基于参数评估方法的不同灌溉方式的适宜性及其比较——以伊朗Khosouyeh Dam子流域为例（英文）

随着人口的急剧增加,人们对粮食和农产品的需求也会增加,与之相关联的农业土地利用问题也必然会越来越多,因此有必要研究土地的最大生产潜力——达到最大的生产能力而对农地不会产生不利影响,土地适宜性评估是实现这一目标的最重要方式。本研究的主要目的是基于参数评估方法对不同灌溉方法的优缺点进行评估与比较,以伊朗南部法尔斯省Khosouyeh Subbasin为例,该区域面积约为221402 ha。首先制备了土地单位图,选择了37个样本点,评估和分析其土壤性质,并采用GIS技术生成区域滴灌和漫灌的适宜性图。结果显示,对漫灌而言,98.42%的土地被归类为永久性不适合(N_2),1.52%目前不适合(N_1);对滴灌而言,77.73%的面积被归类为永久不适合(N_2),6.05%目前不适合(N_1),12.43%略适合(S_3)和3.79%适度适合(S_2)。滴灌和漫灌的限制因素都是土壤深度和土地坡度。     

A new hybrid framework of site selection for groundwater recharge

Since incorrect site selection has sometimes led to the failure of artificial recharge projects,it is necessary to increase the effectiveness of such projects and minimize their failure by employing new techniques.Therefore,the present research used a combination of decision-making models,numerical groundwater modeling and clustering technique to determine suitable sites for implementation of an artificial recharge project.This hybrid approach was employed for the Yasouj aquifer located in southwestern Iran.In the first stage,by employing an AHP decision-making model,hydraulic conductivity,specific yield,slope,land use,depth to groundwater,and aquifer thickness were selected from 21 criteria used in previous research.The selected criteria were then entered as input into the classical k-means clustering model.Using the output,aquifer was divided into seven different regions or clusters.These clusters were then matched with the land use map,and some of the abandoned land areas were selected as the final option for implementing the artificial recharge project.Finally,the MODFLOW code in the GMS software was used to simulate the groundwater level and cluster the sites selected,with regards to increase in groundwater level.Results indicated that the most significant increases in groundwater level(43 and 27 cm) were those of Clusters 2 and 6 in the northern and western parts of the aquifer,respectively.Therefore,this approach can be used in other similar aquifers in arid and semi-arid regions to select the best sites for artificial recharge and to prevent loss of floodwaters.     

Geochemical and geochronological evidence for a Middle Permian oceanic plateau fragment in the Paleo-Tethyan suture zone of NE Iran

The mafic–ultramafic Fariman complex in northeastern Iran has been interpreted as a Paleo-Tethyan ophiolitic fragment with subduction- and plume-related characteristics as well as a basin deposit on an active continental margin. Contributing to this issue, we present geochemical, geochronological, and mineralogical data for transitional and tholeiitic basalts. Thermodynamic modeling suggests picritic parental magmas with 16–21 wt% MgO formed at plume-like mantle potential temperatures of ca. 1460–1600 °C. Rare pyroxene spinifex textures and skeletal to feather-like clinopyroxene attest to crystallization from undercooled magma and high cooling rates. Chromium numbers and TiO₂ concentrations in spinel are similar to those in intraplate basalts. ⁴⁰Ar–³⁹Ar dating of magmatic hornblende yielded a plateau age of 276?±?4 Ma (2σ). Transitional basalt with OIB-like trace element characteristics is the predominant rock-type; less frequent are tholeiitic basalts with mildly LREE depleted patterns and picrites with intermediate trace element characteristics. All samples show MORB-OIB like Pb/Ce, Th/La, and Th/Nb ratios which preclude subduction-modified mantle sources and felsic crustal material. Tholeiitic basalts and related olivine cumulate rocks show MORB-like initial ε_Nd values of +?9.4 to +?6.2 which define a mixing line with the data for the transitional basalts (ε_Nd ca. +?2.6). Initial ¹⁸⁷Os/¹⁸⁸Os ratios of 0.124–0.293 support mixed sources with a high proportion of recycled mafic crust in the transitional basalts. High concentrations of highly siderophile elements are in agreement with the high mantle potential temperatures and inferred high-melting degrees. It is argued that the Fariman complex originated by melting of a mantle plume component as represented by the OIB-like transitional basalt and entrained asthenosphere predominant in the MORB-like tholeiites. Two lines of evidence such as association of the Fariman complex with pelagic to neritic sedimentary rocks and the tectonic position at the boundary of two continental blocks defined by ophiolites and accretionary complexes of different ages suggest formation in an oceanic domain. Thus, we interpret it as a fragment of an oceanic plateau, which escaped subduction and was accreted as exotic block in the Paleo-Tethyan suture zone.     

Assessment of agricultural groundwater users in Iran: a cultural environmental bias

Many environmental problems are rooted in human behavior. This study aimed to explore the causal effect of cultural environmental bias on ‘sustainable behavior’ among agricultural groundwater users in Fars province, Iran, according to Klockner’s comprehensive model. A survey-based research project was conducted to gathering data on the paradigm of environmental psychology. The sample included agricultural groundwater users (n = 296) who were selected at random within a structured sampling regime involving study areas that represent three (higher, medium and lower) bounds of the agricultural-groundwater-vulnerability spectrum. Results showed that the “environment as ductile (EnAD)” variable was a strong determinant of sustainable behavior as it related to groundwater use, and that EnAE had the highest causal effect on the behavior of agricultural groundwater users. The adjusted model explained 41% variance of “groundwater sustainable behavior”. Based on the results, the groundwater sustainable behaviors of agricultural groundwater users were found to be affected by personal and subjective norm variables and that they are influenced by casual effects of the “environment as ductile (EnAD)” variable. The conclusions reflect the Fars agricultural groundwater users’ attitude or worldview on groundwater as an unrecoverable resource; thus, it is necessary that scientific disciplines like hydrogeology and psycho-sociology be considered together in a comprehensive approach for every groundwater study.     

Flash flood hazard mapping based on quantitative hydrology,geomorphology and GIS techniques (case study of Wadi Al Lith,Saudi Arabia)

Flash floods are considered as catastrophic phenomena possessing major hazardous threat to the coastal cities, towns, villages and infrastructures. This study deals with the evaluation of flash flood hazard in the ungauged Wadi Al Lith basin depending on detailed morphometric characteristics of Al Lith basin and its sub-basins. For the detailed study, ASTER data were used for preparing digital elevation model (DEM), and geographical information system (GIS) was used in the evaluation of linear, areal and relief aspects of morphometric parameters. The major parameters such as watershed boundary, flow accumulation, flow direction, flow length and stream ordering are prepared using the ArcHydro Tool. Surface Tool in ArcGIS-10 software, and ASTER (DEM) was used to create different thematic maps such as DEM, contour, slope aspect and hill shade maps. Twenty-five morphometric parameters were measured, calculated and interlinked to produce nine effective parameters for evaluation of the flash flood hazard degree of the study area. Based on nine morphometric parameters which affect the hydrologic behaviour of the Wadi, by influence on time of concentration which has a direct influence on flooding prone area. The flash flood hazard of the Al Lith basin and its sub-basins was identified and classified into three groups (high, medium and low hazard degree). The study provides details on the flash flood-prone area (Wadi Al Lith) and the mitigation measures. This study also helps to plan rainwater harvesting and watershed management in the flash flood alert zones.     

Correction to: New climatic zones in Iran: a comparative study of different empirical methods and clustering technique

Theoretical and Applied Climatology -     

Development of a new wavelet-based hybrid model to forecast multi-scalar SPEI drought index (case study: Zanjan city,Iran)

Theoretical and Applied Climatology - Drought forecasting plays a vital role in managing drought and reducing its effects on agricultural systems and water resources. In the present study, three...     

Estimation of groundwater recharge in arid, data scarce regions; an approach as applied in the El Hawashyia basin and Ghazala sub-basin (Gulf of Suez, Egypt)

In this study, an approach for runoff and recharge estimations that can be applied in arid regions which suffer from lack of data is presented. Estimating groundwater recharge in arid regions is an extremely important but difficult task, the main reason is the scarcity of data in arid regions. This is true for the Eastern Egyptian Desert where groundwater is used for irrigation purposes in agricultural reclamation along the Red Sea coast line. As a result of the scarcity of hydrologic information, the relation between rainfall and runoff was calculated depending on the paleo-flood hydrology information. Two models were used to calculate the rainfall–runoff relationships for El Hawashyia basin and Ghazala sub-basin. Two computer programs known as Gerinne (meaning channel in German) and SMADA6 (Stormwater Management and Design Aid, version 6) were conjunctively used for this purpose. As a result of the model applied to El Hawashyia basin, a rainfall event of a total of 18.3 mm with duration 3 h at the station of Hurghada, which has an exceedance probability of 5–10 %, produces a discharge volume of 10.2 × 10⁶ m³ at the delta, outlet of the basin, as 4.7 mm of the rainfall infiltrates (recharge). For the Ghazala sub-basin, the model yields a runoff volume of 3.16 × 10⁶ m³ transferred from a total rainfall of 25 mm over a period of 3 h, as 3.2 mm of it was lost as infiltration.