The vegetation of the wasteland of Valika chemical industries near Manghopir road, Karachi was studied. Nine plant communities were recognized based on dominant species. In these plant communities the vegetation was disturbed, mostly halophytic and dominated bySuaeda fruticosa,Tamarix indica,Salsola baryosma,Cressa cretica,Atriplex griffithii,Haloxylon recurvum,Indigofera hochstetteri,Prosopis julifloraandChenopodium album.The physico-chemical properties of the soils were also analysed. Soil texture was mostly sandy loam, which exhibited slight variations in the water-holding capacity. The soils contained a sufficient amount of CaCO3−and exhibited mostly alkaline soil pH. The soils of the different plant communities had scarcely any organic matter or inorganic phosphorus. The exchangeable sodium in the soils of many halophytic plant communities was high, with appreciable concentrations of potassium. 相似文献
Geoelectric and hydrochemical approaches are employed to delineate the ground-water potential zones in District Okara, a part of Bari Doab, Punjab, Pakistan. Sixty-seven VES surveys are conducted with the Electrical Resistivity Meter. The resultant resistivity verses depth model for each site is estimated using computer-based software IX1D. Aquifer thickness maps and interpreted resistivity maps were generated from interpreted VES results. Dar-Zarrouk parameters, transverse resistance (TR), longitudinal conductance (SL) and anisotropy (λ) were also calculated from resistivity data to delineate the potential zones of aquifer. 70% of SL value is ≤3S, 30% of SL value is > 3S. According to SL and TR values, the whole area is divided into three potential zones, high, medium and low potential zones. The spatial distribution maps show that north, south and central parts of study area are marked as good potential aquifer zones. Longitudinal conductance values are further utilized to determine aquifer protective capacity of area. The whole area is characterized by moderate to good and up to some extent very good aquifer protective area on the basis of SL values. The groundwater samples from sixty-seven installed tube wells are collected for hydro-chemical analysis. The electrical conductivity values are determined. Correlation is then developed between the EC (μS/cm) of groundwater samples vs. interpreted aquifer resistivity showing R2 value 0.90. 相似文献
A large number of paleo-landslide deposits exist in the Southeastern margin of the Qinghai–Tibet Plateau. Once these deposits are destroyed, the disaster chain will cause huge damage to life and property and have an impact on local geomorphic evolution. Diverse models are applied to analyze different geological problems of paleo-landslide deposits, which can produce the advantages of different models fully, thereby making up for the shortcomings of poor applicability of a single model in a certain type of problem. In this study, the Baimu paleo-landslide deposit located at the North side of Dongjiuqu Bridge of Sichuan-Tibet Railway is taken as the research object to completely analyze the potential damage by combining various technical means and numerical model, aiming to provide certain reference for the design and construction of the project. Firstly, site investigation and terrain interpretation confirm the existence of local deformation and damage. Secondly, the finite element model based on the strength reduction method is used to analyze the stability of the deposit and determine the potential damage area. For the potential damage area, debris avalanche and debris flow as two disaster transformation modes are considered. The discrete element model and shallow flow model are used to simulate the dynamic process of debris avalanche and debris flow under complex terrain, respectively. The results show that potential debris avalanche or debris flow will accumulate at the mouth of the Baimu gully, and there will be no direct threat to the bridge. Finally, the formation and evolution sequence of the deposit is proposed, which plays an important role in analyzing the evolution of local river geomorphology.
The study aims to investigate the possible relationship between Niño 4 and Indian Ocean high longitude (IOHLN) with the Swan coastal river flow by constructing a regression model which predict streamflow patterns and which enables to obtain long time lead to forecasting, in a period when there was not much rainfall. Many streamflow forecast models use rainfall and runoff relationship, which is dependent on basin response time and hence cannot provide large forecasting lead time. For water resource management, this lead time of predictability is not capable for a long period of drying trend. Significant findings of this study suggest that Niño 4 and Indian Ocean high pressure longitude (IOHLN) can be used for forecasting of flow in Swan river. In this study not only qualitative forecast of Swan coastal river is presented based on the conditional probability, but also a quantitative forecast is done by combining Niño.4 and IOHLN indices using multiple regression, which shows enhancement over other climate indicators when used alone. The Conditional probability model correctly predict 7 years category of flow out of 8 years flow. 相似文献
下载免费PDF全文