Groundwater quality mapping of an alluvial aquifer, Eshtehard, Iran

Eshtehard aquifer located in southwest of Tehran province, Iran, provides a large amount of water requirement for inhabitants of Eshtehard district. Monitoring and analyzing of groundwater quality are important for protecting groundwater as sustainable water resource. One of the most advanced techniques for groundwater quality interpolation and mapping is geostatistics methods. The purposes of this study are (1) to investigate major ions concentration and their relative abundance to provide an overview of present groundwater chemistry and (2) to map the groundwater quality in the study area using geostatistics techniques. In this investigation, ArcGIS 9.2 was used for predicting spatial distribution of some groundwater characteristics such as: Chloride, Sulfate, pH, and Conductivity. These methods are applied for data from 44 wells within the study area. The final maps show that the south parts of the Eshtehard aquifer have suitable groundwater quality for human consumption and in general, the groundwater quality degrades south to north and west to east of the Eshtehard plain along the groundwater flow path

Suspended Sediment and Turbidity Relationships for Individual and Multiple Catchments

The relationships between suspended sediment concentrations and turbidity were analysed at rising and falling stages, using individual and combined catchments. Results suggested a high correlation exists between suspended sediment concentration and turbidity for most of the field data. The least square fit of all the data suggested that the relationships obtained followed a power function in the form of Y = a(T)b. Consistent turbidity and suspended sediment concentration relationships found in this study imply that turbidity measurement could reasonably be used as a surrogate in estimating stream suspended sediment concentration of the study catchments and of those under similar conditions

Application of GIS and AHP technique for land-use suitability analysis on coastal area in Terengganu

The land use suitability analysis on coastal area was evaluated by application of GIS and AHP method. Land-use suitability is the ability of a given type of land to support a defined use. GIS has been a powerful tool to handle spatial data in land-use analysis, application of this tool alone could not overcome the issue of inconsistency in expert opinion when trying to judge and assign relative importance to each of many criteria considered in a suitability analysis. To address this issue, the Analytical Hierarchy Process method is used in combination with the GIS tool. This study presents how the integrated tool has handled effectively a land use suitability analysis for building hotels in the coastal area of Terengganu in Malaysia. This study develops a framework for integrating the strengths of GIS and the AHP to incorporate the decision maker’s preferences on a range of factors in finding areas/ land suitable for coastal development. The findings indicate that the area 1(2111 m) is the best area to build hotel in the coastal area of Terengganu

A General Survey of Nitrate-Nitrogen Levels In Well-water under Different Landuses

A general survey on N03 - - N levels in well-water under different landuses was conducted. Four areas were selected to represent different landuses namely mixedfarming (crop and animal production), forest, urban, and crop production only. Water samples from a total of 22 wells in the selected areas were collected and analysedfor N03- - N. The field and statistical data showed that the differences in N03 - - N levels in well- waterfrom different landuses were significant except for agriculture + animal farming. The highest N03 - - N level was observed in agricultural areas followed by urban and forested areas

Hydrogeological framework and groundwater balance of a semi-arid aquifer, a case study from Iran.

Climate changing and associated factors combined with considerably increases in water demand have been accompanied by severe depletion of reservoir storage of the most groundwater supplies of Iran. Shahriar aquifer in west of Tehran is a representative aquifer of these kinds. In order to meet water demand of the area and protecting groundwater from quantity and quality deterioration, precision recognition of geology, hydrologic and hydrogeologic characteristics of the aquifer is first step. The basic objective of this study is to develop the hydrogeological framework of the groundwater system in Shariar, Iran and to estimate ground-water balance as a scientific database for future water resources delevopment programs. Based on this re-search lateral groundwater inflows, direct infiltration of rainfall, stream bed infiltration, irrigation return and surplus drinking and industrial water are the recharging factors of the aquifer. Subsurface outflows, domestic and industrial pumping wells and agricultural abstraction are the main parameters discharge the aquifer system. Water balance in the Shahriar aquifer system is in disequilibrium and a deficit of about 24.7 million cubic meters exists

Quantifcation of runoff as infuenced by morphometric characteristics in a rural complex catchment

This study addresses the critical scientific question of assessing the relationship between morphometric features and the hydrological factors that increase the risk of flooding in Kelantan River basin, Malaysia. Two hypotheses were developed to achieve this aim, namely: the alternate hypothesis (runoff, is influenced by morphometric characteristics in the study watershed) and the null hypothesis (runoff is not influenced by morphometric characteristics). First, the watershed was delineated into four major catchments, namely: Galas, Pergau, Lebir, and Nenggiri. Next, quantitative morphometric characters such as linear aspects, areal aspects, and relief aspects were determined on each of these catchments. Furthermore, HEC–HMS and flood response analyses were employed to simulate the hydrological response of the catchments. From the results of morphometric analysis, profound spatial changes were observed between runoff features of Kelantan River and the morphometric characteristics. The length of overflow that was related to drainage density and constant channel maintenance was found to be 0.12 in Pergau, 0.04 in both Nenggiri and Lebir, and 0.03 in Galas. Drainage density as influenced by geology and vegetation density was found to be low in all the catchments (0.07–0.24). Results of hydrological response indicated that Lebir, Nenggiri, Galas, and Pergau recorded a flood response factor of 0.75, 0.63, 0.40, and 0.05, respectively. Therefore, Lebir and Nenggiri are more likely to be flooded during a rainstorm. There was no clear indication with regard to the catchment that emerged as the most prevailing in all the morphological features. Hence, the alternate hypothesis was affirmed. This study can be replicated in other catchments with different hydrologic setup

Relationship between design floods and land use land cover (LULC) changes in a tropical complex catchment

Rainfall characteristics are directly related to the climate of a basin, but this can only be noticed after a long period. Human activities, such as deforestation, tend to play a major role in transforming the land use land cover (LULC). Knowledge of the relationship between design floods and LULC is important in modeling and designing watershed management strategies. A study was conducted in the Kelantan River basin, Malaysia, to determine the impact of past and present LULC changes on peak discharge and runoff volumes. To achieve this, the basin was delineated into four catchments (Galas, Pergau, Nenggiri, and Lebir) due to its size and increased precision. Hydrologic Engineering Center-Hydrologic Modeling System (HEC-HMS) model was calibrated based on December 20–30th, 2014, flood in Kelantan. Flood hydrographs corresponding to 1984, 2002, and 2013 LULC conditions were simulated, and relative changes in peak discharge and runoff volume were determined for different return periods (2, 5, 10, 20, 50, 100 years). Results of LULC analysis showed that Galas recorded highest deforestation (54.35%). When the four catchments were compared with respect to highest contribution of outlet peak discharge, Lebir under 2013 LULC condition was the highest with 2847.70 m3/s. This was followed by Nenggiri (2196.90 m3/s), Galas (1252.7 m3/s), and Pergau (328.7 m3/s), all under the 2013 LULC condition. Results of unit response approach applied based on 50-year return period to the catchments for ranking their sub-basins revealed that the novel fa index developed in this study provides a better way of ranking sub-basins with respect to their contribution to the outlet and therefore is recommended for use. Methodologies developed in this study may be useful to land use planners from around the world which when applied can provide alternatives that will minimize the adverse effects of floods

Hydrogeochemistry and groundwater quality assessment of Astaneh-Kouchesfahan Plain, Northern Iran.

In this study, the hydrochemical characteristics of 230 bore well samples were analysed in Astaneh-Kouchesfahan Plain. Data interpretation shows that alkaline earths (Ca2+ and Mg2+) exceed the alkalis (Na+ and K+) and weak acids (HCO3−) exceed the strong acids (Cl− and SO42−) and Ca-HCO3 type is the dominant hydrochemical facies. The distribution patterns of the abundant parameters show that changes in chemical composition occurred in the middle, southwest and west of the area due to either natural geochemical process and/or anthropogenic activities. The results of factor analysis show that factor 1 of the pre-monsoon and factor 2 of the post-monsoon have high loading in the ions Na+ and Cl−. Furthermore, it is indicated that there is an increase in the loadings of Ca2+, SO42−, HCO3−, Mg2+ and K+ in post-monsoon compared to pre-monsoon due to the effect of precipitation and subsequent dissolution of the calcareous rocks and fertiliser