Geochemical indications for the Paleocene-Eocene Thermal Maximum (PETM) and Eocene Thermal Maximum 2 (ETM-2) hyperthermals in terrestrial sediments of the Canadian Arctic

During the late Paleocene to early Eocene, clastic fluvial sediments and coals were deposited in northern high latitudes as part of the Marga­ret Formation at Stenkul Fiord (Ellesmere Island, Nunavut, Canada). Syn-sedimentary tectonic movements of the Eurekan deformation continu­ously affected these terrestrial sediments. Different volcanic ash layers occur, and unconformities subdivide the deposits into four sedimentary units. Rare vertebrate fossils indicate an early Eocene (Graybullian) age for the upper part of the Stenkul Fiord outcrop. Here, we present carbon isotope data of bulk coal, related organic-rich mud and siltstones, a plant leaf wax-derived alkane, and additional plant remains. These data provide a complete carbon isotope record of one stratigraphic section with defined unconformity positions and in relation to other Eurekan deformation features. A previously dated ash layer MA-1 provided a U-Pb zircon age of 53.7 Ma and is used as a stratigraphic tie point, together with a discrete negative carbon isotope excursion found above MA-1 in a closely sampled coal seam. The excursion is identified as the likely expression of the I-1 hyperthermal event. Based on our isotope data that reflect the early Eocene dynamics of the carbon cycle, this tie point, and previous paleontological constraints from vertebrate fossils, the locations of the Paleocene-Eocene Thermal Maximum (PETM) and Eocene Thermal Maximum 2 (ETM-2) hyperthermals and their extent along the complete section are herein identified. Within the intervals of the PETM and ETM-2 hyperthermal events, increasing amounts of clastic sediments reached the site toward the respective end of the event. This is interpreted as a response of the fluvial depositional system to an intensified hydrological system during the hyperthermal events. Our study establishes an enhanced stratigraphic framework allowing for the calcula­tion of average sedimentation rates of different intervals and considerations on the completeness of the stratigraphic record. As one of the few high-latitude outcrops of early Eocene terrestrial sediments, the Stenkul Fiord location offers further possibilities to study the effects of extreme warming events in the Paleogene.

Large-sample assessment of spatial scaling effects of the distributed wflow_sbm hydrological model shows that finer spatial resolution does not necessarily lead to better streamflow estimates

Distributed hydrological modelling moves into the realm of hyper-resolution modelling. This results in a plethora of scaling related challenges that remain unsolved. In light of model result interpretation, finer resolution output might implicate to the user an increase in understanding of the complex interplay of heterogeneity within the hydrological system. Here we investigate spatial scaling in the realm of hyper-resolution by evaluating the streamflow estimates of the distributed wflow_sbm hydrological model based on 454 basins from the large-sample CAMELS data set. Model instances were derived at 3 spatial resolutions, namely 3 km, 1 km, and 200 m. The results show that a finer spatial resolution does not necessarily lead to better streamflow estimates at the basin outlet. Statistical testing of the objective function distributions (KGE score) of the 3 model instances show only a statistical difference between the 3 km and 200 m streamflow estimates. However, results indicate strong locality in scaling behaviour between model instances expressed by differences in KGE scores of on average 0.22. This demonstrates the presence of scaling behavior throughout the domain and indicates where locality in results is strong. The results of this study open up research paths that can investigate the changes in flux and state partitioning due to spatial scaling. This will help further understand the challenges that need to be resolved for hyper resolution hydrological modelling.

Hydrological System of the Plitvice Lakes—Trends and Changes in Water Levels, Inflows, and Losses

The Plitvice Lakes National Park is inscribed on UNESCO’s World Heritage List. The lake system is composed of 16 cascading lakes of different sizes separated by tufa barriers, which are the park’s key phenomenon. The lakes are characterized by highly diverse trends of the characteristic hydrological indicators—mean annual water levels, discharges, and tufa barrier growth. The analyses carried out in this paper identified that in the period before the early 1990s, Kozjak Lake had a trend of decreasing discharges, together with a trend of increasing water levels and growing tufa barriers. In contrast to this, in the period after 2001, a trend of increasing discharges was recorded, as well as a trend of decreasing water levels and decreasing tufa barriers. A potential cause of the barriers decreasing in size were the extremely high discharges during the last decade, which resulted in increased erosion of the tufa barriers. Losses of water due to the sinking from the lake system as well as the upper Korana course were confirmed, and it was identified that during the analyzed period the losses had not changed significantly. It was determined that the losses of water from Kozjak Lake occurred during low-water periods; however, they depended not only on the quantity of water flowing through the lakes but also on the hydrological conditions underground. The analyses carried out and the methodological procedures used in the analyzed area of the Plitvice Lakes are useful examples for the performance of analyses at similar lakes in karst formed by tufa deposition processes.

Socio-hydrological modeling of the tradeoff between flood control and hydropower provided by the Columbia River Treaty

The Columbia River Treaty (CRT) signed between the United States and Canada in 1961 is known as one of the most successful transboundary water treaties. Under continued cooperation, both countries equitably share collective responsibilities of reservoir operations, and flood control and hydropower benefits from treaty dams. As the balance of benefits is the key factor of cooperation, future cooperation could be challenged by external social and environmental factors which were not originally anticipated, or change in the social preferences of the two actors. To understand the robustness of cooperation dynamics we address two research questions – i) How does social and environmental change influence cooperation dynamics? and ii) How do social preferences influence the probability of cooperation for both actors? We analyzed infrastructural, hydrological, economic, social, and environmental data to inform the development of a socio-hydrological system dynamics model. The model simulates the dynamics of flood control and hydropower benefit sharing as a function of the probability to cooperate, which in turn is affected by the share of benefits. The model is used to evaluate scenarios that represent environmental and institutional change, and changes in political characteristics based on social preferences. Our findings show that stronger institutional capacity ensures equitable sharing of benefits over the long term. Under current CRT, the utility of cooperation is always higher for Canada than non-cooperation which is in contrast to the U.S. The probability to cooperate for each country is lowest when they are self-interested but fluctuates in other social preferences scenarios.

Water Allocation and the Sustainability of Dairying in the Upper Waitaki River Basin

<p>Water as a resource management issue is gaining prominence in New Zealand, both in terms of quality and quantity. In the Waitaki this became critical in 2003 when several proposed development schemes exposed the inadequacies of the RMA and highlighted the need for a catchment wide plan. Legislation was promulgated and a Regional Plan developed to address the issues of efficient allocation. This thesis aimed to question the efficiency of water allocation within the recent legislation and to examine the sustainability of dairying in this area with regard to cumulative effects to the hydrological system. It was found the Plan has failed to achieve its stated aims. Dairying in the upper Waitaki is currently increasing and applications for resource consent are being heard under legislation that is not backed by the science required within its policies. Fieldwork was undertaken to explore some of the science required under the Regional Plan to enable a 'reasonable use' test to be made. The aim was to assess the response of soils in the upper Waitaki to intensive irrigation. This revealed that the potential impacts of intensive irrigation in this area are significant and highlighted the need for further research. This is a study of how poor policy and planning, based on a lack of robust science has resulted in the inefficient allocation of water. This has implications for long-term sustainable resource use.</p>

Water Allocation and the Sustainability of Dairying in the Upper Waitaki River Basin

<p>Water as a resource management issue is gaining prominence in New Zealand, both in terms of quality and quantity. In the Waitaki this became critical in 2003 when several proposed development schemes exposed the inadequacies of the RMA and highlighted the need for a catchment wide plan. Legislation was promulgated and a Regional Plan developed to address the issues of efficient allocation. This thesis aimed to question the efficiency of water allocation within the recent legislation and to examine the sustainability of dairying in this area with regard to cumulative effects to the hydrological system. It was found the Plan has failed to achieve its stated aims. Dairying in the upper Waitaki is currently increasing and applications for resource consent are being heard under legislation that is not backed by the science required within its policies. Fieldwork was undertaken to explore some of the science required under the Regional Plan to enable a 'reasonable use' test to be made. The aim was to assess the response of soils in the upper Waitaki to intensive irrigation. This revealed that the potential impacts of intensive irrigation in this area are significant and highlighted the need for further research. This is a study of how poor policy and planning, based on a lack of robust science has resulted in the inefficient allocation of water. This has implications for long-term sustainable resource use.</p>

Study on the different type of hydrological input towards the accuracy of catchment discharge hydrograph

For hydrological applications, several rainfall measurement techniques are available, each with its own spatial and temporal resolution and errors. When these rainfall datasets are used as input for hydrological models, errors and uncertainties are propagated throughout the hydrological system. This research paper is using rainfall data from two different measurement tools namely rain gauge and radar. Using these two types of measurement tools, it is expected dissimilar output due to the different working principle. Arau catchment in Perlis were selected as the study area. The rainfall data used is in the unit of intensity with time interval 10 minutes for both instruments. Storm Water Management Model 5 (SWMM5) were used as model to simulate the discharge of catchment area. Sensitivity analysis is carried out in this study to determine the major parameters that influence to shape of hydrograph and peak flow. Then, calibration process using five (5) storm events have been performed using available information such as conduits lengths, shape of conduits, impervious and pervious surface using trial and error process. Good correlation between observed and simulated hydrograph on 18 September 2006 has been found to be the best Correlation coefficient (r) and Root mean square error (RMSE) equal to 0.92 and 0.14 respectively. The same parameter used for that storm event was chosen to be applied in validation event. Validation results also in the acceptable range with r is found more than 50% correlation. Next, using the rainfall data captured by radar that converted using equation Z=40R1.6 developed by researcher [1] for the similar date of storm event and similar catchment conditions, all the hydrograph shape shows significant drop. As a conclusion, different type of measurement tools for rainfall gives significant different to the catchment discharge and can be seen that rain gauge are better to use to simulate rainfall compared to the radar.

Examining optimum prediction time of rainfall dynamics based on chaotic perspective at different temporal scales: a case study in Bojonegoro, Indonesia

As the driving force of the hydrological system, rain has severe impact when dealing with petroleum mining activities, especially in protecting assets and safety. Rainfall has high variability, both spatial and temporal (chaotic data). Due to this reason, ones can only create long-range prediction using the stochastic method. Here we use the Lyapunov exponent to analyze the nonlinear pattern of rainfall dynamics. This method is useful for identifying chaotic deportment in rainfall data. This study uses rainfall data for six years obtained from one of the largest petroleum mining sites in Bojonegoro, Indonesia. Rainfall dynamics have been analyzed on three different time scales, namely daily data, 5-day, and 10-day. The time delay (τ) was obtained by using the Average Mutual Information (AMI) method for the three-rainfall series (3, 2, 3, respectively). The observed rainfall data in Bojonegoro show signs of chaos as the finite correlation dimensions (m) attain values about 4 for all time scales. The maximum Lyapunov exponent λmax for each of three-rainfall series in Bojonegoro is 0.111, 0.057, 0.062, respectively. These values were analyzed to find the optimum prediction time of rainfall occurrence to perform better forecasting. The result shows that the optimum range of prediction time for daily, 5-day, and 10-day have 9, 18, and 16 times longer than their temporal scale.

Quaternary geomorphological and climatic changes associated with the diversification of Iberian freshwater fishes: the case of the genus Cobitis (Cypriniformes, Cobitidae)

We studied the population genetic structure of Cobitis vettonica, an endangered freshwater fish species endemic to the Iberian Peninsula in order to propose a biogeographic model of the responses of species to the multiple changes that occurred in the Iberian hydrological system during the Quaternary period. We also deciphered the relationship of C. vettonica with its sister species C. paludica, particularly in sympatric areas and provide genetic information for conservation purposes. To achieve this end, we analysed both mitochondrial and nuclear data (the cytochrome b and the nuclear recombination activating 1 genes) and a battery of single nucleotide polymorphisms (SNPs) of 248 individuals of C. vettonica or C. paludica from 38 localities, including some sympatric ones, covering the entire distribution area of C. vettonica. We highlight the important role played by the hydrogeomorphological processes and climatic changes that occurred in the Iberian Peninsula during the Quaternary on both the population structure of C. vettonica and its relationship with its sister species C. paludica. Our results support the genetic introgression of populations at the eastern limit of the distribution of C. vettonica. Furthermore, we postulate genetic introgression in sympatric areas. Finally, we propose the establishment or expansion of four OCUs for C. vettonica, and highlight the threat faced by its populations due to the low level of genetic diversity detected for some of its populations and genetic introgression with C. paludica, which could eventually displace C. vettonica, resulting in a loss of diversity in this species.