Groundwater constitutes an important part of the available water resources in arid areas. Knowledge of the quantitative and qualitative status of groundwater is a key aspect in optimal groundwater management. The purpose of this study was to provide technical information on the groundwater in the sand aquifer of two neighboring areas in the United Arab Emirates to support stakeholders working towards sustainable groundwater development. The chemical characteristics of the groundwater have been used to identify the processes controlling groundwater chemistry and assess the suitability of the groundwater for agricultural purposes. Despite tapping into the same aquifer, considerable differences in groundwater quality were found between the two study areas. The area with a shallower water table showed clear indications of irrigation return flow deteriorating the groundwater quality. Using standard agricultural indices, the groundwater at both study areas is classified as unfit for agricultural purposes. However, considering that groundwater is the only available water source for irrigation, it will continue to be used for agriculture. This indicates the need for improved irrigation management and the development of new strategies for sustainable groundwater development in arid areas in the context of food security.

Drought is a continuous process in Thar Desert, Pakistan. The extent of this drought needs to be assessed for future land use and adaptation. The effect of previous drought on vegetation cover of the Thar region was studied, through combined use of drought indices and geographic information (GIS) techniques. Five years (2002, 2005, 2008, 2011 and 2014) were selected to analyze the drought conditions and land use pattern of the Thar region. The drought indices used in this study included the Normalized Difference Vegetation Index (NDVI) and the Standard Precipitation Index (SPI). Images of past drought were compared with post-drought images of our targeted area and land use maps were developed for spatio-temporal analysis. The results of the study revealed that vegetation in Thar showed an improving trend from 2002 to 2011 and then declined from 2011 to 2014. The rainfall occurred at a below average rate and SPI values for each year were calculated to be negative, indicating below average rainfall. This actual precipitation data was then compared with the data obtained from the Tropical Rainfall Measuring Mission (TRMM) satellite and R²; Pearson correlation coefficients were also calculated. The R² values for the years 2002 and 2014 were 0.519 and 0.670 respectively. In the same manner, the Pearson correlation coefficient values for the years 2002 and 2014 were 0.721 and 0.867 respectively. The results showed the TRMM satellite’s over-estimation in calculating rainfall data. Further, the average temperature for the five years under study was analyzed by graphical representation and it was revealed that the temperature of Thar has increased by almost 1 °C during the last decade.

Use of energy in the agriculture sector has directly or indirectly been intensified to increase crop production to fulfill the food demand of the growing population. Considering the energy and water scarcity in Pakistan, the present study was carried out to assess wheat production efficiency with regard to energy consumption. For this purpose, a field experiment was conducted at the Water Management Research Centre (WMRC), University of Agriculture Faisalabad, to compare two irrigation scheduling techniques (climatic- and soil moisture-based) and farmers’ practice. All the inputs, except volume of irrigation water, were the same for all treatments. Energy equivalents (extracted from a scientific source) were used to calculate the energy balance and indices (energy use efficiency, energy productivity (kg MJ⁻¹), specific energy (MJ kg⁻¹), net energy (MJ ha⁻¹) and water productivity (kg m⁻³)). The results show that soil moisture-based treatment (at 30% management allowable depletion (MAD)) gave 7.94% and 27.94% more yield compared to climate-based treatments (20 mm cumulative pan evaporation (CPE)) and farmers’ practice respectively. Pumping water for irrigation was the highest energy consumption input for wheat production after chemical fertilizers. T1 = 30% MAD and T4 = 20 mm CPE treatments saved 33.71% and 35.72% energy, respectively, compared to farmers’ practice, due to water being saved. T1 and T4 treatments increased energy output by 11.40% and 6.38%, respectively, compared to farmers’ practice, in terms of grain yield and biological yield. The highest net energy (155,557.95 MJ ha⁻¹), energy use efficiency (7.478), energy productivity (0.181 kg MJ⁻¹) and water productivity (1.875 kg m⁻³) were achieved with T1 (30% MAD); however, the highest specific energy (8.148 MJ kg⁻¹) was achieved with farmers’ practice. The results thus obtained help the farmers, stakeholder agencies and researchers to make informed decisions when choosing different treatments.

Temporal compound events (TCEs), such as the consecutive occurrence of two complementary extremes of the hydrological spectrum (floods and droughts), exhibit a volatile hydrological cycle that exacerbate the challenges associated with water resources management. This study makes use of bias-corrected climate models output from three modeling experiments (CMIP6, CORDEX, and CORDEX-CORE), to examine moderate to extreme wet and dry events and their temporal compounding over the Upper Jhelum Basin (UJB), under low, medium, and high emission scenarios for two future periods (2040–2059 and 2080–2099). Standardized Precipitation Evapotranspiration Index (SPEI) is used to quantify the meteorological wet and dry events that are the main driver of the hydrologic floods and droughts. The two types of TCEs considered in the current study are wet-to-dry (W-to-D) events and dry-to-wet (D-to-W) events in the adjacent month. Results indicate that (1) under warming conditions, wet and dry events are expected to become more frequent and severe whereas duration of the events exhibits distinct change signals depending on the specific location. (2) The basin is more prone to D-to-W TCEs dominated in the southwest of the region, which was not found to be hotspot historically neither for dry nor for wet extreme events. (3) CORDEX and CORDEX-CORE ensembles show varying climate change signals with no specific spatial pattern whereas the CMIP6 ensemble shows stronger change signals and divides the region into two distinct parts, i.e., northeast and southwest.