水文学: 現在の研究

Hydrogeology is the investigation of the land and hydrological measures that control groundwater stream and groundwater quality, and is thusly an essential part of any ecological geoscience program. Groundwater designing, another name for hydrogeology, is a part of designing which is worried about groundwater development and plan of wells, siphons, and drains.

Physical Hydrology is the study of the development, conveyance and properties of water. With the objective of making a prologue to actual hydrology; this story guide will examine the water cycle, protection of mass, watersheds, and the worldwide water balance.

Effective agricultural water management technologies improve crop and water productivity by allowing for a more efficient use of inputs, such as water and fertilizer, and by enhancing the yields and quality of the crops farmers grow.  The aim of the study was to determine the optimal irrigation scheduling and fertilizer rate for better water use efficiency under irrigated agriculture. The experiment was carried in the randomized completed block design experimental design with combination of five levels of irrigation treatments and three levels of fertilizer rate with three replications of the treatments. The result revealed that the plot received optimal irrigation interval of 14 days in combination of 25% more than the recommended fertilizer rate (292.24 kg/ha) had significantly higher effects on above ground biomass (18.25 t ha^-1) and on grain yield (4.8 t ha^-1 ) of irrigated maize in the study area. However, the maximum water use efficiency of 2.05 kg/m³ was obtained at the irrigation interval of14 days and highest level of fertilizer rate. Hence, the use of 14 days optimal irrigation interval and 25% more fertilizer than the recommended rate is advisable because the grain yield and crop water use efficiency had been improved in the study area. Therefore, the obtained results are valuable in improving maize yield and water use efficiency, but economic analysis should be included for further recommendation.

In context of interaction of a developing country with the world, Pakistan is observed to be immersed in numerous conflict and issues which are social, economic and environmental in nature. Being located in an environmentally stressed zone, it is quite difficult for the nation to cope up with the challenges of food supply for growing population. Reviewing the overall scenario, this study is aimed to highlight the distorted concerns regarding the usage and conservation of the natural resource. In this research it is objectified to analyze the quality of water extracted from underground and consumed for the crop cultivation in adjoining fields. The selected districts of province of Punjab were Faisalabad, Jhang and Toba Tek Singh, as agriculture is the prime activity practiced by the people in this area. Water Quality for the period of Pre and Post monsoon of year 2014 and 2018 were investigated respectively. Salinity, Sodium Absorption Ratio (SAR) and Residual Sodium Carbonate (RSC) were taken as basic quality parameters for groundwater. Secondary data of 328 wells was collected from the Punjab Irrigation Department was first sorted, filtered and analyzed by applying Geo-informatics. IDW Technique of Interpolation was incorporated to represent the data in Arc Map environment. WAPDA irrigation water quality criteria states that all parameters should not exceed the value of 3 in their respective units. Out of 328 selected wells, the concentration of salinity was witnessed to be high in the post-monsoon period of 2014 with a value of 13.02 dS/m. Sodium Absorption Ratio was found in low limits in both of the years, showing a high value of 56.26 during pre-monsoon of 2014. Residual Sodium Carbonate (RSC) was detected as 18.1 me/L in 2014’s post-monsoon. Additionally, estimation of vegetation patterns assisted in assessment of impacts of the selected parameters. The intensification in concentration of these parameters have been reported to decrease soil fertility, crop growth, crop patterns and causes disturbance in soil pH. Hence, increased soil alkalinity or acidity is leading to reduction of the agricultural production from those fields in the study area. It is therefore concluded that strict implementation of laws for a proper check and balance system is urgently required. “Drip Irrigation” is highly recommended for sustainability of agricultural land and healthy food production.

Climate change and variability is expected to trigger changes in temperature and precipitation series. This study aimed at assessing variability and trend of hydro-climatic variables at Modjo River watershed. Long-term climate data of 5 representative stations with in the watershed (1981-2010) and stream flow data of Modjo gauging station (1983 -2010) were used. Rainfall variability was analyzed using Coefficient of variation (CV), Precipitation concentration index (PCI) and Standardized anomaly index (SAI). Climate trends were evaluated using Sen’s slope estimator and Mann Kendall trend test methods. The study revealed Most of the stations showed low variation in annual rainfall (CV% <20) while the main (Kiremt) and short (Belg) season rainfall exhibited CV ranging from low to high. Both annual and seasonal rainfall showed a non-significant trend at all stations for the past 30 years. However, majority of stations showed an increasing trend in annual daily average temperature ranging from 0.2 to 0.6ºC per decade. Following increases in temperature and the subsequent rise in evapotranspiration, stream flow has shown a high significant declining trend. The temporal decline in stream flow at Modjo watershed could likely affect downstream Koka dam water reserve. Thus, any watershed management strategy that can optimize water conservation for sustainable crop production and option that can improve flow to the reserve is vital.