saheb-Gharanieh wastewater treatment plant located in the northern part of Tehran, Iran, was selected as a pilot. The quality and quantity of wastewater of the plant were investigated for a perid of one year. The main aim of the present investigation was to determine the design criteria for the construction of the municipal wastewater treatment plant in Tehran. The population being served by the plant was twice surveyed, in the beginning and at the end of the investigation period, in order to find out the amount of wastewater pollutants and flow generated per person. Based on this research, average population being served by the plant was about 2,300 during the study, which was 0.033% of total population of Tehran (6.8 million according to national census in 1996). The results obtained in this study, which at least may be used as design criteria for wastewater treatment plant construction in the north of Tehran, are summarized below: - The mean per capita wastewater flow was 275liter per day. - The average of hourly maximum factor of wastewater flow rate was1.56 (ratio of the average of maximum hourly wastewater flow to the daily average of the wastewater flow over one year period of the study). - Maximum hourly factor of waste water flow rate was 5.2 (ratio of the maximum hourly wastewater flow to the daily average wastewater flow over one year period of the study). - The average of hourly minimum factor of wastewater flow rate was 0.28 (ratio of the average of minimum hourly wastewater flow rate to the daily average wastewater flow over one year period of the study). - Minimum hourly factor of waste water flow rate was 0.16 (rate of the minimum hourly wastewater flow rate to the daily wastewater flow rate over one year period of the study). - The average amount of waste water pollutants including COD, BOD5, SS, VSS, TKN, and phosphate-P in Saheb-Gharanieh district were 65.5,36,50, 38, 10.5, and 0.8 gram per capita per day respectively.

Recreational planning is one of the important aspects in regional management network of any country. Overpopulation of the cities, settlement pattern changes, and the presence of a wide scope of environmental and social problems and also the higher proportion of recreational activities in peoples" lives, are issues that necessitate the need for planning and programming of proper recreational schemes in urban and suburban areas. In the meantime, there is more demand for recreation and spending time in natural regions due to their scenic beauties and aesthetic and educational values, although these areas are more susceptible and sensitive in terms of their fragile environment. Determining the assimilative or carrying capacity of recrational areas (whether natural or man-made) will not only maintain their potential values, particularly in natural part, but it will also be an effective factor in providing an acceptable recreational experience for the visitors. This paper attempts to analyse and evaluate the carrying capacity of various recreational activities and types and their relative potentials. The existing standards cannot be useful as absolute scientific pattern in our country, however, a comparison of present data and their evaluation under different natural, economic, and social conditions of Iran can be an advantageous approach (strategy) for dynamic management of leisure and recreational resources. Many field observations have indicated that ignoring this, can endanger recreation center and the stability of the resources.