Hassan Khosravi

High Demand in a Land of Water Scarcity: Iran

Since ancient times, humans have mobilized huge efforts to counter water shortages and meet water demands in arid and semiarid areas. If, however, water issues existed on a local scale in the past, in the present and future these problems occur on national, regional, and global scales and could threaten peace keeping, food security, and eventually sustainable development. In Iran, a nation covering about 1,650,000 km2, the supply, transfer, and use of water are major concerns, just as they were in ancient times. At present, about 55% of the water consumed in Iran is provided from groundwater resources and 45% from surface water, and more than 90% of water resources are allocated to the agriculture sector. The freshwater shortage has caused an increase in saltwater consumption, especially in arid and semiarid zones. Misuse and unrestrained water resources and traditional irrigation systems have caused soil salinity, land degradation, and desertification problems. Increasing salinity in most water resources in Iran over the past 10 years has caused an intensive decline of soil and water quality. Therefore, one of the main economical and social strategies of the government of Iran must be management that optimizes the use of water resources to attain sustainable development.

Assessing Environmental Sensitivity Areas to Desertification in North of Iran

The sensitivity map to desertification of Chehel-chai basin (North of Iran) has been elaborated by the crossing of fives criteria including climate, water erosion, soil, vegetation, and management, which have the main impact on the evolutionary process of desertification. The methodology is resulted from the desertification model of MEDALUS, which use qualitative index to define the land sensitive area to desertification. According to the factorial scaling technique, score-ranging from 1(good condition) to 2(deteriorated condition) is assigned to each indicator. Each index was assessed based on selected indicators, which resulted in qualitative mapping of each index based on geometric average of the indicators. Thematic databases, with a 1:50000 scale resolution, were integrated and elaborated in GIS software based on arc view3.2, Ilwis3.1 and ArcGIS9.3. The obtained results indicate that 39.39% of Chehel-chai basin is highly sensitive to desertification, 2.13 % has moderate sensitivity, only 2.43% has low sensitivity and 56.05% is non-sensitive. Studying the mean weight of numerical value, it is distinguished that the intensity of desertification for the total area is 1.32 which is classified as fragile (2).

Assessment of drought risk index using drought hazard and vulnerability indices

This study attempts to determine the spatial and temporal patterns of drought hazard and risk in Semnan province, Iran. Drought risk assessment has been conducted in eight counties of Semnan province using a conceptual framework which emphasizes on the combined role of hazard and vulnerability in defining droughts. The standardized precipitation index (SPI) at synoptic stations at 3 and 12-month time step for period 1985–2011 were used to provide drought hazard index (DHI) map using kriging interpolation and natural break methods by ArcGIS 9.3 software. Eight obtainable/quantifiable socioeconomic and physical indicators including population density, rural ratio, agricultural occupation, irrigated land, food production, and municipal, industrial, and agricultural water consumption were used to provide the map of drought vulnerability index (DVI). Finally, the map of drought risk index (DRI) was provided through the integration of DHI and DVI maps. The overall results showed that at 3-month timescale Shahroud and Damghan and at 12-month timescale Shahroud, Damghan, and Semnan are the most susceptible regions to drought in central Iran. Therefore, consideration of virtual water, cultivation of products with less water requirement and use of appropriate irrigation methods can be two important factors in water demand management which should be addressed by water resource managers.

Soil and Water Salinization in Ghaleh Ghazi Region, Iran

Abstract Approximately 34% of soils in Asia are influenced by salts. With about 25 million ha of saline and alkaline lands, about 15% of the country, Iran has the most saline lands in Asia after China, India, and Pakistan due to its geographical position, climate and human activities. This research was done due to determine the effective factors on soil and water salinization. At the first the boundaries of this region were characterized using GIS, then landuses were determined for field survey and also soil sampling in nine landuses were done according to both factors of planting pattern and water resources in each unit. The soil profile was prepared and soil samples were obtained from surface depths of (0 - 50 cm) and some factors such as soil texture EC, SAR, pH, CaCO3, Cl and potassium were measured. For study of water resources some samples were obtained from 30 wells and also from upland runoff, then soil and water sample were analyzed and some parameters such as EC, SAR, Cl− and pH were measured. Finally, according to data base, geological map, topography map, landuse map, soil and water measured data and also field studies, soil and water salinization schedule and region status were investigated. The results showed that important factors influencing water salinization in Ghaleh Ghazi region (Iran) are geological formations located in aquifer recharge and climate condition. Important factors of soil salinization in region are irrigation with saline water, improper irrigation method, unsuitable planting method, climate condition and landform.