Magnitude of Annual Soil Loss from a Hilly Cultivated Slope in Northern Vietnam and Evaluation of Factors Controlling Water Erosion

A soil erosion experiment was conducted in northern Vietnam over three rainy seasons to clarify the magnitude of soil loss and factors controlling water erosion. The plot had a low (8%) or medium (14.5%) slope with land-cover of cassava or morning glory or being bare. Annual soil loss (177 to 2,361 g/m2) was a tolerable level in all low-slope plots but was not in some medium-slope plots. The effects of slope gradient and seasonal rainfall on the mean daily soil loss of the season were confirmed, but the effect of land-cover was not, owing to the small canopy cover ratio or leaf area index during the season. The very high annual soil loss (>2,200 g/m2) observed in the first year of some medium-slope plots was the site-specific effect from initial land preparation. Since the site-specific effect was large, the preparation must be done carefully on the slope

A Preliminary Monitoring of the No_3-N Concentration in the Surface Water in the Paddy-Cultivated Area of the Central Red River Delta, Viet Nam

The NO_3-N concentration and pH in the surface water in the paddy-cultivated areas of the central Red River Delta, Vietnam were monitored at 24 sites of 5 districts in March 2002 after the spring rice was transplanted. In the areas, fertilizer N of 100-150 kg/ha has been conventionally applied in each of the three cultivations in a year. The measured NO_3-N concentration was in the range of 0.11-3.03 mg/L and was below the permissible level of 11.3 mg/L for drinking water, but some samples exceeded the standard for pH （8.5）. The districts could be separated from one another according to the combination of the NO_3-N and pH levels, but this separation was not due to the comparative land elevation. Relevant factors such as the soil pH, the amount and time of N application in every cultivation, and the NH_4 level are to be monitored in the future study. The NO_3-N concentration was negatively correlated with the pH level in some districts, possibly impacted by nitrification. No remarkable difference was observed in both the NO_3-N and pH levels between the ponding water of the paddy field and the water of the neighboring irrigation/drainage canal

Sexual behaviors among methadone maintenance patients in a mountainous area in northern Vietnam

Abstract Background Methadone maintenance treatment (MMT) improves patients’ ability to access HIV-related services and reduces needle sharing and other risky HIV-related behaviors. However, patients may continue to engage in risky sexual practices. In this study, we evaluate sexual behaviors of MMT patients in a mountainous province in Northern Vietnam. Methods We explored the health status, MMT and substance use history, and sexual practices of 241 male MMT patients in Tuyen Quang province. Health status was investigated using the EuroQOL-5 Dimensions-5 Levels (EQ-5D-5 L). Multivariate logistic regression was employed to assess associated factors. Results Most patients (66.4%) reported having at least one sexual partner within the previous twelve months. Most of these partners were spouses or primary partners (72.6%). About 8.3% of patients had casual partners, and 5.8% had visited sex workers; of those who engaged in casual sexual relationships, 90.9% reported using condoms. Current drug use and living in a remote area were associated with an increased odd of having two or more sexual partners, while anxiety or depression was associated with lower odds. Conclusion This study highlights a low proportion of having sexual risk behaviors among MMT patients in Vietnamese mountainous settings. Integrating education about safe sexual practices into MMT services, along with providing medical care and ensuring methadone treatment adherence, is an important component in HIV risk reduction for these patients who were at risk of unsafe sexual practices