Mariyana Nikolova

Quantifying sediment-associated metal dispersal using Pb isotopes: application of binary and multivariate mixing models at the catchment-scale.

In this study Pb isotope signatures were used to identify the provenance of contaminant metals and establish patterns of downstream sediment dispersal within the River Maritsa catchment, which is impacted by the mining of polymetallic ores. A two-fold modelling approach was undertaken to quantify sediment-associated metal delivery to the Maritsa catchment; employing binary mixing models in tributary systems and a composite fingerprinting and mixing model approach in the wider Maritsa catchment. Composite fingerprints were determined using Pb isotopic and multi-element geochemical data to characterize sediments delivered from tributary catchments. Application of a mixing model allowed a quantification of the percentage contribution of tributary catchments to the sediment load of the River Maritsa. Sediment delivery from tributaries directly affected by mining activity contributes 42-63% to the sediment load of the River Maritsa, with best-fit regression relationships indicating that sediments originating from mining-affected tributaries are being dispersed over 200 km downstream.

Adaptation of the Bulgarian Water Sector to Climate Change Extremes

Extreme weather events and the resulting hydro-climatic disasters have increased in frequency and intensity in recent decades, confirming trends outlined in the Fourth and Fifth IPCC reports on the increased susceptibility of Southeast Europe to drought, extreme temperatures, heat waves, and floods. Currently, climate change in the region is most apparent in the frequency and intensity of climate extremes, specifically in temperature and precipitation. These changes may significantly affect the water sector in Bulgaria by the end of this century.

Flood Hazard in Bulgaria: Case Study of Etropolska Stara Planina

Climate change in Europe is often manifested in the increasing frequency of extreme weather phenomena like storms, intensive rains, and floods. For the period 2000–2009, the highest number of severe floods in Southeastern Europe was registered in Romania (30), Greece (14), and Bulgaria (11). The EM-DAT database (CRED 2012) includes 13 major floods in Bulgaria for 1900–2011. Eleven of them occurred between 2000 and 2009, 1.2 cases per year, a significant increase compared to the average number of 0.1 cases for the past 111 years, mainly due to the extremely wet year 2005. A typical mountain area strongly affected by extreme weather is the upper Malki Iskar River basin on the northern slopes of the Etropolska Stara Planina. The chapter analyses the influence of intense rainfalls (on the examples of events between 1995–2005 and in 2007) on peak river flows and flood hazard, the role of topography in the spatial distribution of rainfall in the basin, and the passage rate of flood waves; identifies critical areas and settlements; and recommends risk mitigation measures. The kinematic runoff and erosion model (KINEROS) was used to simulate the influence of rainfall of different intensity and quantity on peak flow during storm events. The findings allow us to assess flood hazard in the river basin for possible future climate and land use/cover changes and propose management measures directed at reducing flood risk.

Scientific Research Basis for Sustainable Development of the Mountain Regions: Main Concepts and Basic Theories

European policy concerning mountain regions aims at achieving sustainability by using cohesion and integration policies, as well as multi-sectoral and regional approaches. Under conditions of global change, the role of scientific research in the implementation of these policies acquires additional importance. Scientific understanding of the theoretical base and the concepts involved would best serve sustainable development policies in the mountain regions. This study provides an overview of definitions of fundamental concepts, such as “sustainability” and “sustainable development,” “multi-disciplinarity,” “inter-disciplinarity,” and “trans-disciplinarity.” Having in mind that diversity and complexity are typical characteristics of mountain areas, both socially and environmentally, this chapter discusses the advantages and drawbacks of implementation of the DPSIR (Driving forces, Pressures, State, Impact, Responses) model and the concepts of ‘multidisciplinary,’ ‘interdisciplinary,’ and ‘transdisciplinary.’ This analysis is expected to support the following conclusions: (1) sustainable development policies must be grounded in the basic concepts of economic theory, including “throughput,” instead of “utility,” and (2) mountain research necessitates transdisciplinary approaches.