Recent sediment accumulation rates in contrasting lakes in the Carpathians (Romania): impacts of shifts in socio-economic regime

Abstract

Wireless sensor networks have become incredibly popular due to the Internet of Things' (IoT) rapid development. IoT routing is the basis for the efficient operation of the perception-layer network. As a popular type of machine learning, reinforcement learning techniques have gained significant attention due to their successful application in the field of network communication. In the traditional Routing Protocol for lowpower and Lossy Networks (RPL) protocol, to solve the fairness of control message transmission between IoT terminals, a fair broadcast suppression mechanism, or Drizzle algorithm, is usually used, but the Drizzle algorithm cannot allocate priority. Moreover, the Drizzle algorithm keeps changing its redundant constant k value but never converges to the optimal value of k. To address this problem, this paper uses a combination based on reinforcement learning (RL) and trickle timer. This paper proposes an RL Intelligent Adaptive Trickle-Timer Algorithm (RLATT) for routing optimization of the IoT awareness layer. RLATT has triple-optimized the trickle timer algorithm. To verify the algorithm's effectiveness, the simulation is carried out on Contiki operating system and compared with the standard trickling timer and Drizzle algorithm. Experiments show that the proposed algorithm performs better in terms of packet delivery ratio (PDR), power consumption, network convergence time, and total control cost ratio.

Impacts of forest loss in the eastern Carpathian Mountains: linking remote sensing and sediment changes in a mid-altitude catchment (Red Lake, Romania)

“…5) which may have contributed to sediment input. Our inferred moderate changes in forest cover, and their impacts on the catchment stability, over the traditional period are in line with results inferred from other mid-and high-altitude lakes from the Carpathians (Hutchinson et al, 2016). Furthermore, documentary evidence indicates that Harghita County, where Red Lake catchment is located, experienced lower forest loss rates at this time compared to the southern and eastern parts of Romania, where deforestation for agricultural expansion was the result of 1872 and 1921 privatisation events (Munteanu et al 2014; 2016 and references therein).…”

“…The impact of human activities on forest over the last millennia in the Carpathian region is well 450 known (Feurdean et al 2010(Feurdean et al , 2013aTantau et al 2011Tantau et al , 2014Giosan et al 2012). However, only a few studies have focused on investigating the catchment response to more recent human intervention (Begy et al 2009;Enea and Romanescu 2012;Hutchinson et al 2016;Florescu et al 2017). These studies show key hydro-geomorphic changes, especially erosion and lake in-filling, in response to human disturbances and extreme climatic events.…”

“…Whereas the links between forest loss and socio-economic and political regimes have been widely studied in the Carpathian region (e.g., Griffiths et al 2012;Korn et al 2012;Munteanu et al 2014Munteanu et al , 2016, the geomorphological impacts of such changes on the catchment dynamics have been less investigated (Begy et al 2009;Romanescu et al 2013;Hutchinson et al 2016;Florescu et al 2017).…”

Water Surface Overgrowing of the Tatra’s Lakes

“…This fact is confirmed in particular by the analyses of lake sediments (Owens, Slaymaker, 1994;Kotarba, 1996;Šporka et al, 2002;Irmler et al, 2006;Rybníčková, Rybníček, 2005;Hamerlík, Bitušík, 2009;Mîndrescu et al, 2010;Hutchinson et al, 2016;Kłapyta et al, 2015), and also by the results of other studies (Kotarba, 2004;Kapusta et al, 2010;Hreško et al, 2012;Necsoiu et al, 2013;Kohler et al, 2014;Gądek et al, 2015;Kubinský et al, 2015;Gallik, Bolešová, 2016). In particular, smaller and shallower lakes react much more sensitively to changes than larger lakes because of their small volume of the water.…”

Recent morphodynamics of alpine lakes in Southern Carpathian Mountains using high-resolution optical imagery

“…Postdeglaciation, these rock basins turned into lakes, which occasionally evolved into peat bogs or were completely silted. Around 270 glacial lakes (including glacial peat bogs and peat bogs with pool) are estimated to exist in the Romanian Carpathians (Mîndrescu et al, 2015); they are spread unevenly with the largest share (81%) located in the Southern Carpathians.…”