Snapshot Survey of the Presence of Perfluoroalkyl Substances in Products, Articles, and the Environment in Ecuador

The Stockholm Convention on Persistent Organic Pollutants(POPs)is a legally binding instrument for 186 Parties(status:April 2023).Accordingly,among other responsibilities,countries are obliged to report the production,import,or export of the POPs listed in Annexes A,B,or C;provide information to registers;maintain inventories;and monitor the presence of POPs in the environment.In the broader context of international chemicals and waste management,producer responsibilities,harmonized reporting,and compliance with national and international regulations,Ecuador has addressed the newly listed group of perfluorinated alkyl substances(PFAS)in its national implementation plan and sent selected products from its national market for PFAS analysis.The products analyzed came from the initially listed fields of specific exemptions and acceptable purposes,including:fire-fighting foams;photographic aids;greasers/degreasers;various kinds of paper/packaging;textiles;and leather,coatings,cleaners,metal plating,and pesticides.Our results showed that the three PFAS presently listed in the Stockholm Convention could be quantified in only a few samples;additional PFAS,not yet listed in the Convention also had low detection frequencies.Although the number of samples was limited,the samples covered a large spectrum of sample matrices,making it possible to conclude that—once these products become waste and are regulated under the Basel Convention—they would not constitute a disposal problem.Nevertheless,verification of the presence of PFAS in products on the market is expected to pose an analytical challenge for both,developed and developing countries.

Efficiency and effectiveness of systems for the treatment of domestic wastewater based on subsurface flow constructed wetlands in Jarabacoa, Dominican Republic

Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa,the Dominican Republic.The results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal coliforms.In addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic conditions.The concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to increase.The levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge standards.The construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same region.This study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.

First Known Case of Carcass Guarding by Black Kite (Milvus migrans) in Urban Landscape, North India

Behavioral traits of species can play an important role in the functioning of the ecosystem and in evolving behavioural adaptations to survive according to environmental conditions.This note documents evidence of adding a rare observation by providing photographic evidence of the entanglement of a carcass of a juvenile Black Kite(Milvus migrans)from a nest and the use of nest by an adult individual,guarding the carcass.Documenting such behavior contributes to our understanding of the natural history and management of native species in an urban environment.Further,scientific studies/observations are needed to be conducted to reach some conclusion as to why species perform such behaviour.

Growth Efficiency of Local Chickens Using Sweet Potato Vine with Concentration Feed as a Basal Diet

The experiment was conducted at the animal experimental station of the Faculty of Animal Sciences,Royal University of Agriculture,commenced from 10 January to 14 March,2022.The CRD(Completely Randomized Design)was used with 5 treatments and 4 replications.The 500 chicks at one-day-old,local bread,were purchased from farmers who run their small scale hatchery farm.The chicks were kept together till 21 days old,and then were allocated randomly into in five diets(treatments),25 chicks per replication.The feed formulas for this study were designed and calculated to maintain a protein content of approximately 17%,dividing into 5 feed formulas(Treatments),such as concentrated feed only(control treatment:T0),plus 10%of fresh sweet potato vine(T1),plus 20%of fresh sweet potato vine(T2),plus 30%of fresh sweet potato vine(T3)and plus 20%of sweet potato vine meal(T4).The results showed that the treatment T1,had a similar final weight with the treatment T4,but was slightly lower than the treatment T0 which used concentrated feed alone.Feed intake and FCR(Feed Conversion Ratio)were not significantly different among those treatments.In conclusion,the average daily weight gain of chickens seemed to decrease with increasing the level of fresh sweet potato vine.Thus,the optimum level of fresh sweet potato vine was 10%,which may have little effect on the growth performance of local chickens.In addition,it was not far different from the positive control treatment and the treatment using sweet potato vine meal.However,the producers can increase the amount of sweet potato vine in feed formula by processing it into meal and mixing with concentrated feed or using as feed ingredients.

Effects of Using Softwood Pellet Biochar Prepared at Different Temperatures with Grass Chippings on Retention of Heavy Metals in Contaminated Soils

Heavy metals have been viewed as hazardous environmental pollutants, and anthropogenic activities due to their high toxicity and persistent nature in the environment. Anthropogenic activities such as artisanal mining, industrial activities, improper usage of fertilizers and pesticides, and indiscriminate open waste disposal bring about an increase in the presence of heavy metals in the environment. In the Keffi Metropolis, different elements lead to land contamination which debilitates soil quality, plant survival, human well-being, and the environment as a result of extensive dispersion or quantity of heavy metals in the soil and water. In recent years, biochar has emerged as a promising soil amendment for mitigating heavy metal pollution due to its unique physicochemical properties. This paper provides the effects of softwood pellet biochar on the retention of heavy metals in contaminated soils. A microcosm experiment was carried out to investigate the effects of biochar on the retention of heavy metals in contaminated soils. This research aimed to give an overview of the effects of softwood biochar at different temperatures (550˚C and 700˚C) on the retention of heavy metals and metalloids released from the soil during water inundation. The results show that the addition of organic matter (grass chippings) minimizes heavy metal mobilization. Also, biochar at high temperatures is more effective than those at low temperatures. The expected outcome of the research analysis includes providing insights into the role of biochar in retaining heavy metal contamination and further understanding the use of biochar as a sorbent for the management of contaminated soil.

The Effect of Overseas Educational Experience on Pro-Environmental Practices: Evidence from Cambodian Academic Scholars

This paper revealed that after spending years overseas for learning, Cambodian fellows realized that a clean society more likely results from the adopting of a waste management system. The lack of such is the main barrier for waste separation willingness and practices in Cambodia. Self-transcendence values and volunteerism are empirically found as the fundamental factors for any interventions designed to promote pro-environmental intentions and practices respectively. The fellows engaging in volunteerisms appear to do waste separation, ignoring how inconvenient the waste management system or facilities are. Similarly, the fellows concerning the environmental and social issues appear to spare their valuable time to do waste-separation which they find not difficult. This is not the case in this COVID-19 epidemic though. The study results imply that in a society where an inconvenient waste management system is in place the fellows without past volunteering, no matter how knowledgeable they are, will less likely engage in the waste-sorting practice.

Sentinel-1 In SAR observations and time-series analysis of co-and postseismic deformation mechanisms of the 2021 Mw 5.8 Bandar Ganaveh Earthquake,Southern Iran

In the past two decades,because of the significant increase in the availability of differential interferometry from synthetic aperture radar and GPS data,spaceborne geodesy has been widely employed to determine the co-seismic displacement field of earthquakes.On April 18,2021,a moderate earthquake(Mw 5.8)occurred east of Bandar Ganaveh,southern Iran,followed by intensive seismic activity and aftershocks of various magnitudes.We use two-pass D-InSAR and Small Baseline Inversion techniques via the LiCSBAS suite to study the coseismic displacement and monitor the four-month post-seismic deformation of the Bandar Ganaveh earthquake,as well as constrain the fault geometry of the co-seismic faulting mechanism during the seismic sequence.Analyses show that the co-and postseismic deformation are distributed in relatively shallow depths along with an NW-SE striking and NE dipping complex reverse/thrust fault branches of the Zagros Mountain Front Fault,complying with the main trend of the Zagros structures.The average cumulative displacements were obtained from-137.5 to+113.3 mm/yr in the SW and NE blocks of the Mountain Front Fault,respectively.The received maximum uplift amount is approximately consistent with the overall orogen-normal shortening component of the Arabian-Eurasian convergence in the Zagros region.No surface ruptures were associated with the seismic source;therefore,we propose a shallow blind thrust/reverse fault(depth~10 km)connected to the deeper basal decollement fault within a complex tectonic zone,emphasizing the thin-skinned tectonics.

Relative active tectonic in the metamorphic rocks of the Yaounde group: insights from geomorphic indices and topographic analysis

The Yaounde Group(YG),representing the southern edge of the North Equatorial PanAfrican Belt,consists of quartzites,schists,micaschists,amphibolites,gneisses and migmatites.Tectonism has formed a landscape characterized by the development of linear and folded valleys and ridges,fault scarps,V-shaped valleys,incised rivers and knickpoints.These landforms constitute important markers of the regional tectonic activity,which have been computed from spatial sources such as SRTM,DEM,hydrographical networks and geomorphic indices such as AF,T,Smf,Vf,Bs,Hi,U,SI and Li.The results highlighted a mature relief consisting of asymmetric basins generated by tilting and uplift phenomena.The relative index of active tectonics(RIAT)has been estimated from an average of eight geomorphic indices evaluated on 24 subbasins,in the study area.Four classes have been defined:class 1(1.38),very high active(1.0≤RIAT<1.5);class 2(1.50-1.88),high active(1.5≤RIAT<2.0);and class 3(2.00-2.13)moderate active(2.0≤RIAT<2.5).These three classes,respectively covering 10.20%(458 km2),80.10%(3595 km2)and 9.69%(435 km2)of the study area,have shown a highly active tectonic zone,and imply the existence of a neotectonic event in the YG.This tectonic unit(YG)was also affected by the dextral NW-SE strike-slip faulting,which cross-cut the Sanaga Shear Zone(SSZ)at Ebebda and the foliation oriented NW-SE.The tilting and uplift of rocks related to Moho ascending are responsible for crustal thinning in the Cameroon basement,more important to the Adamawa Plateau from the Cretaceous age and the reactivation of existing tectonic accidents.The presence of hills,fault scarps,reverse faults,knickpoints,V and U shaped valleys and rounded mountains testify to the interaction between tectonic uplift,lithology,climate,weathering and erosion.

Determination of Forchlorfenuron Dissipation and Residue in Cucumbers and Red Soil

To assess the risks of forchlorfenuron after application, a residue analysis method for ferchlorfenuron in cucumbers and the red soil of Southern China was established, and the dissipation behavior and residue characteristics of forchlorfenuron were studied under field conditions. The field trials, including dissipation and residue experiments, were conducted in Hunan, Yunnan and Hainan Provinces. Forchlorfenuron was applied at 32 a.i.g ha^-1 rate for the dissipation study and both 21 and 32 a.i.g ha^-1 for the residue study. Representative cucumbers and soil samples were collected at predetermined intervals for HPLC for UV- detector analysis. The average recoveries of the method were 80.8%-92.0% with coefficients variation （CV） between 0.4% and 11.8%. The detection limit of forchlorfenuron in cucumbers and soil samples was 0.003 mg·kg^-1 and the minimum detectable amount was 3.0× 10^-10 g. The half life of forchlorfenuron in cucumbers in the three provinces changed as： Yunnan （5.50 days）, Hunan （5.88 days）, and Hainan （6.53 days） and in the soil was observed： Hainan （6.54 days）, Hunan （7.64 days）, and Yunnan （8.39 days）. The maximum terminal residue in cucumbers at 32 a.i.g ha^-1 rate after 5 days was 0.009 mg·kg^-1 （Yunnan） followed by 0.0085 mg·kg^-1 （Hainan） and 0.0082 mg·kg^-1（Hunan） which was below MRL value of 0.01 mg·kg^-1 established by the USA, EPA. So a waiting period of 5 days should be established after spaying on cucumbers to avoid hazard to human beings.

Regional-scale investigation of salt ions distribution characteristics in bauxite residue: A case study in a disposal area

Revegetation on bauxite residue disposal areas is the most promising strategy to reduce its potential ecological risk during stacking or disposing.Migration of salt ions in bauxite residue is one of the major issues to stimulate soil formation to support plant growth.21 residue samples were collected and the related parameters including exchangeable cations,soluble ions,total salt,pH,electrical conductivity(EC)and exchangeable sodium percentage(ESP)were selected to evaluate alkalization and salinization of bauxite residue.High levels of ions,cation exchange capacity(TOC),total salt,exchangeable sodium percentage(ESP)and cation exchange capacity(CEC)in bauxite residue were detected with greater coefficient of variation(CV),which indicated that distribution characteristics of salt ions varied significantly.The percentage of sulfate-chloride-soda type in the residues accounted for 71.43%.The mean value of pH was 10.10,whilst mean value of ESP was 52.05%.It indicated that the residues in this case study belonged to sulfate-chloride-soda saline and alkaline soil.The research results could provide theoretical basis for soil formation in bauxite residue.

A new species of smooth skink (Squamata： Scincidae： Scincella) from Cambodia

Based on morphological and genetic evidence we evaluated the taxonomic status of a newly discovered forest-dwelling population of skink （genus Scincella） from the Keo Selma Wildlife Sanctuary, Mondulkiri Province, Cambodia. From phylogenetic analysis of a 668-bp fragment of the mtDNA COl and diagnostic morphological characters we allocate the newly discovered population to the Scincella reevesii-S. rufocaudata species complex and describe it as Scincella nigrofasciata sp. nov. The new skink species can be distinguished from all other Southeast Asian congeners by the following combination of morphological characters： snout-vent length （SVL） 40.0-52.6 mm; relative tail length （TaL/SVL ratio） 1.25-1.94; prefrontals in broad contact; infralabials 6; primary temporals 2; relative forelimb length （FIL/SVL ratio） 0.20-0.22; relative hindlimb length （HIL/SVL ratio） 0.30-0.33; relative forearm length （FoL/SVL ratio） 0.14-0.16; adpressed forelimbs and hind limbs either overlapping （0.4-2.2 mm） or separated （1.9-2.3 mm）; midbody scale rows 32-33, paravertebral scales 69-74, vertebral scales 65-69; dorsal scales between dorsolateral stripes 8; comparatively slender fingers and toes, subdigital lamellae under fourth toe 15-17; dark discontinuous regular dorsal stripes 5-7; distinct black dorsolateral stripes, narrowing to lateral sides and extending to 52%-86% of total tail length. We provide additional information on the holotype of Scincella rufocaudata （Darevsky ＆ Nguyen, 1983）, and provide evidence for the species status of Scincella rupicola. Our discovery brings the number of Scincellaspecies in Cambodia to five and emphasizes the incompleteness of knowledge on the herpetofaunal diversity of this country.

Assessment of causes and future deforestation in the mountainous tropical forest of Timor Island, Indonesia

The Mutis-Timau Forest Complex,one of the remaining mountainous tropical forest areas in Timor Island,eastern Indonesia that covers an area of 31,984 ha,tends to decrease gradually.Efforts to secure mountain forest functions and counteract the negative impact of declining forest areas are often constrained by data uncertainty on factors contributing to deforestation.For this reason,this study attempts to develop models of deforestation and predict future deforestation in the Mutis-Timau Forest Complex.We constructed models of deforestation that describe the relationship between deforestation and factors contributing to deforestation using spatial statistical models.In this model,we used the deforestation data for the 1987-2017 period obtained from a previous study as dependent variables and the potential causes of deforestation generated from Geographic Information System spatial analysis as independent variables.Using the probability of deforestation derived from the model,we predicted future deforestation under two different scenarios,namely,business-as-usual(as the reference scenario)and reducing emission fromdeforestation and forest degradation.Our findings showed that a positive relationship exists between probability of deforestation,distance to the settlement,and population density variables,whereas a negative relationship exists between likelihood of deforestation,elevation,slope,distance to the road,distance to the savanna,and forest management unit variables.During the 2017-2030 period,under the business-as-usual scenario,the Mutis-Timau Forest Complex will lose 1327.65 ha in forest area with an annual deforestation rate of 0.54%.Meanwhile,under the reducing emission from deforestation and forest degradation scenario,the overall forest loss was estimated to be 1237.11 ha with an annual deforestation rate of 0.50%.The predicted area of avoided deforestation in 2017-2030 under the reducing emission from deforestation and forest degradation scenario was 90.54 ha.Such data and information are important for the Mutis-Timau Forest Complex authority in prioritizing actions for combating deforestation and designing appropriate forest-related policies and supporting data for reducing emission from deforestation and forest degradation programme or other incentive schemes in reducing deforestation.

Role of debris flow on the change of^10Be concentration in rapidly eroding watersheds:a case study on the Seti River,central Nepal

The concentration of cosmogenic loBe in riverine sediments has been widely used as a proxy for catchment-wide denudation rate （CWDR）. One of the key assumptions of this approach is that sediments originating from sub-basins with different erosional histories are well mixed. A tragic debris flow occurred in the Seti River watershed, central Nepal, on May 5, 2012. This catastrophic debris flow was triggered by slope failure on the peak of Annapurna IV and resulted in many casualties in the lower Seti Khola. However, it provided an opportunity to test the assumption of equal mixing of sediments in an understudied rapidly eroding watershed. This study documents the CWDR of ^10Be to evaluate the extent of the influence of episodic erosional processes such as debris flow on the spatio-temporal redistribution of loBe concentrations. Our data show that the debris flow caused little change in CWDR across the debris flow event. In addition to isotopic measurement, we calculated denudation rates by using the modeled concentrations in pre- and post-landslide sediments based on the local ^10Be production rate. The modeled result showed little change across the event, indicating that the debris flow in May 2012 played a minor role in sediment evacuation, despite the rapid erosion in the catchment. Our study concludes that although the 2012 event caused many casualties and severe damage, it was a low-magnitude, high frequency event.

Cellular Oxidative Damage of HEK293T Cells Induced by Combination of CdCl_2 and Nano-TiO_2

This study investigated the conjoined cellular oxidative damage of human embryo kidney 293T（HEK293T） cells induced by cadmium chloride（CdCl2） and nanometer titanium dioxide（nano-TiO2）.RT-PCR technique was used to detect the expressions of Heme oxygenase-1（HO-1） and 8-oxoguanine DNA glycosylase（OGG1）.The activities of superoxide dismutase（SOD） and catalase enzyme（CAT） and concentrations of reactive oxygen species（ROS） and maldondialdehyde（MDA） were measured by different approaches.The results showed that CdCl2 and nano-TiO2 at a low concen-tration of 0.75 total toxic unit（TU） exerted an additive effects on HO-1 gene expression,CAT activities and MDA concentrations.When the total TU was increased to 1 or 1.25 TU,the interaction was syner-getic.Moreover,the mixture with high proportion of CdCl2 produced an additive effect on the OGG1 gene expression,and the interaction was changed to be synergetic when the concentration of CdCl2 was lower than or equal to that of nano-TiO2.Synergetic effects of CdCl2 and nano-TiO2 on cellular oxida-tive damage of HEK293T cells were found as indicated by the changes in the SOD activities and ROS concentrations.It was concluded that CdCl2 and nano-TiO2 exerts synergistic effects on the cellular oxidative damage of HEK293T cells,and the sensitivity of these indicators of oxidative damage varies with the proportion of CdCl2 and nano-TiO2 in the mixture.

Functional trait profiles and diversity of trees regenerating in disturbed tropical forests and agroforests in Indonesia

A main question in restoration of degraded forests and forest landscapes recovering from logging and fire is what to expect from natural regeneration through surviving propagules in the soil or seed sources and associated dispersal agents from the surrounding landscape mosaic,as alternative to tree planting.Tree diversity in secondary forests may be high,but based on newcomer species of low wood density and long-distance,abiotic dispersal modes.We compiled and analyzed three pairs of case studies(totaling 815 plots and 11.8 ha)of secondary forests recovering from logging,fire and conversion to agroforest in Sumatra and Kalimantan(Indonesia)on mineral soils.Data on tree species diversity,wood density frequency distribution(indicative of successional status)and dispersal modes were compared with those of less disturbed comparator forests in the same landscapes.Relatively undisturbed lowland dipterocarp forest in Kalimantan had close to 200 species of trees(>10 cm diameter)at a 1-ha sample scale(and 450 at a 10-ha scale).After repeated fires a sample area of 2 ha was needed to reach the same species richness.Regulation-based logging had little impact on tree species richness.In rubber agroforest with low-intensity management beyond rubber planting,50 tree species were found at a 1-ha scale and close to 100 species in 3 ha.The Kalimantan forest after repeated fires had a markedly higher fraction of lowwood-density trees(40%),but otherwise,all forests sampled were similar in overall wood density profiles.Selectively logged forest managed by a local community(village forest)and rubber agroforest in Sumatra contained larger fractions of heavy-wood-density trees.The majority of trees(50%–70%)had birds,bats and primates as dispersal agents in all sites.Selectively logged forests had higher fractions of autochorous species(15%)compared to other sites.Anemochorous(wind-dispersed)species,especially Macaranga lowii,were most common(20%)in lowland dipterocarp forest.Comparison between secondary forests and agroforests showed the influence of farmer selection regarding what is allowed to grow beyond the pole stage.Wood density and seed dispersal profiles can be used as degradation indicators of species assemblages across various disturbance levels and types,as they reflect the habitat quality of the surrounding landscape mosaics.

A Preliminary Annotated Checklist of the Amphibians and Reptiles of the Kulen Promtep Wildlife Sanctuary in Northern Cambodia

We present the first herpetological checklist for the Kulen Promtep Wildlife Sanctuary in northern Cambodia, with records of 22 species of amphibians and 33 species of reptiles belonging to 44 genera in 22 families. The checklist includes three species （Ingerophrynus macrotis, Micryletta inornata, Scincella melanosticta） which in Cambodia were formerly only known to occur in the Cardamom Mountains in the southwest of the country. Our findings highlight the importance of countrywide herpetological baseline surveys in lowland habitats.

Rapid Residue Analysis of Sulfonylurea Herbicides in Surface Water: Methodology and Residue Findings in eastern Tiaoxi River of China

A new method combining QuEChERS (quick, easy, cheap, effective, rugged and safe) and DLLME (dispersive liquid–liquid microextraction) for the simultaneous determination of residues of ten sulfonylurea herbicide in water using UPLC-MS/MS was developed and validated. Analytes were extracted and purified with QuEChERS and concentrated in chlorobenzene by applying the DLLME procedure. Several extraction parameters were tested, such as volume, extractive solvent by the QuEChERS method and subsequently used for DLLME, selection of extractive solvent and its volume, was tested. The developed method was validated on the basis of international guidelines. Mean recoveries ranged from 81.2 to 104.9%. Repeatability and reproducibility were lower than 10%. Limits of detection (LODs) and quantification (LOQs) were below 0.074 μg/L and 0.244 μg/L, respectively. Decision limit (CCα) and detection capability (CCβ) were calculated and CCβ ranged from 0.101 μg/L (pyrazosulfuron-ethyl) to 0.260 μg/L (nicosulfuron). Finally, when the method was applied to real samples, traces of three compounds were found in 42 samples and only thifensulfuon-methyl was detected above the LOQ in three samples at 0.17-0.20 μg/L.

An overview of Turkish lignite qualities by logistic analysis

As an indispensable energy source, lignite is almost exclusively used in power generation m TurKey, To assess me quality level of Turkish lignite, a multivariate statistical analysis was conducted. The relationship among the lignite quality parameters has been investigated using a response method that is the logistic regression method. The analysis determines the effect of multiple predictor variables such as moisture, ash and sulphur presented simultaneously to predict membership of the two calorific value categories. By this way, a reliable binary response regression structure was constructed considering all the lignite fields in Turkey. Both the experiments on identifying the influential measurements and the measure of goodness of fit indicated that the overall model has a big capability to exhibit the relationship among the parameters of the Turkish lignite.

Spatio-Temporal Distribution of Southeastern Community Forests in Togo (West Africa)

The present study aimed to provide the basics needed to reconcile the fight against poverty with the need of a good management of community resources in the context of local and sustainable development. It focused on the identification of geographic location and spatio-temporal dynamics of these resources in the southeastern part of Togo. The methodological approach was based on the spatial analysis of the area for the years 1988, 2000 and 2018 by combining optical imagery from Landsat TM, ETM+ and Sentinel-2A MSI satellites with radar imagery from Sentinel-1A IW/GRDH. Spatial analysis showed a fragmented spatial structure undergoing major changes for the period 1988-2018. Plantations, riparian formations, agglomerations, water bodies and wetlands increased respectively by 4.61%, 2.09%, 1.07%, 0.43% and 0.35% annually, while forests, savannahs, crops and fallow lands decreased annually by 0.71%, 5.87% and 1.97%. For the “forests” class, seven community forests geographically organized in three sub-groups were identified and mapped. The analysis of their areas pointed to the fact that out of 667 ha of community forests in 1988, only 415 ha remain in 2018, which means a loss of 37.78% in forest areas over the 30 years, or an annual deforestation rate of 1.64%. The different spatial changes observed could be attributed to several unsustainable human activities. The land use maps for the years 1988, 2000 and 2018 will contribute to resource localization and protection in sensitive areas or, in other words, to the integrated and rational management of these resources. The different identified and mapped community forests could serve as management units for managers in developing their management plans.

A new method for position-sensitive measurement of beta surface contamination

In this paper, we propose a new method for position-sensitive measurement of beta surface contamination. With a position-sensitive detector of enlarged sensitive detection area, accurate information of the contamination distribution can be obtained. The positionsensitive detection is based on a large-area plastic scintillator and the wavelength shifting(WLS) fibers and adopts the ‘‘light center of gravity'' method. Optical transmission of the detector is simulated with a preliminary detector model, and feasibility of the detector design and measurement method is evaluated using an experiment system.The simulation and experiment results at different beta-ray incident points on the scintillator surface show that there is a polynomial relationship between the average amplitude ratio of the output pulses from the two parallel WLS fibers in the same fiber layer and the relative distance from the incident point to the WLS fiber.