Water balance computation and water quality improvement evaluation for Yanghe Basin in semiarid area of North China using coupled MIKE SHE/MIKE 11 modeling

Water shortage and water pollution are two prominent issues in North China. Understanding hydrological cycle and water-quality changes in response to pollution control measures is fundamental for a better water management there. Using coupled MIKE SHE/MIKE 11 modeling, various hydrological components in Yanghe Basin in semiarid area of North China were quantified for three typical hydrological years and concentrations of COD and TP in a national monitoring section of Yanghe were evaluated with/without pollution control measures. The modeling results show that the underground water storage of Yanghe Basin gets depleted due to evapotranspiration compensation and groundwater utilization regardless of hydrological condition, indicating an unsustainable in-situ water resource utilization. Water quality goals set for Yanghe (COD ≤ 20 mg/L and TP ≤ 0.2 mg/L) can hardly be achieved if pollution control measures are not taken, especially for a dry hydrological year. Depending on hydrological conditions, non-point source control technology-related projects in a 109-km2 village and a 7-km river-channel wetland in mainstream of Yanghe will have a positive effect or negligible effect on water quality improvement. To meet water quality goals, implementation of three wetlands is an effective and economic way.

Temporal variation in the diet of the endemic and threatened rodent Kerodon rupestris in the semiarid area of Brazil

We investigated the diet and trophic niche of Kerodon rupestris in Northeastern Brazil for 12 months. The influence of precipitation was evaluated by simple logistic regression. This rodent consumed 23 plant species, mainly the leaves, resulting a low niche breadth. This species presented a greater consumption of leaves of Bauhinia cheilantha, influenced by low rainfall, and fallen flowers of Cenostigma pyramidale, influenced by high precipitation. This rodent showed plasticity in its diet and used different plant resources that provided its survival in semiarid.