Volume 1, Issue 4 (12-2013)
Abstract
This paper presents the analysis of the onset and withdrawal dates and the duration of summer monsoon over Nepal for last 63 years (1951-2013). The trend analysis revealed that both the onset and withdrawal of summer monsoon are delayed in recent years. The statistical analysis using cumulative deviation and Worsley likelihood tests showed a step jump in mean withdrawal date after the year 1997. The mean withdrawal date after 1997 is later than the normal withdrawal date by 10 days. Although, the trend for onset is statistically insignificant, the trend for withdrawal is significant at 5% level. Stationarity tests for the period of 1951-1996 and 1997-2013 also revealed that both the onset and withdrawal series are non-stationary. A step change in withdrawal date with delayed trend on both onset and withdrawal coupled with longer duration suggests a temporal shift in the monsoon pattern over Nepal after 1997. The temporal shift in the monsoon is consistent with published findings on the effect of global climate change on the dynamics of the South Asian summer monsoon precipitation. The shifting pattern of the summer monsoon exerts a strong stress on agriculture, water resources, ecosystems, human health and the overall economy of the country.
Zohreh Soltani, Mehran Loghmani, Mohammad Mansour Toutouni, Mohmood Sinaei,
Volume 9, Issue 4 (11-2020)
Abstract
The aim of this study was to compare the accumulation of heavy metals copper, zinc and cadmium and to investigate the changes of metallothionein as a biomarker of contamination in the gill tissue of the ghost crab Ocypode saratan in the two time periods before Monsoon (May) and after Monsoon (November) in mongrove forests. Chabahar and Gwater Bay was done in 2019. The results of the study showed that in both pre-Monsoon and post-Monsoon seasons the pattern of metal accumulation in the gill tissue of the ghost crab is zinc, copper, cadmium.The mean concentrations of copper, zinc and cadmium were obtained in the pre-monsoon and post-monsoon seasons at Chabahar station, 173.6 ± 3.83, 186.43 ± 3.1, 0.095 ± 0.008, respectively and 156.7±4.15 ،175.13 ± 2.8, 0.026 ±0.003 and in Gwater station the average concentrations of copper, zinc, cadmium in the two pre-Monsoon and post-Monsoon seasons were respectively 237.03 ± 6.4, 231.8 ± 1.8, 0.048 ± 0.003 and 205.9 ± 6.34, 253.2 ± 2.13, 0.037 ± 0.015 μg/g dry weight. The mean levels of metallothionein in pre-monsoon and post-monsoon season in Chabahar station were 2.02 ± 0.01 and 0.1 ± 0.06, respectively, and in goiter station were 2 ± 0.02 and 0.12 ± 0.02, respectively. Comparison of metallothionein levels between Chabahar and Gwater stations was not significant (P<0.05). But in both stations separately between the two pre-Monsoon and post-Monsoon seasons, there was a significant difference (P<0.05). Correlation between metallothionein and metals showed that there was no correlation between metallothionein and the studied metals. Therefore, according to the observations, changes in the concentration of metallothionein in this species are not affected by heavy metals and can be due to changes in the environmental conditions of the seasons.
Volume 22, Issue 2 (3-2020)
Abstract
This paper analyzes the socio-economic determinants of Rainwater Harvesting Systems (RWHS) in Pakistan. The study was based on a survey of 200 farming households selected from two villages in Pakistan. A binary logit model was used to identify determinants of RWHS. The study found that the age of respondents, size of non-irrigated land, and household monthly income were statistically significant and positively related to the adoption of RWHS. On the contrary, variables such as occupation as laborer and membership of any Community-Based Organization (CBO), though significant, had an inverse effect on the adoption of RWHS. The overall model was significant as shown by P< 0.05 which depicts that the socio-economic characteristics of the population are the main factors contributing to the adoption of RWHS. The study recommends that increased public and private investment and active involvement of Non-Governmental Organizations (NGOs) and voluntary organizations for social mobilization are essential for the promotion of RWHS in Pakistan.