Determining the groundwater potential recharge zone and karst springs catchment area: Saldoran region,western Iran

Assessing the groundwater recharge potential zone and differentiation of the spring catchment area are extremely important to effective management of groundwater systems and protection of water quality. The study area is located in the Saldoran karstic region, western Iran. It is characterized by a high rate of precipitation and recharge via highly permeable fractured karstic formations. Pire-Ghar, Sarabe-Babaheydar and Baghe-rostam are three major karstic springs which drain the Saldoran anticline. The mean discharge rate and electrical conductivity values for these springs were 3, 1.9 and 0.98 m³/s, and 475, 438 and 347 μS/cm, respectively. Geology, hydrogeology and geographical information system (GIS) methods were used to define the catchment areas of the major karstic springs and to map recharge zones in the Saldoran anticline. Seven major influencing factors on groundwater recharge rates (lithology, slope value and aspect, drainage, precipitation, fracture density and karstic domains) were integrated using GIS. Geology maps and field verification were used to determine the weights of factors. The final map was produced to reveal major zones of recharge potential. More than 80 % of the study area is terrain that has a recharge rate of 55–70 % (average 63 %). Evaluating the water budget of Saldoran Mountain showed that the total volume of karst water emerging from the Saldoran karst springs is equal to the total annual recharge on the anticline. Therefore, based on the geological and hydrogeological investigations, the catchment area of the mentioned karst springs includes the whole Saldoran anticline.     

Geomorphologic assessment of relative tectonic activity in the Maharlou Lake Basin,Zagros Mountains of Iran

Spatial differences of Quaternary deformation and intensity of tectonic activity are assessed through a detailed quantitative geomorphic study of the fault‐generated mountain fronts and alluvial/fluvial systems around the Maharlou Lake Basin in the Zagros Fold–Thrust Belt of Iran. The Maharlou Lake Basin is defined as an approximately northwest–southeast trending, linear, topographic depression located in the central Zagros Mountains of Iran. The lake is located in a tectonically active area delineated by the Ghareh and Maharlou faults. Combined geomorphic and morphometric data reveal differences between the Ghareh and Maharlou mountain front faults indicating different levels of tectonic activity along each mountain front. Geomorphic indices show a relatively high degree of tectonic activity along the Ghareh Mountain Front in the southwest, in contrast with less tectonic activity along the Ahmadi Mountain Front northeast of the lake which is consistent with field evidence and seismotectonic data for the study area. A ramp valley tectonic setting is proposed to explain the tectonosedimentary evolution of the lake. Copyright © 2011 John Wiley & Sons, Ltd.     

Discharge areas as a useful tool for understanding recharge areas, study case: Mexico Catchment

At present, demographic growth is a significant issue related to environmental damage due to an excessive use of water and forest. Governments are now interested in formulating new strategies that might help to reach a sustainable development. Thus, the Mexican Federal Government initiated an Environmental Hydrological Services Payment Programme in 2003 to preserve its forest territory, specifically to keep its groundwater recharge potential. However, the application of this programme was not supported by hydrogeological studies defining the physical media, rainwater and groundwater flows through proper identification of recharge areas as well as probable impacts to groundwater or to other components of the environment. Wide-view system studies still need to be incorporated. This work highlights the importance of including groundwater flow system investigations as a basis to support environmental projects where a clear understanding of groundwater functioning in relation to a zone receiving payment for hydrological environmental services is required. Stable isotopes and chemical characteristics of non-evaporated groundwater in discharge areas allow the computation of the altitude of recharging precipitation from where possible recharge area location is proposed. Finally, this paper puts forward groundwater flow system definition as a basic tool to support recommendation for an adequate water and environmental management.     

Timing of atmospheric precipitation in the Zagros Mountains inferred from a multi-proxy record from Lake Mirabad, Iran

A sediment core 7.2 m long from Lake Mirabad, Iran, was examined for loss-on-ignition, mineralogy, oxygen-isotopic composition of authigenic calcite, and trace-element composition of ostracodes to complement earlier pollen and ostracode-assemblage studies. Pollen, ostracode-inferred lake level, and high Sr/Ca ratios indicate that the early Holocene (10000 to 6500 cal yr BP) was drier than the late Holocene. Low δ¹⁸O values during this interval are interpreted as resulting from winter-dominated precipitation, characteristic of a Mediterranean climate. Increasing δ¹⁸O values after 6500 cal yr BP signal a gradual increase in spring rains, which are present today. A severe 600-yr drought occurred at ca. 5500 cal yr BP, shortly after the transition from pistachio-almond to oak forest. During the late Holocene, two milder droughts occurred at about 1500 and 500 cal yr BP. Within the resolution of the record, no drought is evident during the collapse of the Akkadian empire (4200–3900 cal yr BP). Rather, a decrease in δ¹⁸O values to early-Holocene levels may indicate the return to a Mediterranean precipitation regime.     

Integrating GIS and DSS for identification of suitable areas for artificial recharge,case study Meimeh Basin,Isfahan, Iran

Flood spreading is an inexpensive method for flood mitigation and artificial recharge of aquifers that results in a large budget return for relatively small investment.It is necessary to study some regional characteristics in order to determine the appropriate areas for artificial groundwater recharge by flood spreading in Meimeh Basin, Isfahan Province, Iran. Necessary regional characteristics to be studied are: slope, infiltration rate, sediment thickness, transmissivity, and water quality. In this research to identify suitable areas for artificial recharge several thematic layers were prepared, assigning each layer to one of the mentioned characteristics. The thematic layers were classified to several classes based on the existing criteria. All of the classes of the thematic layers were integrated and analyzed using a decision support system (DSS) in a geographical information system (GIS) environment. Finally suitability of the integrated classes for artificial recharge was identified in which the following classes were separated:(i) Very suitable, (ii) suitable, (iii) moderate suitability, and (iv) unsuitable.The validity of the generated model was verified by applying the model to a number of successful floodwater spreading stations throughout Iran. The verified model showed satisfactory results for all of the stations. The results for Meimeh Basin showed that about 70% of the Quaternary sediments in the studied area are suitable and moderately suitable for artificial recharge by flood spreading.     

Chemistry of perennial springs of Bhetagad watershed: a case study from central Himalayas,India

A field study was conducted to assess the location and the seasonal variation in physicochemical parameters of springs (outlets of underground water channels) of Bhetagad watershed of Uttaranchal hills, India. Traditionally, spring water is used for multiple purposes in this region. The average population density of the watershed is 366 persons km^?2, distributed within an altitudinal range of 1,090–2,060 m a.m.s.l. and 23.52 km² area. Twelve springs, in three different land uses e.g. pine forest, rainfed agriculture near settlements and irrigated agriculture near settlements were monitored in the winter (January), summer (June) and monsoon (August) during 1998 and 1999. The water quality parameters selected, in the present study are pH, EC, TDS, DO, free CO₂, total hardness, Ca²⁺, Mg²⁺, CO₃^2?, HCO₃^?, Cl^-, NO₃^? and SO₄^2? ions. Some springs in pine forests exhibit lower pH values than the permissible limit. Springs, with their location in agriculture and settlement, show slightly higher EC than the springs in pine forests. All the springs, near the irrigated agricultural land recorded higher nitrate ion concentration.     

A study of erosion rates on salt diapir surfaces in the Zagros Mountains, SE Iran

Salt exposures and weathering residuum on several salt diapirs in different geographic/climatic settings were studied. Anhydrite, gypsum, hematite, calcite, dolomite, quartz, and clay minerals are the main constituents of the weathering residuum covering the salt diapirs in various thicknesses. Erosion rates of residuum as well as of rock salt exposures were measured at selected sites for a period of 5 years by plastic pegs as benchmarks. Recorded data were standardized to a horizontal surface and to long-term mean precipitation. For the rock salt exposures the following long-term denudation rates were determined of 30–40 mm a⁻¹ for coastal diapirs and up to 120 mm a⁻¹ for mountain salt diapirs. Long-term mean superficial denudation rate measured on weathering residuum of low thickness reached 3.5 mm a⁻¹ on coastal diapirs. The total denudation rate estimated for the thin residuum is close to 4–7 mm a⁻¹ based on apparent correlation with the uplift rate on Hormoz and Namakdan diapirs. Denudation of rock salt exposures is much faster compared to parts of diapirs covered by weathering residuum. The extent of salt exposures is an important factor in the morphological evolution of salt diapirs as it can inhibit further expansion of the diapir. Salt exposures produce huge amounts of dissolved and clastic load, thus affecting the surrounding of the diapir.     

Lithospheric structure beneath the south-eastern Zagros Mountains,Iran: recent slab break-off?

Integrated lithospheric modelling, based on the combined interpretation of gravity, geoid and topography data sets, highlights a previously undocumented lithospheric thinning beneath the Zagros collisional belt (Iran), which we propose to relate to recent slab break-off at the continent–ocean transitional lithosphere. Recent published data on the distribution of seismicity at depth support this interpretation. In agreement with other published models for the Zagros Mountains, the overlying crust exhibits, by contrast, a noticeable thickening, reaching a maximum of 52 km. The consequent thermal uplift expected from slab break-off is suggested to have modified the Zagros wedge taper and triggered the recently documented switch from thin-skinned to thick-skinned deformation in the Zagros Fold–Thrust Belt.     

Mineralogical and geochemical investigations of the Mombi bauxite deposit,Zagros Mountains,Iran

The Mombi bauxite deposit is located in 165 km northwest of Dehdasht city, southwestern Iran. The deposit is situated in the Zagros Simply Fold Belt and developed as discontinuous stratified layers in Upper Cretaceous carbonates (Sarvak Formation). Outcrops of the bauxitic horizons occur in NW-SE trending Bangestan anticline and are situated between the marine neritic limestones of the Ilam and Sarvak Formations. From the bottom to top, the deposit is generally consisting of brown, gray, pink, pisolitic, red, and yellow bauxite horizons. Boehmite, diaspore, kaolinite, and hematite are the major mineral components, while gibbsite, goethite, anatase, rutile, pyrite, chlorite, quartz, as well as feldspar occur to a lesser extent. The Eh–pH conditions during bauxitization in the Mombi bauxite deposit show oxidizing to reducing conditions during the Upper Cretaceous. This feature seems to be general and had a significant effect on the mineral composition of Cretaceous bauxite deposits in the Zagros fold belt. Geochemical data show that Al₂O₃, SiO₂, Fe₂O₃ and TiO₂ are the main components in the bauxite ores at Mombi and immobile elements like Al, Ti, Nb, Zr, Hf, Cr, Ta, Y, and Th were enriched while Rb, Ba, K, Sr, and P were depleted during the bauxitization process. Chondrite-normalized REE pattern in the bauxite ores indicate REE enrichment (ΣREE = 162.8–755.28 ppm, ave. ∼399.36 ppm) relative to argillic limestone (ΣREE = 76.26–84.03 ppm, ave. ∼80.145 ppm) and Sarvak Formation (ΣREE = 40.15 ppm). The REE patterns also reflect enrichment in LREE relative to HREE. Both positive and negative Ce anomalies (0.48–2.0) are observed in the Mombi bauxite horizons. These anomalies are related to the change of oxidation state of Ce (from Ce³⁺ to Ce⁴⁺), ionic potential, and complexation of Ce⁴⁺ with carbonate compounds in the studied horizons. It seems that the variations in the chemistry of ore-forming solutions (e.g., Eh and pH), function of carbonate host rock as a geochemical barrier, and leaching degree of lanthanide-bearing minerals are the most important controlling factors in the distribution and concentration of REEs. Several lines of evidences such as Zr/Hf and Nb/Ta ratios as well as similarity in REE patterns indicate that the underlying marly limestone (Sarvak Formation) could be considered as the source of bauxite horizons. Based on mineralogical and geochemical data, it could be inferred that the Mombi deposit has been formed in a karstic environment during karstification and weathering of the Sarvak limy Formation.     

Characterising the main karst aquifers of the Alvand basin, northwest of Zagros, Iran, by a hydrogeochemical approach

The Alvand River basin, situated in the northwest of the Zagros mountain range, Iran, drains carbonate aquifers through some important karst springs. The physical, chemical and isotopic characteristics of spring water were studied for two years in order to assess the origin of groundwater and determine the factors driving the geochemical composition. Principal components analysis was used to identify the main factors controlling the water chemistry. Two groups of springs were identified: (1) low mineralisation, ion concentration, especially sulphate, low temperature, light isotope composition and high elevation of the recharge area, and (2) moderate to high mineralisation, especially sulphate, higher temperature, heavy isotope composition and low altitude of the recharge area. The main factors controlling the groundwater composition and its seasonal variations are the geology, because of the presence of evaporite formations, the elevation and the rate of karst development. In both groups, the carbonate chemistry is diagnostic of the effect of karst development. The supersaturation with respect to calcite indicates CO₂ degassing, occurring either inside the aquifer in open conduits, or at the outlet in reservoirs. The undersaturation with respect to calcite shows the existence of fast flow and short residence-time conditions inside the aquifer. A PCA analysis showed that, contrary to most developed karst systems, where dilution occurs during the wet season, leaching of the gypsum-bearing Gachsaran Formation by rainwater produced higher mineralisation.

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Resumen La cuenca del río Alvand, situada en el noreste de la cadena montañosa Zagros drena acuíferos compuestos por carbonatos a través de manantiales kársticos. Durante dos años se estudiaron las características físicas, químicas e isotópicas del agua de manantial con el objetivo de determinar el origen del agua subterránea y de los factores que controlan su composición geoquímica. Se utililizó el análisis de componentes principales para identificar los factores principales que controlan la química del agua. Se identificaron dos grupos de mantaniales: (1) de baja mineralización, concentración de iones especialmente sulfatos, y baja temperatura, composición de isotopos livianos y elevación alta del área de recarga, y (2) mineralización moderada y alta, especialmente, sulfatos, y temperatura más alta, composición de isotopos pesados y altitud más baja del agua de recarga. Los factores principales que controlan la composición del agua subterránea y sus variaciones estacionales son la geología debido a la presencia de formaciones evaporitas, la elevación y la tasa a la que se desarrolla el karst. En ambos grupos la química de los carbonatos es un diagnóstico del efecto del desarollo de la estructura kárstica. La supersaturación con respecto a la calcita indica presencia de CO₂ que está en proceso de degasificación que ocurre dentro de acuífero en conductos abiertos o a la salida en reservorios. La subsaturación en lo referente a la calcita muestra la existencia de flujo rápido y de tiempos cortos de residencia al interior del acuífero. El análisis de componentes principales muestra que a diferencia de la mayor parte de sistemas kársticos en donde la dilución ocurre durante la temporada de lluvias, la lixiviación de la formación Gachsaran que contiene yeso a causa de lluvia produce mineralizaciones más altas.

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Résumé Le bassin de la rivière Alvand, situé dans le nord-ouest de la chaîne de montagne Zagros, draine des aquifères carbonatés par le biais dun important réseau de sources karstiques. Les caractéristiques physiques, chimiques et isotopiques de leau provenant des sources ont été étudiées pendant deux ans afin de déterminer lorigine de leau souterraine et les facteurs responsables de sa composition chimique actuelle. Lanalyse des éléments chimiques majeurs a été utilisée pour identifier les processus qui contrôlent la composition chimique de leau. Deux groupes différents de sources ont été identifiés: (1) faible minéralisation et concentration en ions, spécialement en sulfates, faible température, composition isotopique légère et haute élévation de la zone de recharge, et (2) minéralisation moyenne à élevée, particulièrement en sulfates, température élevée, composition isotopique lourde et plus basse altitude de la zone de recharge. Les facteurs principaux qui contrôlent la composition et la variation saisonnière de leau souterraine sont la géologie, en raison de la présence dévaporites, lélévation et le taux de développement des karsts. Dans les deux groupes, la teneur en carbonates est un diagnostic de leffet du développement de la structure des karsts. La sursaturation par rapport à la calcite indique un dégazage en CO₂ qui a lieu soit à lintérieur de laquifère, dans les conduits ouverts, ou à sa sortie, dans les réservoirs. La sous-saturation par rapport à la calcite indique lexistence dun écoulement rapide et un faible temps de résidence dans laquifère. Une analyse des éléments chimiques majeurs a démontré que contrairement aux systèmes de karst les mieux développés où la dilution a lieu lors de la saison humide, le lessivage du gypse de la formation de Gachsaran par leau de pluie produit une minéralisation plus élevée.

     

Geohazards analysis of Pisa tunnel in a fractured incompetent rocks in Zagros Mountains, Iran

The Pisa 2 tunnel with 740 m in length and 20° N trend is located along the Kazerun fault zone in Simply Folded Belt of Zagros, Iran. This tunnel has been excavated in the fractured incompetent marl layers with high expansive pressure of up to 2 kg/cm². In this study, the geological hazards along the tunnel have been recognized and categorized. This study revealed that, in the long-term usage of the tunnel, the lining did not endure against the loading and the secondary leakages. It is mainly attributed due to the non-efficiencies of drainage and isolation systems in the tunnel site. Therefore, it caused asphalt damage, drainage damage, and wall distortion. FLAC^3D software has been used in this research. We conducted various analyses for pre-excavation stress states, syn-excavation, and post-excavation strain states. The results showed no indication of instability and critical deformations during the excavation time. It also revealed that due to the non-efficiencies of drainage and isolation systems against secondary leakages and consequently marl expansion, the volumetric and shear strains (i.e., expansions and displacements) have exceeded from the critical states of strain along the tunnel. For various remedy purpose, this paper attempted several measures that can be taken in order to modify the drainage and isolation systems along the tunnel area. The reconstruction of drainage systems with suitable reinforced concrete and adequate slope has been proposed. The width of channel and isolation of backside of lining and implementation of multi-order outlets (i.e., backside of lining) for draining of groundwater into where the main drainage systems are located in the tunnel gallery were suggested.     

Sustainable yield of a karst aquifer system: a case study of Jinan springs in northern China

Based on the long-term monitoring data of rainfall, groundwater levels, groundwater abstraction, spring flow rates and groundwater quality, an assessment has been undertaken of the sustainable yield of a karst aquifer system in Shandong Province, northern China, to maintain perennial outflow of the karst springs while meeting water demands. One of the fundamental indicators for sustainable yield of groundwater is identified as maximum allowable water-level drawdown. A regional three-dimensional finite-difference numerical model has been developed to optimize the schemes associated with well fields and their locations and sustainable yields, in the Jinan spring catchment and its adjacent karst groundwater catchments, with the aim of maintaining the water level higher than the allowable lowest water level of 27.5?m above sea level. Furthermore, measures necessary to move towards sustainable use of the karst groundwater are outlined, drawing on contingency plans of water-source replacement and artificial recharge, dual water supply (based in water quality), use of the spring waters themselves, and groundwater quality protection.     

Appraisal of relative tectonic activity along the Kazerun Fault Zone,Zagros Mountains,Iran: insight from spatial analysis of geomorphic indices

This paper investigates the impact of active tectonics on the geomorphic processes and landscape evolution along the Kazerun Fault Zone (KFZ) in the Zagros Mountains of Iran using spatial analysis of geomorphic indices. We document how topography and morphology are influenced by active tectonic deformation. The Zagros fold–thrust belt is an area of active crustal shortening where northwest–southeast oriented fault‐related folds become younger from north to south and from southeast to northwest. This temporal and spatial evolution of the belt was tested using geomorphic indices of active tectonics that include mountain front sinuosity index (Smf), the valley width/height ratio (Vf), drainage basin asymmetry factor, hypsometric integral, drainage basin shape ratio and mean axial slope of the channel. Change in the geomorphic indices is the result of active fold growth and change in the uplift rate. Decreasing Smf and Vf values from north (Smf = 2.01; Vf = 0.5) to south (Smf = 1.12; Vf = 0.2) and from southeast (Smf = 1.84; Vf = 0.8) to northwest (Smf = 1.54; Vf = 0.1) points to a migration of the active crustal shortening towards W–SW. The combined geomorphic (field evidences) and morphometric data (quantitative analysis of geomorphic indices) provide evidence of relative variation in the tectonic activity along the Kazerun Fault Zone and related landforms. The utilization of geomorphic parameters with comparison to the field observations exhibits change in relative tectonic activities mostly corresponding to the change in mechanism of the prominent fault zones in the study area. Copyright © 2014 John Wiley & Sons, Ltd.     

The Kuh-e-Surmeh mineralization, a carbonate-hosted Zn-Pb deposit in the Simply Folded Belt of the Zagros Mountains, SW Iran

The Kuh-e-Surmeh carbonate-hosted zinc-lead deposit, located within the Simply Folded Belt of the Zagros Mountains in southwestern Iran, is an orogen-related Mississippi Valley type deposit originally formed in the foreland Thrust Belt of the Zagros Mountains. Structural and textural observations indicate that ore deposition took place as open-space fillings in brecciated carbonate rock and as internal sediments consisting of fine-grained ore minerals interlayered with carbonates. The preferred genetic model for the concentration of the ore metals is that of dewatering of the Zard-Kuh basin due to regional tectonic compaction tectonism and expulsion of basin-derived fluids into the highly porous and brecciated dolomitized rocks of the Dalan Formation. The metals precipitated from dense basinal brine (15 wt% equiv. NaCl) at low temperatures (less than 200 °C), typically within strata of a Late Paleozoic carbonate platform. Received: 21 July 1998 / Accepted: 20 August 1999     

Modified DRASTIC assessment for intrinsic vulnerability mapping of karst aquifers: a case study

Groundwater in karstic aquifers can be dangerously sensitive to contamination. In this paper, DRASTIC assessment was modified and applied, for the first time, to address the intrinsic vulnerability for karst aquifers. The theoretical weights of two of DRASTIC’s parameters (aquifer media and hydraulic conductivity) were modified through sensitivity analysis. Two tests of sensitivity analyses were carried out: the map removal and the single parameter sensitivity analyses. The modified assessment was applied for the karst aquifers underlying Ramallah District (Palestine) as a case study. The aquifer vulnerability map indicated that the case study area is under low, moderate and high vulnerability of groundwater to contamination. The vulnerability index can assist in the implementation of groundwater management strategies to prevent degradation of groundwater quality. The modified DRASTIC assessment has proven to be effective because it is relatively straightforward, use data that are commonly available or estimated and produces an end product that is easily interpreted.     

Environmental degradation assessment in arid areas: a case study from Basra Province, southern Iraq

Evaluation of recent land degradation affecting Basra Province, Iraq, resulted in the identification of five prominent environmental degradation processes: desertification, secondary salinization, urbanization, vegetation degradation, and loss of wetlands. This analysis was carried out using ‘3S’ technologies [remote sensing, geographic information system (GIS), and global position system], with the layers extracted and manipulated from available topographic, climatic, and soil maps, as well as satellite image (thematic mapping in 1990 and enhanced thematic mapping in 2003) and field survey data analyses. Rates of conversion were calculated and distribution patterns were mapped with the aid of a GIS. The results revealed that land use changes have affected the wider environment and accelerated land degradation, with severe damage located in southwestern Basra Province representing 28.1 % of the total area. Areas of high to moderate degradation characterize the rest of the south, representing 52.7 % of the total area; while the north of the study region is characterized by very low and low degradation levels accounting for 8.5 and 10.7 %, respectively. Iraq faces serious environmental degradation problems that must be addressed immediately; failure to do so will greatly compound the cost and complexity of later remedial efforts, with environmental degradation beginning even now to pose a major threat to human well-being, especially among the poor.     

DEFLOGIC: a method for assessment of groundwater potential in karst terrains: Gurpi Anticline,southwest Iran

A new hydro-tectonic model, includes eight layers that affect karst hydrogeology was proposed for mapping of groundwater potential in karst areas of Gurpi Anticline, southwest Iran. To produce the groundwater potential map, remote sensing (RS) and GIS techniques were combined with fuzzy logic modeling. Criterion maps include the distances from discharge sites (D), the elevation difference from discharge sites (E), the distance from fractures (F), the fracture length density (L), the slope (O), the lithology (G), the distance from fractures intersections (I), and the fractures intersection density (C) were produced using GIS and RS techniques (DEFLOGIC layers). The approach of fuzzy sets was used to commensurate criterion maps, then fuzzy algebraic sum and gamma operators were applied to aggregate them. The weights of parameters of DEFLOGIC proposed in the range of 1 to 5, which standardized between 0 to 1, based on their importance in karst hydrogeology, professional judgments, and available exploration data. The final groundwater potential maps were verified by geoelectric and well-drilling data. The potential map prepared using fuzzy gamma operator with γ?=?0.92, which it is a flexible distinctive parameters of sum and product of fuzzy operator, depicts the best coincidence with exploration data. The final DEFLOGIC map shows the high groundwater potential in karst formations between Hati and Pebde valleys. The results support the efficiency of DEFLOGIC model to evaluating of groundwater potential in karst terrains, especially in Zagros ranges.     

山区岩溶作用对土地利用方式的响应——以金佛山碧潭泉和水房泉两区岩溶系统为例

不同的土地利用方式可使土地理化性质产生一系列的变化和差异,从而影响到岩溶作用的方向和强度。通过野外溶蚀试片实验法,对金佛山典型岩溶区碧潭泉和水房泉两泉域岩溶生态系统的5种典型土地利用方式下的土壤溶蚀速率进行雨季短时间尺度变化的野外观测。2006年7月中旬开始,重庆地区罕遇43天高温无雨的特殊天气,测试结果表明不同土地利用方式甚至同一土地利用方式下不同海拔的岩溶区石灰岩试片溶蚀速率都存在较大差异,碧潭泉域雨季绝对溶蚀量仅为水房泉域的13.3%,6个测试点土下溶蚀量由大到小依次为水房泉竹林地、水房泉林地、水房泉草地、碧潭泉林地、碧潭泉灌草丛、碧潭泉耕地。在研究时间内降雨量、温度和土壤CaCO3含量差异的基础上,金佛山两泉域岩溶作用主要有两个控制因素:土壤CO2浓度、土壤有机质。