scholarly journals Anthropocene and streamflow: Long-term perspective of streamflow variability and water rights

Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
Pilar Barría ◽  
Maisa Rojas ◽  
Pilar Moraga ◽  
Ariel Muñoz ◽  
Deniz Bozkurt ◽  
...  
Keyword(s):  
Water Allocation ◽  
Time Window ◽  
Water Governance ◽  
Regional Climate ◽  
Water Rights ◽  
Climate Scenario ◽  
Climate Projections ◽  
Ungauged Catchments ◽  
Tree Ring Reconstruction

Since 1981, water allocation in Chile has been based on a water use rights (WURs) market, with limited regulatory and supervisory mechanisms. The volume to be granted as permanent and eventual WURs is calculated from streamflow records, if stream gauge data are available, or from hydrologic parameter transfer from gauged to ungauged catchments, usually with less than 50 years of record. To test the performance of this allocation system, while analyzing the long-term natural variability in water resources, we investigated a 400 year-long (1590–2015) tree-ring reconstruction of runoff and historical water rights for Perquilauquén at Quella catchment, a tributary to the Maule River in Central Chile (35°S–36°30S). Furthermore, we assess how the current legislation would perform under a projected climate scenario, based on historical climate simulations of runoff calibrated against observed data, and future projections. Our analyses indicate that the allocation methodology currently applied by the Water Authority in Chile is very sensitive to the time window of data used, which leads to an underestimation of variability and long-term trends. According to the WURs database provided by the Chilean Water Directorate, WURs at Perquilauquén at Quella are already over-allocated. Considering regional climate projections, this condition will be exacerbated in the future. Furthermore, serious problems regarding the access and quality of information on already-granted WURs and actual water usage have been diagnosed, which further encumber environmental strategies to deal with and adapt to climate change. We emphasize the urgent need for a review and revision of current water allocation methodologies and water law in Chile, which are not concordant with the dynamics and non-stationarity of hydrological processes. Water scarcity and water governance are two of the key issues to be faced by Chile in the Anthropocene.

scholarly journals The 2010–2015 mega drought in Central Chile: Impacts on regional hydroclimate and vegetation

2017 ◽  
Author(s):  
René Garreaud ◽  
Camila Alvarez-Garreton ◽  
Jonathan Barichivich ◽  
Juan Pablo Boisier ◽  
Duncan Christie ◽  
...  
Keyword(s):  
River Flow ◽  
Potential Evapotranspiration ◽  
Regional Climate ◽  
Climate Scenario ◽  
Annual Rainfall ◽  
Central Chile ◽  
Groundwater Levels ◽  
Tree Ring Reconstruction ◽  
Neutral Conditions ◽  
Northern Sector

Abstract. Since 2010 an uninterrupted sequence of dry years, with annual rainfall deficits ranging from 25 to 45 %, has prevailed in Central Chile (western South America, 30–38° S). Although intense 1- or 2-year droughts are recurrent in this Mediterranean-like region, the ongoing event stands out because of its longevity and large spatial extent. The extraordinary character of the so-called Central Chile Mega Drought (MD) was established against century long historical records and a millennial tree-ring reconstruction of regional precipitation. The largest MD-averaged rainfall relative anomalies occurred in the northern, semi-arid sector of central Chile but the event was unprecedented to the south of 35° S. ENSO neutral conditions have prevailed since 2011 (but for the strong El Niño 2015) contrasting with La Niña conditions that often accompanied past droughts. The precipitation deficit diminished the Andean snowpack and resulted in amplified declines (up to 90 %) of river flow, reservoir volumes and groundwater levels along central Chile and westernmost Argentina. In some semiarid basins we also found a conspicuous decrease in the runoff-to-rainfall coefficient. A substantial decrease in vegetation productivity occurred in the shrubland-dominated, northern sector, but a mix of greening and browning patches occurred farther south where irrigated croplands and exotic forest plantations dominate. The ongoing warming in central Chile, making the MD one of the warmest 6-year period on record, may have also contributed to such complex vegetation changes by increasing potential evapotranspiration. The understanding of the nature and biophysical impacts of the MD contributes to preparedness efforts to face a dry, warm future regional climate scenario.

Global Climate Change and the Reallocation of Water

2019 ◽  
Author(s):  
Rhett B. Larson
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Water Allocation ◽  
Global Climate ◽  
Water Governance ◽  
Water Rights ◽  
Public Trust ◽  
Water Markets ◽  
International Level ◽  
Legal Reforms

Increased water variability is one of the most pressing challenges presented by global climate change. A warmer atmosphere will hold more water and will result in more frequent and more intense El Niño events. Domestic and international water rights regimes must adapt to the more extreme drought and flood cycles resulting from these phenomena. Laws that allocate rights to water, both at the domestic level between water users and at the international level between nations sharing transboundary water sources, are frequently rigid governance systems ill-suited to adapt to a changing climate. Often, water laws allocate a fixed quantity of water for a certain type of use. At the domestic level, such rights may be considered legally protected private property rights or guaranteed human rights. At the international level, such water allocation regimes may also be dictated by human rights, as well as concerns for national sovereignty. These legal considerations may ossify water governance and inhibit water managers’ abilities to alter water allocations in response to changing water supplies. To respond to water variability arising from climate change, such laws must be reformed or reinterpreted to enhance their adaptive capacity. Such adaptation should consider both intra-generational equity and inter-generational equity. One potential approach to reinterpreting such water rights regimes is a stronger emphasis on the public trust doctrine. In many nations, water is a public trust resource, owned by the state and held in trust for the benefit of all citizens. Rights to water under this doctrine are merely usufructuary—a right to make a limited use of a specified quantity of water subject to governmental approval. The recognition and enforcement of the fiduciary obligation of water governance institutions to equitably manage the resource, and characterization of water rights as usufructuary, could introduce needed adaptive capacity into domestic water allocation laws. The public trust doctrine has been influential even at the international level, and that influence could be enhanced by recognizing a comparable fiduciary obligation for inter-jurisdictional institutions governing international transboundary waters. Legal reforms to facilitate water markets may also introduce greater adaptive capacity into otherwise rigid water allocation regimes. Water markets are frequently inefficient for several reasons, including lack of clarity in water rights, externalities inherent in a resource that ignores political boundaries, high transaction costs arising from differing economic and cultural valuations of water, and limited competition when water utilities are frequently natural monopolies. Legal reforms that clarify property rights in water, specify the minimum quantity, quality, and affordability of water to meet basic human needs and environmental flows, and mandate participatory and transparent water pricing and contracting could allow greater flexibility in water allocations through more efficient and equitable water markets.

scholarly journals Long-Term Grass Biomass Estimation of Pastures from Satellite Data

2020 ◽  
Vol 12 (13) ◽  
pp. 2160
Author(s):  
Chiara Clementini ◽  
Andrea Pomente ◽  
Daniele Latini ◽  
Hideki Kanamaru ◽  
Maria Raffaella Vuolo ◽  
...  
Keyword(s):  
Climate Change ◽  
Time Window ◽  
Geographic Location ◽  
Primary Source ◽  
Biomass Estimation ◽  
Climate Projections ◽  
African Region ◽  
Long Time ◽  
Grass Biomass

The general consensus on future climate projections poses new and increased concerns about climate change and its impacts. Droughts are primarily worrying, since they contribute to altering the composition, distribution, and abundance of species. Grasslands, for example, are the primary source for grazing mammals and modifications in climate determine variation in the available yields for cattle. To support the agriculture sector, international organizations such as the Food and Agriculture Organization (FAO) of the United Nations are promoting the development of dedicated monitoring initiatives, with particular attention for undeveloped and disadvantaged countries. The temporal scale is very important in this context, where long time series of data are required to compute consistent analyses. In this research, we discuss the results regarding long-term grass biomass estimation in an extended African region. The results are obtained by means of a procedure that is mostly automatic and replicable in other contexts. Zambia has been identified as a significant test area due to its vulnerability to the adverse impacts of climate change as a result of its geographic location, socioeconomic stresses, and low adaptive capacity. In fact, analysis and estimations were performed over a long time window (21 years) to identify correlations with climate variables, such as precipitation, to clarify sensitivity to climate change and possible effects already in place. From the analysis, decline in both grass quality and quantity was not currently evident in the study area. However, pastures in the considered area were found to be vulnerable to changing climate and, in particular, to the water shortages accompanying drought periods.

scholarly journals Water as a transnational element: a reflection on governance and global environmental management

KPGT_dlutz_1 ◽  
2020 ◽  
Vol 34 (3) ◽  
pp. 06-34
Author(s):  
Francine Cansi ◽  
Joaquin Melgarejo Moreno
Keyword(s):  
Water Management ◽  
Water Allocation ◽  
Water Governance ◽  
Global Scale ◽  
Inductive Method ◽  
Global Environmental ◽  
Basic Sanitation ◽  
Long Term Trends ◽  
Life On Earth

Considering water as an essential good for life on earth, reflecting on management and governance will be timely relevant. Governance for equitable water allocation is closely linked to a decentralized regime without strengthening competence at the subnational level. Having made such observations, the present study through the inductive method and the literature review through the thought of classical and contemporary authors, by the succinct writing format, does not wish to propose or hope to present solutions for water management, but rather to offer some contribution for a transnational look, as a possibility of a civilizing governance of an indispensable resource to life in all its senses, water. Considering that the causal elements of inequalities are territorial, there is a lack of coordination that seeks solutions to water, sometimes too much, sometimes in scarcity, sometimes polluted. From a demographic perspective, they reflect the intrinsic characteristics of local dynamics, diversity in access, including basic sanitation and the concentration of the deficit in certain population groups, whose priority is to make management decisions at mutually compatible and effective administrative levels. Thus, with the goal of identifying long-term trends, important factors and actors for defining issues on a global scale seek to understand variables that may influence the international scenario of sustainability and transnational water governance.

Regional Climate Scenarios for use in Nordic Water Resources Studies

2003 ◽  
Vol 34 (5) ◽  
pp. 399-412 ◽  
Author(s):  
M. Rummukainen ◽  
J. Räisänen ◽  
D. Bjørge ◽  
J.H. Christensen ◽  
O.B. Christensen ◽  
...  
Keyword(s):  
Water Resources ◽  
Climate Models ◽  
Global Climate ◽  
Regional Climate ◽  
Regional Climate Models ◽  
Climate Projections ◽  
Climate Scenarios ◽  
Soil Frost ◽  
Nordic Region ◽  
Regional Climate Projections

According to global climate projections, a substantial global climate change will occur during the next decades, under the assumption of continuous anthropogenic climate forcing. Global models, although fundamental in simulating the response of the climate system to anthropogenic forcing are typically geographically too coarse to well represent many regional or local features. In the Nordic region, climate studies are conducted in each of the Nordic countries to prepare regional climate projections with more detail than in global ones. Results so far indicate larger temperature changes in the Nordic region than in the global mean, regional increases and decreases in net precipitation, longer growing season, shorter snow season etc. These in turn affect runoff, snowpack, groundwater, soil frost and moisture, and thus hydropower production potential, flooding risks etc. Regional climate models do not yet fully incorporate hydrology. Water resources studies are carried out off-line using hydrological models. This requires archived meteorological output from climate models. This paper discusses Nordic regional climate scenarios for use in regional water resources studies. Potential end-users of water resources scenarios are the hydropower industry, dam safety instances and planners of other lasting infrastructure exposed to precipitation, river flows and flooding.

scholarly journals Future Changes in Wave Conditions at the German Baltic Sea Coast Based on a Hybrid Approach Using an Ensemble of Regional Climate Change Projections

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 167
Author(s):  
Norman Dreier ◽  
Edgar Nehlsen ◽  
Peter Fröhle ◽  
Diana Rechid ◽  
Laurens M. Bouwer ◽  
...  
Keyword(s):  
21St Century ◽  
Wind Wave ◽  
Regional Climate ◽  
Hybrid Approach ◽  
Wave Modelling ◽  
Long Term Changes ◽  
Mean Wave Period ◽  
Wave Conditions ◽  
Sea Coast

In this study, the projected future long-term changes of the local wave conditions at the German Baltic Sea coast over the course of the 21st century are analyzed and assessed with special focus on model agreement, statistical significance and ranges/spread of the results. An ensemble of new regional climate model (RCM) simulations with the RCM REMO for three RCP forcing scenarios was used as input data. The outstanding feature of the simulations is that the data are available with a high horizontal resolution and at hourly timesteps which is a high temporal resolution and beneficial for the wind–wave modelling. A new data interface between RCM output data and wind–wave modelling has been developed. Suitable spatial aggregation methods of the RCM wind data have been tested and used to generate input for the calculation of waves at quasi deep-water conditions and at a mean water level with a hybrid approach that enables the fast compilation of future long-term time series of significant wave height, mean wave period and direction for an ensemble of RCM data. Changes of the average wind and wave conditions have been found, with a majority of the changes occurring for the RCP8.5 forcing scenario and at the end of the 21st century. At westerly wind-exposed locations mainly increasing values of the wind speed, significant wave height and mean wave period have been noted. In contrast, at easterly wind-exposed locations, decreasing values are predominant. Regarding the changes of the mean wind and wave directions, westerly directions becoming more frequent. Additional research is needed regarding the long-term changes of extreme wave events, e.g., the choice of a best-fit extreme value distribution function and the spatial aggregation method of the wind data.

scholarly journals New Approach for Bias Correction and Stochastic Downscaling of Future Projections for Daily Mean Temperatures to a High-Resolution Grid

2019 ◽  
Vol 58 (12) ◽  
pp. 2617-2632 ◽  
Author(s):  
Qifen Yuan ◽  
Thordis L. Thorarinsdottir ◽  
Stein Beldring ◽  
Wai Kwok Wong ◽  
Shaochun Huang ◽  
...  
Keyword(s):  
High Resolution ◽  
Bias Correction ◽  
Climate Models ◽  
Regional Climate ◽  
Regional Climate Models ◽  
Climate Change Signal ◽  
Climate Projections ◽  
Data Product ◽  
Temporal Features ◽  
Stochastic Downscaling

AbstractIn applications of climate information, coarse-resolution climate projections commonly need to be downscaled to a finer grid. One challenge of this requirement is the modeling of subgrid variability and the spatial and temporal dependence at the finer scale. Here, a postprocessing procedure for temperature projections is proposed that addresses this challenge. The procedure employs statistical bias correction and stochastic downscaling in two steps. In the first step, errors that are related to spatial and temporal features of the first two moments of the temperature distribution at model scale are identified and corrected. Second, residual space–time dependence at the finer scale is analyzed using a statistical model, from which realizations are generated and then combined with an appropriate climate change signal to form the downscaled projection fields. Using a high-resolution observational gridded data product, the proposed approach is applied in a case study in which projections of two regional climate models from the Coordinated Downscaling Experiment–European Domain (EURO-CORDEX) ensemble are bias corrected and downscaled to a 1 km × 1 km grid in the Trøndelag area of Norway. A cross-validation study shows that the proposed procedure generates results that better reflect the marginal distributional properties of the data product and have better consistency in space and time when compared with empirical quantile mapping.

scholarly journals Long-term changes of river discharge regime in Latvia

2008 ◽  
Vol 39 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Maris Klavins ◽  
Valery Rodinov
Keyword(s):  
Climate Variability ◽  
River Discharge ◽  
Water Resource Management ◽  
Regional Climate ◽  
Hydrological Regime ◽  
High Water ◽  
Regime Changes ◽  
Long Term Changes ◽  
Discharge Regime

The study of changes in river discharge is important for regional climate variability characterization and for development of an efficient water resource management system. The hydrological regime of rivers and their long-term changes in Latvia were investigated. Four major types of river hydrological regimes, which depend on climatic and physicogeographic factors, were characterized. These factors are linked to the changes observed in river discharge. Periodic oscillations of discharge, and low- and high-water flow years are common for the major rivers in Latvia. A main frequency of river discharge regime changes of about 20 and 13 years was estimated for the studied rivers. A significant impact of climate variability on the river discharge regime has been found.

scholarly journals Techniques for analyses of trends in GRUAN data

2015 ◽  
Vol 8 (4) ◽  
pp. 1673-1684 ◽  
Author(s):  
G. E. Bodeker ◽  
S. Kremser
Keyword(s):  
Measurement Uncertainty ◽  
Trend Analysis ◽  
Global Climate ◽  
Regional Climate ◽  
Added Value ◽  
Least Squares Regression ◽  
Target Uncertainty ◽  
Reference Quality ◽  
Measurement Uncertainties

Abstract. The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) provides reference quality RS92 radiosonde measurements of temperature, pressure and humidity. A key attribute of reference quality measurements, and hence GRUAN data, is that each datum has a well characterized and traceable estimate of the measurement uncertainty. The long-term homogeneity of the measurement records, and their well characterized uncertainties, make these data suitable for reliably detecting changes in global and regional climate on decadal time scales. Considerable effort is invested in GRUAN operations to (i) describe and analyse all sources of measurement uncertainty to the extent possible, (ii) quantify and synthesize the contribution of each source of uncertainty to the total measurement uncertainty, and (iii) verify that the evaluated net uncertainty is within the required target uncertainty. However, if the climate science community is not sufficiently well informed on how to capitalize on this added value, the significant investment in estimating meaningful measurement uncertainties is largely wasted. This paper presents and discusses the techniques that will need to be employed to reliably quantify long-term trends in GRUAN data records. A pedagogical approach is taken whereby numerical recipes for key parts of the trend analysis process are explored. The paper discusses the construction of linear least squares regression models for trend analysis, boot-strapping approaches to determine uncertainties in trends, dealing with the combined effects of autocorrelation in the data and measurement uncertainties in calculating the uncertainty on trends, best practice for determining seasonality in trends, how to deal with co-linear basis functions, and interpreting derived trends. Synthetic data sets are used to demonstrate these concepts which are then applied to a first analysis of temperature trends in RS92 radiosonde upper air soundings at the GRUAN site at Lindenberg, Germany (52.21° N, 14.12° E).

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