Information about location of marginal lands in a watershed is of interest to those who view these areas as potential land for producing biofuel crops. However, representing marginal lands into a distributed model such as the Soil and Water Assessment Tool (SWAT) is a challenge due to a rigid framework used for watershed subdivision. In this study, we developed a Geographic Information System (GIS) based approach for implementing targeted land use i.e. marginal lands into the SWAT model and evaluated the applicability of the approach on a 8digit Hydrologic Unit Code (HUC) watershed scale. Comparative results showed that conventional targeting approach overestimates the benefit of targeting marginal lands for Alamo switchgrass (Panicum virgatum, L) and g miscanthus (Miscanthus x giganteus) production due to simulation of larger area under marginal land category. Compared to baseline condition, which corresponds to no biofuel crop production on marginal lands, the pollutant losses under new targeting approach with simulation of Alamo switchgrass and giant miscanthus on marginal lands were substantially lower. The new targeting approach advances the science behind landscape representation in the SWAT modelthat has potential to be used in future targeting studies.

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Assessing the performance of appropriate agricultural conservation practices (CPs) frequently relies on the use of simulation models as a cost-effective tool instead of depending solely on the monitoring of water quality at individual field and watershed levels. This study evaluates the predicted impacts of several CPs on nutrient and sediment loss at the hydrological response unit scale in the L'Anguille River Watershed, which is a watershed identified as a "focus watershed" under the Mississippi River Basin healthy watershed Initiative (MRBI) program. The Soil and Water Assessment Tool model was calibrated and validated between 1998-2005 and 2006-2012, respectively for flow, sediment, total phosphorus, and nitrate nitrogen. Out of the seven MRBI CPs modeled in this study, the highest reduction in sediment (80%) and nutrient (58% for total phosphorus and 16% for total nitrogen) was predicted for the critical area planting practice, followed by filter strip, irrigation land leveling, grade stabilization structure, irrigation pipeline, nutrient management, and irrigation water management. Some of the predicted impacts conflicted with expected CP performance. The study underscores the importance of the proper formulation of CP algorithms in using simulation models for predicting impacts on water quality.

SummaryThe problem of estimation of ratio of population proportions is considered and a difference-type eetimator is proposed using auxiliary information. The bias and mean squared error of the proposed estimator is found and compared to the usual estinptor and also to WYNN'S (1976) typeestimator. An example is included for illustration.

Supply chain in upstream oil & gas is complex and riddled with unique challenges. An E&P company transports a variety of materials ranging from an oil rig to a fastener. Large volume of import material is transported across international waters and then hauled to work sites deploying multi-modal transportation. All supply chain operations have to follow strict compliance to various regulatory provisions, law of the land and high HSE standards. In addition the industry demands flexibility and assurance. - a rig standby as a result of material unavailability can cost upto a million dollars per day. Cyclical nature of the oil business requires an efficient supply chain. During the crests the focus is on extracting oil as much and as fast as possible whereas during the troughs cost effectiveness is key. In mature and developed Oil & Gas upstream markets such as USA, North Sea, Middle East the scale of activity has spawned consolidation in supply chains. Local material suppliers have developed significant infrastructure that is shared across different operators in a region. Thus operators partner with material suppliers to maximize efficiency and cost effectiveness across their supply chain. Unlike mature markets, developing oil & gas markets like India reel through fragmented supply chain operations. In general, companies internalize supply chain activities and deploy logistics companies tactically leading to disjointed processes and lack of material visibility. Cairn India (Company) operates the largest onshore producing block in India. Like other E&P companies in the region Cairn handles its supply chain in-house. Due to several challenges in the existing model a strong need to revamp the system was felt. Cairn has taken the initiative to develop a vendor base in India to emulate the structured and integrated supply chain prevalent in mature markets. The contract structure is innovative to enable scale, performance linked compensation and aligns the goal of the service provider with that of the operator. This strategic partnership is expected to fetch multi-fold benefits for the operator including: ○Efficient supply chain management that is scalable as per business requirements○Improved inventory planning and optimization through material visibility and tracking○Enhanced business performance through robust Service Level Agreements○Reduced transactional effort and enhanced focus on core business activities During the development of the model, prospective partners were engaged at multiple levels to validate the practicality of implementation. The paper discusses the model in more detail along with key risks in terms of its implementation, partner performance and execution. This contracting approach is a significant leap towards increasing the efficiency and effectiveness of inbound supply chain in the undeveloped geographies. The success of this model can be easily replicated and the benefits could be reaped by industry at large.