Environmental Groundwater Depth for Groundwater-Dependent Terrestrial Ecosystems in Arid/Semiarid Regions: A Review

Abstract

Groundwater in arid/semiarid regions plays crucial roles in providing drinking water supply, supporting irrigated agriculture, and sustaining important native terrestrial ecosystems. Groundwater depth controls water availability to vegetation and is essential for conserving groundwater-dependent terrestrial ecosystems. Environmental groundwater depth can be defined as a mean depth or a range of depths, satisfying the growth of natural vegetation that is not under stress, either due to lack of water or anoxia or soil salinization. Five methodologies have been reported to estimate environmental groundwater depth: the direct ones rely on response functions that relate vegetation condition, e.g., physiological parameters, appearance frequency, community structure, and remotely sensed physical indexes, to changes in groundwater depth; the indirect one estimates environmental groundwater depth based on the threshold of soil moisture content. To fill a knowledge gap of unique recognized methodology, a conceptual framework was proposed, which involves initial estimation (data collection, response assessment, and estimation) and feedback adjustment (implementation and modification). A key component of the framework is to quantify the linkage between ecological conditions and geohydrological features. This review may provide references for groundwater resources management, ecological conservation, and sustainable development in arid/semiarid regions.

Seepage Velocity: Large Scale Mapping and the Evaluation of Two Different Aquifer Conditions (Silty Clayey and Sandy)

“…Although groundwater is more reliable than surface water, it can also be depleted due to anthropogenic activities (mismanagement) and global climate change [18,19]. Most aquifers around the world are overstressed and subject to depletion because the water withdrawn surpasses the recharged volume [17,20].…”

Relictos de vegetación en tramos fluviales intermitentes en el sector medio de las cuencas de Sama, Caplina y Hospicio, Tacna, Perú

“…Las alteraciones causarán fluctuaciones en la profundidad del agua subterránea, que es el factor ambiental clave (Shang et al, 2016). En estas regiones, especialmente durante los períodos secos con escasa precipitación, el agua subterránea tiene un efecto esencial sobre el contenido de humedad del suelo que influye en la estabilidad ecológica local (Huang et al, 2019). Las zonas áridas, semi-áridas y subhúmedas secas reciben apenas el 2 % de la precipitación pluvial anual que cae en el país.…”

New Pollution Challenges in Groundwater and Wastewater Due to COVID-19

“…Preserving sources of clean and safe drinking water is critical for nations all over the world. Groundwater is the main source of drinking and irrigation water in many countries and is important in sustaining native terrestrial ecosystems (Huang et al 2019). In general, groundwater-dependent ecosystems are divided into three types based on their ecological function: (1) aquifers and cave ecosystems, (2) wetlands, springs, rivers, estuaries and nearshore marine ecosystems and ( 3) terrestrial vegetation ecosystems (Huang et al 2019).…”