Green Fuzzy Tourist Trip Design Problem

Physical and geochemical characteristics of land mud volcanoes along Colombia's Caribbean coast and their societal impacts

Technological developments in recent years led to the emergence of increasingly sophisticated recommender systems to support multi-day travel itineraries that fall under the Tourist Trip Design Problem (TTDP). Various problem analogies are widely used to solve TTDP, such as Traveling Salesman Problem (TSP), Vehicle Routing Problem (VRP), Orienteering Problem (OP), and Team Orienteering Problem with Time Windows (TOPTW). For multi-day route recommendation, TOPTW is suitable as a problem analogy since there is a per-day travel duration constraint. So far, TTDP with TOPTW does not consider the weighting (priority level of users) for each requirement attribute in a multi-attribute-based TOPTW to ensure personalized recommendations. In addition, running time remains a challenge in many studies in the TOPTW area. Many metaheuristic algorithms have been adopted to TOPTW for generating a time-efficient approach. Komodo Mlipir Algorithm (KMA) emerges as a new algorithm that promises good scalability. Therefore, we propose KomoTrip, a method that adopts the discrete version of KMA and Multi-Attribute Utility Theory (MAUT) to recommend optimal travel routes per day by accommodating the multi-attribute preferences of users. We perform three evaluation scenarios, i.e., general performance, Degree of Interest (DOI) combinations, and varying numbers of Points of Interest (POI), consistently demonstrating that KomoTrip outperforms several benchmark algorithms in terms of computational time efficiency and also exhibits robust fitness values across different problem dimension scales. Thus, KomoTrip can be regarded as an efficient algorithm to recommend optimal multi-day tour routes, effectively incorporating weighted multi-attribute preferences into its optimization process. We further benchmarked KomoTrip against state-of-the-art TOPTW heuristics on the public Solomon dataset, where it demonstrated competitive profit values, particularly for a larger number of days (tours), and consistently achieved superior runtime performance.

The Caribbean Sea in Colombia maybe being subjected to discharges of terrigenous solid waste and with these probably, the natural metallic constituents of the sediments, through the discharges of the Magdalena River since the time of the conquest. With the opening of the Dique canal in the mid-seventeenth century, which linked pipes, swamps, and branches from the Magdalena River to its mouth at the southwestern end of the bay, great changes could be caused from the point of view of mixing the fresh and turbid water of the channel with the clear and marine waters of the bay, which led to the beginning of the deterioration of the coral ecosystems present in the bay. Mercury contamination in the Colombian Caribbean has different origins. Artisanal gold mining has the greatest impact and has generated mercury contamination in many ecosystems, particularly in Bolívar and the Mojana region (department of Sucre and Cordoba). In this study, published information on mercury contamination along the Colombian Caribbean coast is compiled. The concentrations present differences between different areas of the coast. The bay of Cartagena is one of the areas most impacted by this pollutant, mainly due to the discharge of waste from a salt processing plant. Other areas are impacted by mercury, the product of the artisanal exploitation of gold, the discharges as a result of this activity are transported mainly to the Magdalena River, and through the different arms that form the delta, they are deposited in the Colombian Caribbean.

The conservation status of the Colombian Caribbean dune system was assessed considering the influence of natural and anthropogenic factors. The study took place in five locations with a gradient of human disturbance. In total, 198 plots and 22 transects were established, three transects in Gairaca and Costa Verde; four in Lipe, and six in Mendihuaca and Salguero. Environmental variables such as dune height, slope, sediment physical-chemical attributes, and anthropogenic impact were assessed in each site, while species composition, frequency, and plant cover were determined for each plot. The results show a correlation between natural and anthropogenic factors and the composition and structure of plant communities growing on the beach and coastal dunes. Human disturbances (urbanized areas, construction, burning, debris, trampling, logging, tourism, groins, sewage, roads, garbage, and sediment extraction) were particularly relevant. Plant cover and species diversity were inversely related to human impact and disturbance. Furthermore, community structure varied among sites: trees and vines were more frequent in the preserved locations, while shrubs and parasitic plants were more abundant in the disturbed sites. Management alternatives should consider the environmental factors (natural and anthropogenic) affecting vegetation to improve the conservation of plant diversity on coastal dunes along the Colombian Caribbean coast.

Distribution, abundance and fishing potential of mega-invertebrates in the sub-euphotic zone (150–535 m) in the Colombian Caribbean

Manzolli, R.P.; Portz, L.; Villate, D.A.; Contreras, M.D.; Padilla, L.C.J., and Alcantará-Carrió, J., 2020. Magnitude and causes of beach accretion on the eastern margin of the Tayrona National Natural Park (Colombian Caribbean), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 299–303. Coconut Creek (Florida), ISSN 0749-0208.Beaches on the eastern margin of Tayrona National Natural Park experienced stability and even accretion over the last decade, in contrast to general erosion along the Colombian Caribbean coast. The objective of this study is to characterize shoreline change and analyze the factors contributing to the accretionary trend. Orthorectified satellite images, combined with topography from both drone images and RTK-DGPS measurements, were used to map successive shorelines from 2002-2008. Net shoreline movement and shoreline migration rates revealed these beaches had an accretionary trend, with the exception of Piscina Beach that eroded during the time period. The maintenance of natural inputs of sediment from local rivers, redistributed by littoral drift with sediment bypassing across the small headlands limiting the beaches, the resilience of the beaches to the impact of hurricanes and low human pressure allows for a positive sedimentary budget for the beaches. Piscinas Beach is the most cut off from fluvial sediment input, and despite it has a coral reef barrier, its dissipative profile indicate that it is the most exposed to wave impact.

In recent years, recommender systems have been used as a solution to support tourists with recommendations oriented to maximize the entertainment value of visiting a tourist destination. However, this is not an easy task because many aspects need to be considered to make realistic recommendations: the context of a tourist destination visited, lack of updated information about points of interest, transport information, weather forecast, etc. The recommendations concerning a tourist destination must be linked to the interests and constraints of the tourist. In this research, we present a mobile recommender system based on Tourist Trip Design Problem (TTDP)/Time Depending (TD) - Orienteering Problem (OP) - Time Windows (TW), which analyzes in real time the user's constraints and the points of interest's constraints. For solving TTDP, we clustered preferences depending on the number of days that a tourist will visit a tourist destination using a k-means algorithm. Then, with a genetic algorithm (GA), we optimize the proposed itineraries to tourists for facilitating the organization of their visits. We also used a parametrized fitness function to include any element of the context to generate an optimized recommendation. Our recommender is different from others because it is scalable and adaptable to environmental changes and users' interests, and it offers real-time recommendations. To test our recommender, we developed an application that uses our algorithm. Finally, 131 tourists used this recommender system and an analysis of users' perceptions was developed. Metrics were also used to detect the percentage of precision, in order to determine the degree of accuracy of the recommender system. This study has implications for researchers interested in developing software to recommend the best itinerary for tourists with constraint controls with regard to the optimized itineraries.

Abundance and distribution of beach litter along the Atlantico Department, Caribbean coast of Colombia

Artisanal fisheries are socially and economically important along the Caribbean coast of Colombia. These fisheries remain poorly characterized, making it difficult to estimate their potential impact, especially on non‐targeted catch such as elasmobranchs. A rapid assessment framework was used to investigate the exploitation, use, and relative abundance of elasmobranchs and predatory teleosts in a region along the Caribbean coast of Colombia. In‐person structured interview surveys (n = 188) were conducted during the autumn of 2016 at eight fishing towns around Cartagena and the islands of the Natural National Park (NNP) Corales del Rosario and San Bernardo. Baited remote underwater video systems (BRUVS) (n = 200) deployed at four reefs were used to assess the relative abundance of elasmobranchs and other predatory teleosts. Fishers reported capturing eight shark and five ray taxa. Although 99% of fishers indicated that they did not target sharks, 83% reported keeping the catches to sell, eat, or both. Similarly, 81% of fishers did not target rays, but 90% reported retaining catches. Most fishers (84%) perceived a decline of sharks in the coastal waters since they started fishing, compared with 41% reporting batoid declines. BRUVS data support the perceptions of elasmobranch declines. Elasmobranch abundances were very low and no difference was detected between protected and unprotected reefs. Results were similar for teleost taxa, but there were higher abundances inside one marine protected area (MPA) that had high enforcement. Taken together, the data suggest considerable degradation of not only elasmobranch populations but also predatory fish populations of coral reef habitats in a region of the Colombian Caribbean. Furthermore, artisanal fishers continue to exploit coral reef resources inside MPAs unless there is strong enforcement. Enforcement can be difficult with limited resources, and therefore community‐based conservation methods may be more effective. Engagement with the local fishing community may help to reduce existing tensions and improve compliance.

Commentary

A new species of drywood termite (Kalotermitidae), Cryptotermes colombianus, is described and new records for Cryptotermes cylindroceps and Cryptotermes mangoldi are presented from the Caribbean coast of Colombia. Cryptotermes colombianus is described from two soldiers and genetic sequences. This unusual species differs noticeably from other regional Cryptotermes species for its weak and inconspicuous definition of the frontal and genal horns and its acute angle of the frons with respect to the vertex. Cryptotermes colombianus clustered with species from the Ethiopian and Oriental region and it is closely related to Cryptotermes havilandi. Cryptotermes cylindroceps is widely distributed along the Colombian Caribbean coast, commonly associated with dead wood in mangrove habitats. It also is commonly found in wooden furniture, constituting an important household pest. Cryptotermes mangoldi is reported from the Caribbean mainland for the first time.With these new records, there are now five Cryptotermes species for Colombia, including the pest species Cryptotermes brevis and Cryptotermes dudleyi. This new description raises the numbers of Neotropical Cryptotermes to a total of 34 species, of which 2 are fossils, 4 introduced, and 28 endemic.

We analyzed diatoms, lithology, and stable isotopes in a sediment core from the Ciénaga Grande de Santa Marta lagoon to reveal the history of late Holocene relative sea level rise and the ontogeny of the lagoon on the Caribbean coast of Colombia. At ~5300 cal. yr BP, the area was characterized by shallow, freshwater ponds that were prone to seasonal flooding. From ~4250 to ~2060 cal. yr BP, these ponds became brackish as relative sea level began to rise, and since ~2060 cal. yr BP, marine conditions have prevailed. In addition to tracking relative sea level rise, we also investigated periods of greater and lesser precipitation during times of brackish and marine conditions, respectively, as indicated by diatom-inferred changes in water salinity and shifts in the source of sediment organic matter. Comparisons with other regional paleoenvironmental records suggest that humid climate conditions prevailed in the Caribbean until about 4000 cal. yr BP. After that time, climate became more variable, with drier conditions registered from ~ 4000 to 2000 cal. yr BP. Wetter conditions returned after ~2000 cal. yr BP.

Abstract.–From July 1998 to June 2000 four thalassohaline aquatic environments along the Colombian Caribbean coast (Manaure, Galerazamba, Salina Cero, and Tayrona) were surveyed monthly to determine the influence of salinity, percent 02 saturation, pH, temperature, and nutrients (NO2‐, NO3‐ and PO4‐3) on Artemia (Crustacean, Anostracan) biomass production and cyst production potential. The effects of the regularly measured physicochemical parameters on biomass and cyst production potential were analyzed using univariate analysis of variance (SPSS VI 0.0). The influence of physicochemical parameters on biomass production was not significant (P > 0.05). In contrast, there was a significant interaction (P<0.05) of salinity, percent 02 saturation, and nitrate (used as a proxy for chlorophyll a) on cyst production potential. In addition, for all four locations nitrate levels were directly proportional to salinity. This might be explained by the fact that in saltworks numerous organisms are trapped and slowly die as salinity increases progressively in the evaporating basins; thus, organic matter accumulates and decomposes. Consequently, the concentration of the nitrogenous compounds, first nitrite and later nitrate, increases through time as salinity increases. Moreover, decreasing nitrate levels seem to increase cyst production potential; thus supporting the notion that when insufficient food is available cyst production increases.

An intensive sampling of the Sur de Chengue (Magdalena) lagoon in the Tayrona National Natural Park of the Colombian Caribbean coast, resulted in 24 species of polychaetes (16 families, 24 genera) that are first records for this ecosystem, five are new records (2 species and 4 genera) for the Colombian Caribbean, and nine others are confirmed for the Magdalena Department. Environmental characteristics are given (26.0-33.5 0 C; 32.0-40.9% o ; pH 7.7-8.4; bottom types, flora and fauna) which show the range of variation, as well as the abundance and distribution of the species found.

An Australian company is faced with the logistics problem of distributing small quantities of fibre boards to hundreds of customers every day. The resulting Heterogeneous Fleet Vehicle Routing Problem with Time Windows and Three-Dimensional Loading Constraints has to be solved within a single hour, hence the use of a heuristic instead of an exact method. In previous work, the loading was performed after optimising the routes, which in some cases generated infeasible solutions in need of a repair mechanism. In this work, the feasibility of the loading constraints is maintained during the route optimisation. Iterated Local Search has proved very effective at solving vehicle routing problems. Its success is mainly due to its biased sampling of locl optima. However, its performance heavily depends on the perturbation procedure. We trialled different perturbation procedures where the first one perturbs the given solution by moving deliveries that incur the highest cost on the objective function, whilst the second one moves deliveries that have been shifted less frequently by the local search in previous iterations. Our industry partner provided six sets of daily orders which have varied characteristics in terms of the number of customers, customer distribution, number of fibre boards and fibre boards’ sizes. Our investigations show that an instance becomes more constrained when the customer order contains many different board sizes, which makes it harder to find feasible solutions. The results show that the proposed perturbation procedures significantly enhances the performance of iterated local search specifically on such constrained problems.