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Volume XXIII |

The climate-agriculture nexus. The water footprint of maize production (Northern Bulgaria as a case study)

Abstract: The water footprint of maize production serves as a comprehensive indicator, encompassing both direct water use for crop yields and indirect water use, including virtual water trade. This indicator provides insight into the total water required throughout the production process, making it essential for understanding water sustainability in agriculture. The main objective of this research is to expand the understanding of how climate variability affects agricultural practices, focusing on promoting sustainable water use in crop production. Specifically, the study emphasizes the assessment and analysis of both green water (rainfall) and blue water (irrigation water) used in maize cultivation in Northern Bulgaria.
The study draws upon several key data sources, including climatic information (such as air temperature, and precipitation) and agricultural and statistical data from local authorities and farmers (covering crop parameters, yields, and irrigation practices). The water footprint for maize cultivation was calculated and assessed using Cropwat software. This analysis determines the irrigation needs across different crop management strategies. The investigated period was 1961-2022, with a specific focus on the water footprints during the extremely dry and wet years. The findings highlight critical areas of water usage and scarcity. Understanding the water footprint and its connection to climate and agriculture can aid in managing water resources and addressing the environmental and economic challenges associated with water scarcity and drought.

Volume XXIII |

Struggles over critical land in the Nigerian Benue Valley: accumulation by dispossession and farmer-herder conflict

Abstract: Conflicts between farmers and pastoralists have had devastating consequences in Nigeria’s Benue Valley. While previous studies have emphasized environmental resource scarcity arising from population growth, environmental degradation, and climate change as the main sources of scarcity engendering conflicts, the social production of scarcity through accumulation by dispossession has received limited attention. This paper fills that gap by investigating the farmer-herder conflicts in the Benue Valley and highlighting how scarcity of critical land is socially produced through capitalist accumulation by dispossession. This scarcity leads to tensions between pastoralists and farmers, underscoring the relevance of accumulation by dispossession in this specific context.

Volume XXIII |

Soil erosion risk assessments for the Catchment of the Dzebelska River (East Rhodopes)

Abstract: Soil erosion is recognized as one of the most serious soil threats in Bulgaria. The paper presents assessments of soil erosion factors and risk in the catchment of the Dzhebelska River (Eastern Rhodopes), Bulgaria. The assessments are based on the USLE approach, which was adapted for Bulgarian conditions and integrated with GIS. It is established that about 45% of the territory of the Dzhebelska River catchment are characterized with rains with an average erosivity between 600 and 800 MJ mm/ha h y. Largest percentage share (47%) of the lands in the catchment area is characterized by medium to high susceptibility to erosion (0.03-0.04 t ha h / MJ ha mm). Almost half of the lands in the studied catchment are with a slope above 15°. Significant share of land (32.5%) is with high potential risk of erosion (100-200 t/ha y). Due to the largest percentage share of forestland (57%), lands with actual erosion risk below 3 t/ha y cover about 58 % of the catchment area, while these with a risk above 40 t/ha y cover about 15%.

Volume XXIII |

Current dilemmas in the urban development of Timișoara (Romania)

Abstract: The post-communist period meant for the city of Timișoara a complex and difficult stage of restructuring urban evolution, of moving from centralized development to development based on the principles of the market economy. The solutions were not simple, especially in the conditions of limited city resources, and often contradictory developments did not take long to appear. The present article tries to capture these contradictory developments and highlight the current urban development dilemmas that the city authorities together with the decision-makers must solve. It is primarily about the rehabilitation of the huge historical spaces that the city has inherited and at the same time the acute need for urban renewal. Secondly, the city of Timișoara is facing a huge increase in road traffic, for which expensive investments in road infrastructure are needed, but on the other hand, the city also needs numerous investments for public transport. And thirdly, Timișoara currently has a strong trend of urban expansion and cumulative density decrease at the same time as an underutilization of available spaces within the city.

Volume XXIII |

Clarity of the Black Sea – historical measurements of Secchi Depth

Abstract: Water transparency is a primary indicator used to evaluate the status of marine ecosystems. Although a subjective measure, Secchi Depth (ZSD) is one of the “oldest” and most widely used optical parameters in studies that focus on surface water clarity, with probably millions of observations available in the last century. As recent satellite observa-tions do not cover such extended periods from the past, a comprehensive understanding of the spatio-temporal dy-namics of water transparency requires consistent historical data. In this regard, the present study aims to integrate in-formation from archives of in situ ZSD measurements available for the entire Black Sea. Several potential sources were investigated. Among them, two were identified to have historical measurements of ZSD in the Black Sea, SeaDataNet and Black Sea Ecosystem Processes and Forecasting / Operational Database Management System (NATO SfP ODBMS). A database with all available observations was aggregated for this study, containing a total of 5100 records between 1960 and 2016. The analysis of the spatial variability of ZSD was performed based on a square grid of 30 km x 30 km covering the entire Black Sea region. For each cell, statistics such as the average and the number of ZSD measurements were calculated. Moreover, the spatial and temporal homogeneity of the in-situ observations are assessed and dis-cussed.