پژوهشنامه مدیریت حوزه آبخیز
پیاپی 9 (بهار و تابستان 1393)

Subwatersheds prioritization is the important procedure in natural resource comprehensive management and sustainable development. In this research prioritization the 11 subwatershed of Lohandar that located in east of Golestan province with 272. 63 km2 using GIS، RS and morphometric analysis. Erosion condition became clear in the each sub watershed. Morphometric analysis includes stream length، bifurcation ratio، drainage density، shape coefficient، circularity coefficient، elongation coefficient and compactness coefficient. Morphometric parameters included two parts (linear and shape coefficient). The preference of each sub watershed was determined using SYI and morphometric parameters. For calculation SYI index using several maps such as land use، land cover، slope، soil texture and 1:50000 topographic map. Finally determination any sub watershed priority by attention to amounts SYI index and total mean Morphometric parameters، that B5 sub watershed from morphometric parameter and A5 from SYI parameter have critical condition and incorporation of these two parameters delineate that B2 has worst condition.

In order to manage the fair allocation to water users associations (WUA) s،application of analytical and integrated method is the way to increase the capacity of water supply and appropriate use of these resources. Various models and tools have been developed in recent years to simulate equitable allocation of water issues and supply and demand analysis. MIKEBASIN model is one of these capable models. In this study، water resources planning at 5 WUAs of the watershed of Babol river was performed by MIKEBASIN model. These areas have demand and its own allocated water and 15 years data from each demand point was entered into the model. Results showed that in time water of Babol River was not adequate to supply WUAs demand. Therefore، using wetlands and groundwater is essential to supply their demands. Also، the results of sensitivity analysis showed that the discharge of watershed had the most effect on the outputs of model among all other parameters. Therefore this parameter should be measured or be predicted accurately.

The answers to decision-making problems and selection of top option in waterresources were previously based on one goal (profit maximization). However، todaywith the use of multi attribute decision-making، there is no need to only take account offinancial and profit making quantities، but we can also use several indicators (in theform of qualitative and quantitative variables)، like political، social and environmentalvariables for adopting the top option. The first stage in a multi Attribute decisionmakingprocess is prioritization، identification and study of limitations existing in theprojects. The next stage is specification of evaluation standards and variables withtaking into account social، economic، and environmental considerations and technicalproblems. Then، measures must be taken for conversion of qualitative variable intoquantitative ones، de scaling the indicators and specification of their relative weightsthrough one of decision-making methods and finally، to deal with evaluation of thegiven project with the concerned algorithm and select the best option. Using modelingwith WEAP software، the present research dealt with the simulation of Zaryngol Basin. Then، with identification of options and indicators of concern to the experts، the bestoption was selected from among the existing scenarios with the application of TOPSISmethod. The results suggest the need for further development in the summer cultivationin the above-said basin.

Drought is a phenomenon that has impacted on human life style throughout the history. In recent decades due to global warming and human interferences on natural ecosystems، drought frequency، duration and intensify has increased. In addition to agricultural and water resources degradations، drought impacts economic and social sectors of human societies. The aim of this study is to evaluate the Arjan- Parishan Plain drought phenomenon (study area of Parishan Lake) during a 37-year period، and to examine the impact of drought on lake’s water level. Drought monitoring of 5 stations around the Lake was conducted using 6 drought indices of SPI، CZI، MCZI، ZSI، PN and DI in three time scales of short-term (3 months)، middle-term (12 months) and longterm (48 months). The overall trends of SPI، CZI، MCZI and ZSI were almost similar، and no significant difference was observed between them. The results of monitored droughts by SPI، CZI، MCZI and ZSI in all stations for short term scale showed that severe drought occurrences had less frequencies and durations، while the mild and moderate drought occurrences had more frequencies and durations. By increase of time scale، severe drought occurrences reduced، while its duration increased. The indices of PN and DI، especially in short time scales، reflected quick and intensified changes in humidity.

In this study in order to investigate soil physical and chemical properties in the slope main aspects of Aghajari and Gachsaran formations، Margha and Kuhe Gach watershed areas in Izeh Township were selected. In Aghajari formation in 8 points with three replicate and in Gachsaran formations also in 8 points and with three replicate and in slope main aspects، northern، southern، eastern، western were sampled. Meanwhile some physical and chemical properties of soil such as clay، sand، silt، sand، pH، Ec، soil moisture، organic matter، calcium carbonate and sodium rate in Gachsaran and Aghajari formations were sampled. After experimental tests the results were analyzed. In comparison of north aspects in Aghajari and Gachsaran formations، many soil parameters such as the percents of silt، sand، gravel، Ec، soil moisture، calcium carbonate and pH showed significant differences. In eastern aspects many of soil parameters such as the percents of clay، calcium carbonate and pH showed significant differences. In western and southern aspects also many of the soil parameters such as the percents of clay، silt، sand، gravel، Ec، organic matter، calcium carbonate and pH showed significant differences. In Aghajari formation in soil physical properties the highest amounts of clay، silt، sand and gravel respectively with 52/33 %، 40/33 %، 39/67 % and 74/16 % were related to western، eastern، southern and western slope aspects. In soil chemical properties also the highest amounts of pH، Ec، soil moisture، sodium rate، lime، organic matter respectively with 8/40، 0/32 ds/m، 6/75 %، 0/029 g/l، 40/11 % and 1/13 % were related to western، eastern، northern، eastern، northern and southern slope aspects. In Gachsaran formation in soil physical properties the highest amounts of clay، silt، sand and gravel respectively with 32/67 %، 62/33 %، 34/33 % and 69/69 % were related to northern، eastern، western and northern slope aspects. In soil chemical properties also the highest amounts of pH، Ec، soil moisture، sodium rate، lime، organic matter respectively with 7/82، 1/60 ds/m، 7/14 %، 0/016 g/l، 34/83 % and 1/01 % were related to northern and eastern، eastern، western، eastern، southern and western slope aspects.

Since vast areas of forest lands have been changed in their usage in Mazandaran province in the past decades، this study examined the impact of changing in usage of forest lands in to the agricultural rain-fed lands (canola)، paddy lands and citrus gardens on some physical and chemical properties of soil in the Eastern part of Sari، Iran. For this purpose، four repetitions from each land use were sampled from 2 depths of 0-20 and 20-50 centimeters as factorial design in complete randomized block pattern. Results showed that land use change causes increase in bulk and particular density، the content of bulk density، which in depth، was more than that in surface layer. The most percentage of silt، clay and sand particles was observed in forest، paddy lands and garden usage، respectively. Change in usage caused decrease in water holding capacity and residual moisture. The most percentage of aggregates stability was found in forest and paddy lands. The highest amount of porosity and previous moisture was observed in paddy lands. Land use change caused an increase in soil reaction which increases with depth too. Land use change caused a decrease in organic carbon، the most percentage of which was 2 percent related to forest lands and the lowest percentage of which was 0. 72 percent which was related to rain-fed lands. The lowest available phosphorus was related to rain-fed lands too and the most amount of electrical conductivity was related to paddy lands.

One of the most important problems in the world is soil erosion that threats the natural resource and it numerates as an important troublesome in environmental and agricultural aspects. In order to obtain these goals it is inevitable to use new techniques such as nanotechnology. Nanotechnology is one of the modern technologies that because of its high potential and particular characteristics، it has extensive application in all aspects of science such as natural resources and soil conservation. This study has been done in order to assess the effects of different percentages of Nanozeolite (0، 0. 2، 0. 4 and 0. 6 gram per square meter) on malry soils in several slopes degree (7، 9 and 14 degree) using FEL3 rainfall simulator. The plot had 50 centimeter width، 100 cm length and 40 cm height that 30 cm of height was used for drainage and 10 cm of height was used by especial soil texture. After adding Nanozeolite to soil surface، the samples were influenced by 90 millimeters per hour rainfall intensity during 30 minutes. Results show that the all of the Nanozeolite levels (0، 0. 2، 0. 4 and 0. 6) in the three levels of steepness (7، 9 and 14 degrees) had not significant differences in decreasing of soil erosion in comparison of control treatment.

Geological formation in Sardabrood river basin are carbonate sedimentary (with ageof cretaceous and Permian)، shamshak formation، basic and acidic and metamorphicrocks in upstream of the basin. To study effect of lithologic and geologic units on heavymetals concentration in sediments، 33 samples from surface water were analysed byICP_MS method in Amdel Company in Australia. This analysis was done using clusteranalysis technique after preparing. The results show that based on type of upstreamrocks، 4 different rock clusters were determined. In addition to geologic units، allsamples shown some organic matter due to rural area in upstream. The results indicatemax. Distribution rate of Mn and Cr is from shamshak formation، Pb originates fromcarbonate formation and Sn is due to magmatic rocks.

Using of flood for identification of plant nessassary water for its growthing and ecreasing of flood damages is possible in many different methods. By using of water preading system، seasonal flood in susceptible land will be spreaded and، will have ifferent effects on ground water tables، plant cover and soil on these lands. In order to easurement of physical soil properties variations in Delijan water spreading stations of arkazi province، seven channel water distributions (distribution area) and regions etween those (wetness area) were selected and then each channel and wetness area fter that were devided to three parts and at center of each parts one compined sample as obtained in two depths of soil (0-25 and 25-50 cm). Also، measuremant of soil nfiltration rate in distribution and wetness area was obtained by double ring method. oil physical properties in two these area and different channel was compared using student nd ANOVA method respectively. The results showed that the water Spreading ctivities has been significant decreasing about sand and infiltration rates at %1 level nd about bulk density at %5 level. Also، about the amounts of clay، silt and Sp there ave been significant increasing at %1 level.