Mobile location-based services usually access large geo databases via a wireless network. Sometimes it is useful to store a certain amount of geo objects on the mobile device. In this paper we present an approach to store geo data in an embedded SQL database on smart phones. Besides the storage of geometries in SQL tables we have to provide an efficient geometric indexing mechanism. We used the...

the purpose of this study was the introduction of seed accumulation index as a new approach in the evaluation of soil seed bank consistency in the populus caspica in noor reserved forest park. sampling were made above ground vegetation at peak vegetation cover during june 2010 by systematic- selective method. soil samples were collected during late june, late november and early february by hamm...

accumulation of trace metals in sediment can cause severe ecological impacts. the present study determines the elemental concentrations and chemical partitioning of heavy metals in surface sediment of shadegan wetland. shadegan wetland is one of the most important wetlands in southwest of iran and it is in ramsar-listed wetlands. for this purpose, 7 sampling stations were selected for sediment ...

Intensified industrialization and human activities have resulted in the release of various contaminants into the environment. Among them, heavy metals are often present as a result of mining, milling and industrial manufacturing. In the present investigation, bulk concentrations Pb, Cd, Zn, Cu, Fe, Ca and Al in Shur River (Iran) bed sediments and water around the Sarcheshmeh copper mine were me...

A practical hierarchical component-based WebGIS model referred to as Geo-Union is presented. Geo-Union consists of four layers: storage layer, service layer, component layer and application layer. Service layer is partitioned into another two layers: Geo-Union client and Geo-Union server. The architectures and object diagram of each layer in Geo-Union are discussed in details. After that, four ...

This paper examined the efficiency of artificial neural network (ANN) and multivariate linear regression (MLR) models in prediction groundwater quality parameters such as ecological risk index (ERI), pollution load (PLI), metal (MPI), Nemerow (NPI), geoaccumulation (Igeo). 40 samples were collected systematically analyzed for mainly heavy metals. Results revealed that adopting measured is effec...

Mercury (Hg) is a global and widely distributed heavy metal pollutant. can affect human health as well the of ecosystems poses ecological risks. The subjects this study are three types grassland in Beidianzi region, Songnen Plains, Northeastern China, characterized by different degrees degradation. mercury content levels atmosphere, soil, forage grass on grasslands were determined. In addition,...

This paper describes the concentration of selected heavy metals (Co, Cu, Ni, Pb, and Zn) in the Mamut river sediments and evaluate the degree of contamination of the river polluted by a disused copper mine. Based on the analytical results, copper showed the highest concentration in most of the river samples. A comparison with Interim Canadian Sediment Quality Guidelines (ICSQG) and Germany Sedi...

Abstract The impact of anthropogenic activities such as mining, agriculture and urbanization is causing heavy metal contamination in many freshwater ecosystems. concentrations eight elements (As, Cr, Cu, Fe, Mn, Ni, Pb Zn) the Spekboom River, South Africa, were studied using enrichment factor (EF) geo-accumulation index (I geo ) to assess extent pollution river. Sediment samples collected analy...