How do climate and forest changes affect long-term streamflow dynamics? A case study in the upper reach of Poyang River basin

Abstract. Globally, there have been many extreme weather events in recent decades. A challenge has been to determine whether these extreme weather events have increased in number and intensity compared to the past. This challenge is made more difficult due to the lack of long-term instrumental data, particularly in terms of river discharge, in many regions including Southeast Asia. Thus our main aim in this paper is to develop a river basin scale approach for assessing interannual hydrometeorological and discharge variability on long, palaeological, time scales. For the development of the basin-wide approach, we used the Mekong River basin as a case study area, although the approach is also intended to be applicable to other basins. Firstly, we derived a basin-wide Palmer Drought Severity Index (PDSI) from the Monsoon Asia Drought Atlas (MADA). Secondly, we compared the basin-wide PDSI with measured discharge to validate our approach. Thirdly, we used basin-wide PDSI to analyse the hydrometeorology and discharge of the case study area over the study period of 1300–2005. For the discharge-MADA comparison and hydrometeorological analyses, we used methods such as linear correlations, smoothing, moving window variances, Levene type tests for variances, and wavelet analyses. We found that the developed basin-wide approach based on MADA can be used for assessing long-term average conditions and interannual variability for river basin hydrometeorology and discharge. It provides a tool for studying interannual discharge variability on a palaeological time scale, and therefore the approach contributes to a better understanding of discharge variability during the most recent decades. Our case study revealed that the Mekong has experienced exceptional levels of interannual variability during the post-1950 period, which could not be observed in any other part of the study period. The increased variability was found to be at least partly associated with increased El Niño Southern Oscillation (ENSO) activity.

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Assessment of climate change parameters impact on long-term sediment transport trend case study: Azam River basin

International Journal of Hydrology Science and Technology ◽

10.1504/ijhst.2020.106482 ◽

2020 ◽

Vol 10 (2) ◽

pp. 191

Author(s):

Mehdi Yazdian ◽

Sara Nazari

Keyword(s):

Climate Change ◽

Sediment Transport ◽

River Basin

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After the Boomerang: Environmental Movements and Politics in the La Plata River Basin

Global Environmental Politics ◽

10.1162/152638002320980614 ◽

2002 ◽

Vol 2 (4) ◽

pp. 35-57 ◽

Cited By ~ 42

Author(s):

Kathryn Hochstetler

Keyword(s):

River Basin ◽

Legal Capacity ◽

Related Factors ◽

La Plata ◽

Target State ◽

Transnational Mobilization ◽

Environmental Norms ◽

National Environmental

This article focuses on one common transnational NGO strategy, the boomerang strategy. In this strategy, Southern NGOs seek international allies to help them pressure their states from outside. The article uses a case study of a transnational mobilization against a water superhighway or “Hidrovia” in the La Plata River basin in South America to develop arguments about the long term impacts of throws of the boomerang. I argue that what happens after the boomerang depends on two related factors: the extent to which the target state(s) have accepted the international norms at stake and the presence or absence of a specific set of domestic capacities in the target state(s). Because Brazil has higher levels of national environmental legal capacity and greater acceptance of international environmental norms than its neighbors, environmentalists were able to block the Hidrovia there after the successful collective pressure, while Argentine environmentalists were not.

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Optimizing Completion Design and Well Spacing in the Powder River Basin Niobrara Oil Play

10.2118/204167-ms ◽

2021 ◽

Author(s):

Blake Burget ◽

Neal Dannemiller ◽

Dylan Garrett ◽

Erik Kling

Keyword(s):

River Basin ◽

Transient Analysis ◽

Powder River Basin ◽

Well Spacing ◽

Rate Transient Analysis ◽

Oil Performance ◽

Reservoir Simulator ◽

Optimal Cluster

Abstract A seven-step workflow to help subsurface teams establish an initial thesis for optimal completion design (cluster spacing, proppant per cluster) and well spacing in emerging / under-explored resource plays is proposed and executed for the Powder River Basin Niobrara unconventional oil play. The workflow uses Rate Transient Analysis (RTA) to determine the Ac∗k parameter and then walks the reader through how to sequentially decouple the parameter into its constituent parts (frac height (h), number of symmetrical fractures achieved (nf), permeability (k) and fracture half-length (xf)). Once these terms were quantified for each of the case study wells, they were used in a black oil reservoir simulator to compare predicted verses actual cumulative oil performance at 30, 60, 90,120 & 180 days. A long-term production match was achieved using xf as the lone history match parameter. xf verses proppant per effective half-cluster yielded an R2 value of > 0.90. 28 simulation scenarios were executed to represent a range of cluster spacing, proppant per cluster and well spacing scenarios. Economics (ROR and/or NPV10/Net Acre) were determined for each of these scenarios under three different commodity pricing assumptions ($40/$2.50, $50/$2.50 and $60/$2.50). An initial thesis for optimal cluster spacing, proppant per designed cluster and well spacing were determined to be 12’, 47,500 lbs and 8-14 wells per section (based on whether or not fracture asymmetry is considered) when WTI and Henry Hub are assumed to be $50 & $2.50 flat.

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Long-term landscape dynamics in the depopulated Carpathian Foothills: A Wiar River basin case study

Geographia Polonica ◽

10.7163/gpol.0160 ◽

2020 ◽

Vol 93 (1) ◽

pp. 5-23

Author(s):

Andrzej Norbert Affek ◽

Maria Zachwatowicz ◽

Jerzy Solon

Keyword(s):

World War Ii ◽

Land Cover ◽

River Basin ◽

Driving Forces ◽

Free Market ◽

Landscape Dynamics ◽

Marginal Lands ◽

Economically Marginalized

Recently, marginal lands have been attracting attention as areas of high cultural and natural value that are undergoing profound, uncontrolled transformations. These changes are seen as a threat to the cohesion and identity of existing landscapes. However, ongoing processes are often difficult to interpret and evaluate without a long-term historical perspective. Here, we focused on understanding the long-term landscape dynamics in the depopulated and economically marginalized Wiar River basin, where 87% of inhabitants were displaced after World War II. A detailed, spatially explicit land-cover analysis based on eight series of topographic data (dating from 1780 to 2017), in line with the review of archival sources and literature, allowed us for identification of patterns and drivers of change. We linked the driving forces and the resulting landscape properties to four distinct historical periods (i.e. pre-industrial, industrial, socialist, and free-market). We demonstrated how the landscape of 25 villages, dominated for centuries by open farmland, shifted after WWII into extensively forested, and that not all regions in Europe follow the pattern of increasing rate of land-cover change.

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