Studying the sediment that accumulates in a stream is an important aspect in the study of water quality and resources. With respect to water quality, the main issue is the turbidity of the water. Increased losses of natural landscape increase the erosion process in turn raising the turbidity of the water and reducing the light that can penetrate to the water reducing the growth of aquatic life. With respect to water resources, sediment accumulates in the river ways, harbors, and in dams reducing the effectiveness of these resources. This study focused on determining the amount of sediment that is outputted at the outlet of a watershed in the form of sediment yield in units of Tonne per square kilometer. The objective of this study was to determine and produce a map that detailed the sediment yield in Tonne per square kilometer for the subbasins within the Los Olmos Creek watershed given a hypothetical frequency storm event. Two frequency storm events were applied and compared and the final outcome would be sediment yield per storm event.

Calcium and magnesium hardness salts in groundwater are very common and caused major problems for drinking and household purposes. This study aims to synthesize zeolite-4A from kaolinite for removing the total hardness ions from Assiut Governorate groundwater wells. Therefore, the kaolin was calcinated hydrothermally through the metakaolinization and zeolitization processes to produce crystalline zeolite-4A. The chemical composition andmorphology ofcrystalline zeolite-4A were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Then the column experiments were conducted to study the performance of crystalline salt-4A as ion exchange and investigate their operation parameters and regeneration conditions. Thomas and Yoon-Nelson models were applied to predict the adsorption capacity and time required for 50% breakthrough curves. The effects of initial concentrations of 550 mg/l for total Ca+2 and Mg+2 hardness, feed flow rate of 10-30 ml/min, and height range of 1.0– 4.0 cm on the breakthrough behavior of the adsorption system were studied. The obtained results indicated that the synthesized zeolite-A4 can remove total hardness (Ca+2 + Mg+2) ions from groundwater to the permissible limit according to the standards drinking water law.

During the nineteenth century, the British colonial forestry and the denial of customary rights of people, led to conflict between the imperial forest department and local society. This study analyzes such a conflict in the northern Indian state of Uttarakhand. It shows how this conflict led to the origin of Van Panchayats, which eventually evolved into community based forest management (CBFM) in 1932. The end of British Empire and the emergence of independent India in 1947 began a new era that gave birth the system of joint forest management (JFM) in early 1990s. However, people’s movement for the restoration customary rights continued. In 2006, the Indian parliament passed the Forest Rights Act, which fully restored peoples sovereign right, independent of either the state or Forest Department interference. Nevertheless, struggle for the full empowerment of local village over their surrounding forest is on going.

In many urban areas, stormwater runoff is often contaminated with zinc (Zn) as it washes through galvanized surfaces in buildings and tire dusts from pavements. Biochars have shown a great potential to treat stormwater runoff contaminated with heavy metals due to their favorable physical and chemical characteristics. Biochar materials produced from pyrolysis of oak tree and wood at 400°C and 450 °C, respectively, were studied to characterize adsorption behaviors of Zn from aqueous solution to assess their applicability as a filter media for stormwater treatment. Two adsorption isotherm models, Freundlich and Langmuir, were fitted to the batch-scale experimental data. The kinetics of Zn adsorption was investigated under two contrasting physical condition (stagnant vs. agitated). The adsorption isotherm was better fitted with the Langmuir model (R2 = 0.99) than the Freundlich model (R2 = 0.62-0.72). Oak tree biochar (~ 21,400 mg kg-1) outperformed wood biochar (~ 6,100 mg kg-1) in the Zn adsorption due to higher molar ratio of oxygen to carbon in the oak tree biochar. The Zn adsorption by the biochars were less effective under stagnant condition, suggesting that external energy for agitation is needed when considering biochar as a stormwater filter media. Overall the kinetics data of Zn adsorption fitted well with the pseudo-second order model (R2 = 0.99), indicating that chemisorption was dominant mechanism for the Zn adsorption onto the biochars. This study highlights a potential for biochar to be an effective adsorbent to remove Zn with relatively short contact time for stormwater and industrial applications.

Dams and reservoirs are a dynamic slice of our national infrastructure and provide power, water, recreation, irrigation, flood protection, and many other advantages to growing populations across Nigeria. Assessing the integrity of these structures is a critical component of sustained operations. Post-Construction Integrity Assessment of Ero Dam at Ikun- Ekiti Southwest Nigeria was undertaken employing spontaneous potential (SP) and electrical resistivity surveys (VES and Dipole – Dipole) with a view to delineate the subsurface geoelectric sequence/parameters and identify structures such as faults and fractured zones, network of joints, seepages and basement depressions that are threats to the existence of the dam. SP survey revealed that the seepage zones were found within stations 2-4 inbetween distance 10-20m and stations 7-10 within 35-50m on the ground. The calculated SP depths for stations 2 – 4 and 7 – 10 were 5m and 6m respectively. The SP survey indicated the peak negative profile of the streaming potential which is a pointer to an area where there is possibility of seepage in the dam embankment. VES survey revealed that VES 1 depicted HK curve type while both VES 2 and 3 were characterized as H curve. There is marked variation in resistivity with depth across the study area with values that ranged from 37 - 251?m. Areas of lower resistivity are due to an increase in pore water content as revealed in the various resistivity values of the sounding locations. The seepage zone has low resistivity value and constitutes a point of weakness in the dam which can result in flooding of the embankment. Dipole – Dipole assessment of the Dam revealed that the first layer in the subsurface configuration of Ero Dam is laterite (? ranged from 100?m to 230?m). The second layer (leaky part of the dam core) is clay with apparent resistivity values ranging between 45?m and 85?m. The resistivity value between 105?m and 213 ?m approximately represents the intact dam core (weathered rock) which is the third layer characterizing competent zone. The moderately low resistivity layers are zones of interest in terms of post construction integrity assessment of a dam. The dam’s core is made up of clay indicating seepage problem. In view of the SP values and results of VES and Dipole – Dipole surveys, Ero Dam suffers seepage problem and needs rehabilitation and constant maintenance.