Rainy Season Temperature Research Articles

Determination of Heavy Metals and Microbial Contaminants in Borehole Water From Ga-Matlala in the Limpopo Province, South Africa

Objective: The objective of the study was to determine the physical parameters, heavy metals and the microbial quality in borehole water from ga-Matlala area in the Limpopo province, South Africa. Theoretical Framework: Many communities around Limpopo to rely on borehole water. The Capricorn District Municipality, where Ga-Matlala area is located, reports that 80 % of the population depend on groundwater supply and the quality of groundwater in some parts of the municipality is not suitable for human consumption. Method: Physical parameters were determined on-site using the Hanna Multiparameter Meter. Heavy metals were determined using Shimadzu AA 7000 AAS. Microbial analysis was performed using the MPN and membrane filtration techniques. Results and Discussion: The results showed, temperature: 15.65 ºC to 18.66 ºC, pH: 7. 70 to 8.54, DO: 0.00 to 6.24 ppm, EC: ≥ 1115.33 µS / cm, TDS: ≥ 585.33 ppm, salinity: ≥ 0.56 psu, Cu: ≥ 0.01mg/L, Fe ≥ 0.19 mg/L, Pb: ≥ 0.01 mg/L during dry season. During rainy season temperature: 25.79 ºC to 29.57 ºC, pH: 7.79 to 8.90, DO: 0.56 to 5.03 ppm, EC: 775.00 to 2665.33 µS / cm, TDS: 349.33 ppm, salinity: ≥ 0.36 psu, Cu ≥ 0.01 mg/L, Fe ≥ 0.22 mg/L, Pb ≥ 0.03 mg/L, Mn ≥ 0.01 mg/L. Research Implications: The findings from the study points to a need for public awareness about health risks associated with consuming the borehole water. Treatment of boreholes is highly recommended Originality/Value: The quality of borehole water from Ga-Matlala has not been analyzed and documented, before the current study. The study will help to bring awareness to the community about the quality of their drinking water.

A multi-region study of carbonate clumped isotope data from terrestrial snails

A multi-region study of carbonate clumped isotope data from terrestrial snails

Effects of Geographical and Climatic Factors on the Intrinsic Water Use Efficiency of Tropical Plants: Evidence from Leaf 13C

Understanding the water use efficiency (WUE) and adaptation strategies of plants in high-temperature and rainy areas is essential under global climate change. The leaf carbon content (LCC) and intrinsic WUE of 424 plant samples (from 312 plant species) on Hainan Island were measured to examine their relationship with geographical and climatic factors in herbs, trees, vines and ferns. The LCC ranged from 306.30 to 559.20 mg g-1, with an average of 418.85 mg g-1, and decreased with increasing mean annual temperature (MAT). The range of intrinsic WUE was 8.61 to 123.39 μmol mol-1 with an average value of 60.66 μmol mol-1. The intrinsic WUE decreased with increasing altitude and relative humidity (RH) and wind speed (WS), but increased with increasing latitude, MAT and rainy season temperature (RST), indicating that geographical and climatic factors affect the intrinsic WUE. Stepwise regression suggested that in tropical regions with high temperature and humidity, the change in plant intrinsic WUE was mainly driven by WS. In addition, the main factors affecting the intrinsic WUE of different plant functional types of plants are unique, implying that plants of different plant functional types have distinctive adaptive strategies to environmental change. The present study may provide an insight in water management in tropical rainforest.

Effect of climatic factors on farm income of rain‐fed and irrigated farming households in Vietnam

AbstractThe paper provides new evidence of the effect of temperature and precipitation on crop profit of farmers applying different farming systems across different seasons as well as geographical regions in Vietnam for the period 2004–2016. The result finds that the effect of fluctuation in temperature and rainfall on the crop profit of farmers is not uniform across the three regions (North, Central and South) and also considerable variation across rain‐fed and irrigated farms. For the rain‐fed farming system, (i) rainfall in the dry season has a nonlinearly (⋂) association with the profit, but rainfall in the rainy season has no effect, and (ii) dry season temperature and rainy season temperature have, respectively, ⋂‐shaped and U‐shaped relationship with the profit. For the irrigated farming systems, the temperatures in the dry season and rainy season have a U‐shaped relationship with the profit. The findings show that the irrigated farming systems have been effective in the long term in the face of climate change. Therefore, in preparation for adaptation to climate change, the Vietnamese agricultural sector needs a complete irrigation system at both farm and regional levels.

Growth response of seven multipurpose tree species to climatic factors: A case study from northwestern Himalayas, India

Identification of the species for dendrochronological studies is of great relevance to understand various aspects of climate change. However, in the northwestern Himalayan region, dendroclimatological investigations are confined to conifer species, with broadleaved species being disregarded. Thus, the present study was conducted to assess the growth response of seven multipurpose tree species (MPTs), namely Bauhinia variegata, Celtis australis, Grewia optiva, Paulownia fortunei, Toona ciliata, Ulmus villosa and Melia composita to local climate variables, viz. temperature as well as rainfall (seasonal, monthly, average) and CO2 level by evaluating the climatic signal in tree ring chronologies at Solan district, India (altitude 1 250 m) in the mid-hills of the northwestern Himalayas. The results indicated that only the maximum, rainy season temperature and CO2 level varied significantly (P < 0.05) between 1991 and 2017. Only G. optiva exhibited a significant (P < 0.05) tendency toward increased growth. C. australis has a remarkable negative correlation with temperature variables, viz. average, maximum, spring season, March temperature, whereas T. ciliata exhibits a positive correlation with temperature variables, such as rainy season, average and April temperature. Similarly, winter, total and December rainfall have a profound effect on P. fortunei, while March rainfall adversely affected the growth of B. variegata. On the other hand, G. optiva demonstrated sensitivity to both temperature (February and May) and rainfall variables (winter, February and May). U. villosa recorded a positive correlation with rainfall (autumn and October rainfall) but a negative correlation with temperature variables (maximum and April temperature). Elevated CO2 levels affected only two species (G. optiva, M. composita) out of the seven selected species. Our findings will contribute to a better understanding of the climate growth relationships of investigated tree species, as a result, to more accurate projections of the effects of climate change on these MPTs and directing future studies.

Multi‐scale patterns of human activity and the incidence of an exotic forest pathogen

Summary Plant pathogens can have major impacts on diverse taxa and ecological systems world‐wide, and some of the most conspicuous of these are invasive non‐native species. Although many factors are known to influence the distribution and abundance of plant pathogens, the extent to which humans play a role is less well‐known but still critical for understanding the dynamics of invasive pathogens in natural systems. One invasive pathogen of great concern world‐wide is Phytophthora ramorum, which causes Sudden Oak Death, an emerging forest disease. Here, we examined the influence of humans and a range of environmental factors on the distribution of P. ramorum at three distinct spatial scales in northern and central California. At the local scale, P. ramorum more commonly occurred in soil on hiking trails used heavily by humans than in soil from adjacent areas off trails. These results support the hypothesis that humans dispersed the pathogen within already infected areas and into areas lacking local sources of inoculum. At the landscape scale, using a network of 202 randomly located plots across a 275 km2 area, we found that forests on public land open to recreation exhibited higher prevalence of disease in a critical infectious host tree (bay laurel, Umbellularia californica), than forests on private lands. Infection levels were also higher in plots surrounded by large amounts of forest with warm climatic conditions and greater potential soil moisture. Although prevalence of diseased canker hosts (Quercus agrifolia, Q. kelloggii and Lithocarpus densiflora) was positively associated with dominance of bay laurel and rainy season temperatures, it was not significantly related to public access, and we hypothesize that this occurred because our study area was in the early stages of infection. At the regional scale, the probability of disease occurrence at 165 sites distributed across the geographic range of P. ramorum in California increased significantly as human population density increased in the surrounding area. Chances of infection also increased significantly with precipitation and presence of bay laurel. Synthesis. Our results suggest that human activity – along with temperature, moisture and host composition – is associated with increased prevalence of an influential exotic forest pathogen. These results indicate that there may be conflicts between humans and disease, and that efforts to address this issue may require aggressive management of human activity.

Hydrological applications of noble gases and temperature measurements in underground water systems: Examples from Israel

Abstract The observations on the behavior of the noble gases in the hydrological cycle may provide the tools to calculate the initial noble-gas contents in recharging water. This is essential for: (a) the use of the noble gases as tracers in geothermal systems; and (b) the evaluation of initial noble-gas contents in ancient waters for paleotemperature studies. Noble-gas contents in four non-karstic and three karstic springs were repeatedly measured, along with the temperatures in the recharge and discharge points. The Ar, Kr, and Xe contents in non-karstic springs are found to reflect the temperature of the base of the aerated zone above the water table. This temperature is seen to be close to the local average annual temperature and different from the rainy season temperature. The difference between the temperature measured at a spring and the noble-gas-deduced temperature indicates the depth of circulation in the saturated aquifer and thus may enable one to recognize the recharge area (e.g., local rain or recharge from adjacent mountains). Karstic springs are found to contain substantial air excesses, revealing a negative correlation to discharge. These air excesses are attributed to air present in some parts of the karstic systems, more so in the low-discharge season than in the high one. This air is sucked in by the water when it rushes through narrow parts of the system. Excess air may provide a tracer for karstic waters.