Environmental Challenges最新文献

Runoff and hydric soil erosion from agricultural fields may lead to a transfer of plant protection products (PPP) to adjacent surface water bodies, in addition to the intrinsic losses of water and topsoil material for plant production. Measures of conservation agriculture are known to be suitable for mitigating these processes. In this study, the pertinent literature on runoff and erosion mitigation following the application of measures from the conservation agriculture toolbox was reviewed to determine the reduction effects of distinct strategies of conservation tillage and the use of cover crops. In total, 1483 and 1076 single data points were considered for runoff and erosion, respectively. We calculated geometric means (with confidence intervals expressed by the geometric SD factor) of the ratios of quantities derived from treated vs. untreated setups following no-tillage of 0.44 [0.17–1.13; n=38 studies] and 0.11 [0.03–0.93; n=37] for runoff and erosion, respectively. Conservation tillage measures other than no-tillage (i.e., reduced tillage, e.g., strip tillage) led to ratios of 0.46 [0.22–0.94; n=42] and 0.18 [0.06–1.16; n=35]. The use of cover crops resulted in ratios of 0.41 [0.19–0.88; n=33] and 0.09 [0.01–0.65; n=30]. Corresponding runoff curve numbers to be included in numerical simulations were calculated to be reduced by 11 % [5 %–25 %; n=16], 10 % [4 %–21 %; n=21], and 12 % [5 %–30 %; n=19], for the three categories of conservation agriculture (no-till, reduced-till, cover crops), respectively. That is equivalent to absolute reductions of the CN scores by 7 [4–13], 5 [2–13], and 5 [2–12]. Analogous PPP transport ratios of treated vs. non-treated are 0.50 [0.13–1.92; n=19], 0.70 [0.29–1.70; n=11], and 0.46 [0.12–1.80; n=4], respectively. This work broadens the database to include no-tillage, conservation tillage and cover crops into the framework of environmental exposure assessment for the registration of plant protection products.

The adoption of land management technology (LMT) is crucial for minimizing soil erosion and increasing agricultural productivity, both of which are essential components of sustainable development. Therefore, different LMTs have been adopted in the Goyrie Watershed of southern Ethiopia. However, the technical designs of the adopted technologies have not yet been assessed. Thus, the objective of this study is to evaluate the technical designs of adopted LMTs in relation to standards as well as to identify the factors that influence households' intentions to adopt LMT dimensions in the suggested standards. Data were collected through field measurements, observations, focus group discussions, key informant interviews, and 291 randomly selected heads of household. Data were analyzed using frequency, mean, standard deviation, and structural equation modeling (SEM). This study found that 30 % of the technical aspects of the adopted LMTs on private farmlands and 12 % on communal lands met the recommended national standards. However, field measurements found that 70 % of private farmlands and 88 % of communal lands in the adopted LMT technical designs failed to fulfill the required national standards. This problem was more pronounced on communal land. The SEM estimation revealed that households’ assumptions about development agents and households’ perceptions of the benefits of LMTs were found to significantly and positively influence the probability of households’ intentions to adopt LMTs in line with the referenced standards. Whereas households trust village memberships, the nature of soil types and training opportunities significantly but negatively predicted the probability of households’ intention to adopt LMTs in relation to standards. The study suggests that national and regional governments provide adequate training opportunities for farmers on how to design and implement LMT dimensions in accordance with recommended standards.

The rising elephant population in Tarangire National Park of northern Tanzania has led to increasing human-elephant interactions in dispersal areas to the northeast of the park. While the movement dynamics of elephants across the landscape are well documented, anthropological dimensions of human-elephant coexistence warrant more research. The present study used stratified random sampling to survey 1076 people living across twelve villages surrounding Manyara Ranch and Randilen Wildlife Management Area (WMA) about their lived experiences, perceptions, attitudes, and tolerance towards elephants. Villages between Manyara Ranch and Randilen WMA reported regular conflicts with elephants, while those to the west of the ranch did not consider elephants to be a major concern. Crop raiding was particularly frequent in Makuyuni, Lengoolwa, Mswakini Juu, Mswakini, Lemooti, and Nafco. Economic impacts of elephant crop raiding ranged from as low as $4USD per household per year in Lolkisale to approximately $812 per year in Mswakini, and accounts of property damage were most severe in Makuyuni and Naitolia. The vast majority of respondents (96 %) did not have a household member who had been injured by elephants over the preceding twelve-month period, suggesting that elephant attacks on humans were relatively infrequent on the whole. However, between 10 and 24 % of participants in Lemooti, Nafco, Mswakini, and Mswakini Juu noted injuries incurred in the past year. Different ethnic groups had statistically significant differences in their attitudes towards elephants. People with higher levels of education had more positive attitudes towards elephants, and elders had more negative attitudes than youth. Elephants disturbed the sleep of men more than women highlighting the gendered dimensions of human-wildlife interactions. Despite these visible and hidden costs of elephants, most people (72 %) across the whole study area were somewhat tolerant of elephants, except in Makuyuni, Lengoolwa, and Nafco where seasonal crop raiding was severe and tolerance for elephants was extremely low. People in those villages, as well as Mswakini Juu and Mswakini, were largely in favor of government-sanctioned culling, though 94 % of all respondents viewed elephant poaching as bad. Tolerance towards elephants was negatively correlated with livestock holdings and positively associated with total farm size. Greater attention to community perspectives is necessary for promoting human-elephant coexistence in the Tarangire ecosystem.

The issue of climate change has become a global concern, and tropical regions are strategically positioned to mitigate its effects through their forest resources. By maintaining the function of forest ecosystems to support life at local and regional levels, carbon stocks can be maintained, and emissions can be reduced. Above-ground biomass can bind and store carbon stocks. This study aims to analyse the CO₂ emissions caused by deforestation and forest degradation in Kubu Raya District, West Kalimantan Province. Primary data was obtained through field observations, and secondary data was obtained through maps of forest areas and land cover for 1996–2021 from the Geospatial Information Agency and the Indonesian Ministry of Environment and Forestry. This study uses a non-destructive approach to calculate Above Ground Biomass. The results showed that Kubu Raya District, West Kalimantan Province, Indonesia, experienced deforestation of 235,597 ha and forest degradation of 9,860 ha from 1990 to 2021. This resulted in CO₂ emissions of 163,702,815.53 tons. The highest level of CO₂ emissions is in Batu Ampar District, and the lowest is in Sungai Kakap District. There is a positive correlation between the amount of deforestation and forest degradation and the level of CO₂ emissions caused by these activities. This means that the amount of CO₂ emissions depends on the area's deforestation and forest degradation. To reduce the concentration of CO₂ in the atmosphere and its effects on climate change, deforestation and forest degradation activities in Kubu Raya Kalimantan should be stopped.

Geomorphology, hydrological conditions and human activities, alter river morphology and shift channels, causing environmental and socio-economic impacts. River shifting in Nepal is well-documented for large rivers like the Koshi and Karnali, while smaller rivers like the Bagmati have received less attention. This study employs geospatial tools and techniques to understand the morphological changes, quantify the spatio-temporal shifting, and erosion and deposition of the Bagmati River channel in Nepal over a 30-year period (1988–2018). The morphological changes were measured in terms of sinuosity index, river width and water area. The entire river maintained a generally sinuous character throughout the study period. The total average width of the river decreased by more than four times from 1287.17 m to 300.01 m from 1988 to 2018, and the water area also decreased by 6.59 km² over the same period, reflecting a transition of the river into a narrower channel over the decades. Overall, the Bagmati River channel slightly shifted eastward in the upstream and downstream sections while significantly shifting westward in the midstream section with an annual rate of 9.94 m, 4.83 m and 41.5 m respectively. The annual rate of bank erosion was found to be one-fourth of the deposition (0.72 km² per year), with the higher erosion and deposition in the east bank and midstream section of the river. This study highlighted the morphological changes, spatio-temporal channel shifting, and erosion and deposition of the Bagmati River located in the floodplain of Tarai region of Nepal.