Global data set of long-term summertime vertical temperature profiles in 153 lakes

peer reviewedClimate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change. © 2021, The Author(s)

Coupled human and natural system dynamics as key to the sustainability of Lake Victoria's ecosystem services

Contains fulltext : 135031.pdf (publisher's version ) (Open Access)East Africa's Lake Victoria provides resources and services to millions of people on the lake's shores and abroad. In particular, the lake's fisheries are an important source of protein, employment, and international economic connections for the whole region. Nonetheless, stock dynamics are poorly understood and currently unpredictable. Furthermore, fishery dynamics are intricately connected to other supporting services of the lake as well as to lakeshore societies and economies. Much research has been carried out piecemeal on different aspects of Lake Victoria’s system; e.g., societies, biodiversity, fisheries, and eutrophication. However, to disentangle drivers and dynamics of change in this complex system, we need to put these pieces together and analyze the system as a whole. We did so by first building a qualitative model of the lake's social-ecological system. We then investigated the model system through a qualitative loop analysis, and finally examined effects of changes on the system state and structure. The model and its contextual analysis allowed us to investigate system-wide chain reactions resulting from disturbances. Importantly, we built a tool that can be used to analyze the cascading effects of management options and establish the requirements for their success. We found that high connectedness of the system at the exploitation level, through fisheries having multiple target stocks, can increase the stocks' vulnerability to exploitation but reduce society's vulnerability to variability in individual stocks. We describe how there are multiple pathways to any change in the system, which makes it difficult to identify the root cause of changes but also broadens the management toolkit. Also, we illustrate how nutrient enrichment is not a self-regulating process, and that explicit management is necessary to halt or reverse eutrophication. This model is simple and usable to assess system-wide effects of management policies, and can serve as a paving stone for future quantitative analyses of system dynamics at local scales.18 p

Tantangan Gereja dalam Mengatasi Kenakalan Remaja Kristen di Gabk Bukit Moria Mangais

The problem of delinquency is a social problem thet can ruin public relationships and unsavory attitudes. The purpose of this study is: to learn how the church plays a role in overcoming Christian delinquency on mount moriah. In this study, the authors examined the problem using qualitative methods to approach case studies to field exploration in order to gain greater knowledge in a given situation or ini a case. The authors use several sources such as, books, journals, ang media as sources of information. As for the results of the study, the authors find that the church is not yet fully responsible and properly for the young. Among the problems involted was delinquency. This has had a negative effect on the development of a youth in his youth. For this the church must take an active role in overcoming Christian delinquency. Thus the writer sees the topic of the church's role in overcoming Christian delinquency as highly relevant and contained in a work of writing

Effects of physical mixing on the environment of satellite lakes and dams of lake Victoria, Kenya

In the Lake Victoria (Kenya) catchment are found several small lakes and dams. The satellite lakes and dams are important aquifers and buffer zones for the lake. Besides the water bodies are important water sources both for livestock and domestic use. A study conducted in the water bodies between January 2003 and December 2004 showed that effects of eutrophication are wide spread in the lakes and dams. An investigation of primary productivity and effects of physical mixing and material transport was done. In Lake Sare, Lake Victoria waters are transported to the satellite lake during both day and night through Goye causeway that connects the two. The water bodies have higher rates of primary productivity than Lake Victoria. Spatial extent of oxygen depletion due to respiration of organic matter in the water column is lower than the rates of primary productivity. Variability of oxygen depletion is dependent on local thermal and hydrodynamic processes that appear to be controlled by seasonal and short-term wind regimes. Advective transport and convective mixing augmented by wind effects control distribution of nutrients. An analysis of sediment grab samples showed that nutrient fluxes and loading is primarily external rather than from sediments. From the chemical parameters that were measured, soluble reactive phosphorus concentrations ranged from 4.44 to 35.28, Nitrate/nitrite ranged from 4.69 to 335.88 mg/l, ammonia from 29.18 mg/l to 473.14 mg/l and silica from 5.01mg/l to 50.06 mg/l. Fish catches particularly indigenous fish species like Schilbe intermedius, Labeo Victorianus, Protopterus aethipicus and Clarius gariepinus depicted stunted growth possibly due to heightened eutrophication and reduced dissolved oxygen levels due to reduced mixing on the water/air interface as a result of macrophyte cover.Publishe

Analysing water provision in the critical interface of formal and informal urban water regimes

Science and technology studies and urban political ecology have made important contributions to the understanding of water provision in the Global South. In this article we develop insights from these fields with the aim to understand the blurring boundaries of urban water regimes and their power relations mediated by actors, institutions and technology. Furthermore, we explore how urban water regimes can form a critical interface which is a form of institutional–actor space where formal and informal water regimes encounter each other through conflict and cooperation

Beyond the (non)piped drinking water regimes: complex configurations of conflicts and cooperation

Historically, water utilities have favored the modern ideal of piped infrastructure despite shortcomings in ensuring water access to the urban poor. Consequently, various state and non-state actors play influential roles in shaping water access to the poor through piped and non-piped socio-technical regimes of water provision. However, the existence of piped and non-piped water regimes and how they interact is often not seen as the work of municipalities, and as a result, a plethora of vital water services and actors are still largely ignored in water policy and decision-making. Drawing upon two empirical case studies in Delhi and Nairobi, this article foregrounds the role of conflict and cooperation in the interaction between piped and non-piped water regimes using an analytical framework that builds on Science Technology Studies and Urban Political Ecology