The emerging water crisis in Bulgaria

Climatic records for the last 15 years indicate that Bulgaria is experiencing a period of exceptionally low precipitation. During 1993, significant water supply problems emerged, approaching crisis proportions in Sofia, the nation's capital, by the end of 1994. The record-setting drought of 1993 can be explained from a synoptic climatic perspective. Whether consequences of the continuing drought could have been foreseen is arguable. That these consequences were fully realized only in 1994 may be understood through examination of Bulgarian water use since the end of the socialist era in 1989. If Bulgaria had experienced the same levels of industrial activity and irrigation as occurred in 1989, the current situation would have been national catastrophe, a situation that could quickly emerge in coming years should climatic patterns persist.     

Urban water conservation

Water conservation may be defined as a demonstrably beneficial reduction inthe amount of water of a certain quality for a specific use. Increasing costs as well as the risk of water shortages are likely to spur more efficient use of existing facilities. In many instances, conservation may be the most cost-effective way of increasing the supply of municipal water. Policymakers need to be familiar with the policy instruments, such as peak responsibility pricing, that could reduce the peak and average demands for municipal water and cost-effective technological options available to customers who wish to reduce water use. This paper is organized around these two themes and reviews the salient empirical findings in this field. Several municipalities have reduced peak demands, and the number of studies in demand management has increased substantially since the early 1960s. However, the interest in applying empirical findings has lagged behind research. Increasing costs are likely to stimulate innovative management and it is critical to explicate the problem and solutions so that policymakers would have the necessary understanding to make rational, cost-effective decisions. Time-and-location specific investigation is essential for enhancing such understanding.     

The water resources of Bulgaria: an overview

Bulgaria's indigenous water resources derive largely from mountain watersheds where orographic effects enhance precipitation. These watersheds provide resources upon which lowland communities, industry, and irrigation depend. On the basis of a comprehensive network of water management structures, Bulgaria has been able to harness a considerable proportion of internal water resources for human use, although the nation is, by European standards, dry. This paper explores the physical and human geography of Bulgarian water resources as a perspective from which the multiple dimensions of current Bulgarian water research and water issues can be seen.     

山水林田湖草系统治理之水土保持要义

山水林田湖草是一个生命共同体,山水林田湖草的系统治理观是水土流失治理与生态修复的重要指导思想.水土流失的发生、发展和变化是一个复杂的系统,有其自身规律,水土保持是一门多学科交叉学科,有其科学性与不可替代性,防治水土流失应坚持系统思维,整体施策,系统和综合是水土保持学科建立和事业发展的生命力所在.水土流失在中国广泛分布并...     

Irrigation in Bulgaria

Agriculture in Bulgaria entered a severe crisis in 1989 following the collapse of the central planning system. Since then it has been going through a transition towards market-based system and a structural transformation from large state cooperatives to smaller privately owned and operated farms and cooperatives. Irrigation, a major water use until recently, has been strongly affected by these processss, and has dropped to a point where less than 15% of the areas equipped for irrigation are actually irrigated. Heavy state investments in the irrigation subsector and its vital importance for the economy make it imperative to up-grade and restructure irrigated agriculture to reflect new forms of land ownership and farming, as well as the current and future organizational patterns of the     

Grid computing for atmospheric composition studies in Bulgaria

Three Grid applications from the SEE-GRID-SCI Environmental VO are developed by the Bulgarian project team: Climate Change Impact on Air Quality (CCIAQ); Multi-scale atmospheric composition modeling (MSACM); Modeling System for Emergency Response to the Release of Harmful Substances in the Atmosphere (MSERRHSA). The three applications concern problems of significant socio-economic significance. They are all dedicated to air pollution studies, but address different goals and so face different problems and requirements. The applications are briefly presented in the paper. Examples of the different applications validations are given. Some application results are shown and commented.     

Rural diversification in Bulgaria

Agriculture has always been very important for the Bulgarian economy, but during the socialist period there was considerable progress made in the diversification of employment opportunities in rural areas. While many people commuted to non-agricultural jobs in the townships (and there was a large permanent transfer from rural to urban areas), there were additional opportunities in small factories and local services in the villages themselves. The transition has seen these opportunities much reduced, at precisely the time when full-time paid work in agriculture has declined due to market restructuring while complex problems have emerged associated with liquidating the state-run cooperatives and establishing a viable alternative. The paper discusses the general issues and presents a case study from the north-central part of the country. The rebuilding of a cooperative farming system (along with other forms of consolidation) is a positive trend which could increase spending power in the villages and help in the growth of employment in rural industries and services. This revised version was published online in July 2006 with corrections to the Cover Date.     

黄土高原地区水土保持生态环境用水量估算研究

立足于黄土高原地区社会经济可持续发展,以实现生态环境良性发展为目标,探讨了水土保持生态环境用水量的内涵,提出了黄土高原地区水土保持生态环境用水量计算框架,以黄山高原地区泾河流域为例,估算其1970-1996年水土保持年生态环境用水量为6.368亿m3.研究成果丰富了生态环境用水量的理论研究,可为黄土高原地区生态环境建设和水资源合理利用提供科学的决策依据.     

Developments of geochemical methods for ore prospecting in Bulgaria

Three periods in the development of geochemical methods for ore prospecting in Bulgaria may be distinguished — initial (1954–1960), middle (1961–1969) and contemporary (since 1970) — which are characterized by successively increasing numbers of samples and improving methods of geochemical data evaluation. Geochemical methods have been recognized as effective, rapid and relatively cheap methods for prospecting for ore deposits (Cu, Pb, Zn, Au, W, Mo, etc.), some nonmetalliferrous raw materials (fluorite, barite, phosphorites) and hydrocarbons. They are used in all stages of exploration at scales from 1:200,000 to 1:200. They have contributed to the elucidation of the ore perspectives in many regions, and a number of new ore bodies and deposits have been discovered.Basic geochemical methods applied to ore prospecting in the country utilize soil and rock to detect secondary and primary aureoles. Stream-sediment surveys, hydrochemical and atmochemical methods are of more restricted use. Samples are analyzed by emission spectrometry, atomic absorption and other methods. A united system of computerized processing of geochemical data has been developed, including automatic drawing of geochemical maps.Interpretation of the data consists in selection of prospective geochemical anomalies and prognostication of the composition, morphology, depth and industrial significance of hidden ore bodies. The main problem in the mathematical processing of data is the presentation of polydimensional results from analyses in the form of generalized quantities — multiplicative or additive geochemical indicator ratios for the type of mineralization, coefficients of zoning, intensity, etc. The geochemical indices for evaluation of the newly found anomalies are derived through studies of the primary geochemical aureoles of typical standard ore deposits.Residual secondary soil aureoles in most cases are well correlated in composition and structure with the ore bodies and primary aureoles which have generated them. Their successful use is related to the landscape-geochemical conditions in the ore regions. Micro- and macro-chemical zoning of ground waters and different concentration of soluble components in different elevation belts are used for evaluation of hydrochemical anomalies.     

Application of an environmentally optimum cooling water system design in water and energy conservation

Recirculating cooling water systems are consist of a cooling tower and heat-exchanger network which conventionally have a parallel configuration. However, reuse of water between different cooling duties enables cooling water networks to be designed with series arrangements. This will results in performance improvement and increased cooling tower capacity. Research on recirculating cooling water systems has mostly focused on the individual components. However, a particular design method represented by Kim and Smith accounts for the whole system interactions. In this study, the Kim and Smith design method is expanded and a comprehensive simulation model of recirculating cooling system was developed to account for the interaction between the cooling tower performance and the heat-exchanger network configuration. Regarding this model and considering cycle water quality through introducing ozone treatment technology, a modern methodology of recirculating cooling water system design was established and developed. This technique, called the integrated ozone treatment cooling system design, is a superior designed tool based on pinch analysis and mathematical programing. It also ensures maximum water and energy conservation, minimum cost and environmental impacts. Related coding in MATLAB version 7.3 was used for the illustrative example to get optimal values in cooling water design method computations. The result of the recently introduced design methodology was compared with the Kim and Smith design method.     

青藏高原水源涵养能力时空变化规律

利用水均衡原理和地表能量平衡原理定量评估青藏高原地区水源涵养量,利用多年降雨和蒸发数据研究青藏高原水源涵养能力在空间上的分布状况及其随时间的变化过程,探讨近几十年来青藏高原水源涵养能力时空变化规律。结果表明,近几十年来青藏高原主要形成了3个水源涵养量持续减少的中心区域和2个水源涵养量增强的区域,其中水源涵养能力减弱的区域主要分布于雅鲁藏布江源头、青藏高原南部边缘地带和青海省东部与甘肃交界地带;水源涵养能力增强的区域主要分布于雅鲁藏布江中游河谷地带、澜沧江和金沙江中游河谷地带。     

The current ethnic panorama in Bulgaria

Although a constant trickle of outmigrants and several larger waves (mostly to Turkey) are characteristic for the modern history of Bulgaria, its ethnic composition was relatively stable. The ethnic Bulgarians are a clear majority, the largest minority groups being in descending order the Turks, Roma (Gypsies), the Muslim Bulgarians and several much smaller groups. The geographical patterns of distribution have been analysed. Over time, the policies of the Bulgarian state towards the minority groups have been varying between benevolence and restriction measures. The ethnocultural communities have worked out moduses of co-existence preventing the escalation of conflicts at the local level.     

Possibilities of seismoelectric methods in search for quartz veins

An analysis of the resistivity and seismic data for a quartz vein intruded into metamorphosed sediments reveals that the vein cannot be located uniquely on the basis of either resistivity or elastic wave propagation data. The piezoelectric field generated by pressure waves which are propagated through the quartz, however, gives a sharp voltage maximum which permits a unique location of the vein.—M. E. Burgunker.     

Seismic hazard of Bulgaria

A simplified seismotectonic model is proposed for Bulgaria by introducing generalized seismogenic areas containing systems of complex geometry faults. A tectonic scheme, which considers the main faults only, is then derived from this. The assessment of the regional seismic hazard is done using different approaches: the Gumbel, the Cornell, and the fault rupture model methods. A series of relations among seismological parameters are derived from the available data. The results obtained by the different approaches are similar: the most dangerous area is the Struma zone, located in southwestern Bulgaria.     

节水及节水型社会的分析和对比评价研究

对节水的内涵和节水型社会的发展进行了讨论,阐述了节水型社会的发展对水政策、水管理以及水工程的实践性的指导作用.基于节水型社会是水资源系统-生态系统-经济社会协调发展的认识,遵循科学、实用及简明的原则,构建了节水型社会评价指标体系,对我国各省(市、区)节水型社会相对水平进行量化评价.