Hydrologic Modeling for Sustainable Water Resources Management in Urbanized Karst Areas

Abstract

The potential of karst aquifers as a drinking water resource is substantial because of their large storage capacity gained in the course of carbonate dissolution. Carbonate dissolution and consequent development of preferential paths are also the reasons for the complex behavior of these aquifers as regards surface and underground flow. Hydrological modeling is therefore of paramount importance for an adequate assessment of flow components in catchments shaped on karsts. The cross tabulation of such components with geology, soils, and land use data in Geographic Information Systems helps decision makers to set up sustainable groundwater abstractions and allocate areas for storage of quality surface water, in the context of conjunctive water resources management. In the present study, a hydrologic modeling using the JAMS J2000 software was conducted in a karst area of Jequitiba River basin located near the Sete Lagoas town in the state of Minas Gerais, Brazil. The results revealed a very high surface water component explained by urbanization of Sete Lagoas, which hampers the recharge of 7.9 hm3 yr−1 of storm water. They also exposed a very large negative difference (−8.3 hm3 yr−1) between groundwater availability (6.3 hm3 yr−1) and current groundwater abstraction from the karst aquifer (14.6 hm3 yr−1), which is in keeping with previously reported water table declines around drilled wells that can reach 48 m in old wells used for public water supply. Artificial recharge of excess surface flow is not recommended within the urban areas, given the high risk of groundwater contamination with metals and hydrocarbons potentially transported in storm water, as well as development of suffosional sinkholes as a consequence of concentrated storm flow. The surface component could however be stored in small dams in forested areas from the catchment headwaters and diverted to the urban area to complement the drinking water supply. The percolation in soil was estimated to be high in areas used for agriculture and pastures. The implementation of correct fertilizing, management, and irrigation practices are considered crucial to attenuate potential contamination of groundwater and suffosional sinkhole development in these areas.

Application of Geophysical and Hydrogeochemical Methods to the Protection of Drinking Groundwater in Karst Regions

“…The study area was located in the hilly areas of the southeastern margin of the Sichuan Basin. It was defined based on hydrogeological conditions and karst development, corresponded to the recharge area of the Gu Song River upper reaches and had an area of 101.68 km 2 . Based on historical rainfall data, the rainfall is obviously controlled by seasonal factors, with 72% of the annual rainfall occurring from May-September, and only 8.8% occurring during winter.…”

“…The geomorphology is obviously controlled by water erosion and accumulation as follows: the surrounding areas belong to the landform of a medium incision mountain in the shape of a spire. The corresponding emergence stratum is clastic rock strata of the Feixianguan and Xujiahe formation of the Triassic, with an exposed area of 30.84 km 2 , accounting for 30% of the study area. The emergence stratum in the center of the study area is carbonate of the Leikoupo and Jialinjiang formations of the Triassic, which have formed low mountains of hoodoos and peak clusters with an area of 63.44 km 2 , accounting for about 63% of the study area.…”

“…Low temperature groundwater in karst development areas, which is mainly discharged in the form of karst springs or underground rivers, has become an important water source because of its stable quality and abundance [1][2][3]. However, the high heterogeneity of carbonate rocks in karst areas greatly increases the difficulty of pollution prevention and control [4].…”

Modeling Stream Flow Using SWAT Model in the Bina River Basin, India

“…The main purpose of hydrological modeling is to quantify the hydrologic response of a watershed to climatic parameters, soils, land use, and management conditions; this, in turn, plays a significant role in water resources planning, flood forecasting, pollution control, and numerous other applications [7]. Sever- [9].…”

Identification and Estimation of Solute Storage and Release in Karst Water Systems, South China

“…Karst depressions and sinkholes are well developed in South China, which are usually inhabited with large settlements and agricultural activities. The karst water systems usually comprise of multiple heterogeneous aquiferous media (i.e., caves, conduits, fissures, and matrix), which make karst aquifers extremely vulnerable to pollution [ 3 ]. The depressions are therefore highly susceptible to groundwater contamination due to this convergence of high anthropogenic activities and favorable meteorological and geomorphological characteristics, which produce autogenic recharge from overland flow.…”