Prediction of total landslide volume in watershed scale under rainfall events using a probability model

This study established a probability model based on the landslide spatial and size probabilities to predict the possible volume and locations of landslides in watershed scale under rainfall events. First, we assessed the landslide spatial probability using a random forest landslide susceptibility model including intrinsic causative factors and extrinsic rainfall factors. Second, we calculated the landslide volume probability using the Pearson type V distribution. Lastly, these probabilities were joined to predict possible landslide volume and locations in the study area, the Taipei Water Source Domain, under rainfall events. The possible total landslide volume in the watershed changed from 1.7 million cubic meter under the event with 2-year recurrence interval to 18.2 million cubic meter under the event with 20-year recurrence interval. Approximately 62% of the total landslide volume triggered by the rainfall events was concentrated in 20% of the slope units. As the recurrence interval of the events increased, the slope units with large landslide volume tended to concentrate in the midstream of Nanshi River subwatershed. The results indicated the probability model posited can be used not only to predict total landslide volume in watershed scale, but also to determine the possible locations of the slope units with large landslide volume.

Analysis of Earthen Road Construction and Land Degradation in the Tankhuwakhola Watershed of Dhankuta District

Earthen road construction has resulted land degradation in the Tankhuwakhola watershed of Dhankuta district, eastern hills of Nepal. The community living near the highway has dramatically changed in their way of living with the adoption of commercial crops. As a result, the people who lived far from the access of roads have interested in the expansion of agricultural link roads to their community. The local government had prepared a District Transport Master Plan (DTMP) and identified 25 rural earthen road schemes in the Tankhuwakhola watershed. The local people have also given high priority to road construction for increasing access to markets, education, health services and other facilities. The analysis of both spatial and non-spatial data reveals that the watershed area losses 1.8 million cubic meter soils due to the cause of earthen road construction. As a result, the area is suffering from the problem of the landslide, soil erosion that ultimately result of land degradation. This paper concludes that the acceleration of land degradation has exerted to the sustainability of population-resource relation. The watershed area has been producing more profitable commercial crops for exporting outside from the hills since the construction of the Koshi highway. The watershed needs an integrated watershed management program to address human-induced vulnerability and sustainability of watershed resources.

Exploring the Effects of Hydraulic Connectivity Scenarios on the Spatial-Temporal Salinity Changes in Bosten Lake through a Model

Lake water salinization in arid areas is a common problem and should be controlled for the better use of freshwater of lakes and for the protection of the environment around lakes. It is well known that the increasing of hydraulic connectivity improves water quality, but for a lake, understanding how hydraulic connectivity changes its water quality in terms of spatial aspects is of great significance for the protection and utilization of different regions of the lake water body. In this paper, the impacts of three connectivity scenarios on the spatial-temporal salinity changes in Bosten Lake were modeled through the three-dimensional (3D) hydrodynamic model, Environmental Fluid Dynamics Code (EFDC). The constructed Bosten Lake EFDC model was calibrated for water level, temperature, and salinity with acceptable results. As for the Bosten Lake, three connectivity scenarios were selected: (1) the increasing of the discharge water amount into the lake from the Kaidu River, (2) the transferring of 1 million cubic meter freshwater to the southwestern part of the lake (the Huangshuigou region of the lake), and (3) the changing of the outflow position from the southwestern part of the lake (the Kongque river) to the southeastern of the lake (the Caohu region). Through the simulations, we found that the region of the lake mainly influenced by the three scenarios presented here were different, and of the three scenarios, scenario 3 was the best means of controlling the overall lake salinity. On the basis of the salinity distribution results gained from the simulations, decision-makers can choose the ways to mitigate the salinity of the lake according to which region they want to improve the most in terms of economic efficiency and preserve in terms of ecological balance.

The Effect of Utilizing Rice Husk Ash on Some Properties of Concrete - A Review

World environmental pollution is having direct and visible influence of construction industry. Relatively, 10 quintal of CO2emitted by the manufacturing of 10 quintal of ordinary portland cement (OPC), which accounts almost seven percent of the global CO2 emissions. Averagely, ten thousand million cubic meter of concrete is produced yearly. Byproducts like rice husk ash (RHA), fly ash, blast-furnace slag, metakaolin and silica fume will be able to utilize as supplementary cementitious material because of their pozzolanic behavior. Rice husk cannot be used as animal’s feed due to the low nutritional value. Neither can it be discarded as landfill nor by burning because it arise a great environment challenge. By converting rice husk into rice husk ash (RHA), it can be used in concrete as a fractional substitution of cement because of high silica quantity in RHA. In this present paper, the result of some authors with the use RHA as a fractional substitution of cement on the properties of concrete like workability, permeability, compressive and tensile strength are reviewed.

Mean green water savings through trade of agricultural and industrial commodities (1996-2005)

The national water saving of a country as a result of trade in a certain commodity is calculated as the net import volume of this commodity times the water footprint of the commodity per commodity unit in the country considered. A negative sign means a net national water loss instead of a saving. Here, green water savings through the trade of industrial and agricultural products are considered. Annual estimations are given for the period 1996-2005, in million cubic meter per year. In the table, data are also disaggregated per commodities: crop products, animal products, and industrial products. Methodology and results can be found here: http://temp.waterfootprint.org/Reports/Report50-NationalWaterFootprints-Vol1.pdf For more information, visit the Water Footprint Network: http://temp.waterfootprint.org Agriculture Supply Use/Reuse

Technical and Economical Evaluation of a Fresh-Water Production from Zero-Wastewater Reverse Osmosis System: A Feasibility Study in Jordan

Jordan endures a shortage of fresh drinking water. Thus, there is a wide use of reverse osmosis (RO) units at homes and industrial zones. Zero wastewater, which is a modified reverse osmosis system, is developed and evaluated to overcome the problem of limited water. In Jordan, for example, Petra Company for Water Treatment Systems was established to mass-produce the newly modified RO units. In this study, a feasibility study is conducted to evaluate the technical and economical aspects of mass production of the new RO systems. With increasing future demand for fresh water, it is expected that the introduction of the new system to regional countries would save huge amounts of water. Additionally, good economical impacts will be achieved as a net profit to the newly established company. This expected extra profit would be set the base for further development to the modified RO system, such as introducing a compact multistage filtration unit. Results of the feasibility study showed a huge amount of water saving per annum estimated by 4.5 million cubic meter. In addition, a half million of Jordanian Dinar (JD) of a net annual profit attained at the current demand of RO units in Jordan.

Mean grey water savings through trade of agricultural and industrial commodities (1996-2005)

The national water saving of a country as a result of trade in a certain commodity is calculated as the net import volume of this commodity times the water footprint of the commodity per commodity unit in the country considered. A negative sign means a net national water loss instead of a saving. Here, grey water savings through the trade of industrial and agricultural products are considered. Annual estimations are given for the period 1996-2005, in million cubic meter per year. In the table, data are also disaggregated per commodities: crop products, animal products, and industrial products. Methodology and results can be found here: http://temp.waterfootprint.org/Reports/Report50-NationalWaterFootprints-Vol1.pdf For more information, visit the Water Footprint Network: http://temp.waterfootprint.org/?page=files/WaterStat Agriculture Cost Use/Reuse

The Cheecham Landslide Event

Land disturbance associated with the progressive expansion of a major pipeline and power corridor, along with extensive timber harvesting, triggered the reactivation of an ancient, 100 million cubic meter deep-seated landslide in northern Alberta. The landslide threatened six major transmission pipelines, and caused a loss of containment in one of the pipelines. The level of landslide activity and associated pipeline damage was surprising given the relatively subtle disturbances in relation to the massive scale of the slide. Given the very shallow 4.5 degree slope inclination and the lack of any surface expression of distress over most of the slope area, this case history underscores the importance of considering regionally specific geological conditions within pipeline geohazard evaluations. An intensive, multi-pronged program was adopted to stabilize and manage the landslide, including a series of targeted surface and ground water control measures that produced an approximate 100-fold reduction in movement rates. This demonstrates that the sensitivity of slides in the region to subtle changes is a negative factor for triggering landslides, but can also be a positive factor for stabilizing them.

ANALYSIS OF JURE LANDSLIDE DAM, SINDHUPALCHOWK USING GIS AND REMOTE SENSING

On 2<sup>nd</sup> August 2014, a rainfall-induced massive landslide hit Jure village, Sindhupalchowk killing 156 people at a distance of 70 km North-East of Kathmandu, Nepal. The landslide was a typical slope failure with massive rock fragments, sand and soil. A total of estimated 6 million cubic meters debris raised more than 100 m from the water level and affected opposite side of the bank. The landslide blocked the Sunkoshi River completely forming an estimated 8 million cubic meter lake of 3km length and 300-350m width upstream. It took nearly 12 hour to fill the lake and overflow the debris dam. The lake affected five Village Development Committees (VDC) including highway, school, health post, postal service, police station, VDC office and temple upstream. The bottom of the dam was composed of highly cemented material and the derbies affected Sunkoshi hydropower downstream. Moreover, it caused the potential threat of Lake Outburst Flood. The lake was released by blasting off part of the landslide blockade and facilitated release of water from the lake. With the help of Remote Sensing (RS), series satellite images were used to identified, compared with previous state and quick estimation of potential treat was analysed. Using geographic information System (GIS) technology, estimation of volume, affected households, service centres, parcels etc. in the area was possible. In such hilly regions where disaster are very frequent, using GIS and RS technology comes very handy for immediate planning and response.