In order to study the aglal flora in this river, 17 sampling sites were determined. Sampling was performed with 45 days interval from May 2000 to Sept. 2001. Using 400x and 1000x microscopic magnification, prepared sub samples were examined taxonomically. In total of 152 taxa were identified. Bacillariophyta with 71 species belonging to 24 genera were found to be the most diverse division in this study. Navicula spp. and Nitzchia spp. were found to be the most common genera in this study. Chlorophyta (with 16 genera and 36 species) and Cyanophyta (with 17 genera and 35 species) were sub-dominant groups. Among Chlorophyta members of Chlorococcales (particulary Scenedesmus spp.) and some desmids were more frequently observed. Oscillatoria spp. (Cyanophyta) were observed in most water samples. Although Euglenophyta (with 2 genera and 5 species) Dinophyta (with 2 genera and 3 species) showed low diversity but some of their members (particularly Euglelw spp. and Peridinium spp.) were frequently observed in this river. Both Chrysophyta and Cryptophyta had one species in the water samples. In comparison with the previous studies showed that a regular survey of Diatoms flora in this river is important in the water quality control and river management.

The climatic circumstances in a local play a significant role in human, animals, and plants distribution. Thus, without knowing the climate, any activity or planning in different fields economic, agriculture and industrial, is no possible. So Climatic Regionalization or knowing different climatic regions is necessary for planning and territory sustainable development. the aim of the present recognize and study the most influential climatic elements affecting on the climate of ZAYANDEHROOD basin, and the spatial separation different climatic regions by using multivariate statistical methods. To do so, the mean annual data of 27 climatic elements from 12 synoptic stations in a 20 years period were used in the limit of ZAYANDEHROOD basin. Then the pointed data was changed in to a matrix 27×1658 by contribution of the capabilities of surfer’s software statistical land and with the help of Kriging interpolation with pixels 5×5 kilometer. In processing data has been used the new method on the base of statistical techniques principal components analysis and cluster analysis by ward method. Analysis works of the principal components on the data correlated matrix showed that with 6 principal components, we can describe 98.6% of variance in data. Tree component (thermal, windy, dusty-windy, dusty) expresses the most variance (92%) data. the scores of the principal components was analyzed by “agglomerative hierarchical cluster analysis”, in “ward” method that the ZAYANDEHROOD basin was divided to 5 regions.

The climatic circumstances in a local play a significant role in human, animals, and plants distribution. Thus, without knowing the climate, any activity or planning in different fields economic, agriculture and industrial, is no possible. So Climatic Regionalization or knowing different climatic regions is necessary for planning and territory sustainable development. the aim of the present recognize and study the most influential climatic elements affecting on the climate of ZAYANDEHROOD basin, and the spatial separation different climatic regions by using multivariate statistical methods. To do so, the mean annual data of 27 climatic elements from 12 synoptic stations in a 20 years period were used in the limit of ZAYANDEHROOD basin. Then the pointed data was changed in to a matrix 27×1658 by contribution of the capabilities of surfer’s software statistical land and with the help of Kriging interpolation with pixels 5×5 kilometer. In processing data has been used the new method on the base of statistical techniques principal components analysis and cluster analysis by ward method. Analysis works of the principal components on the data correlated matrix showed that with 6 principal components, we can describe 98.6% of variance in data. Tree component (thermal, windy, dusty-windy, dusty) expresses the most variance (92%) data. the scores of the principal components was analyzed by "agglomerative hierarchical cluster analysis", in "ward" method that the ZAYANDEHROOD basin was divided to 5 regions.

Introduction: Supplying good water quality to meet the growing demands of different sectors is one of the main challenges faced by water planners and managers in Iran. The purpose of this study, therefore, was to investigate the trend of changes in groundwater quality in the long run and to calculate and map the quality index of water and nitrate in ZAYANDEHROOD sub-aquifers. To quickly assess water quality, a tool should be used to show the amount of water contamination in a short time. To this end, Water Quality Index (WQI) is used to quickly present the water quality assessment, expressing the water quality without mathematical and statistical complexity. The Iranian Water Quality Index (IRWQI) has been developed with the aim of using the appropriate approach to natural conditions and Iran's water resources issues. Materials and methods: some 2935 laboratory samples collected from wet and dry seasons were examined in terms of several water quality indices including EC, TDS, SAR, pH, TH, Cl, CO3, Ca, Mg, Na, K, HCO3, NO3, and heavy elements such as zinc, copper, lead, cadmium and arsenic. The trend of changes in qualitative parameters was evaluated, using MK and TFPW-MK methods whose results showed a decrease in water quality over time. Different interpolation methods were used to map zoning in ArcGIS software. The average IRWQIGC index was calculated in 7 aquifers of ZAYANDEHROOD sub-basin, and nitrate zonation and index were determined through kriging method. Results: The pH parameter displayed a significant negative trend at 1% level in Damanehdaran, Buin Miandasht, Lenjanat, Najafabad and Kron aquifers, at 10% in the forty house aquifer, and at 5% in the Chadegan aquifer. However, in contrast to the negative pH trend, the TDS, EC, and TH parameters showed a positive trendm being significant in the range of Damanehdaran, Buin Miandasht, Chadegan, Lenjanat, and Najafabad. While the anions and cations had no significant trend in the domains of the Damanehdaran, Buin Miandasht and Chadegan, they displayed significant negative trends in the Chehelkhaneh and Kron and a significant positive trend in the Lenjanat and Najafabad aquifers. The results of the study generally indicated a decline of water quality in ZAYANDEHROOD aquifer over time. The amount of heavy elements in the aquifer beneath the southern ZAYANDEHROOD Basin was reported as being within the permissible range. It should be noted that water is industrially corrosive and in some cases sedimentary. If considered in terms of overall hardness, water is often hard. In this regard, the findings of the study suggested that the highest average nitrate levels in Damanehdaran, Kron and Najafabad aquifers were 48. 08, 50. 42, and 63. 13 mg / L, respectively, wheras the maximum nitrate content in these areas often exceeded the permitted range. Moreover, the lowest values of water quality index were found in Kron, Najafabad, and Lenjanat aquifers which could be classified in bad and relatively bad classes, respectively. Discussion and Conclusion: The trend analysis of Groundwater quality showed that water quality in the ZAYANDEHROOD sub-basin aquifers declined over time. The managers and planners are, thus, required to take some practical measures in reducing the contaminations exist in those areas. The lowest values of IRWQIGC index were found in Kron, Najafabad, and Lenjanat aquifers, leading to the lower quality of groundwater in these areas. Most of the average nitrate content was reported in the north and northwestern parts of Najafabad, followed by Kron aquifer and the central part of the slopes. Considering the fact that high nitrate rate in some cases mainly originates from the aquifer below the Southern Basin, it could be argued that the agricultural operations in the area would, due to the use of chemical pesticides and water pollution control activities in the area, be contaminated if measured in future. These areas are essential. The aquifers are located below the ZAYANDEHROOD Dam. Groundwater aquifers are seriously under pressure, especially on the downstream of the ZAYANDEHROOD Basin where water has been permanently off the middle of the river, and dredgers attempt to compensate for water scarcity by exploiting groundwater resources and drilling. As these wells have to compensate for the shortage of water in the region, the quantitative and qualitative decline of water and its pollution is more evident in these areas. A considerable number of researchers have also used the TFPW-MK test in their studies, and many of them have performed qualitative zoning in GIS and regarded kriging method as a suitable method for zoning mapping because the results of kriging are reliable in terms of spatial variance, location, location and sample distribution and then the other ones. Moreover, researchers have been interested in groundwater studies.

Over the past years, population growth, the development of industry and agriculture have led to an increase in surface water and groundwater resources. Excessive withdrawal and severe drop in water levels as well as land degradation in some parts of the country have been to the extent that the resources are at risk, the situation is critical and this has made sustainable use efforts a must. For this reason, a comprehensive management plan is needed to improve feedback and to make accurate management decisions to maintain the balance and sustainability of water resources. Adopting sound management decisions requires proper, accurate, and scientific knowledge of the conditions of the water resources of the region. In discussing the management of groundwater resources and maintaining the balance and stability of aquifers, understanding the performance of the table in normal conditions, as well as simulating the effects of drainage or nutrition is necessary. Over the past years, many indicators have been developed for a quantitative assessment of water resource vulnerability. Therefore, selecting a criterion to demonstrate the correctness of the water situation can bring policy decisions closer to scientific decisions (Kang and Lee, 2011). The WSI index was successfully used to assess the sustainability of water resources in the Geum Basin in South Korea (Rachmad et al 2014). In the assessment of the sustainability of the area in the Batang Merao region of Indonesia in 2006-2011, four indexes of hydrology, environment, life and politics were measured. The purpose of this study was to provide an integrated watershed management framework and to help sustain the area. This study was conducted to investigate the stability of groundwater and surface water of Najaf Abad area. In order to control the crisis and sustainable management of the aquifer in the studied area, review Najaf Abad aquifer management and control solutions and prevent further crises resulting from unwanted harvesting, an analysis of water resources sustainability indexes has been done. Also, to investigate the sustainability of water resources in this area, three indicators of water consumption to renewable water (C / RW), available water (WAI) and water stress (WSI) have been used. The results of indicators showed the inconstancy of water resources in the region. In the next step, aquifer modeling was done using the MODFLOW code in Gms software. The purpose of this model was to validate the findings of sustainability indicators. The results of modelling and survey sustainability were matched by indexes.

Water resources development including interbasin water transfer needs careful study and process the main purpose in this article is water transfer of karoon basin to ZAYANDEHROOD basin. This paper with the application of a statistical approach and a review of the past interbasin water transfer projects introduces the study on water transfer planning in to basin karoon and ZAYANDEHROOD, points out the problems of the study, gives the generals idea about the system for adjusting, and provides measures for taken water of karoon to zayadhrood basin. The method of this study has used the statistical package in order to analysis the systematic way of environmental, economical and social impacts.

The fresh water resources are limited in the world and their distribution is heterogeneous. In the other hand industrial establishment and dam construction decrease the quality of these limited resources, so the monitoring of water quality is necessary and unavoidable. There are different methods for consideration of water quality changes (statistic tests, regression, time series, multivariate methods… ). In this study, monthly time series of water quality parameters (Cl-, HCO3-, pH, EC, SAR, SO4) are used for study of Zayandehrud water quality. For this purpose, procedure presented by Box & Jenkins were used for modeling which contain three stages, including model recognition, parameter estimation and control of estimated parameters. For all parameters in six hydrometric stations, ARIMA, ARMA, AR, MA, multiplicative or seasonal models were obtained. After modeling pH, Cl-and HCO3-were forecasted from August 2005 up to August 2011 and the percentage of error was calculated. The lowest percentage of error was obtained for pH parameter (5%). In additional to modeling, the correlation between the river discharge and other parameters was calculated and it was distinguished that discharge has negative correlation with all parameters except pH in Eskandari station. The mean of discharge in twenty years’ period showed that Ghaleh Shahrokh station with 44. 57 m3/s has the highest and Varzaneh station with 6. 015 m3/s has the lowest mean of discharge.

During an ecological study in biomasses of ZAYANDEHROOD River, five stations were selected. During autumn 2004 to summer 2005 sampling were repeated three times with Grab Walkman method so the amount of organic matter was observed. In this survey, samples were separated and counted. The result showed that the dominant aquatic organism in the river is oligochaetes which were observed in all stations. After oligochaetes, Chironomidae were the most abundant. Tubificidae was seen in all stations and its maximum density was 3635 organisms in each square meter. Maximum biomass of tubificidae was observed in summer with the average figure of 4.06 g/m2 and minimum biomass was observed in winter with average biomass of 0.89g/m2.Maximum and minimum biomass of Chironomidae were recorded in spring and autumn with average biomass of 2.24 g/m2and 0.33 g/m2 respectively. Maximum (3.15 g/m2) and minimum (0.29 g/m2) biomass of benthic organisms were observed in stations 5 and 1.

The impact of land use change in the water quality changes is major challenges in water supply for different expenditure. This article evaluates the land use change effects on ZAYANDEHROOD river water quality. In this study, the change of land use in two periods in 1997 and 2015 was performed by TM and ETM Landsat satellite. Then, change of water quality in the 18-year period was studied. The results showed a major decline in water quality in the river' s profile with increased phosphate, nitrate, EC, BOD, COD and TDS in the study period. Pearson correlation test showed a significant correlation between agricultural land with nitrates, phosphates and electrical conductivity and between the city and electrical conductivity. Mann-Kendall test showed that the trend of the most variables is ascending. Results showed a decline in water quality as a result of land use changes on river basin to reduce rangeland, forest, water and increasing the bare lands, agricultural lands and cities. Thus, there is need to proper implementation of programs to control land use change in order to maintain ecological balance.