Effect of digital elevation model’s resolution in producing flood hazard maps

Flooding is one of the most devastating natural disasters occurring annually in the Philippines. A call for a solution for this malady is very challenging as well as crucial to be addressed. Mapping flood hazard is an effective tool in determining the extent and depth of floods associated with hazard level in specified areas that need to be prioritized during flood occurrences. Precedent to the production of maps is the utilization of reliable and accurate topographic data. In the present study, the performance of 3 digital elevation models having different resolution was evaluated with the aid of flood modeling software such as hydrologic engineering centre-hydrologic modeling system and hydrologic engineering centre-river analysis system. The two-dimensional models were processed using three different digital elevation models, captured through light detection and ranging, interferometric synthetic aperture radar, and synthetic aperture radar technologies, to simulate and compare the flood inundation of 5-, 25- 100-year return periods. The accuracy of the generated flood maps was carried out using statistical analysis tools - Overall accuracy, F-measure and root-mean-square-error. Results reveal that using light detection and ranging–digital elevation model, the overall accuracy of the flood map is 82.5% with a fitness of 0.5333 to ground-truth data and an error of 0.32 meter in simulating flood depth which implies a promising performance of the model compared to other data sources. Thus, higher resolution digital elevation model generates more accurate flood hazard maps while coarser resolution over-predicts the flood extent

Increasing leaf vein density via mutagenesis in rice results in an enhanced rate of photosynthesis, smaller cell sizes and can reduce interveinal mesophyll cell number

Improvements to leaf photosynthetic rates of crops can be achieved by targeted manipulation of individual component processes, such as the activity and properties of RuBisCO or photoprotection. This study shows that simple forward genetic screens of mutant populations can also be used to rapidly generate photosynthesis variants that are useful for breeding. Increasing leaf vein density (concentration of vascular tissue per unit leaf area) has important implications for plant hydraulic properties and assimilate transport. It was an important step to improving photosynthetic rates in the evolution of both C3 and C4 species and is a foundation or prerequisite trait for C4 engineering in crops like rice (Oryza sativa). A previous high throughput screen identified five mutant rice lines (cv. IR64) with increased vein densities and associated narrower leaf widths (Feldman et al., 2014). Here, these high vein density rice variants were analyzed for properties related to photosynthesis. Two lines were identified as having significantly reduced mesophyll to bundle sheath cell number ratios. All five lines had 20% higher light saturated photosynthetic capacity per unit leaf area, higher maximum carboxylation rates, dark respiration rates and electron transport capacities. This was associated with no significant differences in leaf thickness, stomatal conductance or CO2 compensation point between mutants and the wild-type. The enhanced photosynthetic rate in these lines may be a result of increased RuBisCO and electron transport component amount and/or activity and/or enhanced transport of photoassimilates. We conclude that high vein density (associated with altered mesophyll cell length and number) is a trait that may confer increased photosynthetic efficiency without increased transpiration

An assessment of RVM sisters\u27 graduate theses in education to determine the extent of implementation and non-implementation of recommendations

Growth of research in education has been one of the outstanding characteristics of cultural progress during the present century. This growth is evidenced by the continued appearance of new courses dealing with educational problems., the increased number of theses accpeted each year in graduate schools, and new grants for research. This study is an assessment of RVM Sisters\u27 Graduate Theses in education to determine the extent of implementation and non-implementation of recommendations. It is an attempt to give a descriptive picture of the present status of the educational theses written by the RVM Sisters, with a special focus on the recommendations. The study aims to answer the following questions:1. What have been the problem areas covered by recommendations of the educational theses written by the RVM sisters?2. How many recommendations have been implemented?3. How many recommendations have not been implemented?4. What are the reasons for the non-implementation of recommentations?The RVM Sisters have been encouraged to do graduate studies particularly to do research work which will help improve the quality of education in the RVM schools

Varietal Differences in Photosynthetic Rates in Rice Plants, with Special Reference to the Nitrogen Content of Leaves

The photosynthetic rate in the fl ag leaf of rice at the full heading stage was examined in three japonica varieties, Koshihikari, Aikoku and Asanohikari, and the indica high-yielding variety Takanari at the same level of leaf nitrogen. At an ambient CO2 concentration of 350 µL L-1, Takanari had a higher photosynthetic rate and stomatal conductance than the japonica varieties when plants were compared at a leaf nitrogen content of approximately 1.5 g m-2. Stomatal conductance increased considerably with increases in leaf nitrogen content in the japonica varieties. As a result, at a leaf nitrogen content of approximately 2.0 g m-2, differences in terms of the photosynthetic rate among varieties were small. By contrast, there were no clear varietal differences in Rubisco content at any identical nitrogen content of leaves. We conclude that stomatal conductance is responsible for the varietal differences in photosynthetic rate examined at the same leaf nitrogen content

Performance of a High-Yielding Modern Rice Cultivar Takanari and Several Old and New Cultivars Grown with and without Chemical Fertilizer in a Submerged Paddy Field

A high nitrogen-uptake capacity and effective use of absorbed nitrogen for dry matter and grain production are required to improve the production cost and environmental pollution. We characterized grain yield, dry matter production and nitrogen accumulation in six rice cultivars: Sekitori (released in 1848) and Aikoku (1882), referred to as SA cultivars hereafter; Koshihikari (1956); Nipponbare (1963) and Asanohikari (1987), referred to as NA cultivars hereafter; and Takanari (in 1990) as a high-yielding modern cultivar. The plants were grown with and without chemical fertilizer in a submerged paddy field. When plants were supplied with manure and chemical fertilizer, Takanari consistently produced the heaviest grain and dry matter, followed by the NA cultivars, and the SA cultivars the lightest. Dry matter production before heading was greater in Takanari and the NA cultivars due to the longer duration of vegetative growth. Dry matter production after heading was greatest in Takanari, with a larger crop growth rate (CGR), and smallest in the SA cultivars with a shorter ripening time. Greater dry matter production during ripening was accompanied by the greater accumulation of nitrogen by Takanari and NA cultivars. These plants developed a larger amount of roots. The smaller light extinction coefficient of the canopy was also attributed to the higher CGR in Takanari. When plants were grown without chemical fertilizer, Takanari also produced heavier grain and dry matter, followed by the NA cultivars. The heavier grain in these cultivars resulted from the greater dry matter production before heading, which was due to the longer period of vegetative growth. The greater dry matter production and nitrogen accumulation by Takanari and NA cultivars were evident when plants were grown with chemical fertilizer. Koshihikari was characterized by a higher CGR and greater nitrogen accumulation during ripening in the absence of chemical fertilizer which should be noted in efforts to decrease rates of nitrogen application