Research on Construction and Application Of Groundwater Resources Carrying Capacity Model in Typical Semiarid Areas

Groundwater is crucial for the economic development in arid and semi-arid areas. However, groundwater resources have been over-exploited for meeting the increasing demands in agriculture, industry and domestic use. Therefore, identifying the key factors influencing groundwater resources carrying capacity (GRCC)GRCC and providing the optimal strategy is critical for sustainable use of groundwater resources. The present study constructed a new GRCC index (D) for assessing the long-term GRCC variation in Zhangjiakou of Hebei Province, China (ZJK) using Budyko equation, Gravity Recovery and Climate Experiment data (GRACE),Global Land Data Assimilation System data (GLDAS), sector water consumption data and GDP data. And we also identify the key factors influencing the GRCC in ZJK using optimal water allocation model and Decision Support System for Agro-technology Transfer model. Our results shows that Budyko-derived long-term (1948–2018) groundwater storage changes (GWC) have declined from −310.9 to −455.6 cm and the large number of constructed wells for irrigation has accelerated the decline of groundwater resources in ZJK. Our results also showed the time series of D in ZJK were < 30%, 30%3, which was reduced by 14% compared to base scenarios in 2016. Also, cropping rotation systems H7 to H9 (H7: two year fallow-maize rotation; H8: two year fallow-potato rotation; H9: two year fallow-wheat rotation)) obtained the lower annual average net water use (14–70 mm) compared to other cropping rotation systems (62–253 mm). The significant difference of net water use, crop yields, water use efficiency and accumulative groundwater table depth changes of nine different cropping systems indicated H4 and H8 is suitable in the study region. Our results are useful for selecting suitable cropping systems based on the water use for local farmers.