scholarly journals Streamflow Alterations, Attributions, and Implications in Extended East Rapti Watershed, Central-Southern Nepal

2020 ◽  
Vol 12 (9) ◽  
pp. 3829 ◽  
Author(s):  
Vishnu Prasad Pandey ◽  
Dibesh Shrestha ◽  
Mina Adhikari ◽  
Shristi Shakya

Streamflow alteration and subsequent change in long-term average, seasonality, and extremes (e.g., floods and droughts) may affect water security, which is a major concern in many watersheds across the globe. Both climatic and anthropogenic activities may contribute to such changes. Therefore, this study assesses: (i) Streamflow and precipitation trends to identify streamflow alterations in the Extended East Rapti (EER) watershed in central-southern Nepal; (ii) relationship of the alterations to climatic and anthropogenic sources; and (iii) implications of streamflow changes to the socio-environmental system. The trends in streamflow were analyzed for pre-and post-1990 periods considering the abrupt shift in temperature trend in 1990. Results showed a general decreasing trends in discharge post-1990 in the EER watershed. Human activities have significantly contributed in altering streamflow in the EER. Human-induced streamflow alterations have affected the water availability, food security, river health, aquatic biodiversity, and groundwater abstraction in the EER watershed.

2021 ◽  
Author(s):  
Stefano Terzi ◽  
Janez Sušnik ◽  
Stefan Schneiderbauer ◽  
Silvia Torresan ◽  
Andrea Critto

Abstract. Water management in mountain regions is facing multiple pressures due to climate change and anthropogenic activities. This is particularly relevant for mountain areas where water abundance in the past allowed for many anthropogenic activities, exposing them to future water scarcity. To better understand the processes involved in water scarcity impact, an innovative stochastic System Dynamics Modelling (SDM) explores water stored and turbined in the S.Giustina reservoir (Province of Trento, Italy). The integration of outputs from climate change simulations as well as from a hydrological model and statistical models into the SDM is a quick and effective tool to simulate past and future water availability and demand conditions. Short-term RCP4.5 simulations depict conditions of highest volume and outflow reductions starting in spring (−16.1 % and −44.7 % in May compared to the baseline). Long-term RCP8.5 simulations suggest conditions of volume and outflow reductions starting in summer and lasting until the end of the year. The number of events with stored water below the 30th and above the 80th quantiles suggest a general reduction both in terms of low and high volumes. These results call for the need to adapt to acute short-term water availability reductions in spring and summer while preparing for hydroelectric production reductions due to the chronic long-term trends affecting autumn and mid-winter. This study provides results and methodological insights for potential SDM upscaling across strategic mountain socio-economic sectors (e.g., hydropower, agriculture and tourism) to expand water scarcity assessments and prepare for future multi-risk conditions and impacts.


2020 ◽  
Author(s):  
Stefano Terzi ◽  
Janez Sušnik ◽  
Sara Masia ◽  
Silvia Torresan ◽  
Stefan Schneiderbauer ◽  
...  

<p>Mountain regions are facing multiple impacts due to climate change and anthropogenic activities. Shifts in precipitation and temperature are affecting the available water influencing a variety of economic activities that still rely on large quantities of water (e.g. ski tourism, energy production and agriculture). The Alps are among those areas where recent events of decreased water availability triggered emerging water disputes and spread of economic impacts across multiple sectors and from upstream high water availability areas to downstream high water demand areas. In order to make our water management systems more resilient, there is a need to unravel the interplays and dependencies that can lead to multiple impacts across multiple sectors. However, current assessments dealing with climate change usually account for a mono sectoral and single risk perspective.</p><p>This study hence shows an integrative assessment of multi-risk processes across strategic sectors of the Alpine economy. System dynamics modelling (SDM) is applied as a powerful tool to evaluate the multiple impacts stemming from interactions and feedbacks among water-food-energy economic sectors of the Noce river catchment in the Province of Trento (Italy).</p><p>The SDM developed for the Noce catchment combined outputs from physically based models to evaluate water availability and statistical assessments for water demands from three main sectors: (i) apple orchards cultivation, (ii) water releases from large dam reservoirs for hydropower production and (iii) domestic and seasonal tourism activities.</p><p>Hydrological results have been validated on historical time series (i.e. 2009-2017) and projected in the future considering RCP 4.5 and 8.5 climate change scenarios for 2021-2050 medium term and 2041-2070 long term. Results show a precipitation decrease affecting river streamflow with consequences on water stored and turbined in all dam reservoirs of the Noce catchment, especially for long-term climate change scenarios. Moreover, temperature scenarios will increase the amount of water used for agricultural irrigation from upstream to downstream. Nevertheless, decreasing population projections will have a beneficial reduction of water demand from residents, counterbalancing the increasing demand from the other sectors.</p><p>Finally, the integrated SDM fostered discussions in the Noce catchment on interplays between climate change and anthropogenic activities to tackle climate-related water scarcity.</p>


Author(s):  
Jiameng Lai ◽  
Yanan Li ◽  
Jianli Chen ◽  
Guo-Yue Niu ◽  
Peirong Lin ◽  
...  

Abstract Northwestern China (NWC) is among the major global hotspots undergoing massive terrestrial water storage (TWS) depletion. Yet driver(s) underlying such region-wide depletion remain controversial, i.e., warming-induced glacier-melting versus anthropogenic activities. Reconciling this controversy is the core initial step to guide policy-making for combating the dual challenges in agriculture production and water scarcity in the vastly dry NWC towards sustainable development. Utilizing diverse observations, we found persistent cropland expansion by >1.2×104km2 since 2003, leading to 59.9% growth in irrigated area and 19.5% in agricultural water use, despite a steady irrigation efficiency enhancement. Correspondingly, a substantially faster evapotranspiration increase occurred in crop expansion areas, whereas precipitation exhibited no long-term trend. Counterfactual analyses suggest that the region-wide TWS depletion is unlikely to have occurred without crop expansion-driven evapotranspiration increase even in the presence of glacier-melting. These findings imply that sustainable water management is critically needed to ensure agriculture and water security in NWC.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Mao ◽  
Jun Kang Chow ◽  
Pin Siang Tan ◽  
Kuan-fu Liu ◽  
Jimmy Wu ◽  
...  

AbstractAutomatic bird detection in ornithological analyses is limited by the accuracy of existing models, due to the lack of training data and the difficulties in extracting the fine-grained features required to distinguish bird species. Here we apply the domain randomization strategy to enhance the accuracy of the deep learning models in bird detection. Trained with virtual birds of sufficient variations in different environments, the model tends to focus on the fine-grained features of birds and achieves higher accuracies. Based on the 100 terabytes of 2-month continuous monitoring data of egrets, our results cover the findings using conventional manual observations, e.g., vertical stratification of egrets according to body size, and also open up opportunities of long-term bird surveys requiring intensive monitoring that is impractical using conventional methods, e.g., the weather influences on egrets, and the relationship of the migration schedules between the great egrets and little egrets.


Author(s):  
A. D. Chalfoun

Abstract Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies (n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.


Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3281
Author(s):  
Xu He ◽  
Yong Yin

Recently, deep learning-based techniques have shown great power in image inpainting especially dealing with squared holes. However, they fail to generate plausible results inside the missing regions for irregular and large holes as there is a lack of understanding between missing regions and existing counterparts. To overcome this limitation, we combine two non-local mechanisms including a contextual attention module (CAM) and an implicit diversified Markov random fields (ID-MRF) loss with a multi-scale architecture which uses several dense fusion blocks (DFB) based on the dense combination of dilated convolution to guide the generative network to restore discontinuous and continuous large masked areas. To prevent color discrepancies and grid-like artifacts, we apply the ID-MRF loss to improve the visual appearance by comparing similarities of long-distance feature patches. To further capture the long-term relationship of different regions in large missing regions, we introduce the CAM. Although CAM has the ability to create plausible results via reconstructing refined features, it depends on initial predicted results. Hence, we employ the DFB to obtain larger and more effective receptive fields, which benefits to predict more precise and fine-grained information for CAM. Extensive experiments on two widely-used datasets demonstrate that our proposed framework significantly outperforms the state-of-the-art approaches both in quantity and quality.


Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1145
Author(s):  
Zhongyuan Chen ◽  
Hao Xu ◽  
Yanna Wang

This study reviews the monsoonal Yangtze and the arid Nile deltas with the objective of understanding how the process–response between river-basin modifications and delta-estuary ecological degradation are interrelated under contrasting hydroclimate dynamics. Our analysis shows that the Yangtze River had a long-term stepwise reduction in sediment and silicate fluxes to estuary due to dam construction since the 1960s, especially after the Three Gorges Dam (TGD) closed in 2003. By contrast, the Nile had a drastic reduction of sediment, freshwater, and silicate fluxes immediately after the construction of the Aswan High Dam (AHD) in 1964. Seasonal rainfall in the mid-lower Yangtze basin (below TGD) complemented riverine materials to its estuary, but little was available to the Nile coast below the AHD in the hyper-arid climate setting. Nitrogen (N) and phosphate (P) fluxes in both river basins have increased because of the overuse of N- and P-fertilizer, land-use changes, urbanization, and industrialization. Nutrient ratios (N:P:Si) in both delta-estuaries was greatly altered, i.e., Yangtze case: 75:1:946 (1960s–1970s), 86:1:272 (1980s–1990s) and 102:1:75 (2000s–2010s); and Nile case: 6:1:32 (1960s–1970s), 8:1:9 (1980s–1990s), and 45:1:22 (2013), in the context of the optimum of Redfield ratio (N:P:Si = 16:1:16). This led to an ecological regime shift evidenced by a long-term change in phytoplankton communities in the Yangtze estuary, where silicious algae tended to lose dominance since the end of the 1990s, when more toxic dinoflagellates began to emerge. In the Nile estuary, such a regime shift was indicated by the post-dam dramatic reduction in zooplankton standing crop and fish landings until the early 2000s when biological recovery occurred due to nutrient inputs from anthropogenic sources. Although the Yangtze had higher human impacts than the Nile in terms of population, industrialization, and fertilizer application, N concentrations in the Nile estuarine waters surpassed the Yangtze in recent decades. However, eutrophication in the Yangtze estuary is much more intensive than in the Nile, leading to the likelihood of its estuarine water becoming more acidic than ever before. Therefore, ecological degradation in both delta-estuaries does not follow a linear trajectory, due not only to different climate dynamics but also to human forcings. The comparative insights of this study should be incorporated into future integrated coastal management of these two important systems.


1978 ◽  
Vol 16 (4) ◽  
pp. 549-564 ◽  
Author(s):  
J. W. Garmany

This article discusses some of the issues involved in the choice of technology in developing countries, especially those in Africa, and the relationship of this to employment and output. The problem is to find an optimum combination of productive resources that comes nearest to satisfying two objectives: the full and economically efficient utilisation of such resources, and the creation of as much surplus as possible over current consumption, thereby making possible new investment and long-term growth.


2014 ◽  
Vol 4 (3) ◽  
pp. 368 ◽  
Author(s):  
Roshana Gul

Though a lot of studies have been done to conclude customer loyalty as dependent variable but still there is a vast margin of researches to be conducted in future in different spheres of this construct. On the other hand the truth of the importance of customer loyalty as an enduring asset cannot be falsified. It is fundamental for organizations to build up long term and mutual beneficial associations with the customers. The purpose of this research paper is to show the inter relationship of reputation, customer satisfaction and trust on customer loyalty. According to the observations reputation is the major independent variable that has significant relationship with customer satisfaction, customer loyalty, and trust. Data for this research study was taken from the Islamia University, Quaid-e-Azam Medical College, and different banks located at various geographic locations of Bahawalpur region of Pakistan. Data was collected through self administered questionnaire and analyzed by using regression through SPSS. The results have been drawn from 150 users of NISHAT LINEN and it was found that there is positive and significant relationship among reputation, customer satisfaction, trust and customer loyalty. Hence the studies give the positive sign that with the increment of reputation, customer satisfaction and trust the customer loyalty enhances.  


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