Applied Water Science (v.6, #1)
Rainfall detection over northern Algeria by combining MSG and TRMM data by Fethi Ouallouche; Soltane Ameur (1-10).
In this paper, a new method to delineate rain areas in northern Algeria is presented. The proposed approach is based on the blending of the geostationary meteosat second generation (MSG), infrared channel with the low-earth orbiting passive tropical rainfall measuring mission (TRMM). To model the system designed, we use an artificial neural network (ANN). We seek to define a relationships between three parameters calculated from TRMM microwave imager (TMI) associated with four parameters from infrared sensors of MSG satellite and two classes (rain, no-rain) from precipitation radar (PR) TRMM data. The seven spectral parameters issued from MSG and TMI are used as input data. Rain/no-rain classes from PR are used as the output data of this ANN. Two steps are necessary: training and validation. Results in the developed scheme are compared with the results of a reference method which is the scattering index (SI) method. The result shows that the developed model works very well and overcomes the shortcomings of the SI method.
Keywords: Rainfall detection; MSG; TRMM; ANN
Adsorption of blue copper on a natural and electrochemically treated bentonite by M. Hajjaji; Y. Mountassir; A. Benyaich (11-23).
Kinetics and equilibrium studies of the adsorption of blue copper on a natural (NC) and electrochemically treated (EMC) bentonite, taken in different experimental conditions, were carried out. Changes of the dye uptake versus operating factors were evaluated using response surface methodology (RSM). The kinetics at 5–50 °C and pH < 10 obeyed the pseudo-first-order equation. Beyond pH 10, the pseudo-second-order equation also was suitable. The kinetics for NC was essentially controlled by external diffusion. However, both internal and external diffusion were the rate-limiting steps of the EMC kinetics. The NC isotherms were well described by the Langmuir model and the maximum uptake was around 21 mg/g. In the case of EMC, the Freundlich equation was rather fitting. Dye adsorption on both sorbents was a non-spontaneous process (2 < ΔG T 0 < 8 kJ/mol). According to the RSM results, pH had a negative impact on the dye adsorption and was the most influential factor in the case of EMC. For NC, the clay dose was rather the most important parameter.
Keywords: Bentonite; Electrochemical treatment; Blue copper; Adsorption; Response surface methodology
Geostatistical analysis of soil moisture distribution in a part of Solani River catchment by Kamal Kumar; M. K. Arora; K. S. Hariprasad (25-34).
The aim of this paper is to estimate soil moisture at spatial level by applying geostatistical techniques on the point observations of soil moisture in parts of Solani River catchment in Haridwar district of India. Undisturbed soil samples were collected at 69 locations with soil core sampler at a depth of 0–10 cm from the soil surface. Out of these, discrete soil moisture observations at 49 locations were used to generate a spatial soil moisture distribution map of the region. Two geostatistical techniques, namely, moving average and kriging, were adopted. Root mean square error (RMSE) between observed and estimated soil moisture at remaining 20 locations was determined to assess the accuracy of the estimated soil moisture. Both techniques resulted in low RMSE at small limiting distance, which increased with the increase in the limiting distance. The root mean square error varied from 7.42 to 9.77 in moving average method, while in case of kriging it varied from 7.33 to 9.99 indicating similar performance of the two techniques.
Keywords: Soil moisture; Geostatistics; Moving average; Limiting distance; Lag distance; Kriging; Root mean square error
Deciphering transmissivity and hydraulic conductivity of the aquifer by vertical electrical sounding (VES) experiments in Northwest Bangladesh by Golam Shabbir Sattar; Mumnunul Keramat; Shamsuddin Shahid (35-45).
The vertical electrical soundings (VESs) are carried out in 24 selective locations of Chapai-Nawabganj area of northwest Bangladesh to determine the transmissivity and hydraulic conductivity of the aquifer. Initially, the transmissivity and hydraulic conductivity are determined from the pumping data of nearby available production wells. Afterwards, the T and K are correlated with geoelectrical resistance and the total resistivity of the aquifer. The present study deciphers the functional analogous relations of the geoelectrical resistance with the transmissivity and the total resistivity with the hydraulic conductivity of the aquifer in northwest Bangladesh. It has been shown that the given equations provide reasonable values of transmissivity and hydraulic conductivity where pumping test information is unavailable. It can be expected that the aquifer properties viz. transmissivity and hydraulic conductivity of geologically similar area can be determined with the help of the obtained equations by conducting VES experiments.
Keywords: VES; Transmissivity; Hydraulic conductivity; Aquifer; Chapai-Nawabganj
Hydrochemical and microbiological quality of groundwater in the Merdja area, Tébessa, North-East of Algeria by Chemseddine Fehdi; Abdelkader Rouabhia; Abdelbasset Mechai; Manel Debabza; Khalida Abla; Kostas Voudouris (47-55).
The aim of this study was to perform a preliminary assessment of the hydrochemical and microbial groundwater quality of the Merdja plain (Tébessa area). Twenty samples of groundwater collected from Bekkaria (Site 1) to Ain Chabro (Site 2) were assessed for their suitability for human consumption. Groundwater from the aquifer in the Merdja area can be divided into two major groups according to geographical locations and chemical compositions. Water in the center part of the study area is characterized by the dominance of chloride, sulfate, sodium, and potassium; whereas waters in the limestone aquifers in the west are dominated by the same cations but have higher concentrations of bicarbonate. Microbiological parameters were determined in 13 groundwater samples collected from the study area. Total coliforms, thermotolerant coliforms, E. coli, Enterococcus spp., Salmonella sp., Staphylococcus spp., and P. aeruginosa were detected in 96.36, 88.18, 100, 47.5, 97.27, 96.7, and 75 % of the groundwater samples, respectively. The pollution of groundwater comes from a variety of sources, Ouadi El Kebir River, including land application of agricultural chemicals and organic wastes, infiltration of irrigation water, septic tanks, and infiltration of effluent from sewage treatment plants, pits, lagoons, and ponds used for storage.
Keywords: Groundwater; Pollution; Hydrochemistry; Microbiology; Algeria
Experimental evaluation of sorptive removal of fluoride from drinking water using iron ore by Beekam Kebede; Abebe Beyene; Fekadu Fufa; Moa Megersa; Michael Behm (57-65).
High concentrations of fluoride in drinking water is a public health concern globally and of critical importance in the Rift Valley region. As a low-cost water treatment option, the defluoridation capacity of locally available iron ore was investigated. Residence time, pH, agitation rate, particle size of the adsorbent, sorbent dose, initial fluoride concentration and the effect of co-existing anions were assessed. The sorption kinetics was found to follow pseudo-first-order rate and the experimental equilibrium sorption data fitted reasonably well to the Freundlich model. The sorption capacity of iron ore for fluoride was 1.72 mg/g and the equilibrium was attained after 120 min at the optimum pH of 6. The sorption study was also carried out at natural pH conditions using natural ground water samples and the fluoride level was reduced from 14.22 to 1.17 mg/L (below the WHO maximum permissible limit). Overall, we concluded that iron ore can be used in water treatment for fluoride removal in the Rift Valley region and beyond.
Keywords: Fluoride; Defluoridation; Iron ore; Water treatment
Implication of drainage basin parameters of a tropical river basin of South India by K. J. Babu; S. Sreekumar; Arish Aslam (67-75).
Drainage morphometry provides quantitative description of the drainage system which is an important aspect of the characterisation of watersheds. Chalakudi River is one of the important rivers of the South India which has attracted attention of many environmental scientists recently because of the proposed Athirapally Hydel Project across the river. SRTM (Shuttle Radar Topographic Mission) data were used for preparing DEM (Digital Elevation Model), Aspect Map and Slope Map. Geographical Information System (GIS) was used for the evaluation of linear, areal and relief aspects of morphometric parameters. The study reveals that the terrain exhibits dentritic and trellis pattern of drainage. The Chalakudi River Basin has a total area of 1,448.73 km2 and is designated as seventh-order basin. The drainage density of the basin is estimated as 2.54 and the lower-order streams mostly dominate the basin. The high basin relief indicates high runoff and sediment transport. The elongation ratio of the Chalakudi Basin is estimated as 0.48 and indicates that the shape of the basin is elongated. The development of stream segments in the basin area is more or less effected by rainfall. Relief ratio indicates that the discharge capability of watershed is very high and the groundwater potential is meagre. The low value of drainage density in spite of mountainous relief indicates that the area is covered by dense vegetation and resistant rocks permeated by fractures and joints. These studies are helpful in watershed development planning and wise utilization of natural resources.
Keywords: GIS; Morphometric analysis; Geology; Chalakudi River Basin
Assessment of the characteristic of nutrients, total metals, and fecal coliform in Sibu Laut River, Sarawak, Malaysia by Chen-Lin Soo; Teck-Yee Ling; Nyanti Lee; Kasing Apun (77-96).
The concentrations of nutrients (nitrogen and phosphorus), total metals, and fecal coliform (FC) coupling with chlorophyll-a (chl-a), 5-day biochemical oxygen demand (BOD5) and other general environmental parameters were evaluated at the sub-surface and near-bottom water columns of 13 stations in the Sibu Laut River during low and high slack waters. The results indicated that inorganic nitrogen (mainly nitrate) was the primary form of nitrogen whereas organic phosphorus was the major form of phosphorus. The abundance of total heavy metals in Sibu Laut River and its tributaries was in the order of Pb < Cu < Zn < Cd. Fecal coliform concentration was relatively low along Sibu Laut River. The shrimp farm effluents contributed a substantial amount of chl-a, BOD5, nutrients, and FC to the receiving creek except for total metals. Nevertheless, the influence was merely noticeable in the intake creek and amended rapidly along Selang Sibu River and brought minimal effects on the Sibu Laut River. Besides, the domestic sewage effluents from villages nearby also contributed a substantial amount of pollutants.
Keywords: Water quality; Eutrophication; Heavy metals; Fecal coliform; Sibu Laut River
Research on evaluating water resource resilience based on projection pursuit classification model by Dong Liu; Dan Zhao; Xu Liang; Qiuchen Wu (97-105).
Water is a fundamental natural resource while agriculture water guarantees the grain output, which shows that the utilization and management of water resource have a significant practical meaning. Regional agricultural water resource system features with unpredictable, self-organization, and non-linear which lays a certain difficulty on the evaluation of regional agriculture water resource resilience. The current research on water resource resilience remains to focus on qualitative analysis and the quantitative analysis is still in the primary stage, thus, according to the above issues, projection pursuit classification model is brought forward. With the help of artificial fish-swarm algorithm (AFSA), it optimizes the projection index function, seeks for the optimal projection direction, and improves AFSA with the application of self-adaptive artificial fish step and crowding factor. Taking Hongxinglong Administration of Heilongjiang as the research base and on the basis of improving AFSA, it established the evaluation of projection pursuit classification model to agriculture water resource system resilience besides the proceeding analysis of projection pursuit classification model on accelerating genetic algorithm. The research shows that the water resource resilience of Hongxinglong is the best than Raohe Farm, and the last 597 Farm. And the further analysis shows that the key driving factors influencing agricultural water resource resilience are precipitation and agriculture water consumption. The research result reveals the restoring situation of the local water resource system, providing foundation for agriculture water resource management.
Keywords: Hongxinglong administration; Projection pursuit classification model; Artificial fish-swarm algorithm; Water resource system resilience