Jiwen Ge

Water losses in arid and semi-arid zone: Evaporation, evapotranspiration and seepage

The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid zone. Normally, evaporation and seepage are the main causes of water losses. For modeling water losses, a combination of Genetic Programming (GP), Penman-Monteith (PM) and Penman combination model for measurement of evapotranspiration, evaporation and seepage has been developed. The results were found to be varying depending on how the evaporation and seepage phenomena are modeled. These results show that that there is an improvement in reducing evapotranspiration, evaporation and seepage losses in arid and semi-arid region.

Interactions between Soil Characteristics, Environmental Factors, and Plant Species Abundance： A Case Study in the Karst Mountains of Longhushan Nature Reserve, Southwest China

The ability to manage and restore plant communities in the face of human-induced landscape change may rely on our ability to predict how species respond to environmental variables. Understanding this response requires examining factors or their interactions that have influence on plant and resource availability. Our objective was to analyze the relationships between changes in plant abundance and the interaction among environmental habitat factors including soil, geological (rock type), and other environmental variables in the Longhushan karst mountains ecosystem. Species density and dominance were examined using ANOVA, ANCOVA, and Generalized Linear Models to establish the single or combined effects of these groups of factors. The results showed that trends in abundance were mainly affected by rock type (related to the percentage content of dolomite and calcite), soil characteristics in association with topography. Both plant indices were higher in dolomite dominated areas and varied positively with moisture, and elevation, but negatively with organic matter, while density also increased with slope degree. The results demonstrate that significant variations in species abundance was produced with the combination of variables from soil, geological, and environmental factors, suggesting their interaction influence on plants. We postulate that spatial variations in plant abundance in karst ecosystem depends on the carbonate rock type in addition to water and nutrient availability which are mainly controlled by topography and other factors such as soil texture and temperature. The study suggests that in karst areas carbonate rock type, in addition to local environmental variables, should be taken into account when analyzing the factors that have impact on plant communities.

An assessment of the spatial distribution of Pentecost churches in an African urban environment: A case study of Lubumbashi City in the Democratic Republic of the Congo

This paper presents the results of the study undertaken at Lubumbashi City in D.R.Congo to determine the spatial distribution and evolution of Pentecost churches in Africa urban environment. It was shown that in Lubumbashi City the Pentecost Churches were grown from 112 churches in 1990 to 280 Churches in 2008. Four Church Community groups were identified which are 8th CEPAC (19 churches), 30th CEPECO (102 churches), 45th CEP (39 churches) and RESURGENCE CHURHCES (120 churches). The last cited knew a high proliferation and grew from 24 Churches to 120 Churches in the same period. The analysis of their spatial distribution by using the Distribution Model showed that the concentration of spatial distribution is R=0.416. The study of correlation between the number of Churches, the number of population and the area by using the formula of correlation coefficient shows that no correlation exists for their distribution. The need of money, accessibility and good environment were a basis of their proliferation. Finally we addressed the advices and proposed an appropriate method to all actors in order to establish a harmony in urban environment.

Assessment of pH and soil degradation: Case of Rwanda tea growing areas

The aim of this study was to access the pH and soil degradation. Soil samples collected in eleven zones among three locations by zone were analyzed in the laboratory through pH Meter and the results indicates that pH of all soil samples is less than 5 (pH<5) and the general average was found to be 4.4. Heavy materials like Fe, Cu, Mn, and Zn presented a high concentration level. The elements H+ and C were those with minimum concentration, the elements Ca and Na presents a low level concentration, and the elements due to fertilizers which are N, P, and K. The results indicate that the soil in the tea plantations in Country is acidic and this level of pH may result in deficiency of some base elements like calcium, magnesium, potassium and nitrogen.

Notice of Retraction Materials on rivers around tea growing areas of Rwanda

The analysis of water samples collected in rivers streams across the tea growing areas in Rwanda by using spectroscopy technique MS Instrument has clearly indicate the presence of heavy elements (Al, As, Ba, c, Ca, Cu, Fe, H+, K, Mg, Mn, N, P, S, Si, and Zn) in water samples. The highly concentrated are: Ca (37 - 54.9), C (31.5-36.4), S: 12.9-24.1, Mg: 8.5-14.1, N: 4-11 and K: 5.3-7.8. Those with medium concentration are Si: 3.4-5.4, Cu: 1.1-2.5, Mn: 0.7-1.5, Ba: 0.5-1.03, Fe: 0.6-1 and P: 0.6-0.8. And elements with low concentration are Zn: 0.3-0.76, H+: 0.4-0.66, Al: 0.4-0.6 and As: 0.02-0.5. The pH varies between 5.5- 6.7.Water is acidic and this acidity may be caused by the use of fertilizers and pesticides with high quantity of NPK + Mg. Here we proposed the method that can be applied in order to maintain the quality of drinking water.