No abstract

Natural events and anthropogenic activities are the two major driving forces that alter hydrological cycle processes, leading to hydrological extreme events such as floods and droughts. Streamflows are directly influenced by these forces, however, their cumulative effects over time are considered as indirect effects. This study investigated the distinct effects of precipitation, temperature, and human activities on hydrological droughts in five major river basins in South Korea. Change points in the hydrological data were identified after the 1990s in all basins by the sequential Mann-Kendall test. We used two water balance models, the ABCD and the GR2M, in this study, and their integration was used for streamflow simulations. We applied the standardized runoff index (SRI) to identify hydrological drought under different data-driven scenarios (climate change, constant temperature with varying precipitation, constant precipitation with varying temperature, and human influence). Natural and anthropogenic variations had a greater effect on drought severity than on drought duration. Variation in precipitation increased streamflow by 12.42%, followed by human activity at 0.71%; temperature decreased streamflow by-0.7% on average. Precipitation was a dominant factor that increased drought severity by 41.38%, followed by human activity at 15.85%; temperature decreased drought severity by-0.86% on average. This study improves understanding of the response of streamflow and hydrological drought to precipitation, temperature, and human activities, which is beneficial for decision makers and water managers in developing adaptive strategies to alleviate extreme natural disasters.

Water is one of the most important natural resources and is widely used around the globe for various purposes. In fact, the agricultural sector consumes 70% of the world’s accessible water, of which about 60% is wasted. Thus, it needs to be managed scientifically and efficiently to maximize food production to meet the requirements of an ever-increasing population. There is a lack of information on water requirements of crops and irrigation scheduling concerning the Shaheed Benazirabad district, Pakistan. Thus, the present study was conducted to determine the irrigation water requirements (IWR) and irrigation scheduling for the major crops in the Shaheed Benazirabad district, Sindh, Pakistan, using agro-climatic data and the CROPWAT model. Agro-climatic data such as rainfall, maximum and minimum temperature, sunshine hours, humidity, and wind speed were obtained from the NASA website, CLIMWAT 2.0, and world weather However, data about studied crops and soils were obtained from FAO (Food and Agriculture Organization). Analysis revealed that the IWRs per irrigation round for the four major crops—sugarcane, banana, cotton, and wheat—were as 3108.0 mm, 1768.5 mm, 1655.7 mm, and 402.5 mm, respectively. It was observed the IWRs are more sensitive in the hot season because of high temperatures and low relative humidity, and vice versa in the cold season. The use of scientific tools such as CROPWAT is recommended to assess IWRs with a high degree of accuracy and to compute irrigation scheduling. Accordingly, the study results will be helpful for improving food production and supervision of water resources.

No abstract

Irrigation-water quality plays an important role in agriculture productivity. In this study, water quality of the old and new Phuleli canal located in Hyderabad, Pakistan, was characterized for irrigation purpose. Water samples were collected from four different locations of each old and new Phuleli canal. Twelve different irrigation-water quality standards were assessed under the study: pH, Electricity Conductivity, Biochemical Oxygen Demand (BOD), Total Dissolved Solids, Chemical Oxygen Demand (COD), Dissolved Oxygen, Calcium, Magnesium, Sodium, Potassium, Sodium adsorption ratio, Fecal Coliforms. The results showed that the Electricity Conductivity ranges from 910–3,090 MS/cm, Potassium 13–112 mg/l, BOD 61–285 mg/l, COD 97–361 mg/l and Fecal Coliforms 400–2,350 MPN/100 ml concentrations in water of both canals were higher than the National Environmental Quality Standards permissible limits. It was found that the water quality parameters were higher than the permissible pollution level of canal water for the use of irrigation in agriculture.